From 26a029d407be480d791972afb5975cf62c9360a6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 02:47:55 +0200 Subject: Adding upstream version 124.0.1. Signed-off-by: Daniel Baumann --- toolkit/components/reader/.eslintrc.js | 13 + toolkit/components/reader/AboutReader.sys.mjs | 1319 +++++++++++ toolkit/components/reader/Reader.worker.js | 59 + toolkit/components/reader/ReaderMode.sys.mjs | 561 +++++ toolkit/components/reader/ReaderWorker.sys.mjs | 13 + toolkit/components/reader/Readerable.js | 94 + toolkit/components/reader/Readerable.sys.mjs | 9 + toolkit/components/reader/content/aboutReader.html | 121 + toolkit/components/reader/jar.mn | 6 + toolkit/components/reader/moz.build | 28 + toolkit/components/reader/moz.yaml | 26 + .../components/reader/readability/JSDOMParser.js | 1197 ++++++++++ toolkit/components/reader/readability/LICENSE.md | 13 + .../reader/readability/Readability-readerable.js | 108 + .../components/reader/readability/Readability.js | 2314 ++++++++++++++++++++ toolkit/components/reader/test/browser.toml | 76 + .../test/browser_bug1124271_readerModePinnedTab.js | 53 + .../test/browser_bug1453818_samesite_cookie.js | 132 ++ .../browser_bug1780350_readerModeSaveScroll.js | 70 + .../reader/test/browser_drag_url_readerMode.js | 61 + .../reader/test/browser_localfile_readerMode.js | 54 + .../components/reader/test/browser_readerMode.js | 399 ++++ .../reader/test/browser_readerMode_bc_reuse.js | 44 + .../reader/test/browser_readerMode_cached.js | 32 + .../test/browser_readerMode_colorSchemePref.js | 67 + .../reader/test/browser_readerMode_hidden_nodes.js | 56 + .../reader/test/browser_readerMode_menu.js | 69 + .../reader/test/browser_readerMode_pocket.js | 136 ++ .../reader/test/browser_readerMode_readingTime.js | 101 + .../reader/test/browser_readerMode_refresh.js | 49 + .../reader/test/browser_readerMode_remoteType.js | 87 + .../browser_readerMode_samesite_cookie_redirect.js | 52 + .../reader/test/browser_readerMode_with_anchor.js | 89 + toolkit/components/reader/test/getCookies.sjs | 16 + toolkit/components/reader/test/head.js | 59 + .../components/reader/test/linkToGetCookies.html | 13 + .../components/reader/test/readerModeArticle.html | 28 + .../reader/test/readerModeArticleContainsLink.html | 20 + .../reader/test/readerModeArticleHiddenNodes.html | 22 + .../reader/test/readerModeArticleMedium.html | 16 + .../reader/test/readerModeArticleShort.html | 14 + .../reader/test/readerModeArticleTextPlain.txt | 10 + .../reader/test/readerModeNonArticle.html | 9 + .../components/reader/test/readerModeRandom.sjs | 23 + .../components/reader/test/setSameSiteCookie.html | 9 + .../reader/test/setSameSiteCookie.html^headers^ | 1 + 46 files changed, 7748 insertions(+) create mode 100644 toolkit/components/reader/.eslintrc.js create mode 100644 toolkit/components/reader/AboutReader.sys.mjs create mode 100644 toolkit/components/reader/Reader.worker.js create mode 100644 toolkit/components/reader/ReaderMode.sys.mjs create mode 100644 toolkit/components/reader/ReaderWorker.sys.mjs create mode 100644 toolkit/components/reader/Readerable.js create mode 100644 toolkit/components/reader/Readerable.sys.mjs create mode 100644 toolkit/components/reader/content/aboutReader.html create mode 100644 toolkit/components/reader/jar.mn create mode 100644 toolkit/components/reader/moz.build create mode 100644 toolkit/components/reader/moz.yaml create mode 100644 toolkit/components/reader/readability/JSDOMParser.js create mode 100644 toolkit/components/reader/readability/LICENSE.md create mode 100644 toolkit/components/reader/readability/Readability-readerable.js create mode 100644 toolkit/components/reader/readability/Readability.js create mode 100644 toolkit/components/reader/test/browser.toml create mode 100644 toolkit/components/reader/test/browser_bug1124271_readerModePinnedTab.js create mode 100644 toolkit/components/reader/test/browser_bug1453818_samesite_cookie.js create mode 100644 toolkit/components/reader/test/browser_bug1780350_readerModeSaveScroll.js create mode 100644 toolkit/components/reader/test/browser_drag_url_readerMode.js create mode 100644 toolkit/components/reader/test/browser_localfile_readerMode.js create mode 100644 toolkit/components/reader/test/browser_readerMode.js create mode 100644 toolkit/components/reader/test/browser_readerMode_bc_reuse.js create mode 100644 toolkit/components/reader/test/browser_readerMode_cached.js create mode 100644 toolkit/components/reader/test/browser_readerMode_colorSchemePref.js create mode 100644 toolkit/components/reader/test/browser_readerMode_hidden_nodes.js create mode 100644 toolkit/components/reader/test/browser_readerMode_menu.js create mode 100644 toolkit/components/reader/test/browser_readerMode_pocket.js create mode 100644 toolkit/components/reader/test/browser_readerMode_readingTime.js create mode 100644 toolkit/components/reader/test/browser_readerMode_refresh.js create mode 100644 toolkit/components/reader/test/browser_readerMode_remoteType.js create mode 100644 toolkit/components/reader/test/browser_readerMode_samesite_cookie_redirect.js create mode 100644 toolkit/components/reader/test/browser_readerMode_with_anchor.js create mode 100644 toolkit/components/reader/test/getCookies.sjs create mode 100644 toolkit/components/reader/test/head.js create mode 100644 toolkit/components/reader/test/linkToGetCookies.html create mode 100644 toolkit/components/reader/test/readerModeArticle.html create mode 100644 toolkit/components/reader/test/readerModeArticleContainsLink.html create mode 100644 toolkit/components/reader/test/readerModeArticleHiddenNodes.html create mode 100644 toolkit/components/reader/test/readerModeArticleMedium.html create mode 100644 toolkit/components/reader/test/readerModeArticleShort.html create mode 100644 toolkit/components/reader/test/readerModeArticleTextPlain.txt create mode 100644 toolkit/components/reader/test/readerModeNonArticle.html create mode 100644 toolkit/components/reader/test/readerModeRandom.sjs create mode 100644 toolkit/components/reader/test/setSameSiteCookie.html create mode 100644 toolkit/components/reader/test/setSameSiteCookie.html^headers^ (limited to 'toolkit/components/reader') diff --git a/toolkit/components/reader/.eslintrc.js b/toolkit/components/reader/.eslintrc.js new file mode 100644 index 0000000000..4df95dd5f8 --- /dev/null +++ b/toolkit/components/reader/.eslintrc.js @@ -0,0 +1,13 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +"use strict"; + +module.exports = { + rules: { + "no-inner-declarations": "error", + "no-shadow": "error", + "no-unused-vars": ["error", { vars: "all", args: "none" }], + }, +}; diff --git a/toolkit/components/reader/AboutReader.sys.mjs b/toolkit/components/reader/AboutReader.sys.mjs new file mode 100644 index 0000000000..6b1c28c228 --- /dev/null +++ b/toolkit/components/reader/AboutReader.sys.mjs @@ -0,0 +1,1319 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this file, + * You can obtain one at http://mozilla.org/MPL/2.0/. */ + +import { ReaderMode } from "resource://gre/modules/ReaderMode.sys.mjs"; + +import { AppConstants } from "resource://gre/modules/AppConstants.sys.mjs"; + +const lazy = {}; +let gScrollPositions = new Map(); + +ChromeUtils.defineESModuleGetters(lazy, { + AsyncPrefs: "resource://gre/modules/AsyncPrefs.sys.mjs", + NarrateControls: "resource://gre/modules/narrate/NarrateControls.sys.mjs", +}); + +ChromeUtils.defineLazyGetter( + lazy, + "numberFormat", + () => new Services.intl.NumberFormat(undefined) +); +ChromeUtils.defineLazyGetter( + lazy, + "pluralRules", + () => new Services.intl.PluralRules(undefined) +); + +const COLORSCHEME_L10N_IDS = { + light: "about-reader-color-scheme-light", + dark: "about-reader-color-scheme-dark", + sepia: "about-reader-color-scheme-sepia", + auto: "about-reader-color-scheme-auto", +}; + +Services.telemetry.setEventRecordingEnabled("readermode", true); + +const zoomOnCtrl = + Services.prefs.getIntPref("mousewheel.with_control.action", 3) == 3; +const zoomOnMeta = + Services.prefs.getIntPref("mousewheel.with_meta.action", 1) == 3; +const isAppLocaleRTL = Services.locale.isAppLocaleRTL; + +export var AboutReader = function ( + actor, + articlePromise, + docContentType = "document", + docTitle = "" +) { + let win = actor.contentWindow; + let url = this._getOriginalUrl(win); + if ( + !( + url.startsWith("http://") || + url.startsWith("https://") || + url.startsWith("file://") + ) + ) { + let errorMsg = + "Only http://, https:// and file:// URLs can be loaded in about:reader."; + if (Services.prefs.getBoolPref("reader.errors.includeURLs")) { + errorMsg += " Tried to load: " + url + "."; + } + console.error(errorMsg); + win.location.href = "about:blank"; + return; + } + + let doc = win.document; + if (isAppLocaleRTL) { + doc.dir = "rtl"; + } + doc.documentElement.setAttribute("platform", AppConstants.platform); + + doc.title = docTitle; + + this._actor = actor; + + this._docRef = Cu.getWeakReference(doc); + this._winRef = Cu.getWeakReference(win); + this._innerWindowId = win.windowGlobalChild.innerWindowId; + + this._article = null; + this._languagePromise = new Promise(resolve => { + this._foundLanguage = resolve; + }); + + if (articlePromise) { + this._articlePromise = articlePromise; + } + + this._headerElementRef = Cu.getWeakReference( + doc.querySelector(".reader-header") + ); + this._domainElementRef = Cu.getWeakReference( + doc.querySelector(".reader-domain") + ); + this._titleElementRef = Cu.getWeakReference( + doc.querySelector(".reader-title") + ); + this._readTimeElementRef = Cu.getWeakReference( + doc.querySelector(".reader-estimated-time") + ); + this._creditsElementRef = Cu.getWeakReference( + doc.querySelector(".reader-credits") + ); + this._contentElementRef = Cu.getWeakReference( + doc.querySelector(".moz-reader-content") + ); + this._toolbarContainerElementRef = Cu.getWeakReference( + doc.querySelector(".toolbar-container") + ); + this._toolbarElementRef = Cu.getWeakReference( + doc.querySelector(".reader-controls") + ); + this._messageElementRef = Cu.getWeakReference( + doc.querySelector(".reader-message") + ); + this._containerElementRef = Cu.getWeakReference( + doc.querySelector(".container") + ); + + doc.addEventListener("mousedown", this); + doc.addEventListener("click", this); + doc.addEventListener("touchstart", this); + + win.addEventListener("pagehide", this); + win.addEventListener("resize", this); + win.addEventListener("wheel", this, { passive: false }); + + this.colorSchemeMediaList = win.matchMedia("(prefers-color-scheme: dark)"); + this.colorSchemeMediaList.addEventListener("change", this); + + this.forcedColorsMediaList = win.matchMedia("(forced-colors)"); + this.forcedColorsMediaList.addEventListener("change", this); + + this._topScrollChange = this._topScrollChange.bind(this); + this._intersectionObs = new win.IntersectionObserver(this._topScrollChange, { + root: null, + threshold: [0, 1], + }); + this._intersectionObs.observe(doc.querySelector(".top-anchor")); + + Services.obs.addObserver(this, "inner-window-destroyed"); + + this._setupButton("close-button", this._onReaderClose.bind(this)); + + // we're ready for any external setup, send a signal for that. + this._actor.sendAsyncMessage("Reader:OnSetup"); + + let colorSchemeValues = JSON.parse( + Services.prefs.getCharPref("reader.color_scheme.values") + ); + let colorSchemeOptions = colorSchemeValues.map(value => ({ + l10nId: COLORSCHEME_L10N_IDS[value], + groupName: "color-scheme", + value, + itemClass: value + "-button", + })); + let colorScheme = Services.prefs.getCharPref("reader.color_scheme"); + + this._setupSegmentedButton( + "color-scheme-buttons", + colorSchemeOptions, + colorScheme, + this._setColorSchemePref.bind(this) + ); + this._setColorSchemePref(colorScheme); + + let fontTypeOptions = [ + { + l10nId: "about-reader-font-type-sans-serif", + groupName: "font-type", + value: "sans-serif", + itemClass: "sans-serif-button", + }, + { + l10nId: "about-reader-font-type-serif", + groupName: "font-type", + value: "serif", + itemClass: "serif-button", + }, + ]; + + let fontType = Services.prefs.getCharPref("reader.font_type"); + this._setupSegmentedButton( + "font-type-buttons", + fontTypeOptions, + fontType, + this._setFontType.bind(this) + ); + this._setFontType(fontType); + + this._setupFontSizeButtons(); + + this._setupContentWidthButtons(); + + this._setupLineHeightButtons(); + + if (win.speechSynthesis && Services.prefs.getBoolPref("narrate.enabled")) { + new lazy.NarrateControls(win, this._languagePromise); + } + + this._loadArticle(docContentType); +}; + +AboutReader.prototype = { + _BLOCK_IMAGES_SELECTOR: + ".content p > img:only-child, " + + ".content p > a:only-child > img:only-child, " + + ".content .wp-caption img, " + + ".content figure img", + + _TABLES_SELECTOR: ".content table", + + FONT_SIZE_MIN: 1, + + FONT_SIZE_LEGACY_MAX: 9, + + FONT_SIZE_MAX: 15, + + FONT_SIZE_EXTENDED_VALUES: [32, 40, 56, 72, 96, 128], + + get _doc() { + return this._docRef.get(); + }, + + get _win() { + return this._winRef.get(); + }, + + get _headerElement() { + return this._headerElementRef.get(); + }, + + get _domainElement() { + return this._domainElementRef.get(); + }, + + get _titleElement() { + return this._titleElementRef.get(); + }, + + get _readTimeElement() { + return this._readTimeElementRef.get(); + }, + + get _creditsElement() { + return this._creditsElementRef.get(); + }, + + get _contentElement() { + return this._contentElementRef.get(); + }, + + get _toolbarElement() { + return this._toolbarElementRef.get(); + }, + + get _toolbarContainerElement() { + return this._toolbarContainerElementRef.get(); + }, + + get _messageElement() { + return this._messageElementRef.get(); + }, + + get _containerElement() { + return this._containerElementRef.get(); + }, + + get _isToolbarVertical() { + if (this._toolbarVertical !== undefined) { + return this._toolbarVertical; + } + return (this._toolbarVertical = Services.prefs.getBoolPref( + "reader.toolbar.vertical" + )); + }, + + receiveMessage({ data, name }) { + const doc = this._doc; + switch (name) { + case "Reader:AddButton": { + if (data.id && data.image && !doc.getElementsByClassName(data.id)[0]) { + let btn = doc.createElement("button"); + btn.dataset.buttonid = data.id; + btn.dataset.telemetryId = `reader-${data.telemetryId}`; + btn.className = "toolbar-button " + data.id; + btn.setAttribute("aria-labelledby", "label-" + data.id); + let tip = doc.createElement("span"); + tip.className = "hover-label"; + tip.id = "label-" + data.id; + doc.l10n.setAttributes(tip, data.l10nId); + btn.append(tip); + btn.style.backgroundImage = "url('" + data.image + "')"; + if (data.width && data.height) { + btn.style.backgroundSize = `${data.width}px ${data.height}px`; + } + let tb = this._toolbarElement; + tb.appendChild(btn); + this._setupButton(data.id, button => { + this._actor.sendAsyncMessage( + "Reader:Clicked-" + button.dataset.buttonid, + { article: this._article } + ); + }); + } + break; + } + case "Reader:RemoveButton": { + if (data.id) { + let btn = doc.getElementsByClassName(data.id)[0]; + if (btn) { + btn.remove(); + } + } + break; + } + case "Reader:ZoomIn": { + this._changeFontSize(+1); + break; + } + case "Reader:ZoomOut": { + this._changeFontSize(-1); + break; + } + case "Reader:ResetZoom": { + this._resetFontSize(); + break; + } + } + }, + + handleEvent(aEvent) { + if (!aEvent.isTrusted) { + return; + } + + let target = aEvent.target; + switch (aEvent.type) { + case "touchstart": + /* fall through */ + case "mousedown": + if ( + !target.closest(".dropdown-popup") && + // Skip handling the toggle button here becase + // the dropdown will get toggled with the 'click' event. + !target.classList.contains("dropdown-toggle") + ) { + this._closeDropdowns(); + } + break; + case "click": + const buttonLabel = + target.attributes.getNamedItem(`data-telemetry-id`)?.value; + + if (buttonLabel) { + Services.telemetry.recordEvent( + "readermode", + "button", + "click", + null, + { + label: buttonLabel, + } + ); + } + + if (target.classList.contains("dropdown-toggle")) { + this._toggleDropdownClicked(aEvent); + } + break; + case "scroll": + let lastHeight = this._lastHeight; + let { windowUtils } = this._win; + this._lastHeight = windowUtils.getBoundsWithoutFlushing( + this._doc.body + ).height; + // Only close dropdowns if the scroll events are not a result of line + // height / font-size changes that caused a page height change. + if (lastHeight == this._lastHeight) { + this._closeDropdowns(true); + } + + break; + case "resize": + this._updateImageMargins(); + this._scheduleToolbarOverlapHandler(); + break; + + case "wheel": + let doZoom = + (aEvent.ctrlKey && zoomOnCtrl) || (aEvent.metaKey && zoomOnMeta); + if (!doZoom) { + return; + } + aEvent.preventDefault(); + + // Throttle events to once per 150ms. This avoids excessively fast zooming. + if (aEvent.timeStamp <= this._zoomBackoffTime) { + return; + } + this._zoomBackoffTime = aEvent.timeStamp + 150; + + // Determine the direction of the delta (we don't care about its size); + // This code is adapted from normalizeWheelEventDelta in + // toolkit/components/pdfjs/content/web/viewer.mjs + let delta = Math.abs(aEvent.deltaX) + Math.abs(aEvent.deltaY); + let angle = Math.atan2(aEvent.deltaY, aEvent.deltaX); + if (-0.25 * Math.PI < angle && angle < 0.75 * Math.PI) { + delta = -delta; + } + + if (delta > 0) { + this._changeFontSize(+1); + } else if (delta < 0) { + this._changeFontSize(-1); + } + break; + + case "pagehide": + this._closeDropdowns(); + this._saveScrollPosition(); + + this._actor.readerModeHidden(); + this.clearActor(); + + // Disconnect and delete IntersectionObservers to prevent memory leaks: + + this._intersectionObs.unobserve(this._doc.querySelector(".top-anchor")); + + delete this._intersectionObs; + + break; + + case "change": + let colorScheme; + if (this.forcedColorsMediaList.matches) { + colorScheme = "hcm"; + } else { + colorScheme = Services.prefs.getCharPref("reader.color_scheme"); + // We should be changing the color scheme in relation to a preference change + // if the user has the color scheme preference set to "Auto". + if (colorScheme == "auto") { + colorScheme = this.colorSchemeMediaList.matches ? "dark" : "light"; + } + } + this._setColorScheme(colorScheme); + + break; + } + }, + + clearActor() { + this._actor = null; + }, + + _onReaderClose() { + if (this._actor) { + this._actor.closeReaderMode(); + } + }, + + async _resetFontSize() { + await lazy.AsyncPrefs.reset("reader.font_size"); + let currentSize = Services.prefs.getIntPref("reader.font_size"); + this._setFontSize(currentSize); + }, + + _setFontSize(newFontSize) { + this._fontSize = Math.min( + this.FONT_SIZE_MAX, + Math.max(this.FONT_SIZE_MIN, newFontSize) + ); + let size; + if (this._fontSize > this.FONT_SIZE_LEGACY_MAX) { + // -1 because we're indexing into a 0-indexed array, so the first value + // over the legacy max should be 0, the next 1, etc. + let index = this._fontSize - this.FONT_SIZE_LEGACY_MAX - 1; + size = this.FONT_SIZE_EXTENDED_VALUES[index]; + } else { + size = 10 + 2 * this._fontSize; + } + + let readerBody = this._doc.body; + readerBody.style.setProperty("--font-size", size + "px"); + return lazy.AsyncPrefs.set("reader.font_size", this._fontSize); + }, + + _setupFontSizeButtons() { + let plusButton = this._doc.querySelector(".plus-button"); + let minusButton = this._doc.querySelector(".minus-button"); + + let currentSize = Services.prefs.getIntPref("reader.font_size"); + this._setFontSize(currentSize); + this._updateFontSizeButtonControls(); + + plusButton.addEventListener( + "click", + event => { + if (!event.isTrusted) { + return; + } + event.stopPropagation(); + this._changeFontSize(+1); + }, + true + ); + + minusButton.addEventListener( + "click", + event => { + if (!event.isTrusted) { + return; + } + event.stopPropagation(); + this._changeFontSize(-1); + }, + true + ); + }, + + _updateFontSizeButtonControls() { + let plusButton = this._doc.querySelector(".plus-button"); + let minusButton = this._doc.querySelector(".minus-button"); + + let currentSize = this._fontSize; + let fontValue = this._doc.querySelector(".font-size-value"); + fontValue.textContent = currentSize; + + if (currentSize === this.FONT_SIZE_MIN) { + minusButton.setAttribute("disabled", true); + } else { + minusButton.removeAttribute("disabled"); + } + if (currentSize === this.FONT_SIZE_MAX) { + plusButton.setAttribute("disabled", true); + } else { + plusButton.removeAttribute("disabled"); + } + }, + + _changeFontSize(changeAmount) { + let currentSize = + Services.prefs.getIntPref("reader.font_size") + changeAmount; + this._setFontSize(currentSize); + this._updateFontSizeButtonControls(); + this._scheduleToolbarOverlapHandler(); + }, + + _setContentWidth(newContentWidth) { + this._contentWidth = newContentWidth; + this._displayContentWidth(newContentWidth); + let width = 20 + 5 * (this._contentWidth - 1) + "em"; + this._doc.body.style.setProperty("--content-width", width); + this._scheduleToolbarOverlapHandler(); + return lazy.AsyncPrefs.set("reader.content_width", this._contentWidth); + }, + + _displayContentWidth(currentContentWidth) { + let contentWidthValue = this._doc.querySelector(".content-width-value"); + contentWidthValue.textContent = currentContentWidth; + }, + + _setupContentWidthButtons() { + const CONTENT_WIDTH_MIN = 1; + const CONTENT_WIDTH_MAX = 9; + + let currentContentWidth = Services.prefs.getIntPref("reader.content_width"); + currentContentWidth = Math.max( + CONTENT_WIDTH_MIN, + Math.min(CONTENT_WIDTH_MAX, currentContentWidth) + ); + + this._displayContentWidth(currentContentWidth); + + let plusButton = this._doc.querySelector(".content-width-plus-button"); + let minusButton = this._doc.querySelector(".content-width-minus-button"); + + function updateControls() { + if (currentContentWidth === CONTENT_WIDTH_MIN) { + minusButton.setAttribute("disabled", true); + } else { + minusButton.removeAttribute("disabled"); + } + if (currentContentWidth === CONTENT_WIDTH_MAX) { + plusButton.setAttribute("disabled", true); + } else { + plusButton.removeAttribute("disabled"); + } + } + + updateControls(); + this._setContentWidth(currentContentWidth); + + plusButton.addEventListener( + "click", + event => { + if (!event.isTrusted) { + return; + } + event.stopPropagation(); + + if (currentContentWidth >= CONTENT_WIDTH_MAX) { + return; + } + + currentContentWidth++; + updateControls(); + this._setContentWidth(currentContentWidth); + }, + true + ); + + minusButton.addEventListener( + "click", + event => { + if (!event.isTrusted) { + return; + } + event.stopPropagation(); + + if (currentContentWidth <= CONTENT_WIDTH_MIN) { + return; + } + + currentContentWidth--; + updateControls(); + this._setContentWidth(currentContentWidth); + }, + true + ); + }, + + _setLineHeight(newLineHeight) { + this._displayLineHeight(newLineHeight); + let height = 1 + 0.2 * (newLineHeight - 1) + "em"; + this._containerElement.style.setProperty("--line-height", height); + return lazy.AsyncPrefs.set("reader.line_height", newLineHeight); + }, + + _displayLineHeight(currentLineHeight) { + let lineHeightValue = this._doc.querySelector(".line-height-value"); + lineHeightValue.textContent = currentLineHeight; + }, + + _setupLineHeightButtons() { + const LINE_HEIGHT_MIN = 1; + const LINE_HEIGHT_MAX = 9; + + let currentLineHeight = Services.prefs.getIntPref("reader.line_height"); + currentLineHeight = Math.max( + LINE_HEIGHT_MIN, + Math.min(LINE_HEIGHT_MAX, currentLineHeight) + ); + + this._displayLineHeight(currentLineHeight); + + let plusButton = this._doc.querySelector(".line-height-plus-button"); + let minusButton = this._doc.querySelector(".line-height-minus-button"); + + function updateControls() { + if (currentLineHeight === LINE_HEIGHT_MIN) { + minusButton.setAttribute("disabled", true); + } else { + minusButton.removeAttribute("disabled"); + } + if (currentLineHeight === LINE_HEIGHT_MAX) { + plusButton.setAttribute("disabled", true); + } else { + plusButton.removeAttribute("disabled"); + } + } + + updateControls(); + this._setLineHeight(currentLineHeight); + + plusButton.addEventListener( + "click", + event => { + if (!event.isTrusted) { + return; + } + event.stopPropagation(); + + if (currentLineHeight >= LINE_HEIGHT_MAX) { + return; + } + + currentLineHeight++; + updateControls(); + this._setLineHeight(currentLineHeight); + }, + true + ); + + minusButton.addEventListener( + "click", + event => { + if (!event.isTrusted) { + return; + } + event.stopPropagation(); + + if (currentLineHeight <= LINE_HEIGHT_MIN) { + return; + } + + currentLineHeight--; + updateControls(); + this._setLineHeight(currentLineHeight); + }, + true + ); + }, + + _setColorScheme(newColorScheme) { + // There's nothing to change if the new color scheme is the same as our current scheme. + if (this._colorScheme === newColorScheme) { + return; + } + + let bodyClasses = this._doc.body.classList; + + if (this._colorScheme) { + bodyClasses.remove(this._colorScheme); + } + + if (!this._win.matchMedia("(forced-colors)").matches) { + if (newColorScheme === "auto") { + this._colorScheme = this.colorSchemeMediaList.matches + ? "dark" + : "light"; + } else { + this._colorScheme = newColorScheme; + } + } else { + this._colorScheme = "hcm"; + } + + bodyClasses.add(this._colorScheme); + }, + + // Pref values include "dark", "light", "sepia", and "auto" + _setColorSchemePref(colorSchemePref) { + this._setColorScheme(colorSchemePref); + + lazy.AsyncPrefs.set("reader.color_scheme", colorSchemePref); + }, + + _setFontType(newFontType) { + if (this._fontType === newFontType) { + return; + } + + let bodyClasses = this._doc.body.classList; + + if (this._fontType) { + bodyClasses.remove(this._fontType); + } + + this._fontType = newFontType; + bodyClasses.add(this._fontType); + + lazy.AsyncPrefs.set("reader.font_type", this._fontType); + }, + + async _loadArticle(docContentType = "document") { + let url = this._getOriginalUrl(); + this._showProgressDelayed(); + + let article; + if (this._articlePromise) { + article = await this._articlePromise; + } + + if (!article) { + try { + article = await ReaderMode.downloadAndParseDocument( + url, + docContentType + ); + } catch (e) { + if (e?.newURL && this._actor) { + await this._actor.sendQuery("RedirectTo", { + newURL: e.newURL, + article: e.article, + }); + + let readerURL = "about:reader?url=" + encodeURIComponent(e.newURL); + this._win.location.replace(readerURL); + return; + } + } + } + + if (!this._actor) { + return; + } + + // Replace the loading message with an error message if there's a failure. + // Users are supposed to navigate away by themselves (because we cannot + // remove ourselves from session history.) + if (!article) { + this._showError(); + return; + } + + this._showContent(article); + }, + + async _requestFavicon() { + let iconDetails = await this._actor.sendQuery("Reader:FaviconRequest", { + url: this._article.url, + preferredWidth: 16 * this._win.devicePixelRatio, + }); + + if (iconDetails) { + this._loadFavicon(iconDetails.url, iconDetails.faviconUrl); + } + }, + + _loadFavicon(url, faviconUrl) { + if (this._article.url !== url) { + return; + } + + let doc = this._doc; + + let link = doc.createElement("link"); + link.rel = "shortcut icon"; + link.href = faviconUrl; + + doc.getElementsByTagName("head")[0].appendChild(link); + }, + + _updateImageMargins() { + let windowWidth = this._win.innerWidth; + let bodyWidth = this._doc.body.clientWidth; + + let setImageMargins = function (img) { + img.classList.add("moz-reader-block-img"); + + // If the image is at least as wide as the window, make it fill edge-to-edge on mobile. + if (img.naturalWidth >= windowWidth) { + img.setAttribute("moz-reader-full-width", true); + } else { + img.removeAttribute("moz-reader-full-width"); + } + + // If the image is at least half as wide as the body, center it on desktop. + if (img.naturalWidth >= bodyWidth / 2) { + img.setAttribute("moz-reader-center", true); + } else { + img.removeAttribute("moz-reader-center"); + } + }; + + let imgs = this._doc.querySelectorAll(this._BLOCK_IMAGES_SELECTOR); + for (let i = imgs.length; --i >= 0; ) { + let img = imgs[i]; + + if (img.naturalWidth > 0) { + setImageMargins(img); + } else { + img.onload = function () { + setImageMargins(img); + }; + } + } + }, + + _updateWideTables() { + let windowWidth = this._win.innerWidth; + + // Avoid horizontal overflow in the document by making tables that are wider than half browser window's size + // by making it scrollable. + let tables = this._doc.querySelectorAll(this._TABLES_SELECTOR); + for (let i = tables.length; --i >= 0; ) { + let table = tables[i]; + let rect = table.getBoundingClientRect(); + let tableWidth = rect.width; + + if (windowWidth / 2 <= tableWidth) { + table.classList.add("moz-reader-wide-table"); + } + } + }, + + _maybeSetTextDirection: function Read_maybeSetTextDirection(article) { + // Set the article's "dir" on the contents. + // If no direction is specified, the contents should automatically be LTR + // regardless of the UI direction to avoid inheriting the parent's direction + // if the UI is RTL. + this._containerElement.dir = article.dir || "ltr"; + + // The native locale could be set differently than the article's text direction. + this._readTimeElement.dir = isAppLocaleRTL ? "rtl" : "ltr"; + + // This is used to mirror the line height buttons in the toolbar, when relevant. + this._toolbarElement.setAttribute("articledir", article.dir || "ltr"); + }, + + _showError() { + this._headerElement.classList.remove("reader-show-element"); + this._contentElement.classList.remove("reader-show-element"); + + this._doc.l10n.setAttributes( + this._messageElement, + "about-reader-load-error" + ); + this._doc.l10n.setAttributes( + this._doc.getElementById("reader-title"), + "about-reader-load-error" + ); + this._messageElement.style.display = "block"; + + this._doc.documentElement.dataset.isError = true; + + this._error = true; + + this._doc.dispatchEvent( + new this._win.CustomEvent("AboutReaderContentError", { + bubbles: true, + cancelable: false, + }) + ); + }, + + // This function is the JS version of Java's StringUtils.stripCommonSubdomains. + _stripHost(host) { + if (!host) { + return host; + } + + let start = 0; + + if (host.startsWith("www.")) { + start = 4; + } else if (host.startsWith("m.")) { + start = 2; + } else if (host.startsWith("mobile.")) { + start = 7; + } + + return host.substring(start); + }, + + _showContent(article) { + this._messageElement.classList.remove("reader-show-element"); + + this._article = article; + + this._domainElement.href = article.url; + let articleUri = Services.io.newURI(article.url); + + try { + this._domainElement.textContent = this._stripHost(articleUri.host); + } catch (ex) { + let url = this._actor.document.URL; + url = url.substring(url.indexOf("%2F") + 6); + url = url.substring(0, url.indexOf("%2F")); + + this._domainElement.textContent = url; + } + + this._creditsElement.textContent = article.byline; + + this._titleElement.textContent = article.title; + + const slow = article.readingTimeMinsSlow; + const fast = article.readingTimeMinsFast; + const fastStr = lazy.numberFormat.format(fast); + const readTimeRange = lazy.numberFormat.formatRange(fast, slow); + this._doc.l10n.setAttributes( + this._readTimeElement, + "about-reader-estimated-read-time", + { + range: fast === slow ? `~${fastStr}` : `${readTimeRange}`, + rangePlural: + fast === slow + ? lazy.pluralRules.select(fast) + : lazy.pluralRules.selectRange(fast, slow), + } + ); + + // If a document title was not provided in the constructor, we'll fall back + // to using the article title. + if (!this._doc.title) { + this._doc.title = article.title; + } + + this._containerElement.setAttribute("lang", article.lang); + + this._headerElement.classList.add("reader-show-element"); + + let parserUtils = Cc["@mozilla.org/parserutils;1"].getService( + Ci.nsIParserUtils + ); + let contentFragment = parserUtils.parseFragment( + article.content, + Ci.nsIParserUtils.SanitizerDropForms | + Ci.nsIParserUtils.SanitizerAllowStyle, + false, + articleUri, + this._contentElement + ); + this._contentElement.innerHTML = ""; + this._contentElement.appendChild(contentFragment); + this._maybeSetTextDirection(article); + this._foundLanguage(article.language); + + this._contentElement.classList.add("reader-show-element"); + this._updateImageMargins(); + this._updateWideTables(); + + this._requestFavicon(); + this._doc.body.classList.add("loaded"); + + this._goToReference(articleUri.ref); + this._getScrollPosition(); + + Services.obs.notifyObservers(this._win, "AboutReader:Ready"); + + this._doc.dispatchEvent( + new this._win.CustomEvent("AboutReaderContentReady", { + bubbles: true, + cancelable: false, + }) + ); + }, + + _hideContent() { + this._headerElement.classList.remove("reader-show-element"); + this._contentElement.classList.remove("reader-show-element"); + }, + + _showProgressDelayed() { + this._win.setTimeout(() => { + // No need to show progress if the article has been loaded, + // if the window has been unloaded, or if there was an error + // trying to load the article. + if (this._article || !this._actor || this._error) { + return; + } + + this._headerElement.classList.remove("reader-show-element"); + this._contentElement.classList.remove("reader-show-element"); + + this._doc.l10n.setAttributes( + this._messageElement, + "about-reader-loading" + ); + this._messageElement.classList.add("reader-show-element"); + }, 300); + }, + + /** + * Returns the original article URL for this about:reader view. + */ + _getOriginalUrl(win) { + let url = win ? win.location.href : this._win.location.href; + return ReaderMode.getOriginalUrl(url) || url; + }, + + _setupSegmentedButton(id, options, initialValue, callback) { + let doc = this._doc; + let segmentedButton = doc.getElementsByClassName(id)[0]; + + for (let option of options) { + let radioButton = doc.createElement("input"); + radioButton.id = "radio-item" + option.itemClass; + radioButton.type = "radio"; + radioButton.classList.add("radio-button"); + radioButton.name = option.groupName; + segmentedButton.appendChild(radioButton); + + let item = doc.createElement("label"); + item.htmlFor = radioButton.id; + item.classList.add(option.itemClass); + doc.l10n.setAttributes(item, option.l10nId); + + segmentedButton.appendChild(item); + + radioButton.addEventListener( + "input", + function (aEvent) { + if (!aEvent.isTrusted) { + return; + } + + let labels = segmentedButton.children; + for (let label of labels) { + label.removeAttribute("checked"); + } + + aEvent.target.nextElementSibling.setAttribute("checked", "true"); + callback(option.value); + }, + true + ); + + if (option.value === initialValue) { + radioButton.checked = true; + item.setAttribute("checked", "true"); + } + } + }, + + _setupButton(id, callback) { + let button = this._doc.querySelector("." + id); + button.removeAttribute("hidden"); + button.addEventListener( + "click", + function (aEvent) { + if (!aEvent.isTrusted) { + return; + } + + let btn = aEvent.target; + callback(btn); + }, + true + ); + }, + + _toggleDropdownClicked(event) { + let dropdown = event.target.closest(".dropdown"); + + if (!dropdown) { + return; + } + + event.stopPropagation(); + + if (dropdown.classList.contains("open")) { + this._closeDropdowns(); + } else { + this._openDropdown(dropdown); + } + }, + + /* + * If the ReaderView banner font-dropdown is closed, open it. + */ + _openDropdown(dropdown, window) { + if (dropdown.classList.contains("open")) { + return; + } + + this._closeDropdowns(); + + // Get the height of the doc and start handling scrolling: + let { windowUtils } = this._win; + this._lastHeight = windowUtils.getBoundsWithoutFlushing( + this._doc.body + ).height; + this._doc.addEventListener("scroll", this); + + dropdown.classList.add("open"); + this._toolbarElement.classList.add("dropdown-open"); + + this._toolbarContainerElement.classList.add("dropdown-open"); + this._toggleToolbarFixedPosition(true); + }, + + /* + * If the ReaderView has open dropdowns, close them. If we are closing the + * dropdowns because the page is scrolling, allow popups to stay open with + * the keep-open class. + */ + _closeDropdowns(scrolling) { + let selector = ".dropdown.open"; + if (scrolling) { + selector += ":not(.keep-open)"; + } + + let openDropdowns = this._doc.querySelectorAll(selector); + let haveOpenDropdowns = openDropdowns.length; + for (let dropdown of openDropdowns) { + dropdown.classList.remove("open"); + } + this._toolbarElement.classList.remove("dropdown-open"); + + if (haveOpenDropdowns) { + this._toolbarContainerElement.classList.remove("dropdown-open"); + this._toggleToolbarFixedPosition(false); + } + + // Stop handling scrolling: + this._doc.removeEventListener("scroll", this); + }, + + _toggleToolbarFixedPosition(shouldBeFixed) { + let el = this._toolbarContainerElement; + let fontSize = this._doc.body.style.getPropertyValue("--font-size"); + let contentWidth = this._doc.body.style.getPropertyValue("--content-width"); + if (shouldBeFixed) { + el.style.setProperty("--font-size", fontSize); + el.style.setProperty("--content-width", contentWidth); + el.classList.add("transition-location"); + } else { + let expectTransition = + el.style.getPropertyValue("--font-size") != fontSize || + el.style.getPropertyValue("--content-width") != contentWidth; + if (expectTransition) { + el.addEventListener( + "transitionend", + () => el.classList.remove("transition-location"), + { once: true } + ); + } else { + el.classList.remove("transition-location"); + } + el.style.removeProperty("--font-size"); + el.style.removeProperty("--content-width"); + el.classList.remove("overlaps"); + } + }, + + _scheduleToolbarOverlapHandler() { + if (this._enqueuedToolbarOverlapHandler) { + return; + } + this._enqueuedToolbarOverlapHandler = this._win.requestAnimationFrame( + () => { + this._win.setTimeout(() => this._toolbarOverlapHandler(), 0); + } + ); + }, + + _toolbarOverlapHandler() { + delete this._enqueuedToolbarOverlapHandler; + // Ensure the dropdown is still open to avoid racing with that changing. + if (this._toolbarContainerElement.classList.contains("dropdown-open")) { + let { windowUtils } = this._win; + let toolbarBounds = windowUtils.getBoundsWithoutFlushing( + this._toolbarElement.parentNode + ); + let textBounds = windowUtils.getBoundsWithoutFlushing( + this._containerElement + ); + let overlaps = false; + if (isAppLocaleRTL) { + overlaps = textBounds.right > toolbarBounds.left; + } else { + overlaps = textBounds.left < toolbarBounds.right; + } + this._toolbarContainerElement.classList.toggle("overlaps", overlaps); + } + }, + + _topScrollChange(entries) { + if (!entries.length) { + return; + } + // If we don't intersect the item at the top of the document, we're + // scrolled down: + let scrolled = !entries[entries.length - 1].isIntersecting; + let tbc = this._toolbarContainerElement; + tbc.classList.toggle("scrolled", scrolled); + }, + + /* + * Scroll reader view to a reference + */ + _goToReference(ref) { + if (ref) { + if (this._doc.readyState == "complete") { + this._win.location.hash = ref; + } else { + this._win.addEventListener( + "load", + () => { + this._win.location.hash = ref; + }, + { once: true } + ); + } + } + }, + + _scrollToSavedPosition(pos) { + this._win.scrollTo({ + top: pos, + left: 0, + behavior: "auto", + }); + gScrollPositions.delete(this._win.location.href); + }, + + /* + * Save reader view vertical scroll position + */ + _saveScrollPosition() { + let scrollTop = this._doc.documentElement.scrollTop; + gScrollPositions.set(this._win.location.href, scrollTop); + }, + + /* + * Scroll reader view to a saved position + */ + _getScrollPosition() { + let scrollPosition = gScrollPositions.get(this._win.location.href); + if (scrollPosition !