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|
/* -*- 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/. */
import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
const lazy = {};
ChromeUtils.defineESModuleGetters(lazy, {
clearTimeout: "resource://gre/modules/Timer.sys.mjs",
setTimeout: "resource://gre/modules/Timer.sys.mjs",
PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.sys.mjs",
});
XPCOMUtils.defineLazyPreferenceGetter(
lazy,
"serviceMode",
"cookiebanners.service.mode",
Ci.nsICookieBannerService.MODE_DISABLED
);
XPCOMUtils.defineLazyPreferenceGetter(
lazy,
"serviceModePBM",
"cookiebanners.service.mode.privateBrowsing",
Ci.nsICookieBannerService.MODE_DISABLED
);
XPCOMUtils.defineLazyPreferenceGetter(
lazy,
"prefDetectOnly",
"cookiebanners.service.detectOnly",
false
);
XPCOMUtils.defineLazyPreferenceGetter(
lazy,
"bannerClickingEnabled",
"cookiebanners.bannerClicking.enabled",
false
);
XPCOMUtils.defineLazyPreferenceGetter(
lazy,
"observeTimeout",
"cookiebanners.bannerClicking.timeout",
3000
);
XPCOMUtils.defineLazyPreferenceGetter(
lazy,
"testing",
"cookiebanners.bannerClicking.testing",
false
);
XPCOMUtils.defineLazyGetter(lazy, "logConsole", () => {
return console.createInstance({
prefix: "CookieBannerChild",
maxLogLevelPref: "cookiebanners.bannerClicking.logLevel",
});
});
export class CookieBannerChild extends JSWindowActorChild {
#clickRules;
#originalBannerDisplay = null;
#observerCleanUp;
#observerCleanUpTimer;
// Indicates whether the page "load" event occurred.
#didLoad = false;
// Used to keep track of click telemetry for the current window.
#telemetryStatus = {
currentStage: null,
success: false,
successStage: null,
failReason: null,
bannerVisibilityFail: false,
};
// For measuring the cookie banner handling duration.
#gleanBannerHandlingTimer = null;
handleEvent(event) {
if (!this.#isEnabled) {
// Automated tests may still expect the test message to be sent.
this.#maybeSendTestMessage();
return;
}
switch (event.type) {
case "DOMContentLoaded":
this.#onDOMContentLoaded();
break;
case "load":
this.#onLoad();
break;
default:
lazy.logConsole.warn(`Unexpected event ${event.type}.`, event);
}
}
get #isPrivateBrowsing() {
return lazy.PrivateBrowsingUtils.isContentWindowPrivate(this.contentWindow);
}
/**
* Whether the feature is enabled based on pref state.
* @type {boolean} true if feature is enabled, false otherwise.
*/
get #isEnabled() {
if (!lazy.bannerClickingEnabled) {
return false;
}
if (this.#isPrivateBrowsing) {
return lazy.serviceModePBM != Ci.nsICookieBannerService.MODE_DISABLED;
}
return lazy.serviceMode != Ci.nsICookieBannerService.MODE_DISABLED;
}
/**
* Whether the feature is enabled in detect-only-mode where cookie banner
* detection events are dispatched, but banners aren't handled.
* @type {boolean} true if feature mode is enabled, false otherwise.
*/
get #isDetectOnly() {
// We can't be in detect-only-mode if fully disabled.
if (!this.#isEnabled) {
return false;
}
return lazy.prefDetectOnly;
}
/**
* @returns {boolean} Whether we handled a banner for the current load by
* injecting cookies.
*/
get #hasInjectedCookieForCookieBannerHandling() {
return this.docShell?.currentDocumentChannel?.loadInfo
?.hasInjectedCookieForCookieBannerHandling;
}
/**
* Checks whether we handled a banner for this site by injecting cookies and
* dispatches events.
* @returns {boolean} Whether we handled the banner and dispatched events.
