Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 672 insertions, 0 deletions

diff --git a/dom/l10n/DOMLocalization.cpp b/dom/l10n/DOMLocalization.cpp
new file mode 100644
index 0000000000..456b67ab22
--- /dev/null
+++ b/dom/l10n/DOMLocalization.cpp
@@ -0,0 +1,672 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 "js/ForOfIterator.h"  // JS::ForOfIterator
+#include "js/JSON.h"           // JS_ParseJSON
+#include "nsContentUtils.h"
+#include "nsIScriptError.h"
+#include "DOMLocalization.h"
+#include "mozilla/intl/L10nRegistry.h"
+#include "mozilla/intl/LocaleService.h"
+#include "mozilla/dom/AutoEntryScript.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/dom/L10nOverlays.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+using namespace mozilla::intl;
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(DOMLocalization)
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(DOMLocalization, Localization)
+  tmp->DisconnectMutations();
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mMutations)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mRoots)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(DOMLocalization, Localization)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mMutations)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mRoots)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_ADDREF_INHERITED(DOMLocalization, Localization)
+NS_IMPL_RELEASE_INHERITED(DOMLocalization, Localization)
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DOMLocalization)
+NS_INTERFACE_MAP_END_INHERITING(Localization)
+
+DOMLocalization::DOMLocalization(nsIGlobalObject* aGlobal, bool aSync)
+    : Localization(aGlobal, aSync) {
+  mMutations = new L10nMutations(this);
+}
+
+DOMLocalization::DOMLocalization(nsIGlobalObject* aGlobal, bool aIsSync,
+                                 const ffi::LocalizationRc* aRaw)
+    : Localization(aGlobal, aIsSync, aRaw) {
+  mMutations = new L10nMutations(this);
+}
+
+already_AddRefed<DOMLocalization> DOMLocalization::Constructor(
+    const GlobalObject& aGlobal,
+    const Sequence<dom::OwningUTF8StringOrResourceId>& aResourceIds,
+    bool aIsSync, const Optional<NonNull<L10nRegistry>>& aRegistry,
+    const Optional<Sequence<nsCString>>& aLocales, ErrorResult& aRv) {
+  auto ffiResourceIds{L10nRegistry::ResourceIdsToFFI(aResourceIds)};
+  Maybe<nsTArray<nsCString>> locales;
+
+  if (aLocales.WasPassed()) {
+    locales.emplace();
+    locales->SetCapacity(aLocales.Value().Length());
+    for (const auto& locale : aLocales.Value()) {
+      locales->AppendElement(locale);
+    }
+  }
+
+  RefPtr<const ffi::LocalizationRc> raw;
+  bool result;
+
+  if (aRegistry.WasPassed()) {
+    result = ffi::localization_new_with_locales(
+        &ffiResourceIds, aIsSync, aRegistry.Value().Raw(),
+        locales.ptrOr(nullptr), getter_AddRefs(raw));
+  } else {
+    result = ffi::localization_new_with_locales(&ffiResourceIds, aIsSync,
+                                                nullptr, locales.ptrOr(nullptr),
+                                                getter_AddRefs(raw));
+  }
+
+  if (result) {
+    nsCOMPtr<nsIGlobalObject> global =
+        do_QueryInterface(aGlobal.GetAsSupports());
+
+    return do_AddRef(new DOMLocalization(global, aIsSync, raw));
+  }
+  aRv.ThrowInvalidStateError(
+      "Failed to create the Localization. Check the locales arguments.");
+  return nullptr;
+}
+
+JSObject* DOMLocalization::WrapObject(JSContext* aCx,
+                                      JS::Handle<JSObject*> aGivenProto) {
+  return DOMLocalization_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+void DOMLocalization::Destroy() { DisconnectMutations(); }
+
+DOMLocalization::~DOMLocalization() { Destroy(); }
+
+bool DOMLocalization::HasPendingMutations() const {