== undefined) { + if (this._doc.readyState == "complete") { + this._scrollToSavedPosition(scrollPosition); + } else { + this._win.addEventListener( + "load", + () => { + this._scrollToSavedPosition(scrollPosition); + }, + { once: true } + ); + } + } + }, +}; diff --git a/toolkit/components/reader/Reader.worker.js b/toolkit/components/reader/Reader.worker.js new file mode 100644 index 0000000000..148c57534c --- /dev/null +++ b/toolkit/components/reader/Reader.worker.js @@ -0,0 +1,59 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this file, + * You can obtain one at http://mozilla.org/MPL/2.0/. */ + +"use strict"; + +/** + * A worker dedicated to handle parsing documents for reader view. + */ + +/* import-globals-from /toolkit/components/workerloader/require.js */ +/* global JSDOMParser */ +/* import-globals-from /toolkit/components/reader/readability/Readability.js */ +importScripts( + "resource://gre/modules/workers/require.js", + "resource://gre/modules/reader/JSDOMParser.js", + "resource://gre/modules/reader/Readability.js" +); + +var PromiseWorker = require("resource://gre/modules/workers/PromiseWorker.js"); + +const DEBUG = false; + +var worker = new PromiseWorker.AbstractWorker(); +worker.dispatch = function (method, args = []) { + return Agent[method](...args); +}; +worker.postMessage = function (result, ...transfers) { + self.postMessage(result, ...transfers); +}; +worker.close = function () { + self.close(); +}; +worker.log = function (...args) { + if (DEBUG) { + dump("ReaderWorker: " + args.join(" ") + "\n"); + } +}; + +self.addEventListener("message", msg => worker.handleMessage(msg)); +self.addEventListener("unhandledrejection", function (error) { + throw error.reason; +}); + +var Agent = { + /** + * Parses structured article data from a document. + * + * @param {object} uri URI data for the document. + * @param {string} serializedDoc The serialized document. + * @param {object} options Options object to pass to Readability. + * + * @return {object} Article object returned from Readability. + */ + parseDocument(uri, serializedDoc, options) { + let doc = new JSDOMParser().parse(serializedDoc, uri.spec); + return new Readability(doc, options).parse(); + }, +}; diff --git a/toolkit/components/reader/ReaderMode.sys.mjs b/toolkit/components/reader/ReaderMode.sys.mjs new file mode 100644 index 0000000000..4b754d88b0 --- /dev/null +++ b/toolkit/components/reader/ReaderMode.sys.mjs @@ -0,0 +1,561 @@ +// -*- indent-tabs-mode: nil; js-indent-level: 2 -*- +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this file, + * You can obtain one at http://mozilla.org/MPL/2.0/. */ + +// Constants for telemetry. +const DOWNLOAD_SUCCESS = 0; +const DOWNLOAD_ERROR_XHR = 1; +const DOWNLOAD_ERROR_NO_DOC = 2; + +const PARSE_SUCCESS = 0; +const PARSE_ERROR_TOO_MANY_ELEMENTS = 1; +const PARSE_ERROR_WORKER = 2; +const PARSE_ERROR_NO_ARTICLE = 3; + +// Class names to preserve in the readerized output. We preserve these class +// names so that rules in aboutReader.css can match them. +const CLASSES_TO_PRESERVE = [ + "caption", + "emoji", + "hidden", + "invisible", + "sr-only", + "visually-hidden", + "visuallyhidden", + "wp-caption", + "wp-caption-text", + "wp-smiley", +]; + +import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs"; + +const lazy = {}; + +ChromeUtils.defineESModuleGetters(lazy, { + LanguageDetector: + "resource://gre/modules/translation/LanguageDetector.sys.mjs", + ReaderWorker: "resource://gre/modules/reader/ReaderWorker.sys.mjs", + Readerable: "resource://gre/modules/Readerable.sys.mjs", +}); + +const gIsFirefoxDesktop = + Services.appinfo.ID == "{ec8030f7-c20a-464f-9b0e-13a3a9e97384}"; + +Services.telemetry.setEventRecordingEnabled("readermode", true); + +export var ReaderMode = { + DEBUG: 0, + + // For time spent telemetry + enterTime: undefined, + leaveTime: undefined, + + /** + * Enter the reader mode by going forward one step in history if applicable, + * if not, append the about:reader page in the history instead. + */ + enterReaderMode(docShell, win) { + this.enterTime = Date.now(); + + Services.telemetry.recordEvent("readermode", "view", "on", null, { + subcategory: "feature", + }); + + let url = win.document.location.href; + let readerURL = "about:reader?url=" + encodeURIComponent(url); + + if (!Services.appinfo.sessionHistoryInParent) { + let webNav = docShell.QueryInterface(Ci.nsIWebNavigation); + let sh = webNav.sessionHistory; + if (webNav.canGoForward) { + let forwardEntry = sh.legacySHistory.getEntryAtIndex(sh.index + 1); + let forwardURL = forwardEntry.URI.spec; + if (forwardURL && (forwardURL == readerURL || !readerURL)) { + webNav.goForward(); + return; + } + } + } + + // This could possibly move to the parent. See bug 1664982. + win.document.location = readerURL; + }, + + /** + * Exit the reader mode by going back one step in history if applicable, + * if not, append the original page in the history instead. + */ + leaveReaderMode(docShell, win) { + this.leaveTime = Date.now(); + + // Measured in seconds (whole number) + let timeSpentInReaderMode = Math.floor( + (this.leaveTime - this.enterTime) / 1000 + ); + + // Measured as percentage (whole number) + let scrollPosition = Math.floor( + ((win.scrollY + win.innerHeight) / win.document.body.clientHeight) * 100 + ); + + Services.telemetry.recordEvent("readermode", "view", "off", null, { + subcategory: "feature", + reader_time: `${timeSpentInReaderMode}`, + scroll_position: `${scrollPosition}`, + }); + + let url = win.document.location.href; + let originalURL = this.getOriginalUrl(url); + let webNav = docShell.QueryInterface(Ci.nsIWebNavigation); + + if (!Services.appinfo.sessionHistoryInParent) { + let sh = webNav.sessionHistory; + if (webNav.canGoBack) { + let prevEntry = sh.legacySHistory.getEntryAtIndex(sh.index - 1); + let prevURL = prevEntry.URI.spec; + if (prevURL && (prevURL == originalURL || !originalURL)) { + webNav.goBack(); + return; + } + } + } + + let referrerURI, principal; + try { + referrerURI = Services.io.newURI(url); + principal = Services.scriptSecurityManager.createContentPrincipal( + referrerURI, + win.document.nodePrincipal.originAttributes + ); + } catch (e) { + console.error(e); + return; + } + let loadFlags = webNav.LOAD_FLAGS_DISALLOW_INHERIT_PRINCIPAL; + let ReferrerInfo = Components.Constructor( + "@mozilla.org/referrer-info;1", + "nsIReferrerInfo", + "init" + ); + let loadURIOptions = { + triggeringPrincipal: principal, + loadFlags, + referrerInfo: new ReferrerInfo( + Ci.nsIReferrerInfo.EMPTY, + true, + referrerURI + ), + }; + // This could possibly move to the parent. See bug 1664982. + webNav.fixupAndLoadURIString(originalURL, loadURIOptions); + }, + + /** + * Returns original URL from an about:reader URL. + * + * @param url An about:reader URL. + * @return The original URL for the article, or null if we did not find + * a properly formatted about:reader URL. + */ + getOriginalUrl(url) { + if (!url.startsWith("about:reader?")) { + return null; + } + + let outerHash = ""; + try { + let uriObj = Services.io.newURI(url); + url = uriObj.specIgnoringRef; + outerHash = uriObj.ref; + } catch (ex) { + /* ignore, use the raw string */ + } + + let searchParams = new URLSearchParams( + url.substring("about:reader?".length) + ); + if (!searchParams.has("url")) { + return null; + } + let originalUrl = searchParams.get("url"); + if (outerHash) { + try { + let uriObj = Services.io.newURI(originalUrl); + uriObj = Services.io.newURI("#" + outerHash, null, uriObj); + originalUrl = uriObj.spec; + } catch (ex) {} + } + return originalUrl; + }, + + getOriginalUrlObjectForDisplay(url) { + let originalUrl = this.getOriginalUrl(url); + if (originalUrl) { + let uriObj; + try { + uriObj = Services.uriFixup.getFixupURIInfo(originalUrl).preferredURI; + } catch (ex) { + return null; + } + try { + return Services.io.createExposableURI(uriObj); + } catch (ex) { + return null; + } + } + return null; + }, + + /** + * Gets an article from a loaded browser's document. This method will not attempt + * to parse certain URIs (e.g. about: URIs). + * + * @param doc A document to parse. + * @return {Promise} + * @resolves JS object representing the article, or null if no article is found. + */ + parseDocument(doc) { + if ( + !lazy.Readerable.shouldCheckUri(doc.documentURIObject) || + !lazy.Readerable.shouldCheckUri(doc.baseURIObject, true) + ) { + this.log("Reader mode disabled for URI"); + return null; + } + + return this._readerParse(doc); + }, + + /** + * Downloads and parses a document from a URL. + * + * @param url URL to download and parse. + * @return {Promise} + * @resolves JS object representing the article, or null if no article is found. + */ + async downloadAndParseDocument(url, docContentType = "document") { + let result = await this._downloadDocument(url, docContentType); + if (!result?.doc) { + return null; + } + let { doc, newURL } = result; + if ( + !lazy.Readerable.shouldCheckUri(doc.documentURIObject) || + !lazy.Readerable.shouldCheckUri(doc.baseURIObject, true) + ) { + this.log("Reader mode disabled for URI"); + return null; + } + + let article = await this._readerParse(doc); + // If we have to redirect, reject to the caller with the parsed article, + // so we can update the URL before displaying it. + if (newURL) { + return Promise.reject({ newURL, article }); + } + // Otherwise, we can just continue with the article. + return article; + }, + + _downloadDocument(url, docContentType = "document") { + try { + if (!lazy.Readerable.shouldCheckUri(Services.io.newURI(url))) { + return null; + } + } catch (ex) { + console.error( + new Error(`Couldn't create URI from ${url} to download: ${ex}`) + ); + return null; + } + let histogram = Services.telemetry.getHistogramById( + "READER_MODE_DOWNLOAD_RESULT" + ); + return new Promise((resolve, reject) => { + let xhr = new XMLHttpRequest(); + xhr.open("GET", url, true); + xhr.onerror = evt => reject(evt.error); + xhr.responseType = docContentType === "text/plain" ? "text" : "document"; + xhr.onload = evt => { + if (xhr.status !== 200) { + reject("Reader mode XHR failed with status: " + xhr.status); + histogram.add(DOWNLOAD_ERROR_XHR); + return; + } + + let doc = + xhr.responseType === "text" ? xhr.responseText : xhr.responseXML; + if (!doc) { + reject("Reader mode XHR didn't return a document"); + histogram.add(DOWNLOAD_ERROR_NO_DOC); + return; + } + + let responseURL = xhr.responseURL; + let givenURL = url; + // Convert these to real URIs to make sure the escaping (or lack + // thereof) is identical: + try { + responseURL = Services.io.newURI(responseURL).specIgnoringRef; + } catch (ex) { + /* Ignore errors - we'll use what we had before */ + } + try { + givenURL = Services.io.newURI(givenURL).specIgnoringRef; + } catch (ex) { + /* Ignore errors - we'll use what we had before */ + } + + if (xhr.responseType != "document") { + let initialText = doc; + let parser = new DOMParser(); + doc = parser.parseFromString(`
`, "text/html");
+          doc.querySelector("pre").textContent = initialText;
+        }
+
+        // We treat redirects as download successes here:
+        histogram.add(DOWNLOAD_SUCCESS);
+
+        let result = { doc };
+        if (responseURL != givenURL) {
+          result.newURL = xhr.responseURL;
+        }
+
+        resolve(result);
+      };
+      xhr.send();
+    });
+  },
+
+  log(msg) {
+    if (this.DEBUG) {
+      dump("Reader: " + msg);
+    }
+  },
+
+  /**
+   * Attempts to parse a document into an article. Heavy lifting happens
+   * in Reader.worker.js.
+   *
+   * @param doc The document to parse.
+   * @return {Promise}
+   * @resolves JS object representing the article, or null if no article is found.
+   */
+  async _readerParse(doc) {
+    let histogram = Services.telemetry.getHistogramById(
+      "READER_MODE_PARSE_RESULT"
+    );
+    if (this.parseNodeLimit) {
+      let numTags = doc.getElementsByTagName("*").length;
+      if (numTags > this.parseNodeLimit) {
+        this.log(
+          "Aborting parse for " +
+            doc.baseURIObject.spec +
+            "; " +
+            numTags +
+            " elements found"
+        );
+        histogram.add(PARSE_ERROR_TOO_MANY_ELEMENTS);
+        return null;
+      }
+    }
+
+    // Fetch this here before we send `doc` off to the worker thread, as later on the
+    // document might be nuked but we will still want the URI.
+    let { documentURI } = doc;
+
+    let uriParam;
+    uriParam = {
+      spec: doc.baseURIObject.spec,
+      prePath: doc.baseURIObject.prePath,
+      scheme: doc.baseURIObject.scheme,
+
+      // Fallback
+      host: documentURI,
+      pathBase: documentURI,
+    };
+
+    // nsIURI.host throws an exception if a host doesn't exist.
+    try {
+      uriParam.host = doc.baseURIObject.host;
+      uriParam.pathBase = Services.io.newURI(".", null, doc.baseURIObject).spec;
+    } catch (ex) {
+      // Fall back to the initial values we assigned.
+      console.warn("Error accessing host name: ", ex);
+    }
+
+    // convert text/plain document, if any, to XHTML format
+    if (this._isDocumentPlainText(doc)) {
+      doc = this._convertPlainTextDocument(doc);
+    }
+
+    let serializer = new XMLSerializer();
+    let serializedDoc = serializer.serializeToString(doc);
+    // Explicitly null out doc to make it clear it might not be available from this
+    // point on.
+    doc = null;
+
+    let options = {
+      classesToPreserve: CLASSES_TO_PRESERVE,
+    };
+
+    let article = null;
+    try {
+      article = await lazy.ReaderWorker.post("parseDocument", [
+        uriParam,
+        serializedDoc,
+        options,
+      ]);
+    } catch (e) {
+      console.error("Error in ReaderWorker: ", e);
+      histogram.add(PARSE_ERROR_WORKER);
+    }
+
+    if (!article) {
+      this.log("Worker did not return an article");
+      histogram.add(PARSE_ERROR_NO_ARTICLE);
+      return null;
+    }
+
+    // Readability returns a URI object based on the baseURI, but we only care
+    // about the original document's URL from now on. This also avoids spoofing
+    // attempts where the baseURI doesn't match the domain of the documentURI
+    article.url = documentURI;
+    delete article.uri;
+
+    let flags =
+      Ci.nsIDocumentEncoder.OutputSelectionOnly |
+      Ci.nsIDocumentEncoder.OutputAbsoluteLinks;
+    article.title = Cc["@mozilla.org/parserutils;1"]
+      .getService(Ci.nsIParserUtils)
+      .convertToPlainText(article.title, flags, 0);
+    if (gIsFirefoxDesktop) {
+      await this._assignLanguage(article);
+      this._maybeAssignTextDirection(article);
+    }
+
+    this._assignReadTime(article);
+
+    histogram.add(PARSE_SUCCESS);
+    return article;
+  },
+
+  /**
+   * Sets a global language string value if the result is confident
+   *
+   * @return Promise
+   * @resolves when the language is detected
+   */
+  _assignLanguage(article) {
+    return lazy.LanguageDetector.detectLanguage(article.textContent).then(
+      result => {
+        article.language = result.confident ? result.language : null;
+      }
+    );
+  },
+
+  _maybeAssignTextDirection(article) {
+    // TODO: Remove the hardcoded language codes below once bug 1320265 is resolved.
+    if (
+      !article.dir &&
+      ["ar", "fa", "he", "ug", "ur"].includes(article.language)
+    ) {
+      article.dir = "rtl";
+    }
+  },
+
+  /**
+   * Assigns the estimated reading time range of the article to the article object.
+   *
+   * @param article the article object to assign the reading time estimate to.
+   */
+  _assignReadTime(article) {
+    let lang = article.language || "en";
+    const readingSpeed = this._getReadingSpeedForLanguage(lang);
+    const charactersPerMinuteLow = readingSpeed.cpm - readingSpeed.variance;
+    const charactersPerMinuteHigh = readingSpeed.cpm + readingSpeed.variance;
+    const length = article.length;
+
+    article.readingTimeMinsSlow = Math.ceil(length / charactersPerMinuteLow);
+    article.readingTimeMinsFast = Math.ceil(length / charactersPerMinuteHigh);
+  },
+
+  /**
+   * Returns the reading speed of a selection of languages with likely variance.
+   *
+   * Reading speed estimated from a study done on reading speeds in various languages.
+   * study can be found here: http://iovs.arvojournals.org/article.aspx?articleid=2166061
+   *
+   * @return object with characters per minute and variance. Defaults to English
+   *         if no suitable language is found in the collection.
+   */
+  _getReadingSpeedForLanguage(lang) {
+    const readingSpeed = new Map([
+      ["en", { cpm: 987, variance: 118 }],
+      ["ar", { cpm: 612, variance: 88 }],
+      ["de", { cpm: 920, variance: 86 }],
+      ["es", { cpm: 1025, variance: 127 }],
+      ["fi", { cpm: 1078, variance: 121 }],
+      ["fr", { cpm: 998, variance: 126 }],
+      ["he", { cpm: 833, variance: 130 }],
+      ["it", { cpm: 950, variance: 140 }],
+      ["jw", { cpm: 357, variance: 56 }],
+      ["nl", { cpm: 978, variance: 143 }],
+      ["pl", { cpm: 916, variance: 126 }],
+      ["pt", { cpm: 913, variance: 145 }],
+      ["ru", { cpm: 986, variance: 175 }],
+      ["sk", { cpm: 885, variance: 145 }],
+      ["sv", { cpm: 917, variance: 156 }],
+      ["tr", { cpm: 1054, variance: 156 }],
+      ["zh", { cpm: 255, variance: 29 }],
+    ]);
+
+    return readingSpeed.get(lang) || readingSpeed.get("en");
+  },
+  /**
+   *
+   * Check if the document to be parsed is text document.
+   * @param doc the doc object to be parsed.
+   * @return boolean
+   *
+   */
+  _isDocumentPlainText(doc) {
+    return doc.contentType == "text/plain";
+  },
+  /**
+   *
+   * The document to be parsed is text document and is converted to HTML format.
+   * @param doc the doc object to be parsed.
+   * @return doc
+   *
+   */
+  _convertPlainTextDocument(doc) {
+    let preTag = doc.querySelector("pre");
+    let docFrag = doc.createDocumentFragment();
+    let content = preTag.textContent;
+    let paragraphs = content.split(/\r?\n\r?\n/);
+    for (let para of paragraphs) {
+      let pElem = doc.createElement("p");
+      let lines = para.split(/\n/);
+      for (let line of lines) {
+        pElem.append(line);
+        let brElem = doc.createElement("br");
+        pElem.append(brElem);
+      }
+      docFrag.append(pElem);
+    }
+    // Clone the document to avoid the original document being affected
+    // (which shows up when exiting reader mode again).
+    let clone = doc.documentElement.cloneNode(true);
+    clone.querySelector("pre").replaceWith(docFrag);
+    return clone;
+  },
+};
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  ReaderMode,
+  "maxElemsToParse",
+  "reader.parse-node-limit",
+  0
+);
diff --git a/toolkit/components/reader/ReaderWorker.sys.mjs b/toolkit/components/reader/ReaderWorker.sys.mjs
new file mode 100644
index 0000000000..16c47c45dd
--- /dev/null
+++ b/toolkit/components/reader/ReaderWorker.sys.mjs
@@ -0,0 +1,13 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Interface to a dedicated thread handling readability parsing.
+ */
+
+import { BasePromiseWorker } from "resource://gre/modules/PromiseWorker.sys.mjs";
+
+export var ReaderWorker = new BasePromiseWorker(
+  "resource://gre/modules/reader/Reader.worker.js"
+);
diff --git a/toolkit/components/reader/Readerable.js b/toolkit/components/reader/Readerable.js
new file mode 100644
index 0000000000..828b4f507c
--- /dev/null
+++ b/toolkit/components/reader/Readerable.js
@@ -0,0 +1,94 @@
+// -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// This file and Readability-readerable.js are merged together into
+// Readerable.sys.mjs.
+
+/* exported Readerable */
+/* import-globals-from readability/Readability-readerable.js */
+
+const { XPCOMUtils } = ChromeUtils.importESModule(
+  "resource://gre/modules/XPCOMUtils.sys.mjs"
+);
+
+var Readerable = {
+  get isEnabledForParseOnLoad() {
+    return this.isEnabled;
+  },
+
+  /**
+   * Decides whether or not a document is reader-able without parsing the whole thing.
+   *
+   * @param doc A document to parse.
+   * @return boolean Whether or not we should show the reader mode button.
+   */
+  isProbablyReaderable(doc) {
+    // Only care about 'real' HTML documents:
+    if (
+      doc.mozSyntheticDocument ||
+      !doc.defaultView.HTMLDocument.isInstance(doc)
+    ) {
+      return false;
+    }
+
+    let uri = Services.io.newURI(doc.location.href);
+    if (!this.shouldCheckUri(uri)) {
+      return false;
+    }
+
+    return isProbablyReaderable(doc, this._isNodeVisible);
+  },
+
+  _isNodeVisible(node) {
+    return node.clientHeight > 0 && node.clientWidth > 0;
+  },
+
+  _blockedHosts: [
+    "amazon.com",
+    "github.com",
+    "mail.google.com",
+    "pinterest.com",
+    "reddit.com",
+    "twitter.com",
+    "youtube.com",
+    "app.slack.com",
+  ],
+
+  shouldCheckUri(uri, isBaseUri = false) {
+    if (!["http", "https", "file", "moz-nullprincipal"].includes(uri.scheme)) {
+      return false;
+    }
+
+    if (!isBaseUri && uri.scheme.startsWith("http")) {
+      // Sadly, some high-profile pages have false positives, so bail early for those:
+      let { host } = uri;
+      if (this._blockedHosts.some(blockedHost => host.endsWith(blockedHost))) {
+        // Allow github on non-project pages
+        if (
+          host == "github.com" &&
+          !uri.filePath.includes("/projects") &&
+          !uri.filePath.includes("/issues")
+        ) {
+          return true;
+        }
+        return false;
+      }
+
+      if (uri.filePath == "/") {
+        return false;
+      }
+    }
+
+    return true;
+  },
+};
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  Readerable,
+  "isEnabled",
+  "reader.parse-on-load.enabled",
+  true
+);
diff --git a/toolkit/components/reader/Readerable.sys.mjs b/toolkit/components/reader/Readerable.sys.mjs
new file mode 100644
index 0000000000..200fa48a48
--- /dev/null
+++ b/toolkit/components/reader/Readerable.sys.mjs
@@ -0,0 +1,9 @@
+// -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include readability/Readability-readerable.js
+#include Readerable.js
+
+export { Readerable };
diff --git a/toolkit/components/reader/content/aboutReader.html b/toolkit/components/reader/content/aboutReader.html
new file mode 100644
index 0000000000..db93e9f80b
--- /dev/null
+++ b/toolkit/components/reader/content/aboutReader.html
@@ -0,0 +1,121 @@
+
+
+
+
+  
+    
+    
+    
+    
+    
+    
+    
+  
+
+  
+    