*/
#dispatchEventsForBannerHandledByInjection() {
if (!this.#hasInjectedCookieForCookieBannerHandling) {
return false;
}
// Strictly speaking we don't actively detect a banner when we handle it by
// cookie injection. We still dispatch "cookiebannerdetected" in this case
// for consistency.
this.sendAsyncMessage("CookieBanner::DetectedBanner");
this.sendAsyncMessage("CookieBanner::HandledBanner");
return true;
}
/**
* Handler for DOMContentLoaded events which is the entry point for cookie
* banner handling.
*/
async #onDOMContentLoaded() {
lazy.logConsole.debug("onDOMContentLoaded", { didLoad: this.#didLoad });
this.#didLoad = false;
this.#telemetryStatus.currentStage = "dom_content_loaded";
let principal = this.document?.nodePrincipal;
// We only apply banner auto-clicking if the document has a content
// principal.
if (!principal?.isContentPrincipal) {
return;
}
// We don't need to do auto-clicking if it's not a http/https page.
if (!principal.schemeIs("http") && !principal.schemeIs("https")) {
return;
}
lazy.logConsole.debug("Send message to get rule", {
baseDomain: principal.baseDomain,
isTopLevel: this.browsingContext == this.browsingContext?.top,
});
let rules;
try {
rules = await this.sendQuery("CookieBanner::GetClickRules", {});
} catch (e) {
lazy.logConsole.warn("Failed to get click rule from parent.", e);
return;
}
lazy.logConsole.debug("Got rules:", rules);
// We can stop here if we don't have a rule.
if (!rules.length) {
// If the cookie injector has handled the banner and there are no click
// rules we still need to dispatch a "cookiebannerhandled" event.
let dispatchedEvents = this.#dispatchEventsForBannerHandledByInjection();
// Record telemetry about handling the banner via cookie injection.
// Note: The success state recorded here may be invalid if the given
// cookie fails to handle the banner. Since we don't have a presence
// detector for this rule we can't determine whether the banner is still
// showing or not.
if (dispatchedEvents) {
this.#telemetryStatus.failReason = null;
this.#telemetryStatus.success = true;
this.#telemetryStatus.successStage = "cookie_injected";
}
this.#maybeSendTestMessage();
return;
}
this.#clickRules = rules;
if (!this.#isDetectOnly) {
// Start a timer to measure how long it takes for the banner to appear and
// be handled.
this.#gleanBannerHandlingTimer =
Glean.cookieBannersClick.handleDuration.start();
}
let { bannerHandled, bannerDetected, matchedRule } =
await this.handleCookieBanner();
let dispatchedEventsForCookieInjection =
this.#dispatchEventsForBannerHandledByInjection();
// A cookie injection followed by not detecting the banner via querySelector
// is a success state. Record that in telemetry.
// Note: The success state reported may be invalid in edge cases where both
// the cookie injection and the banner detection via query selector fails.
if (dispatchedEventsForCookieInjection && !bannerDetected) {
this.#telemetryStatus.success = true;
this.#telemetryStatus.successStage = "cookie_injected";
}
// 1. Detected event.
if (bannerDetected) {
lazy.logConsole.info("Detected cookie banner.", {
url: this.document?.location.href,
});
// Avoid dispatching a duplicate "cookiebannerdetected" event.
if (!dispatchedEventsForCookieInjection) {
this.sendAsyncMessage("CookieBanner::DetectedBanner");
}
}
// 2. Handled event.
if (bannerHandled) {
lazy.logConsole.info("Handled cookie banner.", {
url: this.document?.location.href,
rule: matchedRule,
});
// Stop the timer to record how long it took to handle the banner.
lazy.logConsole.debug(
"Telemetry timer: stop and accumulate",
this.#gleanBannerHandlingTimer
);
Glean.cookieBannersClick.handleDuration.stopAndAccumulate(
this.#gleanBannerHandlingTimer
);
// Avoid dispatching a duplicate "cookiebannerhandled" event.
if (!dispatchedEventsForCookieInjection) {
this.sendAsyncMessage("CookieBanner::HandledBanner");
}
} else if (!this.#isDetectOnly) {
// Cancel the timer we didn't handle the banner.