+  return mMutations && mMutations->HasPendingMutations();
+}
+
+/**
+ * DOMLocalization API
+ */
+
+void DOMLocalization::ConnectRoot(nsINode& aNode) {
+  nsCOMPtr<nsIGlobalObject> global = aNode.GetOwnerGlobal();
+  if (!global) {
+    return;
+  }
+  MOZ_ASSERT(global == mGlobal,
+             "Cannot add a root that overlaps with existing root.");
+
+#ifdef DEBUG
+  for (nsINode* root : mRoots) {
+    MOZ_ASSERT(
+        root != &aNode && !root->Contains(&aNode) && !aNode.Contains(root),
+        "Cannot add a root that overlaps with existing root.");
+  }
+#endif
+
+  mRoots.Insert(&aNode);
+
+  aNode.AddMutationObserverUnlessExists(mMutations);
+}
+
+void DOMLocalization::DisconnectRoot(nsINode& aNode) {
+  if (mRoots.Contains(&aNode)) {
+    aNode.RemoveMutationObserver(mMutations);
+    mRoots.Remove(&aNode);
+  }
+}
+
+void DOMLocalization::PauseObserving() { mMutations->PauseObserving(); }
+
+void DOMLocalization::ResumeObserving() { mMutations->ResumeObserving(); }
+
+void DOMLocalization::SetAttributes(
+    JSContext* aCx, Element& aElement, const nsAString& aId,
+    const Optional<JS::Handle<JSObject*>>& aArgs, ErrorResult& aRv) {
+  if (aArgs.WasPassed() && aArgs.Value()) {
+    nsAutoString data;
+    JS::Rooted<JS::Value> val(aCx, JS::ObjectValue(*aArgs.Value()));
+    if (!nsContentUtils::StringifyJSON(aCx, val, data,
+                                       UndefinedIsNullStringLiteral)) {
+      aRv.NoteJSContextException(aCx);
+      return;
+    }
+    if (!aElement.AttrValueIs(kNameSpaceID_None, nsGkAtoms::datal10nargs, data,
+                              eCaseMatters)) {
+      aElement.SetAttr(kNameSpaceID_None, nsGkAtoms::datal10nargs, data, true);
+    }
+  } else {
+    aElement.UnsetAttr(kNameSpaceID_None, nsGkAtoms::datal10nargs, true);
+  }
+
+  if (!aElement.AttrValueIs(kNameSpaceID_None, nsGkAtoms::datal10nid, aId,
+                            eCaseMatters)) {
+    aElement.SetAttr(kNameSpaceID_None, nsGkAtoms::datal10nid, aId, true);
+  }
+}
+
+void DOMLocalization::GetAttributes(Element& aElement, L10nIdArgs& aResult,
+                                    ErrorResult& aRv) {
+  nsAutoString l10nId;
+  nsAutoString l10nArgs;
+
+  if (aElement.GetAttr(kNameSpaceID_None, nsGkAtoms::datal10nid, l10nId)) {
+    CopyUTF16toUTF8(l10nId, aResult.mId);
+  }
+
+  if (aElement.GetAttr(kNameSpaceID_None, nsGkAtoms::datal10nargs, l10nArgs)) {
+    ConvertStringToL10nArgs(l10nArgs, aResult.mArgs.SetValue(), aRv);
+  }
+}
+
+void DOMLocalization::SetArgs(JSContext* aCx, Element& aElement,
+                              const Optional<JS::Handle<JSObject*>>& aArgs,
+                              ErrorResult& aRv) {
+  if (aArgs.WasPassed() && aArgs.Value()) {
+    nsAutoString data;
+    JS::Rooted<JS::Value> val(aCx, JS::ObjectValue(*aArgs.Value()));
+    if (!nsContentUtils::StringifyJSON(aCx, val, data,
+                                       UndefinedIsNullStringLiteral)) {
+      aRv.NoteJSContextException(aCx);
+      return;
+    }
+    if (!aElement.AttrValueIs(kNameSpaceID_None, nsGkAtoms::datal10nargs, data,
+                              eCaseMatters)) {
+      aElement.SetAttr(kNameSpaceID_None, nsGkAtoms::datal10nargs, data, true);
+    }
+  } else {
+    aElement.UnsetAttr(kNameSpaceID_None, nsGkAtoms::datal10nargs, true);
+  }
+}
+
+already_AddRefed<Promise> DOMLocalization::TranslateFragment(nsINode& aNode,
+                                                             ErrorResult& aRv) {
+  Sequence<OwningNonNull<Element>> elements;
+  GetTranslatables(aNode, elements, aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+  return TranslateElements(elements, aRv);
+}
+
+/**
+ * A Promise Handler used to apply the result of
+ * a call to Localization::FormatMessages onto the list
+ * of translatable elements.