+
+    

+      

+        

+          
+          
    
+            
  • 
+              
+            
    • 
+            
  • 
+              
    
+              
    
+              
    
+                
+                
+                
+              
    
+              
    
+                
+                
+                
+              
    
+              
    
+                
+                
+                
+              
    
+              
    
+            
    • 
+          

+        

+      

+    

+
+    

+      

+        
+        

+        

+        

+        

+          

+        

+      

+
+      

+
+      

+        

+      

+
+      

+        

+      

+      

+    

+  
+
diff --git a/toolkit/components/reader/jar.mn b/toolkit/components/reader/jar.mn
new file mode 100644
index 0000000000..4b72136192
--- /dev/null
+++ b/toolkit/components/reader/jar.mn
@@ -0,0 +1,6 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+toolkit.jar:
+  content/global/reader/aboutReader.html             (content/aboutReader.html)
diff --git a/toolkit/components/reader/moz.build b/toolkit/components/reader/moz.build
new file mode 100644
index 0000000000..e57a0fe705
--- /dev/null
+++ b/toolkit/components/reader/moz.build
@@ -0,0 +1,28 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+JAR_MANIFESTS += ["jar.mn"]
+
+EXTRA_JS_MODULES += [
+    "AboutReader.sys.mjs",
+    "ReaderMode.sys.mjs",
+]
+
+EXTRA_PP_JS_MODULES += [
+    "Readerable.sys.mjs",
+]
+
+EXTRA_JS_MODULES.reader = [
+    "readability/JSDOMParser.js",
+    "readability/Readability.js",
+    "Reader.worker.js",
+    "ReaderWorker.sys.mjs",
+]
+
+BROWSER_CHROME_MANIFESTS += ["test/browser.toml"]
+
+with Files("**"):
+    BUG_COMPONENT = ("Toolkit", "Reader Mode")
diff --git a/toolkit/components/reader/moz.yaml b/toolkit/components/reader/moz.yaml
new file mode 100644
index 0000000000..104038d0a4
--- /dev/null
+++ b/toolkit/components/reader/moz.yaml
@@ -0,0 +1,26 @@
+schema: 1
+
+bugzilla:
+  product: Toolkit
+  component: Reader Mode
+
+origin:
+  name: Readability
+  description: Readability library used for Firefox Reader View
+  url: https://github.com/mozilla/readability
+  license: Apache-2.0
+  release: 0.5.0 (2023-12-15T17:20:28+00:00).
+  revision: 0.5.0
+
+vendoring:
+  url: https://github.com/mozilla/readability
+  source-hosting: github
+  tracking: tag
+  vendor-directory: toolkit/components/reader/readability
+  exclude:
+    - "**"
+  include:
+    - LICENSE.md
+    - Readability.js
+    - Readability-readerable.js
+    - JSDOMParser.js
diff --git a/toolkit/components/reader/readability/JSDOMParser.js b/toolkit/components/reader/readability/JSDOMParser.js
new file mode 100644
index 0000000000..7b6d241b43
--- /dev/null
+++ b/toolkit/components/reader/readability/JSDOMParser.js
@@ -0,0 +1,1197 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * This is a relatively lightweight DOMParser that is safe to use in a web
+ * worker. This is far from a complete DOM implementation; however, it should
+ * contain the minimal set of functionality necessary for Readability.js.
+ *
+ * Aside from not implementing the full DOM API, there are other quirks to be
+ * aware of when using the JSDOMParser:
+ *
+ *   1) Properly formed HTML/XML must be used. This means you should be extra
+ *      careful when using this parser on anything received directly from an
+ *      XMLHttpRequest. Providing a serialized string from an XMLSerializer,
+ *      however, should be safe (since the browser's XMLSerializer should
+ *      generate valid HTML/XML). Therefore, if parsing a document from an XHR,
+ *      the recommended approach is to do the XHR in the main thread, use
+ *      XMLSerializer.serializeToString() on the responseXML, and pass the
+ *      resulting string to the worker.
+ *
+ *   2) Live NodeLists are not supported. DOM methods and properties such as
+ *      getElementsByTagName() and childNodes return standard arrays. If you
+ *      want these lists to be updated when nodes are removed or added to the
+ *      document, you must take care to manually update them yourself.
+ */
+(function (global) {
+
+  // XML only defines these and the numeric ones:
+
+  var entityTable = {
+    "lt": "<",
+    "gt": ">",
+    "amp": "&",
+    "quot": '"',
+    "apos": "'",
+  };
+
+  var reverseEntityTable = {
+    "<": "<",
+    ">": ">",
+    "&": "&",
+    '"': """,
+    "'": "'",
+  };
+
+  function encodeTextContentHTML(s) {
+    return s.replace(/[&<>]/g, function(x) {
+      return reverseEntityTable[x];
+    });
+  }
+
+  function encodeHTML(s) {
+    return s.replace(/[&<>'"]/g, function(x) {
+      return reverseEntityTable[x];
+    });
+  }
+
+  function decodeHTML(str) {
+    return str.replace(/&(quot|amp|apos|lt|gt);/g, function(match, tag) {
+      return entityTable[tag];
+    }).replace(/&#(?:x([0-9a-z]{1,4})|([0-9]{1,4}));/gi, function(match, hex, numStr) {
+      var num = parseInt(hex || numStr, hex ? 16 : 10); // read num
+      return String.fromCharCode(num);
+    });
+  }
+
+  // When a style is set in JS, map it to the corresponding CSS attribute
+  var styleMap = {
+    "alignmentBaseline": "alignment-baseline",
+    "background": "background",
+    "backgroundAttachment": "background-attachment",
+    "backgroundClip": "background-clip",
+    "backgroundColor": "background-color",
+    "backgroundImage": "background-image",
+    "backgroundOrigin": "background-origin",
+    "backgroundPosition": "background-position",
+    "backgroundPositionX": "background-position-x",
+    "backgroundPositionY": "background-position-y",
+    "backgroundRepeat": "background-repeat",
+    "backgroundRepeatX": "background-repeat-x",
+    "backgroundRepeatY": "background-repeat-y",
+    "backgroundSize": "background-size",
+    "baselineShift": "baseline-shift",
+    "border": "border",
+    "borderBottom": "border-bottom",
+    "borderBottomColor": "border-bottom-color",
+    "borderBottomLeftRadius": "border-bottom-left-radius",
+    "borderBottomRightRadius": "border-bottom-right-radius",
+    "borderBottomStyle": "border-bottom-style",
+    "borderBottomWidth": "border-bottom-width",
+    "borderCollapse": "border-collapse",
+    "borderColor": "border-color",
+    "borderImage": "border-image",
+    "borderImageOutset": "border-image-outset",
+    "borderImageRepeat": "border-image-repeat",
+    "borderImageSlice": "border-image-slice",
+    "borderImageSource": "border-image-source",
+    "borderImageWidth": "border-image-width",
+    "borderLeft": "border-left",
+    "borderLeftColor": "border-left-color",
+    "borderLeftStyle": "border-left-style",
+    "borderLeftWidth": "border-left-width",
+    "borderRadius": "border-radius",
+    "borderRight": "border-right",
+    "borderRightColor": "border-right-color",
+    "borderRightStyle": "border-right-style",
+    "borderRightWidth": "border-right-width",
+    "borderSpacing": "border-spacing",
+    "borderStyle": "border-style",
+    "borderTop": "border-top",
+    "borderTopColor": "border-top-color",
+    "borderTopLeftRadius": "border-top-left-radius",
+    "borderTopRightRadius": "border-top-right-radius",
+    "borderTopStyle": "border-top-style",
+    "borderTopWidth": "border-top-width",
+    "borderWidth": "border-width",
+    "bottom": "bottom",
+    "boxShadow": "box-shadow",
+    "boxSizing": "box-sizing",
+    "captionSide": "caption-side",
+    "clear": "clear",
+    "clip": "clip",
+    "clipPath": "clip-path",
+    "clipRule": "clip-rule",
+    "color": "color",
+    "colorInterpolation": "color-interpolation",
+    "colorInterpolationFilters": "color-interpolation-filters",
+    "colorProfile": "color-profile",
+    "colorRendering": "color-rendering",
+    "content": "content",
+    "counterIncrement": "counter-increment",
+    "counterReset": "counter-reset",
+    "cursor": "cursor",
+    "direction": "direction",
+    "display": "display",
+    "dominantBaseline": "dominant-baseline",
+    "emptyCells": "empty-cells",
+    "enableBackground": "enable-background",
+    "fill": "fill",
+    "fillOpacity": "fill-opacity",
+    "fillRule": "fill-rule",
+    "filter": "filter",
+    "cssFloat": "float",
+    "floodColor": "flood-color",
+    "floodOpacity": "flood-opacity",
+    "font": "font",
+    "fontFamily": "font-family",
+    "fontSize": "font-size",
+    "fontStretch": "font-stretch",
+    "fontStyle": "font-style",
+    "fontVariant": "font-variant",
+    "fontWeight": "font-weight",
+    "glyphOrientationHorizontal": "glyph-orientation-horizontal",
+    "glyphOrientationVertical": "glyph-orientation-vertical",
+    "height": "height",
+    "imageRendering": "image-rendering",
+    "kerning": "kerning",
+    "left": "left",
+    "letterSpacing": "letter-spacing",
+    "lightingColor": "lighting-color",
+    "lineHeight": "line-height",
+    "listStyle": "list-style",
+    "listStyleImage": "list-style-image",
+    "listStylePosition": "list-style-position",
+    "listStyleType": "list-style-type",
+    "margin": "margin",
+    "marginBottom": "margin-bottom",
+    "marginLeft": "margin-left",
+    "marginRight": "margin-right",
+    "marginTop": "margin-top",
+    "marker": "marker",
+    "markerEnd": "marker-end",
+    "markerMid": "marker-mid",
+    "markerStart": "marker-start",
+    "mask": "mask",
+    "maxHeight": "max-height",
+    "maxWidth": "max-width",
+    "minHeight": "min-height",
+    "minWidth": "min-width",
+    "opacity": "opacity",
+    "orphans": "orphans",
+    "outline": "outline",
+    "outlineColor": "outline-color",
+    "outlineOffset": "outline-offset",
+    "outlineStyle": "outline-style",
+    "outlineWidth": "outline-width",
+    "overflow": "overflow",
+    "overflowX": "overflow-x",
+    "overflowY": "overflow-y",
+    "padding": "padding",
+    "paddingBottom": "padding-bottom",
+    "paddingLeft": "padding-left",
+    "paddingRight": "padding-right",
+    "paddingTop": "padding-top",
+    "page": "page",
+    "pageBreakAfter": "page-break-after",
+    "pageBreakBefore": "page-break-before",
+    "pageBreakInside": "page-break-inside",
+    "pointerEvents": "pointer-events",
+    "position": "position",
+    "quotes": "quotes",
+    "resize": "resize",
+    "right": "right",
+    "shapeRendering": "shape-rendering",
+    "size": "size",
+    "speak": "speak",
+    "src": "src",
+    "stopColor": "stop-color",
+    "stopOpacity": "stop-opacity",
+    "stroke": "stroke",
+    "strokeDasharray": "stroke-dasharray",
+    "strokeDashoffset": "stroke-dashoffset",
+    "strokeLinecap": "stroke-linecap",
+    "strokeLinejoin": "stroke-linejoin",
+    "strokeMiterlimit": "stroke-miterlimit",
+    "strokeOpacity": "stroke-opacity",
+    "strokeWidth": "stroke-width",
+    "tableLayout": "table-layout",
+    "textAlign": "text-align",
+    "textAnchor": "text-anchor",
+    "textDecoration": "text-decoration",
+    "textIndent": "text-indent",
+    "textLineThrough": "text-line-through",
+    "textLineThroughColor": "text-line-through-color",
+    "textLineThroughMode": "text-line-through-mode",
+    "textLineThroughStyle": "text-line-through-style",
+    "textLineThroughWidth": "text-line-through-width",
+    "textOverflow": "text-overflow",
+    "textOverline": "text-overline",
+    "textOverlineColor": "text-overline-color",
+    "textOverlineMode": "text-overline-mode",
+    "textOverlineStyle": "text-overline-style",
+    "textOverlineWidth": "text-overline-width",
+    "textRendering": "text-rendering",
+    "textShadow": "text-shadow",
+    "textTransform": "text-transform",
+    "textUnderline": "text-underline",
+    "textUnderlineColor": "text-underline-color",
+    "textUnderlineMode": "text-underline-mode",
+    "textUnderlineStyle": "text-underline-style",
+    "textUnderlineWidth": "text-underline-width",
+    "top": "top",
+    "unicodeBidi": "unicode-bidi",
+    "unicodeRange": "unicode-range",
+    "vectorEffect": "vector-effect",
+    "verticalAlign": "vertical-align",
+    "visibility": "visibility",
+    "whiteSpace": "white-space",
+    "widows": "widows",
+    "width": "width",
+    "wordBreak": "word-break",
+    "wordSpacing": "word-spacing",
+    "wordWrap": "word-wrap",
+    "writingMode": "writing-mode",
+    "zIndex": "z-index",
+    "zoom": "zoom",
+  };
+
+  // Elements that can be self-closing
+  var voidElems = {
+    "area": true,
+    "base": true,
+    "br": true,
+    "col": true,
+    "command": true,
+    "embed": true,
+    "hr": true,
+    "img": true,
+    "input": true,
+    "link": true,
+    "meta": true,
+    "param": true,
+    "source": true,
+    "wbr": true
+  };
+
+  var whitespace = [" ", "\t", "\n", "\r"];
+
+  // See https://developer.mozilla.org/en-US/docs/Web/API/Node/nodeType
+  var nodeTypes = {
+    ELEMENT_NODE: 1,
+    ATTRIBUTE_NODE: 2,
+    TEXT_NODE: 3,
+    CDATA_SECTION_NODE: 4,
+    ENTITY_REFERENCE_NODE: 5,
+    ENTITY_NODE: 6,
+    PROCESSING_INSTRUCTION_NODE: 7,
+    COMMENT_NODE: 8,
+    DOCUMENT_NODE: 9,
+    DOCUMENT_TYPE_NODE: 10,
+    DOCUMENT_FRAGMENT_NODE: 11,
+    NOTATION_NODE: 12
+  };
+
+  function getElementsByTagName(tag) {
+    tag = tag.toUpperCase();
+    var elems = [];
+    var allTags = (tag === "*");
+    function getElems(node) {
+      var length = node.children.length;
+      for (var i = 0; i < length; i++) {
+        var child = node.children[i];
+        if (allTags || (child.tagName === tag))
+          elems.push(child);
+        getElems(child);
+      }
+    }
+    getElems(this);
+    elems._isLiveNodeList = true;
+    return elems;
+  }
+
+  var Node = function () {};
+
+  Node.prototype = {
+    attributes: null,
+    childNodes: null,
+    localName: null,
+    nodeName: null,
+    parentNode: null,
+    textContent: null,
+    nextSibling: null,
+    previousSibling: null,
+
+    get firstChild() {
+      return this.childNodes[0] || null;
+    },
+
+    get firstElementChild() {
+      return this.children[0] || null;
+    },
+
+    get lastChild() {
+      return this.childNodes[this.childNodes.length - 1] || null;
+    },
+
+    get lastElementChild() {
+      return this.children[this.children.length - 1] || null;
+    },
+
+    appendChild: function (child) {
+      if (child.parentNode) {
+        child.parentNode.removeChild(child);
+      }
+
+      var last = this.lastChild;
+      if (last)
+        last.nextSibling = child;
+      child.previousSibling = last;
+
+      if (child.nodeType === Node.ELEMENT_NODE) {
+        child.previousElementSibling = this.children[this.children.length - 1] || null;
+        this.children.push(child);
+        child.previousElementSibling && (child.previousElementSibling.nextElementSibling = child);
+      }
+      this.childNodes.push(child);
+      child.parentNode = this;
+    },
+
+    removeChild: function (child) {
+      var childNodes = this.childNodes;
+      var childIndex = childNodes.indexOf(child);
+      if (childIndex === -1) {
+        throw "removeChild: node not found";
+      } else {
+        child.parentNode = null;
+        var prev = child.previousSibling;
+        var next = child.nextSibling;
+        if (prev)
+          prev.nextSibling = next;
+        if (next)
+          next.previousSibling = prev;
+
+        if (child.nodeType === Node.ELEMENT_NODE) {
+          prev = child.previousElementSibling;
+          next = child.nextElementSibling;
+          if (prev)
+            prev.nextElementSibling = next;
+          if (next)
+            next.previousElementSibling = prev;
+          this.children.splice(this.children.indexOf(child), 1);
+        }
+
+        child.previousSibling = child.nextSibling = null;
+        child.previousElementSibling = child.nextElementSibling = null;
+
+        return childNodes.splice(childIndex, 1)[0];
+      }
+    },
+
+    replaceChild: function (newNode, oldNode) {
+      var childNodes = this.childNodes;
+      var childIndex = childNodes.indexOf(oldNode);
+      if (childIndex === -1) {
+        throw "replaceChild: node not found";
+      } else {
+        // This will take care of updating the new node if it was somewhere else before:
+        if (newNode.parentNode)
+          newNode.parentNode.removeChild(newNode);
+
+        childNodes[childIndex] = newNode;
+
+        // update the new node's sibling properties, and its new siblings' sibling properties
+        newNode.nextSibling = oldNode.nextSibling;
+        newNode.previousSibling = oldNode.previousSibling;
+        if (newNode.nextSibling)
+          newNode.nextSibling.previousSibling = newNode;
+        if (newNode.previousSibling)
+          newNode.previousSibling.nextSibling = newNode;
+
+        newNode.parentNode = this;
+
+        // Now deal with elements before we clear out those values for the old node,
+        // because it can help us take shortcuts here:
+        if (newNode.nodeType === Node.ELEMENT_NODE) {
+          if (oldNode.nodeType === Node.ELEMENT_NODE) {
+            // Both were elements, which makes this easier, we just swap things out:
+            newNode.previousElementSibling = oldNode.previousElementSibling;
+            newNode.nextElementSibling = oldNode.nextElementSibling;
+            if (newNode.previousElementSibling)
+              newNode.previousElementSibling.nextElementSibling = newNode;
+            if (newNode.nextElementSibling)
+              newNode.nextElementSibling.previousElementSibling = newNode;
+            this.children[this.children.indexOf(oldNode)] = newNode;
+          } else {
+            // Hard way:
+            newNode.previousElementSibling = (function() {
+              for (var i = childIndex - 1; i >= 0; i--) {
+                if (childNodes[i].nodeType === Node.ELEMENT_NODE)
+                  return childNodes[i];
+              }
+              return null;
+            })();
+            if (newNode.previousElementSibling) {
+              newNode.nextElementSibling = newNode.previousElementSibling.nextElementSibling;
+            } else {
+              newNode.nextElementSibling = (function() {
+                for (var i = childIndex + 1; i < childNodes.length; i++) {
+                  if (childNodes[i].nodeType === Node.ELEMENT_NODE)
+                    return childNodes[i];
+                }
+                return null;
+              })();
+            }
+            if (newNode.previousElementSibling)
+              newNode.previousElementSibling.nextElementSibling = newNode;
+            if (newNode.nextElementSibling)
+              newNode.nextElementSibling.previousElementSibling = newNode;
+
+            if (newNode.nextElementSibling)
+              this.children.splice(this.children.indexOf(newNode.nextElementSibling), 0, newNode);
+            else
+              this.children.push(newNode);
+          }
+        } else if (oldNode.nodeType === Node.ELEMENT_NODE) {
+          // new node is not an element node.
+          // if the old one was, update its element siblings:
+          if (oldNode.previousElementSibling)
+            oldNode.previousElementSibling.nextElementSibling = oldNode.nextElementSibling;
+          if (oldNode.nextElementSibling)
+            oldNode.nextElementSibling.previousElementSibling = oldNode.previousElementSibling;
+          this.children.splice(this.children.indexOf(oldNode), 1);
+
+          // If the old node wasn't an element, neither the new nor the old node was an element,
+          // and the children array and its members shouldn't need any updating.
+        }
+
+
+        oldNode.parentNode = null;
+        oldNode.previousSibling = null;
+        oldNode.nextSibling = null;
+        if (oldNode.nodeType === Node.ELEMENT_NODE) {
+          oldNode.previousElementSibling = null;
+          oldNode.nextElementSibling = null;
+        }
+        return oldNode;
+      }
+    },
+
+    __JSDOMParser__: true,
+  };
+
+  for (var nodeType in nodeTypes) {
+    Node[nodeType] = Node.prototype[nodeType] = nodeTypes[nodeType];
+  }
+
+  var Attribute = function (name, value) {
+    this.name = name;
+    this._value = value;
+  };
+
+  Attribute.prototype = {
+    get value() {
+      return this._value;
+    },
+    setValue: function(newValue) {
+      this._value = newValue;
+    },
+    getEncodedValue: function() {
+      return encodeHTML(this._value);
+    },
+  };
+
+  var Comment = function () {
+    this.childNodes = [];
+  };
+
+  Comment.prototype = {
+    __proto__: Node.prototype,
+
+    nodeName: "#comment",
+    nodeType: Node.COMMENT_NODE
+  };
+
+  var Text = function () {
+    this.childNodes = [];
+  };
+
+  Text.prototype = {
+    __proto__: Node.prototype,
+
+    nodeName: "#text",
+    nodeType: Node.TEXT_NODE,
+    get textContent() {
+      if (typeof this._textContent === "undefined") {
+        this._textContent = decodeHTML(this._innerHTML || "");
+      }
+      return this._textContent;
+    },
+    get innerHTML() {
+      if (typeof this._innerHTML === "undefined") {
+        this._innerHTML = encodeTextContentHTML(this._textContent || "");
+      }
+      return this._innerHTML;
+    },
+
+    set innerHTML(newHTML) {
+      this._innerHTML = newHTML;
+      delete this._textContent;
+    },
+    set textContent(newText) {
+      this._textContent = newText;
+      delete this._innerHTML;
+    },
+  };
+
+  var Document = function (url) {
+    this.documentURI = url;
+    this.styleSheets = [];
+    this.childNodes = [];
+    this.children = [];
+  };
+
+  Document.prototype = {
+    __proto__: Node.prototype,
+
+    nodeName: "#document",
+    nodeType: Node.DOCUMENT_NODE,
+    title: "",
