dom/base/CustomElementRegistry.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "mozilla/dom/CustomElementRegistry.h"
   8
   9 #include "mozilla/AsyncEventDispatcher.h"
  10 #include "mozilla/CycleCollectedJSContext.h"
  11 #include "mozilla/dom/AutoEntryScript.h"
  12 #include "mozilla/dom/CustomElementRegistryBinding.h"
  13 #include "mozilla/dom/ElementBinding.h"
  14 #include "mozilla/dom/HTMLElement.h"
  15 #include "mozilla/dom/HTMLElementBinding.h"
  16 #include "mozilla/dom/PrimitiveConversions.h"
  17 #include "mozilla/dom/ShadowIncludingTreeIterator.h"
  18 #include "mozilla/dom/XULElementBinding.h"
  19 #include "mozilla/dom/Promise.h"
  20 #include "mozilla/dom/DocGroup.h"
  21 #include "mozilla/dom/CustomEvent.h"
  22 #include "mozilla/dom/ShadowRoot.h"
  23 #include "mozilla/dom/UnionTypes.h"
  24 #include "mozilla/AutoRestore.h"
  25 #include "mozilla/HoldDropJSObjects.h"
  26 #include "mozilla/UseCounter.h"
  27 #include "nsContentUtils.h"
  28 #include "nsHTMLTags.h"
  29 #include "nsInterfaceHashtable.h"
  30 #include "nsPIDOMWindow.h"
  31 #include "jsapi.h"
  32 #include "js/ForOfIterator.h"       // JS::ForOfIterator
  33 #include "js/PropertyAndElement.h"  // JS_GetProperty, JS_GetUCProperty
  34 #include "xpcprivate.h"
  35 #include "nsNameSpaceManager.h"
  36
  37 namespace mozilla::dom {
  38
  39 //-----------------------------------------------------
  40 // CustomElementUpgradeReaction
  41
  42 class CustomElementUpgradeReaction final : public CustomElementReaction {
  43  public:
  44   explicit CustomElementUpgradeReaction(CustomElementDefinition* aDefinition)
  45       : mDefinition(aDefinition) {
  46     mIsUpgradeReaction = true;
  47   }
  48
  49   virtual void Traverse(
  50       nsCycleCollectionTraversalCallback& aCb) const override {
  51     NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(aCb, "mDefinition");
  52     aCb.NoteNativeChild(
  53         mDefinition, NS_CYCLE_COLLECTION_PARTICIPANT(CustomElementDefinition));
  54   }
  55
  56   size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const override {
  57     // We don't really own mDefinition.
  58     return aMallocSizeOf(this);
  59   }
  60
  61  private:
  62   MOZ_CAN_RUN_SCRIPT
  63   virtual void Invoke(Element* aElement, ErrorResult& aRv) override {
  64     CustomElementRegistry::Upgrade(aElement, mDefinition, aRv);
  65   }
  66
  67   const RefPtr<CustomElementDefinition> mDefinition;
  68 };
  69
  70 //-----------------------------------------------------
  71 // CustomElementCallbackReaction
  72
  73 class CustomElementCallback {
  74  public:
  75   CustomElementCallback(Element* aThisObject, ElementCallbackType aCallbackType,
  76                         CallbackFunction* aCallback,
  77                         const LifecycleCallbackArgs& aArgs);
  78   void Traverse(nsCycleCollectionTraversalCallback& aCb) const;
  79   size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const;
  80   void Call();
  81
  82   static UniquePtr<CustomElementCallback> Create(
  83       ElementCallbackType aType, Element* aCustomElement,
  84       const LifecycleCallbackArgs& aArgs, CustomElementDefinition* aDefinition);
  85
  86  private:
  87   // The this value to use for invocation of the callback.
  88   RefPtr<Element> mThisObject;
  89   RefPtr<CallbackFunction> mCallback;
  90   // The type of callback (eCreated, eAttached, etc.)