Glean.cookieBannersClick.handleDuration.cancel(
this.#gleanBannerHandlingTimer
);
}
this.#maybeSendTestMessage();
}
/**
* Handler for "load" events. Used as a signal to stop observing the DOM for
* cookie banners after a timeout.
*/
#onLoad() {
this.#didLoad = true;
// Exit early if we are not handling banners for this site.
if (!this.#clickRules?.length) {
return;
}
lazy.logConsole.debug("Observed 'load' event", {
href: this.document?.location.href,
hasActiveObserver: !!this.#observerCleanUp,
observerCleanupTimer: this.#observerCleanUpTimer,
});
// Update stage for click telemetry.
if (!this.#telemetryStatus.success) {
this.#telemetryStatus.currentStage = "mutation_post_load";
}
this.#startObserverCleanupTimer();
}
/**
* If there is an active mutation observer, start a timeout to unregister it.
*/
#startObserverCleanupTimer() {
// We limit how long we observe cookie banner mutations for performance
// reasons. If not present initially on DOMContentLoaded, cookie banners are
// expected to show up during or shortly after page load.
if (!this.#observerCleanUp || this.#observerCleanUpTimer) {
return;
}
lazy.logConsole.debug("Starting MutationObserver cleanup timeout");
this.#observerCleanUpTimer = lazy.setTimeout(() => {
lazy.logConsole.debug(
`MutationObserver timeout after ${lazy.observeTimeout}ms.`
);
this.#observerCleanUp();
}, lazy.observeTimeout);
}
didDestroy() {
this.#reportTelemetry();
// Clean up the observer and timer if needed.
this.#observerCleanUp?.();
}
#reportTelemetry() {
// Nothing to report, banner handling didn't run.
if (
this.#telemetryStatus.successStage == null &&
this.#telemetryStatus.failReason == null
) {
lazy.logConsole.debug(
"Skip telemetry",
this.#telemetryStatus,
this.#clickRules
);
return;
}
let { success, successStage, currentStage, failReason } =
this.#telemetryStatus;
// Check if we got interrupted during an observe.
if (this.#observerCleanUp && !success) {
failReason = "actor_destroyed";
}
let status, reason;
if (success) {
status = "success";
reason = successStage;
} else {
status = "fail";
reason = failReason;
}
// Increment general success or failure counter.
Glean.cookieBannersClick.result[status].add(1);
// Increment reason counters.
if (reason) {
Glean.cookieBannersClick.result[`${status}_${reason}`].add(1);
} else {
lazy.logConsole.debug(
"Could not determine success / fail reason for telemetry."
);
}
lazy.logConsole.debug("Submitted clickResult telemetry", status, reason, {
success,
successStage,
currentStage,
failReason,
});
}
/**
* The function to perform the core logic of handing the cookie banner. It
* will detect the banner and click the banner button whenever possible
* according to the given click rules.
* If the service mode pref is set to detect only mode we will only attempt to
* find the cookie banner element and return early.
*
* @returns A promise which resolves when it finishes auto clicking.
*/
async handleCookieBanner() {
lazy.logConsole.debug("handleCookieBanner", this.document?.location.href);
// First, we detect if the banner is shown on the page
let rules = await this.#detectBanner();
if (!rules.length) {
// The banner was never shown.
this.#telemetryStatus.success = false;
if (this.#telemetryStatus.bannerVisibilityFail) {
this.#telemetryStatus.failReason = "banner_not_visible";
} else {
this.#telemetryStatus.failReason = "banner_not_found";
}
return { bannerHandled: false, bannerDetected: false };
}
// No rule with valid button to click. This can happen if we're in
// MODE_REJECT and there are only opt-in buttons available.