+
+    getElementsByTagName: getElementsByTagName,
+
+    getElementById: function (id) {
+      function getElem(node) {
+        var length = node.children.length;
+        if (node.id === id)
+          return node;
+        for (var i = 0; i < length; i++) {
+          var el = getElem(node.children[i]);
+          if (el)
+            return el;
+        }
+        return null;
+      }
+      return getElem(this);
+    },
+
+    createElement: function (tag) {
+      var node = new Element(tag);
+      return node;
+    },
+
+    createTextNode: function (text) {
+      var node = new Text();
+      node.textContent = text;
+      return node;
+    },
+
+    get baseURI() {
+      if (!this.hasOwnProperty("_baseURI")) {
+        this._baseURI = this.documentURI;
+        var baseElements = this.getElementsByTagName("base");
+        var href = baseElements[0] && baseElements[0].getAttribute("href");
+        if (href) {
+          try {
+            this._baseURI = (new URL(href, this._baseURI)).href;
+          } catch (ex) {/* Just fall back to documentURI */}
+        }
+      }
+      return this._baseURI;
+    },
+  };
+
+  var Element = function (tag) {
+    // We use this to find the closing tag.
+    this._matchingTag = tag;
+    // We're explicitly a non-namespace aware parser, we just pretend it's all HTML.
+    var lastColonIndex = tag.lastIndexOf(":");
+    if (lastColonIndex != -1) {
+      tag = tag.substring(lastColonIndex + 1);
+    }
+    this.attributes = [];
+    this.childNodes = [];
+    this.children = [];
+    this.nextElementSibling = this.previousElementSibling = null;
+    this.localName = tag.toLowerCase();
+    this.tagName = tag.toUpperCase();
+    this.style = new Style(this);
+  };
+
+  Element.prototype = {
+    __proto__: Node.prototype,
+
+    nodeType: Node.ELEMENT_NODE,
+
+    getElementsByTagName: getElementsByTagName,
+
+    get className() {
+      return this.getAttribute("class") || "";
+    },
+
+    set className(str) {
+      this.setAttribute("class", str);
+    },
+
+    get id() {
+      return this.getAttribute("id") || "";
+    },
+
+    set id(str) {
+      this.setAttribute("id", str);
+    },
+
+    get href() {
+      return this.getAttribute("href") || "";
+    },
+
+    set href(str) {
+      this.setAttribute("href", str);
+    },
+
+    get src() {
+      return this.getAttribute("src") || "";
+    },
+
+    set src(str) {
+      this.setAttribute("src", str);
+    },
+
+    get srcset() {
+      return this.getAttribute("srcset") || "";
+    },
+
+    set srcset(str) {
+      this.setAttribute("srcset", str);
+    },
+
+    get nodeName() {
+      return this.tagName;
+    },
+
+    get innerHTML() {
+      function getHTML(node) {
+        var i = 0;
+        for (i = 0; i < node.childNodes.length; i++) {
+          var child = node.childNodes[i];
+          if (child.localName) {
+            arr.push("<" + child.localName);
+
+            // serialize attribute list
+            for (var j = 0; j < child.attributes.length; j++) {
+              var attr = child.attributes[j];
+              // the attribute value will be HTML escaped.
+              var val = attr.getEncodedValue();
+              var quote = (val.indexOf('"') === -1 ? '"' : "'");
+              arr.push(" " + attr.name + "=" + quote + val + quote);
+            }
+
+            if (child.localName in voidElems && !child.childNodes.length) {
+              // if this is a self-closing element, end it here
+              arr.push("/>");
+            } else {
+              // otherwise, add its children
+              arr.push(">");
+              getHTML(child);
+              arr.push("");
+            }
+          } else {
+            // This is a text node, so asking for innerHTML won't recurse.
+            arr.push(child.innerHTML);
+          }
+        }
+      }
+
+      // Using Array.join() avoids the overhead from lazy string concatenation.
+      var arr = [];
+      getHTML(this);
+      return arr.join("");
+    },
+
+    set innerHTML(html) {
+      var parser = new JSDOMParser();
+      var node = parser.parse(html);
+      var i;
+      for (i = this.childNodes.length; --i >= 0;) {
+        this.childNodes[i].parentNode = null;
+      }
+      this.childNodes = node.childNodes;
+      this.children = node.children;
+      for (i = this.childNodes.length; --i >= 0;) {
+        this.childNodes[i].parentNode = this;
+      }
+    },
+
+    set textContent(text) {
+      // clear parentNodes for existing children
+      for (var i = this.childNodes.length; --i >= 0;) {
+        this.childNodes[i].parentNode = null;
+      }
+
+      var node = new Text();
+      this.childNodes = [ node ];
+      this.children = [];
+      node.textContent = text;
+      node.parentNode = this;
+    },
+
+    get textContent() {
+      function getText(node) {
+        var nodes = node.childNodes;
+        for (var i = 0; i < nodes.length; i++) {
+          var child = nodes[i];
+          if (child.nodeType === 3) {
+            text.push(child.textContent);
+          } else {
+            getText(child);
+          }
+        }
+      }
+
+      // Using Array.join() avoids the overhead from lazy string concatenation.
+      // See http://blog.cdleary.com/2012/01/string-representation-in-spidermonkey/#ropes
+      var text = [];
+      getText(this);
+      return text.join("");
+    },
+
+    getAttribute: function (name) {
+      for (var i = this.attributes.length; --i >= 0;) {
+        var attr = this.attributes[i];
+        if (attr.name === name) {
+          return attr.value;
+        }
+      }
+      return undefined;
+    },
+
+    setAttribute: function (name, value) {
+      for (var i = this.attributes.length; --i >= 0;) {
+        var attr = this.attributes[i];
+        if (attr.name === name) {
+          attr.setValue(value);
+          return;
+        }
+      }
+      this.attributes.push(new Attribute(name, value));
+    },
+
+    removeAttribute: function (name) {
+      for (var i = this.attributes.length; --i >= 0;) {
+        var attr = this.attributes[i];
+        if (attr.name === name) {
+          this.attributes.splice(i, 1);
+          break;
+        }
+      }
+    },
+
+    hasAttribute: function (name) {
+      return this.attributes.some(function (attr) {
+        return attr.name == name;
+      });
+    },
+  };
+
+  var Style = function (node) {
+    this.node = node;
+  };
+
+  // getStyle() and setStyle() use the style attribute string directly. This
+  // won't be very efficient if there are a lot of style manipulations, but
+  // it's the easiest way to make sure the style attribute string and the JS
+  // style property stay in sync. Readability.js doesn't do many style
+  // manipulations, so this should be okay.
+  Style.prototype = {
+    getStyle: function (styleName) {
+      var attr = this.node.getAttribute("style");
+      if (!attr)
+        return undefined;
+
+      var styles = attr.split(";");
+      for (var i = 0; i < styles.length; i++) {
+        var style = styles[i].split(":");
+        var name = style[0].trim();
+        if (name === styleName)
+          return style[1].trim();
+      }
+
+      return undefined;
+    },
+
+    setStyle: function (styleName, styleValue) {
+      var value = this.node.getAttribute("style") || "";
+      var index = 0;
+      do {
+        var next = value.indexOf(";", index) + 1;
+        var length = next - index - 1;
+        var style = (length > 0 ? value.substr(index, length) : value.substr(index));
+        if (style.substr(0, style.indexOf(":")).trim() === styleName) {
+          value = value.substr(0, index).trim() + (next ? " " + value.substr(next).trim() : "");
+          break;
+        }
+        index = next;
+      } while (index);
+
+      value += " " + styleName + ": " + styleValue + ";";
+      this.node.setAttribute("style", value.trim());
+    }
+  };
+
+  // For each item in styleMap, define a getter and setter on the style
+  // property.
+  for (var jsName in styleMap) {
+    (function (cssName) {
+      Style.prototype.__defineGetter__(jsName, function () {
+        return this.getStyle(cssName);
+      });
+      Style.prototype.__defineSetter__(jsName, function (value) {
+        this.setStyle(cssName, value);
+      });
+    })(styleMap[jsName]);
+  }
+
+  var JSDOMParser = function () {
+    this.currentChar = 0;
+
+    // In makeElementNode() we build up many strings one char at a time. Using
+    // += for this results in lots of short-lived intermediate strings. It's
+    // better to build an array of single-char strings and then join() them
+    // together at the end. And reusing a single array (i.e. |this.strBuf|)
+    // over and over for this purpose uses less memory than using a new array
+    // for each string.
+    this.strBuf = [];
+
+    // Similarly, we reuse this array to return the two arguments from
+    // makeElementNode(), which saves us from having to allocate a new array
+    // every time.
+    this.retPair = [];
+
+    this.errorState = "";
+  };
+
+  JSDOMParser.prototype = {
+    error: function(m) {
+      if (typeof console !== "undefined") {
+        console.log("JSDOMParser error: " + m + "\n");
+      } else if (typeof dump !== "undefined") {
+        /* global dump */
+        dump("JSDOMParser error: " + m + "\n");
+      }
+      this.errorState += m + "\n";
+    },
+
+    /**
+     * Look at the next character without advancing the index.
+     */
+    peekNext: function () {
+      return this.html[this.currentChar];
+    },
+
+    /**
+     * Get the next character and advance the index.
+     */
+    nextChar: function () {
+      return this.html[this.currentChar++];
+    },
+
+    /**
+     * Called after a quote character is read. This finds the next quote
+     * character and returns the text string in between.
+     */
+    readString: function (quote) {
+      var str;
+      var n = this.html.indexOf(quote, this.currentChar);
+      if (n === -1) {
+        this.currentChar = this.html.length;
+        str = null;
+      } else {
+        str = this.html.substring(this.currentChar, n);
+        this.currentChar = n + 1;
+      }
+
+      return str;
+    },
+
+    /**
+     * Called when parsing a node. This finds the next name/value attribute
+     * pair and adds the result to the attributes list.
+     */
+    readAttribute: function (node) {
+      var name = "";
+
+      var n = this.html.indexOf("=", this.currentChar);
+      if (n === -1) {
+        this.currentChar = this.html.length;
+      } else {
+        // Read until a '=' character is hit; this will be the attribute key
+        name = this.html.substring(this.currentChar, n);
+        this.currentChar = n + 1;
+      }
+
+      if (!name)
+        return;
+
+      // After a '=', we should see a '"' for the attribute value
+      var c = this.nextChar();
+      if (c !== '"' && c !== "'") {
+        this.error("Error reading attribute " + name + ", expecting '\"'");
+        return;
+      }
+
+      // Read the attribute value (and consume the matching quote)
+      var value = this.readString(c);
+
+      node.attributes.push(new Attribute(name, decodeHTML(value)));
+
+      return;
+    },
+
+    /**
+     * Parses and returns an Element node. This is called after a '<' has been
+     * read.
+     *
+     * @returns an array; the first index of the array is the parsed node;
+     *          the second index is a boolean indicating whether this is a void
+     *          Element
+     */
+    makeElementNode: function (retPair) {
+      var c = this.nextChar();
+
+      // Read the Element tag name
+      var strBuf = this.strBuf;
+      strBuf.length = 0;
+      while (whitespace.indexOf(c) == -1 && c !== ">" && c !== "/") {
+        if (c === undefined)
+          return false;
+        strBuf.push(c);
+        c = this.nextChar();
+      }
+      var tag = strBuf.join("");
+
+      if (!tag)
+        return false;
+
+      var node = new Element(tag);
+
+      // Read Element attributes
+      while (c !== "/" && c !== ">") {
+        if (c === undefined)
+          return false;
+        while (whitespace.indexOf(this.html[this.currentChar++]) != -1) {
+          // Advance cursor to first non-whitespace char.
+        }
+        this.currentChar--;
+        c = this.nextChar();
+        if (c !== "/" && c !== ">") {
+          --this.currentChar;
+          this.readAttribute(node);
+        }
+      }
+
+      // If this is a self-closing tag, read '/>'
+      var closed = false;
+      if (c === "/") {
+        closed = true;
+        c = this.nextChar();
+        if (c !== ">") {
+          this.error("expected '>' to close " + tag);
+          return false;
+        }
+      }
+
+      retPair[0] = node;
+      retPair[1] = closed;
+      return true;
+    },
+
+    /**
+     * If the current input matches this string, advance the input index;
+     * otherwise, do nothing.
+     *
+     * @returns whether input matched string
+     */
+    match: function (str) {
+      var strlen = str.length;
+      if (this.html.substr(this.currentChar, strlen).toLowerCase() === str.toLowerCase()) {
+        this.currentChar += strlen;
+        return true;
+      }
+      return false;
+    },
+
+    /**
+     * Searches the input until a string is found and discards all input up to
+     * and including the matched string.
+     */
+    discardTo: function (str) {
+      var index = this.html.indexOf(str, this.currentChar) + str.length;
+      if (index === -1)
+        this.currentChar = this.html.length;
+      this.currentChar = index;
+    },
+
+    /**
+     * Reads child nodes for the given node.
+     */
+    readChildren: function (node) {
+      var child;
+      while ((child = this.readNode())) {
+        // Don't keep Comment nodes
+        if (child.nodeType !== 8) {
+          node.appendChild(child);
+        }
+      }
+    },
+
+    discardNextComment: function() {
+      if (this.match("--")) {
+        this.discardTo("-->");
+      } else {
+        var c = this.nextChar();
+        while (c !== ">") {
+          if (c === undefined)
+            return null;
+          if (c === '"' || c === "'")
+            this.readString(c);
+          c = this.nextChar();
+        }
+      }
+      return new Comment();
+    },
+
+
+    /**
+     * Reads the next child node from the input. If we're reading a closing
+     * tag, or if we've reached the end of input, return null.
+     *
+     * @returns the node
+     */
+    readNode: function () {
+      var c = this.nextChar();
+
+      if (c === undefined)
+        return null;
+
+      // Read any text as Text node
+      var textNode;
+      if (c !== "<") {
+        --this.currentChar;
+        textNode = new Text();
+        var n = this.html.indexOf("<", this.currentChar);
+        if (n === -1) {
+          textNode.innerHTML = this.html.substring(this.currentChar, this.html.length);
+          this.currentChar = this.html.length;
+        } else {
+          textNode.innerHTML = this.html.substring(this.currentChar, n);
+          this.currentChar = n;
+        }
+        return textNode;
+      }
+
+      if (this.match("![CDATA[")) {
+        var endChar = this.html.indexOf("]]>", this.currentChar);
+        if (endChar === -1) {
+          this.error("unclosed CDATA section");
+          return null;
+        }
+        textNode = new Text();
+        textNode.textContent = this.html.substring(this.currentChar, endChar);
+        this.currentChar = endChar + ("]]>").length;
+        return textNode;
+      }
+
+      c = this.peekNext();
+
+      // Read Comment node. Normally, Comment nodes know their inner
+      // textContent, but we don't really care about Comment nodes (we throw
+      // them away in readChildren()). So just returning an empty Comment node
+      // here is sufficient.
+      if (c === "!" || c === "?") {
+        // We're still before the ! or ? that is starting this comment:
+        this.currentChar++;
+        return this.discardNextComment();
+      }
+
+      // If we're reading a closing tag, return null. This means we've reached
+      // the end of this set of child nodes.
+      if (c === "/") {
+        --this.currentChar;
+        return null;
+      }
+
+      // Otherwise, we're looking at an Element node
+      var result = this.makeElementNode(this.retPair);
+      if (!result)
+        return null;
+
+      var node = this.retPair[0];
+      var closed = this.retPair[1];
+      var localName = node.localName;
+
+      // If this isn't a void Element, read its child nodes
+      if (!closed) {
+        this.readChildren(node);
+        var closingTag = "";
+        if (!this.match(closingTag)) {
+          this.error("expected '" + closingTag + "' and got " + this.html.substr(this.currentChar, closingTag.length));
+          return null;
+        }
+      }
+
+      // Only use the first title, because SVG might have other
+      // title elements which we don't care about (medium.com
+      // does this, at least).
+      if (localName === "title" && !this.doc.title) {
+        this.doc.title = node.textContent.trim();
+      } else if (localName === "head") {
+        this.doc.head = node;
+      } else if (localName === "body") {
+        this.doc.body = node;
+      } else if (localName === "html") {
+        this.doc.documentElement = node;
+      }
+
+      return node;
+    },
+
+    /**
+     * Parses an HTML string and returns a JS implementation of the Document.
+     */
+    parse: function (html, url) {
+      this.html = html;
+      var doc = this.doc = new Document(url);
+      this.readChildren(doc);
+
+      // If this is an HTML document, remove root-level children except for the
+      //  node
+      if (doc.documentElement) {
+        for (var i = doc.childNodes.length; --i >= 0;) {
+          var child = doc.childNodes[i];
+          if (child !== doc.documentElement) {
+            doc.removeChild(child);
+          }
+        }
+      }
+
+      return doc;
+    }
+  };
+
+  // Attach the standard DOM types to the global scope
+  global.Node = Node;
+  global.Comment = Comment;
+  global.Document = Document;
+  global.Element = Element;
+  global.Text = Text;
+
+  // Attach JSDOMParser to the global scope
+  global.JSDOMParser = JSDOMParser;
+
+})(this);
+
+if (typeof module === "object") {
+  /* global module */
+  module.exports = this.JSDOMParser;
+}
diff --git a/toolkit/components/reader/readability/LICENSE.md b/toolkit/components/reader/readability/LICENSE.md
new file mode 100644
index 0000000000..ca8e58b203
--- /dev/null
+++ b/toolkit/components/reader/readability/LICENSE.md
@@ -0,0 +1,13 @@
+Copyright (c) 2010 Arc90 Inc
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
diff --git a/toolkit/components/reader/readability/Readability-readerable.js b/toolkit/components/reader/readability/Readability-readerable.js
new file mode 100644
index 0000000000..892169fb94
--- /dev/null
+++ b/toolkit/components/reader/readability/Readability-readerable.js
@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2010 Arc90 Inc
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * This code is heavily based on Arc90's readability.js (1.7.1) script
+ * available at: http://code.google.com/p/arc90labs-readability
+ */
+
+var REGEXPS = {
+  // NOTE: These two regular expressions are duplicated in
+  // Readability.js. Please keep both copies in sync.
+  unlikelyCandidates: /-ad-|ai2html|banner|breadcrumbs|combx|comment|community|cover-wrap|disqus|extra|footer|gdpr|header|legends|menu|related|remark|replies|rss|shoutbox|sidebar|skyscraper|social|sponsor|supplemental|ad-break|agegate|pagination|pager|popup|yom-remote/i,
+  okMaybeItsACandidate: /and|article|body|column|content|main|shadow/i,
+};
+
+function isNodeVisible(node) {
+  // Have to null-check node.style and node.className.indexOf to deal with SVG and MathML nodes.
+  return (!node.style || node.style.display != "none")
+    && !node.hasAttribute("hidden")
+    //check for "fallback-image" so that wikimedia math images are displayed
+    && (!node.hasAttribute("aria-hidden") || node.getAttribute("aria-hidden") != "true" || (node.className && node.className.indexOf && node.className.indexOf("fallback-image") !== -1));
+}
+
+/**
+ * Decides whether or not the document is reader-able without parsing the whole thing.
+ * @param {Object} options Configuration object.
+ * @param {number} [options.minContentLength=140] The minimum node content length used to decide if the document is readerable.
+ * @param {number} [options.minScore=20] The minumum cumulated 'score' used to determine if the document is readerable.
+ * @param {Function} [options.visibilityChecker=isNodeVisible] The function used to determine if a node is visible.
+ * @return {boolean} Whether or not we suspect Readability.parse() will suceeed at returning an article object.
+ */
+function isProbablyReaderable(doc, options = {}) {
+  // For backward compatibility reasons 'options' can either be a configuration object or the function used
+  // to determine if a node is visible.
+  if (typeof options == "function") {
+    options = { visibilityChecker: options };
+  }
+
+  var defaultOptions = { minScore: 20, minContentLength: 140, visibilityChecker: isNodeVisible };
+  options = Object.assign(defaultOptions, options);
+
+  var nodes = doc.querySelectorAll("p, pre, article");
+
+  // Get 
 nodes which have 
 node(s) and append them into the `nodes` variable.
+  // Some articles' DOM structures might look like
+  // 