  91   ElementCallbackType mType;
  92   // Arguments to be passed to the callback,
  93   LifecycleCallbackArgs mArgs;
  94 };
  95
  96 class CustomElementCallbackReaction final : public CustomElementReaction {
  97  public:
  98   explicit CustomElementCallbackReaction(
  99       UniquePtr<CustomElementCallback> aCustomElementCallback)
 100       : mCustomElementCallback(std::move(aCustomElementCallback)) {}
 101
 102   virtual void Traverse(
 103       nsCycleCollectionTraversalCallback& aCb) const override {
 104     mCustomElementCallback->Traverse(aCb);
 105   }
 106
 107   size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const override {
 108     size_t n = aMallocSizeOf(this);
 109
 110     n += mCustomElementCallback->SizeOfIncludingThis(aMallocSizeOf);
 111
 112     return n;
 113   }
 114
 115  private:
 116   virtual void Invoke(Element* aElement, ErrorResult& aRv) override {
 117     mCustomElementCallback->Call();
 118   }
 119
 120   UniquePtr<CustomElementCallback> mCustomElementCallback;
 121 };
 122
 123 //-----------------------------------------------------
 124 // CustomElementCallback
 125
 126 size_t LifecycleCallbackArgs::SizeOfExcludingThis(
 127     MallocSizeOf aMallocSizeOf) const {
 128   size_t n = mOldValue.SizeOfExcludingThisIfUnshared(aMallocSizeOf);
 129   n += mNewValue.SizeOfExcludingThisIfUnshared(aMallocSizeOf);
 130   n += mNamespaceURI.SizeOfExcludingThisIfUnshared(aMallocSizeOf);
 131   return n;
 132 }
 133
 134 /* static */
 135 UniquePtr<CustomElementCallback> CustomElementCallback::Create(
 136     ElementCallbackType aType, Element* aCustomElement,
 137     const LifecycleCallbackArgs& aArgs, CustomElementDefinition* aDefinition) {
 138   MOZ_ASSERT(aDefinition, "CustomElementDefinition should not be null");
 139   MOZ_ASSERT(aCustomElement->GetCustomElementData(),
 140              "CustomElementData should exist");
 141
 142   // Let CALLBACK be the callback associated with the key NAME in CALLBACKS.
 143   CallbackFunction* func = nullptr;
 144   switch (aType) {
 145     case ElementCallbackType::eConnected:
 146       if (aDefinition->mCallbacks->mConnectedCallback.WasPassed()) {
 147         func = aDefinition->mCallbacks->mConnectedCallback.Value();
 148       }
 149       break;
 150
 151     case ElementCallbackType::eDisconnected:
 152       if (aDefinition->mCallbacks->mDisconnectedCallback.WasPassed()) {
 153         func = aDefinition->mCallbacks->mDisconnectedCallback.Value();
 154       }
 155       break;
 156
 157     case ElementCallbackType::eAdopted:
 158       if (aDefinition->mCallbacks->mAdoptedCallback.WasPassed()) {
 159         func = aDefinition->mCallbacks->mAdoptedCallback.Value();
 160       }
 161       break;
 162
 163     case ElementCallbackType::eAttributeChanged:
 164       if (aDefinition->mCallbacks->mAttributeChangedCallback.WasPassed()) {
 165         func = aDefinition->mCallbacks->mAttributeChangedCallback.Value();
 166       }
 167       break;
 168
 169     case ElementCallbackType::eFormAssociated:
 170       if (aDefinition->mFormAssociatedCallbacks->mFormAssociatedCallback
 171               .WasPassed()) {
 172         func = aDefinition->mFormAssociatedCallbacks->mFormAssociatedCallback
 173                    .Value();
 174       }
 175       break;
 176
 177     case ElementCallbackType::eFormReset:
 178       if (aDefinition->mFormAssociatedCallbacks->mFormResetCallback
 179               .WasPassed()) {
 180         func =
 181             aDefinition->mFormAssociatedCallbacks->mFormResetCallback.Value();
 182       }
 183       break;
 184
 185     case ElementCallbackType::eFormDisabled:
 186       if (aDefinition->mFormAssociatedCallbacks->mFormDisabledCallback
 187               .WasPassed()) {
 188         func = aDefinition->mFormAssociatedCallbacks->mFormDisabledCallback
 189                    .Value();
 190       }
 191       break;
 192
 193     case ElementCallbackType::eFormStateRestore:
 194       if (aDefinition->mFormAssociatedCallbacks->mFormStateRestoreCallback
 195               .WasPassed()) {
 196         func = aDefinition->mFormAssociatedCallbacks->mFormStateRestoreCallback
 197                    .Value();
 198       }
 199       break;
 200
 201     case ElementCallbackType::eGetCustomInterface:
 202       MOZ_ASSERT_UNREACHABLE("Don't call GetCustomInterface through callback");
 203       break;
 204   }
 205
 206   // If there is no such callback, stop.