// This also applies when detect-only mode is enabled. We only want to
// dispatch events matching the current service mode.
if (rules.every(rule => rule.target == null)) {
this.#telemetryStatus.success = false;
this.#telemetryStatus.failReason = "no_rule_for_mode";
return { bannerHandled: false, bannerDetected: false };
}
// If the cookie banner prefs only enable detection but not handling we're done here.
if (this.#isDetectOnly) {
return { bannerHandled: false, bannerDetected: true };
}
// Hide the banner.
let matchedRule = this.#hideBanner(rules);
let successClick = false;
try {
successClick = await this.#clickTarget(rules);
} finally {
if (!successClick) {
// We cannot successfully click the target button. Show the banner on
// the page so that user can interact with the banner.
this.#showBanner(matchedRule);
}
}
if (successClick) {
// For telemetry, Keep track of in which stage we successfully handled the banner.
this.#telemetryStatus.successStage = this.#telemetryStatus.currentStage;
} else {
this.#telemetryStatus.failReason = "button_not_found";
this.#telemetryStatus.successStage = null;
}
this.#telemetryStatus.success = successClick;
return { bannerHandled: successClick, bannerDetected: true, matchedRule };
}
/**
* The helper function to observe the changes on the document with a timeout.
* It will call the check function when it observes mutations on the document
* body. Once the check function returns a truthy value, it will resolve with
* that value. Otherwise, it will resolve with null on timeout.
*
* @param {function} [checkFn] - The check function.
* @returns {Promise} - A promise which resolves with the return value of the
* check function or null if the function times out.
*/
#promiseObserve(checkFn) {
if (this.#observerCleanUp) {
throw new Error(
"The promiseObserve is called before previous one resolves."
);
}
lazy.logConsole.debug("#promiseObserve", { didLoad: this.#didLoad });
return new Promise(resolve => {
let win = this.contentWindow;
let observer = new win.MutationObserver(mutationList => {
lazy.logConsole.debug(
"#promiseObserve: Mutation observed",
mutationList
);
let result = checkFn?.();
if (result) {
cleanup(result, observer);
}
});
observer.observe(win.document.body, {
attributes: true,
subtree: true,
childList: true,
});
let cleanup = (result, observer) => {
lazy.logConsole.debug(
"#promiseObserve cleanup",
result,
observer,
this.#observerCleanUpTimer
);
if (observer) {
observer.disconnect();
observer = null;
}
if (this.#observerCleanUpTimer) {
lazy.clearTimeout(this.#observerCleanUpTimer);
}
this.#observerCleanUp = null;
resolve(result);
};
// The clean up function to clean unfinished observer and timer when the
// actor destroys.
this.#observerCleanUp = () => {
cleanup(null, observer);
};
// If we already observed a load event we can start the cleanup timer
// straight away.
// Otherwise wait for the load event via the #onLoad method.
if (this.#didLoad) {
this.#startObserverCleanupTimer();
}
});
}
// Detecting if the banner is shown on the page.
async #detectBanner() {
if (!this.#clickRules?.length) {
return [];
}
lazy.logConsole.debug("Starting to detect the banner");
// Returns an array of rules for which a cookie banner exists for the
// current site.
let presenceDetector = () => {
lazy.logConsole.debug("presenceDetector start");
let matchingRules = this.#clickRules.filter(rule => {
let { presence, skipPresenceVisibilityCheck } = rule;
let banner = this.document.querySelector(presence);
lazy.logConsole.debug("Testing banner el presence", {
result: banner,
rule,
presence,
});
if (!banner) {
return false;
}
if (skipPresenceVisibilityCheck) {
return true;
}
let isVisible = this.#isVisible(banner);
// Store visibility of banner element to keep track of why detection
// failed.