+ */
+class ElementTranslationHandler : public PromiseNativeHandler {
+ public:
+  explicit ElementTranslationHandler(DOMLocalization* aDOMLocalization,
+                                     nsXULPrototypeDocument* aProto)
+      : mDOMLocalization(aDOMLocalization), mProto(aProto){};
+
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_CLASS(ElementTranslationHandler)
+
+  nsTArray<nsCOMPtr<Element>>& Elements() { return mElements; }
+
+  void SetReturnValuePromise(Promise* aReturnValuePromise) {
+    mReturnValuePromise = aReturnValuePromise;
+  }
+
+  virtual void ResolvedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue,
+                                ErrorResult& aRv) override {
+    ErrorResult rv;
+
+    nsTArray<Nullable<L10nMessage>> l10nData;
+    if (aValue.isObject()) {
+      JS::ForOfIterator iter(aCx);
+      if (!iter.init(aValue, JS::ForOfIterator::AllowNonIterable)) {
+        mReturnValuePromise->MaybeRejectWithUndefined();
+        return;
+      }
+      if (!iter.valueIsIterable()) {
+        mReturnValuePromise->MaybeRejectWithUndefined();
+        return;
+      }
+
+      JS::Rooted<JS::Value> temp(aCx);
+      while (true) {
+        bool done;
+        if (!iter.next(&temp, &done)) {
+          mReturnValuePromise->MaybeRejectWithUndefined();
+          return;
+        }
+
+        if (done) {
+          break;
+        }
+
+        Nullable<L10nMessage>* slotPtr =
+            l10nData.AppendElement(mozilla::fallible);
+        if (!slotPtr) {
+          mReturnValuePromise->MaybeRejectWithUndefined();
+          return;
+        }
+
+        if (!temp.isNull()) {
+          if (!slotPtr->SetValue().Init(aCx, temp)) {
+            mReturnValuePromise->MaybeRejectWithUndefined();
+            return;
+          }
+        }
+      }
+    }
+
+    bool allTranslated =
+        mDOMLocalization->ApplyTranslations(mElements, l10nData, mProto, rv);
+    if (NS_WARN_IF(rv.Failed()) || !allTranslated) {
+      mReturnValuePromise->MaybeRejectWithUndefined();
+      return;
+    }
+
+    mReturnValuePromise->MaybeResolveWithUndefined();
+  }
+
+  virtual void RejectedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue,
+                                ErrorResult& aRv) override {
+    mReturnValuePromise->MaybeRejectWithClone(aCx, aValue);
+  }
+
+ private:
+  ~ElementTranslationHandler() = default;
+
+  nsTArray<nsCOMPtr<Element>> mElements;
+  RefPtr<DOMLocalization> mDOMLocalization;
+  RefPtr<Promise> mReturnValuePromise;
+  RefPtr<nsXULPrototypeDocument> mProto;
+};
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ElementTranslationHandler)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(ElementTranslationHandler)
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(ElementTranslationHandler)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(ElementTranslationHandler)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(ElementTranslationHandler)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mElements)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mDOMLocalization)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mReturnValuePromise)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mProto)
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(ElementTranslationHandler)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mElements)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDOMLocalization)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mReturnValuePromise)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mProto)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+already_AddRefed<Promise> DOMLocalization::TranslateElements(
+    const nsTArray<OwningNonNull<Element>>& aElements, ErrorResult& aRv) {
+  return TranslateElements(aElements, nullptr, aRv);
+}
+
+already_AddRefed<Promise> DOMLocalization::TranslateElements(
+    const nsTArray<OwningNonNull<Element>>& aElements,
+    nsXULPrototypeDocument* aProto, ErrorResult& aRv) {
+  Sequence<OwningUTF8StringOrL10nIdArgs> l10nKeys;
+  RefPtr<ElementTranslationHandler> nativeHandler =
+      new ElementTranslationHandler(this, aProto);
+  nsTArray<nsCOMPtr<Element>>& domElements = nativeHandler->Elements();
+  domElements.SetCapacity(aElements.Length());
+
+  if (!mGlobal) {
+    aRv.Throw(NS_ERROR_UNEXPECTED);
+    return nullptr;
+  }
+
+  for (auto& domElement : aElements) {
+    if (!domElement->HasAttr(nsGkAtoms::datal10nid)) {
+      continue;
+    }
+
+    OwningUTF8StringOrL10nIdArgs* key = l10nKeys.AppendElement(fallible);
+    if (!key) {
+      aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+      return nullptr;
+    }
+
+    GetAttributes(*domElement, key->SetAsL10nIdArgs(), aRv);
+    if (NS_WARN_IF(aRv.Failed())) {
+      return nullptr;
+    }
+
+    if (!domElements.AppendElement(domElement, fallible)) {
+      // This can't really happen, we SetCapacity'd above...