 207   if (!func) {
 208     return nullptr;
 209   }
 210
 211   // Add CALLBACK to ELEMENT's callback queue.
 212   return MakeUnique<CustomElementCallback>(aCustomElement, aType, func, aArgs);
 213 }
 214
 215 void CustomElementCallback::Call() {
 216   switch (mType) {
 217     case ElementCallbackType::eConnected:
 218       static_cast<LifecycleConnectedCallback*>(mCallback.get())
 219           ->Call(mThisObject);
 220       break;
 221     case ElementCallbackType::eDisconnected:
 222       static_cast<LifecycleDisconnectedCallback*>(mCallback.get())
 223           ->Call(mThisObject);
 224       break;
 225     case ElementCallbackType::eAdopted:
 226       static_cast<LifecycleAdoptedCallback*>(mCallback.get())
 227           ->Call(mThisObject, mArgs.mOldDocument, mArgs.mNewDocument);
 228       break;
 229     case ElementCallbackType::eAttributeChanged:
 230       static_cast<LifecycleAttributeChangedCallback*>(mCallback.get())
 231           ->Call(mThisObject, nsDependentAtomString(mArgs.mName),
 232                  mArgs.mOldValue, mArgs.mNewValue, mArgs.mNamespaceURI);
 233       break;
 234     case ElementCallbackType::eFormAssociated:
 235       static_cast<LifecycleFormAssociatedCallback*>(mCallback.get())
 236           ->Call(mThisObject, mArgs.mForm);
 237       break;
 238     case ElementCallbackType::eFormReset:
 239       static_cast<LifecycleFormResetCallback*>(mCallback.get())
 240           ->Call(mThisObject);
 241       break;
 242     case ElementCallbackType::eFormDisabled:
 243       static_cast<LifecycleFormDisabledCallback*>(mCallback.get())
 244           ->Call(mThisObject, mArgs.mDisabled);
 245       break;
 246     case ElementCallbackType::eFormStateRestore: {
 247       if (mArgs.mState.IsNull()) {
 248         MOZ_ASSERT_UNREACHABLE(
 249             "A null state should never be restored to a form-associated "
 250             "custom element");
 251         return;
 252       }
 253
 254       const OwningFileOrUSVStringOrFormData& owningValue = mArgs.mState.Value();
 255       Nullable<FileOrUSVStringOrFormData> value;
 256       if (owningValue.IsFormData()) {
 257         value.SetValue().SetAsFormData() = owningValue.GetAsFormData();
 258       } else if (owningValue.IsFile()) {
 259         value.SetValue().SetAsFile() = owningValue.GetAsFile();
 260       } else {
 261         value.SetValue().SetAsUSVString().ShareOrDependUpon(
 262             owningValue.GetAsUSVString());
 263       }
 264       static_cast<LifecycleFormStateRestoreCallback*>(mCallback.get())
 265           ->Call(mThisObject, value, mArgs.mReason);
 266     } break;
 267     case ElementCallbackType::eGetCustomInterface:
 268       MOZ_ASSERT_UNREACHABLE("Don't call GetCustomInterface through callback");
 269       break;
 270   }
 271 }
 272
 273 void CustomElementCallback::Traverse(
 274     nsCycleCollectionTraversalCallback& aCb) const {
 275   NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(aCb, "mThisObject");
 276   aCb.NoteXPCOMChild(mThisObject);
 277
 278   NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(aCb, "mCallback");
 279   aCb.NoteXPCOMChild(mCallback);
 280 }
 281
 282 size_t CustomElementCallback::SizeOfIncludingThis(
 283     MallocSizeOf aMallocSizeOf) const {
 284   size_t n = aMallocSizeOf(this);
 285
 286   // We don't uniquely own mThisObject.