this.#telemetryStatus.bannerVisibilityFail = !isVisible;
return isVisible;
});
// For no rules matched return null explicitly so #promiseObserve knows we
// want to keep observing.
if (!matchingRules.length) {
return null;
}
return matchingRules;
};
lazy.logConsole.debug("Initial call to presenceDetector");
let rules = presenceDetector();
// If we couldn't detect the banner at the beginning, we register an
// observer with the timeout to observe if the banner was shown within the
// timeout.
if (!rules?.length) {
lazy.logConsole.debug(
"Initial presenceDetector failed, registering MutationObserver",
rules
);
this.#telemetryStatus.currentStage = "mutation_pre_load";
rules = await this.#promiseObserve(presenceDetector, lazy.observeTimeout);
}
if (!rules?.length) {
lazy.logConsole.debug("Couldn't detect the banner", rules);
return [];
}
lazy.logConsole.debug("Detected the banner for rules", rules);
return rules;
}
// Clicking the target button.
async #clickTarget(rules) {
lazy.logConsole.debug("Starting to detect the target button");
let targetEl;
for (let rule of rules) {
targetEl = this.document.querySelector(rule.target);
if (targetEl) {
break;
}
}
// The target button is not available. We register an observer to wait until
// it's ready.
if (!targetEl) {
targetEl = await this.#promiseObserve(() => {
for (let rule of rules) {
let el = this.document.querySelector(rule.target);
lazy.logConsole.debug("Testing button el presence", {
result: el,
rule,
target: rule.target,
});
if (el) {
lazy.logConsole.debug(
"Found button from rule",
rule,
rule.target,
el
);
return el;
}
}
return null;
}, lazy.observeTimeout);
if (!targetEl) {
lazy.logConsole.debug("Cannot find the target button.");
return false;
}
}
lazy.logConsole.debug("Found the target button, click it.", targetEl);
targetEl.click();
return true;
}
// The helper function to check if the given element if visible.
#isVisible(element) {
return element.checkVisibility({
checkOpacity: true,
checkVisibilityCSS: true,
});
}
// The helper function to hide the banner. It will store the original display
// value of the banner, so it can be used to show the banner later if needed.
#hideBanner(rules) {
if (this.#originalBannerDisplay) {
// We've already hidden the banner.
return null;
}
let banner;
let rule;
for (let r of rules) {
banner = this.document.querySelector(r.hide);
if (banner) {
rule = r;
break;
}
}
// Failed to find banner el to hide.
if (!banner) {
lazy.logConsole.debug(
"Failed to find banner element to hide from rules.",
rules
);
return null;
}
lazy.logConsole.debug("Found banner element to hide from rules.", rules);
this.#originalBannerDisplay = banner.style.display;
// Change the display of the banner right before the style flush occurs to
// avoid the unnecessary sync reflow.
banner.ownerGlobal.requestAnimationFrame(() => {
banner.style.display = "none";
});
return rule;
}
// The helper function to show the banner by reverting the display of the
// banner to the original value.
#showBanner({ hide }) {
if (this.#originalBannerDisplay === null) {
// We've never hidden the banner.
return;
}
let banner = this.document.querySelector(hide);
// Banner no longer present or destroyed or content window has been
// destroyed.
if (!banner || Cu.isDeadWrapper(banner) || !banner.ownerGlobal) {
return;
}
let originalDisplay = this.#originalBannerDisplay;
this.#originalBannerDisplay = null;
// Change the display of the banner right before the style flush occurs to
// avoid the unnecessary sync reflow.
banner.ownerGlobal.requestAnimationFrame(() => {
banner.style.display = originalDisplay;
});
}
#maybeSendTestMessage() {
if (lazy.testing) {
let win = this.contentWindow;
// Report the clicking is finished after the style has been flushed.
win.requestAnimationFrame(() => {
win.setTimeout(() => {
this.sendAsyncMessage("CookieBanner::Test-FinishClicking");
}, 0);
});
}
}
}
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