+      aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+      return nullptr;
+    }
+  }
+
+  RefPtr<Promise> promise = Promise::Create(mGlobal, aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+
+  if (IsSync()) {
+    nsTArray<Nullable<L10nMessage>> l10nMessages;
+
+    FormatMessagesSync(l10nKeys, l10nMessages, aRv);
+
+    if (NS_WARN_IF(aRv.Failed())) {
+      promise->MaybeRejectWithUndefined();
+      return promise.forget();
+    }
+
+    bool allTranslated =
+        ApplyTranslations(domElements, l10nMessages, aProto, aRv);
+    if (NS_WARN_IF(aRv.Failed()) || !allTranslated) {
+      promise->MaybeRejectWithUndefined();
+      return promise.forget();
+    }
+
+    promise->MaybeResolveWithUndefined();
+    return promise.forget();
+  }
+  RefPtr<Promise> callbackResult = FormatMessages(l10nKeys, aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+  nativeHandler->SetReturnValuePromise(promise);
+  callbackResult->AppendNativeHandler(nativeHandler);
+  return MaybeWrapPromise(promise);
+}
+
+/**
+ * Promise handler used to set localization data on
+ * roots of elements that got successfully translated.
+ */
+class L10nRootTranslationHandler final : public PromiseNativeHandler {
+ public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_CLASS(L10nRootTranslationHandler)
+
+  explicit L10nRootTranslationHandler(Element* aRoot) : mRoot(aRoot) {}
+
+  void ResolvedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue,
+                        ErrorResult& aRv) override {
+    DOMLocalization::SetRootInfo(mRoot);
+  }
+
+  void RejectedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue,
+                        ErrorResult& aRv) override {}
+
+ private:
+  ~L10nRootTranslationHandler() = default;
+
+  RefPtr<Element> mRoot;
+};
+
+NS_IMPL_CYCLE_COLLECTION(L10nRootTranslationHandler, mRoot)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(L10nRootTranslationHandler)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(L10nRootTranslationHandler)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(L10nRootTranslationHandler)
+
+already_AddRefed<Promise> DOMLocalization::TranslateRoots(ErrorResult& aRv) {
+  nsTArray<RefPtr<Promise>> promises;
+
+  for (nsINode* root : mRoots) {
+    RefPtr<Promise> promise = TranslateFragment(*root, aRv);
+    if (MOZ_UNLIKELY(aRv.Failed())) {
+      return nullptr;
+    }
+
+    // If the root is an element, we'll add a native handler
+    // to set root info (language, direction etc.) on it
+    // once the localization finishes.