 287
 288   // We own mCallback but it doesn't have any special memory reporting we can do
 289   // for it other than report its own size.
 290   n += aMallocSizeOf(mCallback);
 291
 292   n += mArgs.SizeOfExcludingThis(aMallocSizeOf);
 293
 294   return n;
 295 }
 296
 297 CustomElementCallback::CustomElementCallback(
 298     Element* aThisObject, ElementCallbackType aCallbackType,
 299     mozilla::dom::CallbackFunction* aCallback,
 300     const LifecycleCallbackArgs& aArgs)
 301     : mThisObject(aThisObject),
 302       mCallback(aCallback),
 303       mType(aCallbackType),
 304       mArgs(aArgs) {}
 305
 306 //-----------------------------------------------------
 307 // CustomElementData
 308
 309 CustomElementData::CustomElementData(nsAtom* aType)
 310     : CustomElementData(aType, CustomElementData::State::eUndefined) {}
 311
 312 CustomElementData::CustomElementData(nsAtom* aType, State aState)
 313     : mState(aState), mType(aType) {}
 314
 315 void CustomElementData::SetCustomElementDefinition(
 316     CustomElementDefinition* aDefinition) {
 317   // Only allow reset definition to nullptr if the custom element state is
 318   // "failed".
 319   MOZ_ASSERT(aDefinition ? !mCustomElementDefinition
 320                          : mState == State::eFailed);
 321   MOZ_ASSERT_IF(aDefinition, aDefinition->mType == mType);
 322
 323   mCustomElementDefinition = aDefinition;
 324 }
 325
 326 void CustomElementData::AttachedInternals() {
 327   MOZ_ASSERT(!mIsAttachedInternals);
 328
 329   mIsAttachedInternals = true;
 330 }
 331
 332 CustomElementDefinition* CustomElementData::GetCustomElementDefinition() const {
 333   // Per spec, if there is a definition, the custom element state should be
 334   // either "failed" (during upgrade) or "customized".
 335   MOZ_ASSERT_IF(mCustomElementDefinition, mState != State::eUndefined);
 336
 337   return mCustomElementDefinition;
 338 }
 339
 340 bool CustomElementData::IsFormAssociated() const {
 341   // https://html.spec.whatwg.org/#form-associated-custom-element
 342   return mCustomElementDefinition &&
 343          !mCustomElementDefinition->IsCustomBuiltIn() &&
 344          mCustomElementDefinition->mFormAssociated;
 345 }
 346
 347 void CustomElementData::Traverse(
 348     nsCycleCollectionTraversalCallback& aCb) const {
 349   for (uint32_t i = 0; i < mReactionQueue.Length(); i++) {
 350     if (mReactionQueue[i]) {
 351       mReactionQueue[i]->Traverse(aCb);
 352     }
 353   }
 354
 355   if (mCustomElementDefinition) {
 356     NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(aCb, "mCustomElementDefinition");
 357     aCb.NoteNativeChild(
 358         mCustomElementDefinition,
 359         NS_CYCLE_COLLECTION_PARTICIPANT(CustomElementDefinition));
 360   }
 361
 362   if (mElementInternals) {
 363     NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(aCb, "mElementInternals");
 364     aCb.NoteXPCOMChild(ToSupports(mElementInternals.get()));
 365   }
 366 }
 367
 368 void CustomElementData::Unlink() {
 369   mReactionQueue.Clear();
 370   if (mElementInternals) {
 371     mElementInternals->Unlink();
 372     mElementInternals = nullptr;
 373   }
 374   mCustomElementDefinition = nullptr;
 375 }
 376
 377 size_t CustomElementData::SizeOfIncludingThis(
 378     MallocSizeOf aMallocSizeOf) const {
 379   size_t n = aMallocSizeOf(this);
 380
 381   n += mReactionQueue.ShallowSizeOfExcludingThis(aMallocSizeOf);
 382
 383   for (auto& reaction : mReactionQueue) {
 384     // "reaction" can be null if we're being called indirectly from
 385     // InvokeReactions (e.g. due to a reaction causing a memory report to be
 386     // captured somehow).