+  //   Sentences

+  //   

+  //   Sentences

+  // 

+  var brNodes = doc.querySelectorAll("div > br");
+  if (brNodes.length) {
+    var set = new Set(nodes);
+    [].forEach.call(brNodes, function (node) {
+      set.add(node.parentNode);
+    });
+    nodes = Array.from(set);
+  }
+
+  var score = 0;
+  // This is a little cheeky, we use the accumulator 'score' to decide what to return from
+  // this callback:
+  return [].some.call(nodes, function (node) {
+    if (!options.visibilityChecker(node)) {
+      return false;
+    }
+
+    var matchString = node.className + " " + node.id;
+    if (REGEXPS.unlikelyCandidates.test(matchString) &&
+        !REGEXPS.okMaybeItsACandidate.test(matchString)) {
+      return false;
+    }
+
+    if (node.matches("li p")) {
+      return false;
+    }
+
+    var textContentLength = node.textContent.trim().length;
+    if (textContentLength < options.minContentLength) {
+      return false;
+    }
+
+    score += Math.sqrt(textContentLength - options.minContentLength);
+
+    if (score > options.minScore) {
+      return true;
+    }
+    return false;
+  });
+}
+
+if (typeof module === "object") {
+  /* global module */
+  module.exports = isProbablyReaderable;
+}
diff --git a/toolkit/components/reader/readability/Readability.js b/toolkit/components/reader/readability/Readability.js
new file mode 100644
index 0000000000..b745aa01d8
--- /dev/null
+++ b/toolkit/components/reader/readability/Readability.js
@@ -0,0 +1,2314 @@
+/*
+ * Copyright (c) 2010 Arc90 Inc
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * This code is heavily based on Arc90's readability.js (1.7.1) script
+ * available at: http://code.google.com/p/arc90labs-readability
+ */
+
+/**
+ * Public constructor.
+ * @param {HTMLDocument} doc     The document to parse.
+ * @param {Object}       options The options object.
+ */
+function Readability(doc, options) {
+  // In some older versions, people passed a URI as the first argument. Cope:
+  if (options && options.documentElement) {
+    doc = options;
+    options = arguments[2];
+  } else if (!doc || !doc.documentElement) {
+    throw new Error("First argument to Readability constructor should be a document object.");
+  }
+  options = options || {};
+
+  this._doc = doc;
+  this._docJSDOMParser = this._doc.firstChild.__JSDOMParser__;
+  this._articleTitle = null;
+  this._articleByline = null;
+  this._articleDir = null;
+  this._articleSiteName = null;
+  this._attempts = [];
+
+  // Configurable options
+  this._debug = !!options.debug;
+  this._maxElemsToParse = options.maxElemsToParse || this.DEFAULT_MAX_ELEMS_TO_PARSE;
+  this._nbTopCandidates = options.nbTopCandidates || this.DEFAULT_N_TOP_CANDIDATES;
+  this._charThreshold = options.charThreshold || this.DEFAULT_CHAR_THRESHOLD;
+  this._classesToPreserve = this.CLASSES_TO_PRESERVE.concat(options.classesToPreserve || []);
+  this._keepClasses = !!options.keepClasses;
+  this._serializer = options.serializer || function(el) {
+    return el.innerHTML;
+  };
+  this._disableJSONLD = !!options.disableJSONLD;
+  this._allowedVideoRegex = options.allowedVideoRegex || this.REGEXPS.videos;
+
+  // Start with all flags set
+  this._flags = this.FLAG_STRIP_UNLIKELYS |
+                this.FLAG_WEIGHT_CLASSES |
+                this.FLAG_CLEAN_CONDITIONALLY;
+
+
+  // Control whether log messages are sent to the console
+  if (this._debug) {
+    let logNode = function(node) {
+      if (node.nodeType == node.TEXT_NODE) {
+        return `${node.nodeName} ("${node.textContent}")`;
+      }
+      let attrPairs = Array.from(node.attributes || [], function(attr) {
+        return `${attr.name}="${attr.value}"`;
+      }).join(" ");
+      return `<${node.localName} ${attrPairs}>`;
+    };
+    this.log = function () {
+      if (typeof console !== "undefined") {
+        let args = Array.from(arguments, arg => {
+          if (arg && arg.nodeType == this.ELEMENT_NODE) {
+            return logNode(arg);
+          }
+          return arg;
+        });
+        args.unshift("Reader: (Readability)");
+        console.log.apply(console, args);
+      } else if (typeof dump !== "undefined") {
+        /* global dump */
+        var msg = Array.prototype.map.call(arguments, function(x) {
+          return (x && x.nodeName) ? logNode(x) : x;
+        }).join(" ");
+        dump("Reader: (Readability) " + msg + "\n");
+      }
+    };
+  } else {
+    this.log = function () {};
+  }
+}
+
+Readability.prototype = {
+  FLAG_STRIP_UNLIKELYS: 0x1,
+  FLAG_WEIGHT_CLASSES: 0x2,
+  FLAG_CLEAN_CONDITIONALLY: 0x4,
+
+  // https://developer.mozilla.org/en-US/docs/Web/API/Node/nodeType
+  ELEMENT_NODE: 1,
+  TEXT_NODE: 3,
+
+  // Max number of nodes supported by this parser. Default: 0 (no limit)
+  DEFAULT_MAX_ELEMS_TO_PARSE: 0,
+
+  // The number of top candidates to consider when analysing how
+  // tight the competition is among candidates.
+  DEFAULT_N_TOP_CANDIDATES: 5,
+
+  // Element tags to score by default.
+  DEFAULT_TAGS_TO_SCORE: "section,h2,h3,h4,h5,h6,p,td,pre".toUpperCase().split(","),
+
+  // The default number of chars an article must have in order to return a result
+  DEFAULT_CHAR_THRESHOLD: 500,
+
+  // All of the regular expressions in use within readability.
+  // Defined up here so we don't instantiate them repeatedly in loops.
+  REGEXPS: {
+    // NOTE: These two regular expressions are duplicated in
+    // Readability-readerable.js. Please keep both copies in sync.
+    unlikelyCandidates: /-ad-|ai2html|banner|breadcrumbs|combx|comment|community|cover-wrap|disqus|extra|footer|gdpr|header|legends|menu|related|remark|replies|rss|shoutbox|sidebar|skyscraper|social|sponsor|supplemental|ad-break|agegate|pagination|pager|popup|yom-remote/i,
+    okMaybeItsACandidate: /and|article|body|column|content|main|shadow/i,
+
+    positive: /article|body|content|entry|hentry|h-entry|main|page|pagination|post|text|blog|story/i,
+    negative: /-ad-|hidden|^hid$| hid$| hid |^hid |banner|combx|comment|com-|contact|foot|footer|footnote|gdpr|masthead|media|meta|outbrain|promo|related|scroll|share|shoutbox|sidebar|skyscraper|sponsor|shopping|tags|tool|widget/i,
+    extraneous: /print|archive|comment|discuss|e[\-]?mail|share|reply|all|login|sign|single|utility/i,
+    byline: /byline|author|dateline|writtenby|p-author/i,
+    replaceFonts: /<(\/?)font[^>]*>/gi,
+    normalize: /\s{2,}/g,
+    videos: /\/\/(www\.)?((dailymotion|youtube|youtube-nocookie|player\.vimeo|v\.qq)\.com|(archive|upload\.wikimedia)\.org|player\.twitch\.tv)/i,
+    shareElements: /(\b|_)(share|sharedaddy)(\b|_)/i,
+    nextLink: /(next|weiter|continue|>([^\|]|$)|»([^\|]|$))/i,
+    prevLink: /(prev|earl|old|new|<|«)/i,
+    tokenize: /\W+/g,
+    whitespace: /^\s*$/,
+    hasContent: /\S$/,
+    hashUrl: /^#.+/,
+    srcsetUrl: /(\S+)(\s+[\d.]+[xw])?(\s*(?:,|$))/g,
+    b64DataUrl: /^data:\s*([^\s;,]+)\s*;\s*base64\s*,/i,
+    // Commas as used in Latin, Sindhi, Chinese and various other scripts.
+    // see: https://en.wikipedia.org/wiki/Comma#Comma_variants
+    commas: /\u002C|\u060C|\uFE50|\uFE10|\uFE11|\u2E41|\u2E34|\u2E32|\uFF0C/g,
+    // See: https://schema.org/Article
+    jsonLdArticleTypes: /^Article|AdvertiserContentArticle|NewsArticle|AnalysisNewsArticle|AskPublicNewsArticle|BackgroundNewsArticle|OpinionNewsArticle|ReportageNewsArticle|ReviewNewsArticle|Report|SatiricalArticle|ScholarlyArticle|MedicalScholarlyArticle|SocialMediaPosting|BlogPosting|LiveBlogPosting|DiscussionForumPosting|TechArticle|APIReference$/
+  },
+
+  UNLIKELY_ROLES: [ "menu", "menubar", "complementary", "navigation", "alert", "alertdialog", "dialog" ],
+
+  DIV_TO_P_ELEMS: new Set([ "BLOCKQUOTE", "DL", "DIV", "IMG", "OL", "P", "PRE", "TABLE", "UL" ]),
+
+  ALTER_TO_DIV_EXCEPTIONS: ["DIV", "ARTICLE", "SECTION", "P"],
+
+  PRESENTATIONAL_ATTRIBUTES: [ "align", "background", "bgcolor", "border", "cellpadding", "cellspacing", "frame", "hspace", "rules", "style", "valign", "vspace" ],
+
+  DEPRECATED_SIZE_ATTRIBUTE_ELEMS: [ "TABLE", "TH", "TD", "HR", "PRE" ],
+
+  // The commented out elements qualify as phrasing content but tend to be
+  // removed by readability when put into paragraphs, so we ignore them here.
+  PHRASING_ELEMS: [
+    // "CANVAS", "IFRAME", "SVG", "VIDEO",
+    "ABBR", "AUDIO", "B", "BDO", "BR", "BUTTON", "CITE", "CODE", "DATA",
+    "DATALIST", "DFN", "EM", "EMBED", "I", "IMG", "INPUT", "KBD", "LABEL",
+    "MARK", "MATH", "METER", "NOSCRIPT", "OBJECT", "OUTPUT", "PROGRESS", "Q",
+    "RUBY", "SAMP", "SCRIPT", "SELECT", "SMALL", "SPAN", "STRONG", "SUB",
+    "SUP", "TEXTAREA", "TIME", "VAR", "WBR"
+  ],
+
+  // These are the classes that readability sets itself.
+  CLASSES_TO_PRESERVE: [ "page" ],
+
+  // These are the list of HTML entities that need to be escaped.
+  HTML_ESCAPE_MAP: {
+    "lt": "<",
+    "gt": ">",
+    "amp": "&",
+    "quot": '"',
+    "apos": "'",
+  },
+
+  /**
+   * Run any post-process modifications to article content as necessary.
+   *
+   * @param Element
+   * @return void
+  **/
+  _postProcessContent: function(articleContent) {
+    // Readability cannot open relative uris so we convert them to absolute uris.
+    this._fixRelativeUris(articleContent);
+
+    this._simplifyNestedElements(articleContent);
+
+    if (!this._keepClasses) {
+      // Remove classes.
+      this._cleanClasses(articleContent);
+    }
+  },
+
+  /**
+   * Iterates over a NodeList, calls `filterFn` for each node and removes node
+   * if function returned `true`.
+   *
+   * If function is not passed, removes all the nodes in node list.
+   *
+   * @param NodeList nodeList The nodes to operate on
+   * @param Function filterFn the function to use as a filter
+   * @return void
+   */
+  _removeNodes: function(nodeList, filterFn) {
+    // Avoid ever operating on live node lists.
+    if (this._docJSDOMParser && nodeList._isLiveNodeList) {
+      throw new Error("Do not pass live node lists to _removeNodes");
+    }
+    for (var i = nodeList.length - 1; i >= 0; i--) {
+      var node = nodeList[i];
+      var parentNode = node.parentNode;
+      if (parentNode) {
+        if (!filterFn || filterFn.call(this, node, i, nodeList)) {
+          parentNode.removeChild(node);
+        }
+      }
+    }
+  },
+
+  /**
+   * Iterates over a NodeList, and calls _setNodeTag for each node.
+   *
+   * @param NodeList nodeList The nodes to operate on
+   * @param String newTagName the new tag name to use
+   * @return void
+   */
+  _replaceNodeTags: function(nodeList, newTagName) {
+    // Avoid ever operating on live node lists.
+    if (this._docJSDOMParser && nodeList._isLiveNodeList) {
+      throw new Error("Do not pass live node lists to _replaceNodeTags");
+    }
+    for (const node of nodeList) {
+      this._setNodeTag(node, newTagName);
+    }
+  },
+
+  /**
+   * Iterate over a NodeList, which doesn't natively fully implement the Array
+   * interface.
+   *
+   * For convenience, the current object context is applied to the provided
+   * iterate function.
+   *
+   * @param  NodeList nodeList The NodeList.
+   * @param  Function fn       The iterate function.
+   * @return void
+   */
+  _forEachNode: function(nodeList, fn) {
+    Array.prototype.forEach.call(nodeList, fn, this);
+  },
+
+  /**
+   * Iterate over a NodeList, and return the first node that passes
+   * the supplied test function
+   *
+   * For convenience, the current object context is applied to the provided
+   * test function.
+   *
+   * @param  NodeList nodeList The NodeList.
+   * @param  Function fn       The test function.
+   * @return void
+   */
+  _findNode: function(nodeList, fn) {
+    return Array.prototype.find.call(nodeList, fn, this);
+  },
+
+  /**
+   * Iterate over a NodeList, return true if any of the provided iterate
+   * function calls returns true, false otherwise.
+   *
+   * For convenience, the current object context is applied to the
+   * provided iterate function.
+   *
+   * @param  NodeList nodeList The NodeList.
+   * @param  Function fn       The iterate function.
+   * @return Boolean
+   */
+  _someNode: function(nodeList, fn) {
+    return Array.prototype.some.call(nodeList, fn, this);
+  },
+
+  /**
+   * Iterate over a NodeList, return true if all of the provided iterate
+   * function calls return true, false otherwise.
+   *
+   * For convenience, the current object context is applied to the
+   * provided iterate function.
+   *
+   * @param  NodeList nodeList The NodeList.
+   * @param  Function fn       The iterate function.
+   * @return Boolean
+   */
+  _everyNode: function(nodeList, fn) {
+    return Array.prototype.every.call(nodeList, fn, this);
+  },
+
+  /**
+   * Concat all nodelists passed as arguments.
+   *
+   * @return ...NodeList
+   * @return Array
+   */
+  _concatNodeLists: function() {
+    var slice = Array.prototype.slice;
+    var args = slice.call(arguments);
+    var nodeLists = args.map(function(list) {
+      return slice.call(list);
+    });
+    return Array.prototype.concat.apply([], nodeLists);
+  },
+
+  _getAllNodesWithTag: function(node, tagNames) {
+    if (node.querySelectorAll) {
+      return node.querySelectorAll(tagNames.join(","));
+    }
+    return [].concat.apply([], tagNames.map(function(tag) {
+      var collection = node.getElementsByTagName(tag);
+      return Array.isArray(collection) ? collection : Array.from(collection);
+    }));
+  },
+
+  /**
+   * Removes the class="" attribute from every element in the given
+   * subtree, except those that match CLASSES_TO_PRESERVE and
+   * the classesToPreserve array from the options object.
+   *
+   * @param Element
+   * @return void
+   */
+  _cleanClasses: function(node) {
+    var classesToPreserve = this._classesToPreserve;
+    var className = (node.getAttribute("class") || "")
+      .split(/\s+/)
+      .filter(function(cls) {
+        return classesToPreserve.indexOf(cls) != -1;
+      })
+      .join(" ");
+
+    if (className) {
+      node.setAttribute("class", className);
+    } else {
+      node.removeAttribute("class");
+    }
+
+    for (node = node.firstElementChild; node; node = node.nextElementSibling) {
+      this._cleanClasses(node);
+    }
+  },
+
+  /**
+   * Converts each  and  uri in the given element to an absolute URI,
+   * ignoring #ref URIs.
+   *
+   * @param Element
+   * @return void
+   */
+  _fixRelativeUris: function(articleContent) {
+    var baseURI = this._doc.baseURI;
+    var documentURI = this._doc.documentURI;
+    function toAbsoluteURI(uri) {
+      // Leave hash links alone if the base URI matches the document URI:
+      if (baseURI == documentURI && uri.charAt(0) == "#") {
+        return uri;
+      }
+
+      // Otherwise, resolve against base URI:
+      try {
+        return new URL(uri, baseURI).href;
+      } catch (ex) {
+        // Something went wrong, just return the original:
+      }
+      return uri;
+    }
+
+    var links = this._getAllNodesWithTag(articleContent, ["a"]);
+    this._forEachNode(links, function(link) {
+      var href = link.getAttribute("href");
+      if (href) {
+        // Remove links with javascript: URIs, since
+        // they won't work after scripts have been removed from the page.
+        if (href.indexOf("javascript:") === 0) {
+          // if the link only contains simple text content, it can be converted to a text node
+          if (link.childNodes.length === 1 && link.childNodes[0].nodeType === this.TEXT_NODE) {
+            var text = this._doc.createTextNode(link.textContent);
+            link.parentNode.replaceChild(text, link);
+          } else {
+            // if the link has multiple children, they should all be preserved
+            var container = this._doc.createElement("span");
+            while (link.firstChild) {
+              container.appendChild(link.firstChild);
+            }
+            link.parentNode.replaceChild(container, link);
+          }
+        } else {
+          link.setAttribute("href", toAbsoluteURI(href));
+        }
+      }
+    });
+
+    var medias = this._getAllNodesWithTag(articleContent, [
+      "img", "picture", "figure", "video", "audio", "source"
+    ]);
+
+    this._forEachNode(medias, function(media) {
+      var src = media.getAttribute("src");
+      var poster = media.getAttribute("poster");
+      var srcset = media.getAttribute("srcset");
+
+      if (src) {
+        media.setAttribute("src", toAbsoluteURI(src));
+      }
+
+      if (poster) {
+        media.setAttribute("poster", toAbsoluteURI(poster));
+      }
+
+      if (srcset) {
+        var newSrcset = srcset.replace(this.REGEXPS.srcsetUrl, function(_, p1, p2, p3) {
+          return toAbsoluteURI(p1) + (p2 || "") + p3;
+        });
+
+        media.setAttribute("srcset", newSrcset);
+      }
+    });
+  },
+
+  _simplifyNestedElements: function(articleContent) {
+    var node = articleContent;
+
+    while (node) {
+      if (node.parentNode && ["DIV", "SECTION"].includes(node.tagName) && !(node.id && node.id.startsWith("readability"))) {
+        if (this._isElementWithoutContent(node)) {
+          node = this._removeAndGetNext(node);
+          continue;
+        } else if (this._hasSingleTagInsideElement(node, "DIV") || this._hasSingleTagInsideElement(node, "SECTION")) {
+          var child = node.children[0];
+          for (var i = 0; i < node.attributes.length; i++) {
+            child.setAttribute(node.attributes[i].name, node.attributes[i].value);
+          }
+          node.parentNode.replaceChild(child, node);
+          node = child;
+          continue;
+        }
+      }
+
+      node = this._getNextNode(node);
+    }
+  },
+
+  /**
+   * Get the article title as an H1.
+   *
+   * @return string
+   **/
+  _getArticleTitle: function() {
+    var doc = this._doc;
+    var curTitle = "";
+    var origTitle = "";
+
+    try {
+      curTitle = origTitle = doc.title.trim();
+
+      // If they had an element with id "title" in their HTML
+      if (typeof curTitle !== "string")
+        curTitle = origTitle = this._getInnerText(doc.getElementsByTagName("title")[0]);
+    } catch (e) {/* ignore exceptions setting the title. */}
+
+    var titleHadHierarchicalSeparators = false;
+    function wordCount(str) {
+      return str.split(/\s+/).length;
+    }
+
+    // If there's a separator in the title, first remove the final part
+    if ((/ [\|\-\\\/>»] /).test(curTitle)) {
+      titleHadHierarchicalSeparators = / [\\\/>»] /.test(curTitle);
+      curTitle = origTitle.replace(/(.*)[\|\-\\\/>»] .*/gi, "$1");
+
+      // If the resulting title is too short (3 words or fewer), remove
+      // the first part instead:
+      if (wordCount(curTitle) < 3)
+        curTitle = origTitle.replace(/[^\|\-\\\/>»]*[\|\-\\\/>»](.*)/gi, "$1");
+    } else if (curTitle.indexOf(": ") !== -1) {
+      // Check if we have an heading containing this exact string, so we
+      // could assume it's the full title.
+      var headings = this._concatNodeLists(
+        doc.getElementsByTagName("h1"),
+        doc.getElementsByTagName("h2")
+      );
+      var trimmedTitle = curTitle.trim();
+      var match = this._someNode(headings, function(heading) {
+        return heading.textContent.trim() === trimmedTitle;
+      });
+
+      // If we don't, let's extract the title out of the original title string.
+      if (!match) {
+        curTitle = origTitle.substring(origTitle.lastIndexOf(":") + 1);
+
+        // If the title is now too short, try the first colon instead:
+        if (wordCount(curTitle) < 3) {
+          curTitle = origTitle.substring(origTitle.indexOf(":") + 1);
+          // But if we have too many words before the colon there's something weird
+          // with the titles and the H tags so let's just use the original title instead
+        } else if (wordCount(origTitle.substr(0, origTitle.indexOf(":"))) > 5) {
+          curTitle = origTitle;
+        }
+      }
+    } else if (curTitle.length > 150 || curTitle.length < 15) {
+      var hOnes = doc.getElementsByTagName("h1");
+
+      if (hOnes.length === 1)
+        curTitle = this._getInnerText(hOnes[0]);
+    }
+
+    curTitle = curTitle.trim().replace(this.REGEXPS.normalize, " ");
+    // If we now have 4 words or fewer as our title, and either no
+    // 'hierarchical' separators (\, /, > or ») were found in the original
+    // title or we decreased the number of words by more than 1 word, use
+    // the original title.
+    var curTitleWordCount = wordCount(curTitle);
+    if (curTitleWordCount <= 4 &&
+        (!titleHadHierarchicalSeparators ||
+         curTitleWordCount != wordCount(origTitle.replace(/[\|\-\\\/>»]+/g, "")) - 1)) {
+      curTitle = origTitle;
+    }
+
+    return curTitle;
+  },
+
+  /**
+   * Prepare the HTML document for readability to scrape it.
+   * This includes things like stripping javascript, CSS, and handling terrible markup.
+   *
+   * @return void
+   **/
+  _prepDocument: function() {
+    var doc = this._doc;
+
+    // Remove all style tags in head
+    this._removeNodes(this._getAllNodesWithTag(doc, ["style"]));
+
+    if (doc.body) {
+      this._replaceBrs(doc.body);
+    }
+
+    this._replaceNodeTags(this._getAllNodesWithTag(doc, ["font"]), "SPAN");
+  },
+
+  /**
+   * Finds the next node, starting from the given node, and ignoring
+   * whitespace in between. If the given node is an element, the same node is
+   * returned.
+   */
+  _nextNode: function (node) {
+    var next = node;
+    while (next
+        && (next.nodeType != this.ELEMENT_NODE)
+        && this.REGEXPS.whitespace.test(next.textContent)) {
+      next = next.nextSibling;
+    }
+    return next;
+  },
+
+  /**
+   * Replaces 2 or more successive 
 elements with a single 
.
+   * Whitespace between 
 elements are ignored. For example:
+   *   
foo
bar
 