+    if (root->IsElement()) {
+      RefPtr<L10nRootTranslationHandler> nativeHandler =
+          new L10nRootTranslationHandler(root->AsElement());
+      promise->AppendNativeHandler(nativeHandler);
+    }
+
+    promises.AppendElement(promise);
+  }
+  AutoEntryScript aes(mGlobal, "DOMLocalization TranslateRoots");
+  return Promise::All(aes.cx(), promises, aRv);
+}
+
+/**
+ * Helper methods
+ */
+
+/* static */
+void DOMLocalization::GetTranslatables(
+    nsINode& aNode, Sequence<OwningNonNull<Element>>& aElements,
+    ErrorResult& aRv) {
+  nsIContent* node =
+      aNode.IsContent() ? aNode.AsContent() : aNode.GetFirstChild();
+  for (; node; node = node->GetNextNode(&aNode)) {
+    if (!node->IsElement()) {
+      continue;
+    }
+
+    Element* domElement = node->AsElement();
+
+    if (!domElement->HasAttr(kNameSpaceID_None, nsGkAtoms::datal10nid)) {
+      continue;
+    }
+
+    if (!aElements.AppendElement(*domElement, fallible)) {
+      aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+      return;
+    }
+  }
+}
+
+/* static */
+void DOMLocalization::SetRootInfo(Element* aElement) {
+  nsAutoCString primaryLocale;
+  LocaleService::GetInstance()->GetAppLocaleAsBCP47(primaryLocale);
+  aElement->SetAttr(kNameSpaceID_None, nsGkAtoms::lang,
+                    NS_ConvertUTF8toUTF16(primaryLocale), true);
+
+  nsAutoString dir;
+  if (LocaleService::GetInstance()->IsAppLocaleRTL()) {
+    nsGkAtoms::rtl->ToString(dir);
+  } else {
+    nsGkAtoms::ltr->ToString(dir);
+  }
+
+  uint32_t nameSpace = aElement->GetNameSpaceID();
+  nsAtom* dirAtom =
+      nameSpace == kNameSpaceID_XUL ? nsGkAtoms::localedir : nsGkAtoms::dir;
+
+  aElement->SetAttr(kNameSpaceID_None, dirAtom, dir, true);
+}
+
+bool DOMLocalization::ApplyTranslations(
+    nsTArray<nsCOMPtr<Element>>& aElements,
+    nsTArray<Nullable<L10nMessage>>& aTranslations,
+    nsXULPrototypeDocument* aProto, ErrorResult& aRv) {
+  if (aElements.Length() != aTranslations.Length()) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return false;
+  }
+
+  PauseObserving();
+
+  bool hasMissingTranslation = false;
+
+  nsTArray<L10nOverlaysError> errors;
+  for (size_t i = 0; i < aTranslations.Length(); ++i) {
+    nsCOMPtr elem = aElements[i];
+    if (aTranslations[i].IsNull()) {
+      hasMissingTranslation = true;
+      continue;
+    }
+    // If we have a proto, we expect all elements are connected up.
+    // If they're not, they may have been removed by earlier translations.
+    // We will have added an error in L10nOverlays in this case.
+    // This is an error in fluent use, but shouldn't be crashing. There's
+    // also no point translating the element - skip it:
+    if (aProto && !elem->IsInComposedDoc()) {
+      continue;
+    }
+
+    // It is possible that someone removed the `data-l10n-id` from the element
+    // before the async translation completed. In that case, skip applying
+    // the translation.
+    if (!elem->HasAttr(kNameSpaceID_None, nsGkAtoms::datal10nid)) {
+      continue;
+    }
+    L10nOverlays::TranslateElement(*elem, aTranslations[i].Value(), errors,
+                                   aRv);
+    if (NS_WARN_IF(aRv.Failed())) {
+      hasMissingTranslation = true;
+      continue;
+    }
+    if (aProto) {
+      // We only need to rebuild deep if the translation has a value.
+      // Otherwise we'll only rebuild the attributes.