abc

+   * will become:
+   *   
foo
bar
abc

+   */
+  _replaceBrs: function (elem) {
+    this._forEachNode(this._getAllNodesWithTag(elem, ["br"]), function(br) {
+      var next = br.nextSibling;
+
+      // Whether 2 or more 
 elements have been found and replaced with a
+      // 
 block.
+      var replaced = false;
+
+      // If we find a 
 chain, remove the 
s until we hit another node
+      // or non-whitespace. This leaves behind the first 
 in the chain
+      // (which will be replaced with a 
 later).
+      while ((next = this._nextNode(next)) && (next.tagName == "BR")) {
+        replaced = true;
+        var brSibling = next.nextSibling;
+        next.parentNode.removeChild(next);
+        next = brSibling;
+      }
+
+      // If we removed a 
 chain, replace the remaining 
 with a 
. Add
+      // all sibling nodes as children of the 
 until we hit another 

+      // chain.
+      if (replaced) {
+        var p = this._doc.createElement("p");
+        br.parentNode.replaceChild(p, br);
+
+        next = p.nextSibling;
+        while (next) {
+          // If we've hit another 

, we're done adding children to this 
.
+          if (next.tagName == "BR") {
+            var nextElem = this._nextNode(next.nextSibling);
+            if (nextElem && nextElem.tagName == "BR")
+              break;
+          }
+
+          if (!this._isPhrasingContent(next))
+            break;
+
+          // Otherwise, make this node a child of the new 
.
+          var sibling = next.nextSibling;
+          p.appendChild(next);
+          next = sibling;
+        }
+
+        while (p.lastChild && this._isWhitespace(p.lastChild)) {
+          p.removeChild(p.lastChild);
+        }
+
+        if (p.parentNode.tagName === "P")
+          this._setNodeTag(p.parentNode, "DIV");
+      }
+    });
+  },
+
+  _setNodeTag: function (node, tag) {
+    this.log("_setNodeTag", node, tag);
+    if (this._docJSDOMParser) {
+      node.localName = tag.toLowerCase();
+      node.tagName = tag.toUpperCase();
+      return node;
+    }
+
+    var replacement = node.ownerDocument.createElement(tag);
+    while (node.firstChild) {
+      replacement.appendChild(node.firstChild);
+    }
+    node.parentNode.replaceChild(replacement, node);
+    if (node.readability)
+      replacement.readability = node.readability;
+
+    for (var i = 0; i < node.attributes.length; i++) {
+      try {
+        replacement.setAttribute(node.attributes[i].name, node.attributes[i].value);
+      } catch (ex) {
+        /* it's possible for setAttribute() to throw if the attribute name
+         * isn't a valid XML Name. Such attributes can however be parsed from
+         * source in HTML docs, see https://github.com/whatwg/html/issues/4275,
+         * so we can hit them here and then throw. We don't care about such
+         * attributes so we ignore them.
+         */
+      }
+    }
+    return replacement;
+  },
+
+  /**
+   * Prepare the article node for display. Clean out any inline styles,
+   * iframes, forms, strip extraneous 
 tags, etc.
+   *
+   * @param Element
+   * @return void
+   **/
+  _prepArticle: function(articleContent) {
+    this._cleanStyles(articleContent);
+
+    // Check for data tables before we continue, to avoid removing items in
+    // those tables, which will often be isolated even though they're
+    // visually linked to other content-ful elements (text, images, etc.).
+    this._markDataTables(articleContent);
+
+    this._fixLazyImages(articleContent);
+
+    // Clean out junk from the article content
+    this._cleanConditionally(articleContent, "form");
+    this._cleanConditionally(articleContent, "fieldset");
+    this._clean(articleContent, "object");
+    this._clean(articleContent, "embed");
+    this._clean(articleContent, "footer");
+    this._clean(articleContent, "link");
+    this._clean(articleContent, "aside");
+
+    // Clean out elements with little content that have "share" in their id/class combinations from final top candidates,
+    // which means we don't remove the top candidates even they have "share".
+
+    var shareElementThreshold = this.DEFAULT_CHAR_THRESHOLD;
+
+    this._forEachNode(articleContent.children, function (topCandidate) {
+      this._cleanMatchedNodes(topCandidate, function (node, matchString) {
+        return this.REGEXPS.shareElements.test(matchString) && node.textContent.length < shareElementThreshold;
+      });
+    });
+
+    this._clean(articleContent, "iframe");
+    this._clean(articleContent, "input");
+    this._clean(articleContent, "textarea");
+    this._clean(articleContent, "select");
+    this._clean(articleContent, "button");
+    this._cleanHeaders(articleContent);
+
+    // Do these last as the previous stuff may have removed junk
+    // that will affect these
+    this._cleanConditionally(articleContent, "table");
+    this._cleanConditionally(articleContent, "ul");
+    this._cleanConditionally(articleContent, "div");
+
+    // replace H1 with H2 as H1 should be only title that is displayed separately
+    this._replaceNodeTags(this._getAllNodesWithTag(articleContent, ["h1"]), "h2");
+
+    // Remove extra paragraphs
+    this._removeNodes(this._getAllNodesWithTag(articleContent, ["p"]), function (paragraph) {
+      var imgCount = paragraph.getElementsByTagName("img").length;
+      var embedCount = paragraph.getElementsByTagName("embed").length;
+      var objectCount = paragraph.getElementsByTagName("object").length;
+      // At this point, nasty iframes have been removed, only remain embedded video ones.
+      var iframeCount = paragraph.getElementsByTagName("iframe").length;
+      var totalCount = imgCount + embedCount + objectCount + iframeCount;
+
+      return totalCount === 0 && !this._getInnerText(paragraph, false);
+    });
+
+    this._forEachNode(this._getAllNodesWithTag(articleContent, ["br"]), function(br) {
+      var next = this._nextNode(br.nextSibling);
+      if (next && next.tagName == "P")
+        br.parentNode.removeChild(br);
+    });
+
+    // Remove single-cell tables
+    this._forEachNode(this._getAllNodesWithTag(articleContent, ["table"]), function(table) {
+      var tbody = this._hasSingleTagInsideElement(table, "TBODY") ? table.firstElementChild : table;
+      if (this._hasSingleTagInsideElement(tbody, "TR")) {
+        var row = tbody.firstElementChild;
+        if (this._hasSingleTagInsideElement(row, "TD")) {
+          var cell = row.firstElementChild;
+          cell = this._setNodeTag(cell, this._everyNode(cell.childNodes, this._isPhrasingContent) ? "P" : "DIV");
+          table.parentNode.replaceChild(cell, table);
+        }
+      }
+    });
+  },
+
+  /**
+   * Initialize a node with the readability object. Also checks the
+   * className/id for special names to add to its score.
+   *
+   * @param Element
+   * @return void
+  **/
+  _initializeNode: function(node) {
+    node.readability = {"contentScore": 0};
+
+    switch (node.tagName) {
+      case "DIV":
+        node.readability.contentScore += 5;
+        break;
+
+      case "PRE":
+      case "TD":
+      case "BLOCKQUOTE":
+        node.readability.contentScore += 3;
+        break;
+
+      case "ADDRESS":
+      case "OL":
+      case "UL":
+      case "DL":
+      case "DD":
+      case "DT":
+      case "LI":
+      case "FORM":
+        node.readability.contentScore -= 3;
+        break;
+
+      case "H1":
+      case "H2":
+      case "H3":
+      case "H4":
+      case "H5":
+      case "H6":
+      case "TH":
+        node.readability.contentScore -= 5;
+        break;
+    }
+
+    node.readability.contentScore += this._getClassWeight(node);
+  },
+
+  _removeAndGetNext: function(node) {
+    var nextNode = this._getNextNode(node, true);
+    node.parentNode.removeChild(node);
+    return nextNode;
+  },
+
+  /**
+   * Traverse the DOM from node to node, starting at the node passed in.
+   * Pass true for the second parameter to indicate this node itself
+   * (and its kids) are going away, and we want the next node over.
+   *
+   * Calling this in a loop will traverse the DOM depth-first.
+   */
+  _getNextNode: function(node, ignoreSelfAndKids) {
+    // First check for kids if those aren't being ignored
+    if (!ignoreSelfAndKids && node.firstElementChild) {
+      return node.firstElementChild;
+    }
+    // Then for siblings...
+    if (node.nextElementSibling) {
+      return node.nextElementSibling;
+    }
+    // And finally, move up the parent chain *and* find a sibling
+    // (because this is depth-first traversal, we will have already
+    // seen the parent nodes themselves).
+    do {
+      node = node.parentNode;
+    } while (node && !node.nextElementSibling);
+    return node && node.nextElementSibling;
+  },
+
+  // compares second text to first one
+  // 1 = same text, 0 = completely different text
+  // works the way that it splits both texts into words and then finds words that are unique in second text
+  // the result is given by the lower length of unique parts
+  _textSimilarity: function(textA, textB) {
+    var tokensA = textA.toLowerCase().split(this.REGEXPS.tokenize).filter(Boolean);
+    var tokensB = textB.toLowerCase().split(this.REGEXPS.tokenize).filter(Boolean);
+    if (!tokensA.length || !tokensB.length) {
+      return 0;
+    }
+    var uniqTokensB = tokensB.filter(token => !tokensA.includes(token));
+    var distanceB = uniqTokensB.join(" ").length / tokensB.join(" ").length;
+    return 1 - distanceB;
+  },
+
+  _checkByline: function(node, matchString) {
+    if (this._articleByline) {
+      return false;
+    }
+
+    if (node.getAttribute !== undefined) {
+      var rel = node.getAttribute("rel");
+      var itemprop = node.getAttribute("itemprop");
+    }
+
+    if ((rel === "author" || (itemprop && itemprop.indexOf("author") !== -1) || this.REGEXPS.byline.test(matchString)) && this._isValidByline(node.textContent)) {
+      this._articleByline = node.textContent.trim();
+      return true;
+    }
+
+    return false;
+  },
+
+  _getNodeAncestors: function(node, maxDepth) {
+    maxDepth = maxDepth || 0;
+    var i = 0, ancestors = [];
+    while (node.parentNode) {
+      ancestors.push(node.parentNode);
+      if (maxDepth && ++i === maxDepth)
+        break;
+      node = node.parentNode;
+    }
+    return ancestors;
+  },
+
+  /***
+   * grabArticle - Using a variety of metrics (content score, classname, element types), find the content that is
+   *         most likely to be the stuff a user wants to read. Then return it wrapped up in a div.
+   *
+   * @param page a document to run upon. Needs to be a full document, complete with body.
+   * @return Element
+  **/
+  _grabArticle: function (page) {
+    this.log("**** grabArticle ****");
+    var doc = this._doc;
+    var isPaging = page !== null;
+    page = page ? page : this._doc.body;
+
+    // We can't grab an article if we don't have a page!
+    if (!page) {
+      this.log("No body found in document. Abort.");
+      return null;
+    }
+
+    var pageCacheHtml = page.innerHTML;
+
+    while (true) {
+      this.log("Starting grabArticle loop");
+      var stripUnlikelyCandidates = this._flagIsActive(this.FLAG_STRIP_UNLIKELYS);
+
+      // First, node prepping. Trash nodes that look cruddy (like ones with the
+      // class name "comment", etc), and turn divs into P tags where they have been
+      // used inappropriately (as in, where they contain no other block level elements.)
+      var elementsToScore = [];
+      var node = this._doc.documentElement;
+
+      let shouldRemoveTitleHeader = true;
+
+      while (node) {
+
+        if (node.tagName === "HTML") {
+          this._articleLang = node.getAttribute("lang");
+        }
+
+        var matchString = node.className + " " + node.id;
+
+        if (!this._isProbablyVisible(node)) {
+          this.log("Removing hidden node - " + matchString);
+          node = this._removeAndGetNext(node);
+          continue;
+        }
+
+        // User is not able to see elements applied with both "aria-modal = true" and "role = dialog"
+        if (node.getAttribute("aria-modal") == "true" && node.getAttribute("role") == "dialog") {
+          node = this._removeAndGetNext(node);
+          continue;
+        }
+
+        // Check to see if this node is a byline, and remove it if it is.
+        if (this._checkByline(node, matchString)) {
+          node = this._removeAndGetNext(node);
+          continue;
+        }
+
+        if (shouldRemoveTitleHeader && this._headerDuplicatesTitle(node)) {
+          this.log("Removing header: ", node.textContent.trim(), this._articleTitle.trim());
+          shouldRemoveTitleHeader = false;
+          node = this._removeAndGetNext(node);
+          continue;
+        }
+
+        // Remove unlikely candidates
+        if (stripUnlikelyCandidates) {
+          if (this.REGEXPS.unlikelyCandidates.test(matchString) &&
+              !this.REGEXPS.okMaybeItsACandidate.test(matchString) &&
+              !this._hasAncestorTag(node, "table") &&
+              !this._hasAncestorTag(node, "code") &&
+              node.tagName !== "BODY" &&
+              node.tagName !== "A") {
+            this.log("Removing unlikely candidate - " + matchString);
+            node = this._removeAndGetNext(node);
+            continue;
+          }
+
+          if (this.UNLIKELY_ROLES.includes(node.getAttribute("role"))) {
+            this.log("Removing content with role " + node.getAttribute("role") + " - " + matchString);
+            node = this._removeAndGetNext(node);
+            continue;
+          }
+        }
+
+        // Remove DIV, SECTION, and HEADER nodes without any content(e.g. text, image, video, or iframe).
+        if ((node.tagName === "DIV" || node.tagName === "SECTION" || node.tagName === "HEADER" ||
+             node.tagName === "H1" || node.tagName === "H2" || node.tagName === "H3" ||
+             node.tagName === "H4" || node.tagName === "H5" || node.tagName === "H6") &&
+            this._isElementWithoutContent(node)) {
+          node = this._removeAndGetNext(node);
+          continue;
+        }
+
+        if (this.DEFAULT_TAGS_TO_SCORE.indexOf(node.tagName) !== -1) {
+          elementsToScore.push(node);
+        }
+
+        // Turn all divs that don't have children block level elements into p's
+        if (node.tagName === "DIV") {
+          // Put phrasing content into paragraphs.
+          var p = null;
+          var childNode = node.firstChild;
+          while (childNode) {
+            var nextSibling = childNode.nextSibling;
+            if (this._isPhrasingContent(childNode)) {
+              if (p !== null) {
+                p.appendChild(childNode);
+              } else if (!this._isWhitespace(childNode)) {
+                p = doc.createElement("p");
+                node.replaceChild(p, childNode);
+                p.appendChild(childNode);
+              }
+            } else if (p !== null) {
+              while (p.lastChild && this._isWhitespace(p.lastChild)) {
+                p.removeChild(p.lastChild);
+              }
+              p = null;
+            }
+            childNode = nextSibling;
+          }
+
+          // Sites like http://mobile.slate.com encloses each paragraph with a DIV
+          // element. DIVs with only a P element inside and no text content can be
+          // safely converted into plain P elements to avoid confusing the scoring
+          // algorithm with DIVs with are, in practice, paragraphs.
+          if (this._hasSingleTagInsideElement(node, "P") && this._getLinkDensity(node) < 0.25) {
+            var newNode = node.children[0];
+            node.parentNode.replaceChild(newNode, node);
+            node = newNode;
+            elementsToScore.push(node);
+          } else if (!this._hasChildBlockElement(node)) {
+            node = this._setNodeTag(node, "P");
+            elementsToScore.push(node);
+          }
+        }
+        node = this._getNextNode(node);
+      }
+
+      /**
+       * Loop through all paragraphs, and assign a score to them based on how content-y they look.
+       * Then add their score to their parent node.
+       *
+       * A score is determined by things like number of commas, class names, etc. Maybe eventually link density.
+      **/
+      var candidates = [];
+      this._forEachNode(elementsToScore, function(elementToScore) {
+        if (!elementToScore.parentNode || typeof(elementToScore.parentNode.tagName) === "undefined")
+          return;
+
+        // If this paragraph is less than 25 characters, don't even count it.
+        var innerText = this._getInnerText(elementToScore);
+        if (innerText.length < 25)
+          return;
+
+        // Exclude nodes with no ancestor.
+        var ancestors = this._getNodeAncestors(elementToScore, 5);
+        if (ancestors.length === 0)
+          return;
+
+        var contentScore = 0;
+
+        // Add a point for the paragraph itself as a base.
+        contentScore += 1;
+
+        // Add points for any commas within this paragraph.
+        contentScore += innerText.split(this.REGEXPS.commas).length;
+
+        // For every 100 characters in this paragraph, add another point. Up to 3 points.
+        contentScore += Math.min(Math.floor(innerText.length / 100), 3);
+
+        // Initialize and score ancestors.
+        this._forEachNode(ancestors, function(ancestor, level) {
+          if (!ancestor.tagName || !ancestor.parentNode || typeof(ancestor.parentNode.tagName) === "undefined")
+            return;
+
+          if (typeof(ancestor.readability) === "undefined") {
+            this._initializeNode(ancestor);
+            candidates.push(ancestor);
+          }
+
+          // Node score divider:
+          // - parent:             1 (no division)
+          // - grandparent:        2
+          // - great grandparent+: ancestor level * 3
+          if (level === 0)
+            var scoreDivider = 1;
+          else if (level === 1)
+            scoreDivider = 2;
+          else
+            scoreDivider = level * 3;
+          ancestor.readability.contentScore += contentScore / scoreDivider;
+        });
+      });
+
+      // After we've calculated scores, loop through all of the possible
+      // candidate nodes we found and find the one with the highest score.
+      var topCandidates = [];
+      for (var c = 0, cl = candidates.length; c < cl; c += 1) {
+        var candidate = candidates[c];
+
+        // Scale the final candidates score based on link density. Good content
+        // should have a relatively small link density (5% or less) and be mostly
+        // unaffected by this operation.
+        var candidateScore = candidate.readability.contentScore * (1 - this._getLinkDensity(candidate));
+        candidate.readability.contentScore = candidateScore;
+
+        this.log("Candidate:", candidate, "with score " + candidateScore);
+
+        for (var t = 0; t < this._nbTopCandidates; t++) {
+          var aTopCandidate = topCandidates[t];
+
+          if (!aTopCandidate || candidateScore > aTopCandidate.readability.contentScore) {
+            topCandidates.splice(t, 0, candidate);
+            if (topCandidates.length > this._nbTopCandidates)
+              topCandidates.pop();
+            break;
+          }
+        }
+      }
+
+      var topCandidate = topCandidates[0] || null;
+      var neededToCreateTopCandidate = false;
+      var parentOfTopCandidate;
+
+      // If we still have no top candidate, just use the body as a last resort.
+      // We also have to copy the body node so it is something we can modify.
+      if (topCandidate === null || topCandidate.tagName === "BODY") {
+        // Move all of the page's children into topCandidate
+        topCandidate = doc.createElement("DIV");
+        neededToCreateTopCandidate = true;
+        // Move everything (not just elements, also text nodes etc.) into the container
+        // so we even include text directly in the body:
+        while (page.firstChild) {
+          this.log("Moving child out:", page.firstChild);
+          topCandidate.appendChild(page.firstChild);
+        }
+
+        page.appendChild(topCandidate);
+
+        this._initializeNode(topCandidate);
+      } else if (topCandidate) {
+        // Find a better top candidate node if it contains (at least three) nodes which belong to `topCandidates` array
+        // and whose scores are quite closed with current `topCandidate` node.
+        var alternativeCandidateAncestors = [];
+        for (var i = 1; i < topCandidates.length; i++) {
+          if (topCandidates[i].readability.contentScore / topCandidate.readability.contentScore >= 0.75) {
+            alternativeCandidateAncestors.push(this._getNodeAncestors(topCandidates[i]));
+          }
+        }
+        var MINIMUM_TOPCANDIDATES = 3;
+        if (alternativeCandidateAncestors.length >= MINIMUM_TOPCANDIDATES) {
+          parentOfTopCandidate = topCandidate.parentNode;
+          while (parentOfTopCandidate.tagName !== "BODY") {
+            var listsContainingThisAncestor = 0;
+            for (var ancestorIndex = 0; ancestorIndex < alternativeCandidateAncestors.length && listsContainingThisAncestor < MINIMUM_TOPCANDIDATES; ancestorIndex++) {
+              listsContainingThisAncestor += Number(alternativeCandidateAncestors[ancestorIndex].includes(parentOfTopCandidate));
+            }
+            if (listsContainingThisAncestor >= MINIMUM_TOPCANDIDATES) {
+              topCandidate = parentOfTopCandidate;
+              break;
+            }
+            parentOfTopCandidate = parentOfTopCandidate.parentNode;
+          }
+        }
+        if (!topCandidate.readability) {
+          this._initializeNode(topCandidate);
+        }
+
+        // Because of our bonus system, parents of candidates might have scores
+        // themselves. They get half of the node. There won't be nodes with higher
+        // scores than our topCandidate, but if we see the score going *up* in the first
+        // few steps up the tree, that's a decent sign that there might be more content
+        // lurking in other places that we want to unify in. The sibling stuff
+        // below does some of that - but only if we've looked high enough up the DOM
+        // tree.
+        parentOfTopCandidate = topCandidate.parentNode;
+        var lastScore = topCandidate.readability.contentScore;
+        // The scores shouldn't get too low.
+        var scoreThreshold = lastScore / 3;
+        while (parentOfTopCandidate.tagName !== "BODY") {
+          if (!parentOfTopCandidate.readability) {
+            parentOfTopCandidate = parentOfTopCandidate.parentNode;
+            continue;
+          }
+          var parentScore = parentOfTopCandidate.readability.contentScore;
+          if (parentScore < scoreThreshold)
+            break;
+          if (parentScore > lastScore) {
+            // Alright! We found a better parent to use.
+            topCandidate = parentOfTopCandidate;
+            break;
+          }
+          lastScore = parentOfTopCandidate.readability.contentScore;
+          parentOfTopCandidate = parentOfTopCandidate.parentNode;
+        }
+
+        // If the top candidate is the only child, use parent instead. This will help sibling
+        // joining logic when adjacent content is actually located in parent's sibling node.
+        parentOfTopCandidate = topCandidate.parentNode;
+        while (parentOfTopCandidate.tagName != "BODY" && parentOfTopCandidate.children.length == 1) {
+          topCandidate = parentOfTopCandidate;
+          parentOfTopCandidate = topCandidate.parentNode;
+        }
+        if (!topCandidate.readability) {
+          this._initializeNode(topCandidate);
+        }
+      }
+
+      // Now that we have the top candidate, look through its siblings for content
+      // that might also be related. Things like preambles, content split by ads
+      // that we removed, etc.
+      var articleContent = doc.createElement("DIV");
+      if (isPaging)
+        articleContent.id = "readability-content";
+
+      var siblingScoreThreshold = Math.max(10, topCandidate.readability.contentScore * 0.2);
+      // Keep potential top candidate's parent node to try to get text direction of it later.
+      parentOfTopCandidate = topCandidate.parentNode;
+      var siblings = parentOfTopCandidate.children;
+
+      for (var s = 0, sl = siblings.length; s < sl; s++) {
+        var sibling = siblings[s];
+        var append = false;
+
+        this.log("Looking at sibling node:", sibling, sibling.readability ? ("with score " + sibling.readability.contentScore) : "");
+        this.log("Sibling has score", sibling.readability ? sibling.readability.contentScore : "Unknown");
+
+        if (sibling === topCandidate) {
+          append = true;
+        } else {
+          var contentBonus = 0;
+
+          // Give a bonus if sibling nodes and top candidates have the example same classname
+          if (sibling.className === topCandidate.className && topCandidate.className !== "")
+            contentBonus += topCandidate.readability.contentScore * 0.2;
+
+          if (sibling.readability &&
+              ((sibling.readability.contentScore + contentBonus) >= siblingScoreThreshold)) {
+            append = true;
+          } else if (sibling.nodeName === "P") {
+            var linkDensity = this._getLinkDensity(sibling);
+            var nodeContent = this._getInnerText(sibling);
+            var nodeLength = nodeContent.length;
+
+            if (nodeLength > 80 && linkDensity < 0.25) {
+              append = true;
+            } else if (nodeLength < 80 && nodeLength > 0 && linkDensity === 0 &&
+                       nodeContent.search(/\.( |$)/) !== -1) {
+              append = true;
+            }
+          }
+        }
+
+        if (append) {
+          this.log("Appending node:", sibling);
+
+          if (this.ALTER_TO_DIV_EXCEPTIONS.indexOf(sibling.nodeName) === -1) {
+            // We have a node that isn't a common block level element, like a form or td tag.
+            // Turn it into a div so it doesn't get filtered out later by accident.
+            this.log("Altering sibling:", sibling, "to div.");
+
+            sibling = this._setNodeTag(sibling, "DIV");
+          }
+
+          articleContent.appendChild(sibling);
+          // Fetch children again to make it compatible
+          // with DOM parsers without live collection support.
+          siblings = parentOfTopCandidate.children;
+          // siblings is a reference to the children array, and
+          // sibling is removed from the array when we call appendChild().
+          // As a result, we must revisit this index since the nodes
+          // have been shifted.
+          s -= 1;
+          sl -= 1;
+        }
+      }
+
+      if (this._debug)
+        this.log("Article content pre-prep: " + articleContent.innerHTML);
+      // So we have all of the content that we need. Now we clean it up for presentation.
+      this._prepArticle(articleContent);
+      if (this._debug)
+        this.log("Article content post-prep: " + articleContent.innerHTML);
+
+      if (neededToCreateTopCandidate) {
+        // We already created a fake div thing, and there wouldn't have been any siblings left
+        // for the previous loop, so there's no point trying to create a new div, and then
+        // move all the children over. Just assign IDs and class names here. No need to append
+        // because that already happened anyway.
+        topCandidate.id = "readability-page-1";
+        topCandidate.className = "page";
+      } else {
+        var div = doc.createElement("DIV");
+        div.id = "readability-page-1";
+        div.className = "page";
+        while (articleContent.firstChild) {
+          div.appendChild(articleContent.firstChild);
+        }
+        articleContent.appendChild(div);
+      }
+
+      if (this._debug)
+        this.log("Article content after paging: " + articleContent.innerHTML);
+
+      var parseSuccessful = true;
+
+      // Now that we've gone through the full algorithm, check to see if
+      // we got any meaningful content. If we didn't, we may need to re-run
+      // grabArticle with different flags set. This gives us a higher likelihood of
+      // finding the content, and the sieve approach gives us a higher likelihood of
+      // finding the -right- content.
+      var textLength = this._getInnerText(articleContent, true).length;
+      if (textLength < this._charThreshold) {
+        parseSuccessful = false;
+        page.innerHTML = pageCacheHtml;
+
+        if (this._flagIsActive(this.FLAG_STRIP_UNLIKELYS)) {
+          this._removeFlag(this.FLAG_STRIP_UNLIKELYS);
+          this._attempts.push({articleContent: articleContent, textLength: textLength});
+        } else if (this._flagIsActive(this.FLAG_WEIGHT_CLASSES)) {
+          this._removeFlag(this.FLAG_WEIGHT_CLASSES);
+          this._attempts.push({articleContent: articleContent, textLength: textLength});
+        } else if (this._flagIsActive(this.FLAG_CLEAN_CONDITIONALLY)) {
+          this._removeFlag(this.FLAG_CLEAN_CONDITIONALLY);
+          this._attempts.push({articleContent: articleContent, textLength: textLength});
+        } else {
+          this._attempts.push({articleContent: articleContent, textLength: textLength});
+          // No luck after removing flags, just return the longest text we found during the different loops
+          this._attempts.sort(function (a, b) {
+            return b.textLength - a.textLength;
+          });
+
+          // But first check if we actually have something
+          if (!this._attempts[0].textLength) {
+            return null;
+          }
+
+          articleContent = this._attempts[0].articleContent;
+          parseSuccessful = true;
+        }
+      }
+
+      if (parseSuccessful) {
+        // Find out text direction from ancestors of final top candidate.
+        var ancestors = [parentOfTopCandidate, topCandidate].concat(this._getNodeAncestors(parentOfTopCandidate));
+        this._someNode(ancestors, function(ancestor) {
+          if (!ancestor.tagName)
+            return false;
+          var articleDir = ancestor.getAttribute("dir");
+          if (articleDir) {
+            this._articleDir = articleDir;
+            return true;
+          }
+          return false;
+        });
+        return articleContent;
+      }
+    }
+  },
+
+  /**
+   * Check whether the input string could be a byline.
+   * This verifies that the input is a string, and that the length
+   * is less than 100 chars.
+   *
+   * @param possibleByline {string} - a string to check whether its a byline.
+   * @return Boolean - whether the input string is a byline.
+   */
+  _isValidByline: function(byline) {
+    if (typeof byline == "string" || byline instanceof String) {
+      byline = byline.trim();
+      return (byline.length > 0) && (byline.length < 100);
+    }
+    return false;
+  },
+
+  /**
+   * Converts some of the common HTML entities in string to their corresponding characters.
+   *
+   * @param str {string} - a string to unescape.
+   * @return string without HTML entity.
+   */
+  _unescapeHtmlEntities: function(str) {
+    if (!str) {
+      return str;
+    }
+
+    var htmlEscapeMap = this.HTML_ESCAPE_MAP;
+    return str.replace(/&(quot|amp|apos|lt|gt);/g, function(_, tag) {
+      return htmlEscapeMap[tag];
+    }).replace(/&#(?:x([0-9a-z]{1,4})|([0-9]{1,4}));/gi, function(_, hex, numStr) {
+      var num = parseInt(hex || numStr, hex ? 16 : 10);
+      return String.fromCharCode(num);
+    });
+  },
+
+  /**
+   * Try to extract metadata from JSON-LD object.
+   * For now, only Schema.org objects of type Article or its subtypes are supported.
+   * @return Object with any metadata that could be extracted (possibly none)
+   */
+  _getJSONLD: function (doc) {
+    var scripts = this._getAllNodesWithTag(doc, ["script"]);
+
+    var metadata;
+
+    this._forEachNode(scripts, function(jsonLdElement) {
+      if (!metadata && jsonLdElement.getAttribute("type") === "application/ld+json") {
+        try {
+          // Strip CDATA markers if present
+          var content = jsonLdElement.textContent.replace(/^\s*\s*$/g, "");
+          var parsed = JSON.parse(content);
+          if (
+            !parsed["@context"] ||
+            !parsed["@context"].match(/^https?\:\/\/schema\.org$/)
+          ) {
+            return;
+          }
+
+          if (!parsed["@type"] && Array.isArray(parsed["@graph"])) {
+            parsed = parsed["@graph"].find(function(it) {
+              return (it["@type"] || "").match(
+                this.REGEXPS.jsonLdArticleTypes
+              );
+            });
+          }
+
+          if (
+            !parsed ||
+            !parsed["@type"] ||
+            !parsed["@type"].match(this.REGEXPS.jsonLdArticleTypes)
+          ) {
+            return;
+          }
+
+          metadata = {};
+
+          if (typeof parsed.name === "string" && typeof parsed.headline === "string" && parsed.name !== parsed.headline) {
+            // we have both name and headline element in the JSON-LD. They should both be the same but some websites like aktualne.cz
+            // put their own name into "name" and the article title to "headline" which confuses Readability. So we try to check if either
+            // "name" or "headline" closely matches the html title, and if so, use that one. If not, then we use "name" by default.
+
+            var title = this._getArticleTitle();
+            var nameMatches = this._textSimilarity(parsed.name, title) > 0.75;
+            var headlineMatches = this._textSimilarity(parsed.headline, title) > 0.75;
+
+            if (headlineMatches && !nameMatches) {
+              metadata.title = parsed.headline;
+            } else {
+              metadata.title = parsed.name;
+            }
+          } else if (typeof parsed.name === "string") {
+            metadata.title = parsed.name.trim();
+          } else if (typeof parsed.headline === "string") {
+            metadata.title = parsed.headline.trim();
+          }
+          if (parsed.author) {
+            if (typeof parsed.author.name === "string") {
+              metadata.byline = parsed.author.name.trim();
+            } else if (Array.isArray(parsed.author) && parsed.author[0] && typeof parsed.author[0].name === "string") {
+              metadata.byline = parsed.author
+                .filter(function(author) {
+                  return author && typeof author.name === "string";
+                })
+                .map(function(author) {
+                  return author.name.trim();
+                })
+                .join(", ");
+            }
+          }
+          if (typeof parsed.description === "string") {
+            metadata.excerpt = parsed.description.trim();
+          }
+          if (
+            parsed.publisher &&
+            typeof parsed.publisher.name === "string"
+          ) {
+            metadata.siteName = parsed.publisher.name.trim();
+          }
+          if (typeof parsed.datePublished === "string") {
+            metadata.datePublished = parsed.datePublished.trim();
+          }
+          return;
+        } catch (err) {
+          this.log(err.message);
+        }
+      }
+    });
+    return metadata ? metadata : {};
+  },
+
+  /**
+   * Attempts to get excerpt and byline metadata for the article.
+   *
+   * @param {Object} jsonld — object containing any metadata that
+   * could be extracted from JSON-LD object.
+   *
+   * @return Object with optional "excerpt" and "byline" properties
+   */
+  _getArticleMetadata: function(jsonld) {
+    var metadata = {};
+    var values = {};
+    var metaElements = this._doc.getElementsByTagName("meta");
+
+    // property is a space-separated list of values
+    var propertyPattern = /\s*(article|dc|dcterm|og|twitter)\s*:\s*(author|creator|description|published_time|title|site_name)\s*/gi;
+
+    // name is a single value
+    var namePattern = /^\s*(?:(dc|dcterm|og|twitter|weibo:(article|webpage))\s*[\.:]\s*)?(author|creator|description|title|site_name)\s*$/i;
+
+    // Find description tags.
+    this._forEachNode(metaElements, function(element) {
+      var elementName = element.getAttribute("name");
+      var elementProperty = element.getAttribute("property");
+      var content = element.getAttribute("content");
+      if (!content) {
+        return;
+      }
+      var matches = null;
+      var name = null;
+
+      if (elementProperty) {
+        matches = elementProperty.match(propertyPattern);
+        if (matches) {
+          // Convert to lowercase, and remove any whitespace
+          // so we can match below.
+          name = matches[0].toLowerCase().replace(/\s/g, "");
+          // multiple authors
+          values[name] = content.trim();
+        }
+      }
+      if (!matches && elementName && namePattern.test(elementName)) {
+        name = elementName;
+        if (content) {
+          // Convert to lowercase, remove any whitespace, and convert dots
+          // to colons so we can match below.
+          name = name.toLowerCase().replace(/\s/g, "").replace(/\./g, ":");
+          values[name] = content.trim();
+        }
+      }
+    });
+
+    // get title
+    metadata.title = jsonld.title ||
+                     values["dc:title"] ||
+                     values["dcterm:title"] ||
+                     values["og:title"] ||
+                     values["weibo:article:title"] ||
+                     values["weibo:webpage:title"] ||
+                     values["title"] ||
+                     values["twitter:title"];
+
+    if (!metadata.title) {
+      metadata.title = this._getArticleTitle();
+    }
+
+    // get author
+    metadata.byline = jsonld.byline ||
+                      values["dc:creator"] ||
+                      values["dcterm:creator"] ||
+                      values["author"];
+
+    // get description
+    metadata.excerpt = jsonld.excerpt ||
+                       values["dc:description"] ||
+                       values["dcterm:description"] ||
+                       values["og:description"] ||
+                       values["weibo:article:description"] ||
+                       values["weibo:webpage:description"] ||
+                       values["description"] ||
+                       values["twitter:description"];
+
+    // get site name
+    metadata.siteName = jsonld.siteName ||
+                        values["og:site_name"];
+
+    // get article published time
+    metadata.publishedTime = jsonld.datePublished ||
+      values["article:published_time"] || null;
+
+    // in many sites the meta value is escaped with HTML entities,
+    // so here we need to unescape it
+    metadata.title = this._unescapeHtmlEntities(metadata.title);
+    metadata.byline = this._unescapeHtmlEntities(metadata.byline);
+    metadata.excerpt = this._unescapeHtmlEntities(metadata.excerpt);
+    metadata.siteName = this._unescapeHtmlEntities(metadata.siteName);
+    metadata.publishedTime = this._unescapeHtmlEntities(metadata.publishedTime);
+
+    return metadata;
+  },
+
+  /**
+   * Check if node is image, or if node contains exactly only one image
+   * whether as a direct child or as its descendants.
+   *
+   * @param Element
+  **/
+  _isSingleImage: function(node) {
+    if (node.tagName === "IMG") {
+      return true;
+    }
+
+    if (node.children.length !== 1 || node.textContent.trim() !== "") {
+      return false;
+    }
+
+    return this._isSingleImage(node.children[0]);
+  },
+
+  /**
+   * Find all