+      aProto->RebuildL10nPrototype(elem,
+                                   !aTranslations[i].Value().mValue.IsVoid());
+    }
+  }
+
+  ReportL10nOverlaysErrors(errors);
+
+  ResumeObserving();
+
+  return !hasMissingTranslation;
+}
+
+/* Protected */
+
+void DOMLocalization::OnChange() {
+  Localization::OnChange();
+  RefPtr<Promise> promise = TranslateRoots(IgnoreErrors());
+}
+
+void DOMLocalization::DisconnectMutations() {
+  if (mMutations) {
+    mMutations->Disconnect();
+    DisconnectRoots();
+  }
+}
+
+void DOMLocalization::DisconnectRoots() {
+  for (nsINode* node : mRoots) {
+    node->RemoveMutationObserver(mMutations);
+  }
+  mRoots.Clear();
+}
+
+void DOMLocalization::ReportL10nOverlaysErrors(
+    nsTArray<L10nOverlaysError>& aErrors) {
+  nsAutoString msg;
+
+  for (auto& error : aErrors) {
+    if (error.mCode.WasPassed()) {
+      msg = u"[fluent-dom] "_ns;
+      switch (error.mCode.Value()) {
+        case L10nOverlays_Binding::ERROR_FORBIDDEN_TYPE:
+          msg += u"An element of forbidden type \""_ns +
+                 error.mTranslatedElementName.Value() +
+                 nsLiteralString(
+                     u"\" was found in the translation. Only safe text-level "
+                     "elements and elements with data-l10n-name are allowed.");
+          break;
+        case L10nOverlays_Binding::ERROR_NAMED_ELEMENT_MISSING:
+          msg += u"An element named \""_ns + error.mL10nName.Value() +
+                 u"\" wasn't found in the source."_ns;
+          break;
+        case L10nOverlays_Binding::ERROR_NAMED_ELEMENT_TYPE_MISMATCH:
+          msg += u"An element named \""_ns + error.mL10nName.Value() +
+                 nsLiteralString(
+                     u"\" was found in the translation but its type ") +
+                 error.mTranslatedElementName.Value() +
+                 nsLiteralString(
+                     u" didn't match the element found in the source ") +
+                 error.mSourceElementName.Value() + u"."_ns;
+          break;
+        case L10nOverlays_Binding::ERROR_TRANSLATED_ELEMENT_DISCONNECTED:
+          msg += u"The element using message \""_ns + error.mL10nName.Value() +
+                 nsLiteralString(
+                     u"\" was removed from the DOM when translating its \"") +
+                 error.mTranslatedElementName.Value() + u"\" parent."_ns;
+          break;
+        case L10nOverlays_Binding::ERROR_TRANSLATED_ELEMENT_DISALLOWED_DOM:
+          msg += nsLiteralString(
+                     u"While translating an element with fluent ID \"") +
+                 error.mL10nName.Value() + u"\" a child element of type \""_ns +
+                 error.mTranslatedElementName.Value() +
+                 nsLiteralString(
+                     u"\" was removed. Either the fluent message "
+                     "does not contain markup, or it does not contain markup "
+                     "of this type.");
+          break;
+        case L10nOverlays_Binding::ERROR_UNKNOWN:
+        default:
+          msg += nsLiteralString(
+              u"Unknown error happened while translating an element.");
+          break;
+      }
+      nsPIDOMWindowInner* innerWindow = GetParentObject()->AsInnerWindow();
+      Document* doc = innerWindow ? innerWindow->GetExtantDoc() : nullptr;
+      if (doc) {
+        nsContentUtils::ReportToConsoleNonLocalized(
+            msg, nsIScriptError::warningFlag, "DOM"_ns, doc);
+      } else {
+        NS_WARNING("Failed to report l10n DOM Overlay errors to console.");
+      }
+      printf_stderr("%s\n", NS_ConvertUTF16toUTF8(msg).get());
+    }
+  }
+}
+
+void DOMLocalization::ConvertStringToL10nArgs(const nsString& aInput,
+                                              intl::L10nArgs& aRetVal,
+                                              ErrorResult& aRv) {
+  if (aInput.IsEmpty()) {
+    // There are no properties.
+    return;
+  }
+  // This method uses a temporary dictionary to automate
+  // converting a JSON string into an IDL Record via a dictionary.
+  //
+  // Once we get Record::Init(const nsAString& aJSON), we'll switch to
+  // that.
+  L10nArgsHelperDict helperDict;
+  if (!helperDict.Init(u"{\"args\": "_ns + aInput + u"}"_ns)) {
+    nsTArray<nsCString> errors{
+        "[dom/l10n] Failed to parse l10n-args JSON: "_ns +
+            NS_ConvertUTF16toUTF8(aInput),
+    };
+    MaybeReportErrorsToGecko(errors, aRv, GetParentObject());
+    return;
+  }
+  for (auto& entry : helperDict.mArgs.Entries()) {
+    L10nArgs::EntryType* newEntry = aRetVal.Entries().AppendElement(fallible);
+    if (!newEntry) {
+      aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+      return;
+    }
+    newEntry->mKey = entry.mKey;
+    newEntry->mValue = entry.mValue;
+  }
+}