 387     if (reaction) {
 388       n += reaction->SizeOfIncludingThis(aMallocSizeOf);
 389     }
 390   }
 391
 392   return n;
 393 }
 394
 395 //-----------------------------------------------------
 396 // CustomElementRegistry
 397
 398 namespace {
 399
 400 class MOZ_RAII AutoConstructionStackEntry final {
 401  public:
 402   AutoConstructionStackEntry(nsTArray<RefPtr<Element>>& aStack,
 403                              Element* aElement)
 404       : mStack(aStack) {
 405     MOZ_ASSERT(aElement->IsHTMLElement() || aElement->IsXULElement());
 406
 407 #ifdef DEBUG
 408     mIndex = mStack.Length();
 409 #endif
 410     mStack.AppendElement(aElement);
 411   }
 412
 413   ~AutoConstructionStackEntry() {
 414     MOZ_ASSERT(mIndex == mStack.Length() - 1,
 415                "Removed element should be the last element");
 416     mStack.RemoveLastElement();
 417   }
 418
 419  private:
 420   nsTArray<RefPtr<Element>>& mStack;
 421 #ifdef DEBUG
 422   uint32_t mIndex;
 423 #endif
 424 };
 425
 426 }  // namespace
 427
 428 NS_IMPL_CYCLE_COLLECTION_CLASS(CustomElementRegistry)
 429
 430 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(CustomElementRegistry)
 431   tmp->mConstructors.clear();
 432   NS_IMPL_CYCLE_COLLECTION_UNLINK(mCustomDefinitions)
 433   NS_IMPL_CYCLE_COLLECTION_UNLINK(mWhenDefinedPromiseMap)
 434   NS_IMPL_CYCLE_COLLECTION_UNLINK(mElementCreationCallbacks)
 435   NS_IMPL_CYCLE_COLLECTION_UNLINK(mWindow)
 436   NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
 437 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 438
 439 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(CustomElementRegistry)
 440   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCustomDefinitions)
 441   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mWhenDefinedPromiseMap)
 442   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mElementCreationCallbacks)
 443   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mWindow)
 444 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 445
 446 NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(CustomElementRegistry)
 447   for (auto iter = tmp->mConstructors.iter(); !iter.done(); iter.next()) {
 448     aCallbacks.Trace(&iter.get().mutableKey(), "mConstructors key", aClosure);
 449   }
 450   NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER
 451 NS_IMPL_CYCLE_COLLECTION_TRACE_END
 452
 453 NS_IMPL_CYCLE_COLLECTING_ADDREF(CustomElementRegistry)
 454 NS_IMPL_CYCLE_COLLECTING_RELEASE(CustomElementRegistry)
 455
 456 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(CustomElementRegistry)
 457   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
 458   NS_INTERFACE_MAP_ENTRY(nsISupports)
 459 NS_INTERFACE_MAP_END
 460
 461 CustomElementRegistry::CustomElementRegistry(nsPIDOMWindowInner* aWindow)
 462     : mWindow(aWindow), mIsCustomDefinitionRunning(false) {
 463   MOZ_ASSERT(aWindow);
 464
 465   mozilla::HoldJSObjects(this);
 466 }
 467
 468 CustomElementRegistry::~CustomElementRegistry() {
 469   mozilla::DropJSObjects(this);
 470 }
 471
 472 NS_IMETHODIMP
 473 CustomElementRegistry::RunCustomElementCreationCallback::Run() {
 474   ErrorResult er;
 475   nsDependentAtomString value(mAtom);
 476   mCallback->Call(value, er);
 477   MOZ_ASSERT(NS_SUCCEEDED(er.StealNSResult()),
 478              "chrome JavaScript error in the callback.");
 479
 480   RefPtr<CustomElementDefinition> definition =
 481       mRegistry->mCustomDefinitions.Get(mAtom);
 482   MOZ_ASSERT(definition, "Callback should define the definition of type.");
 483   MOZ_ASSERT(!mRegistry->mElementCreationCallbacks.GetWeak(mAtom),
 484              "Callback should be removed.");
 485
 486   mozilla::UniquePtr<nsTHashSet<RefPtr<nsIWeakReference>>> elements;
 487   mRegistry->mElementCreationCallbacksUpgradeCandidatesMap.Remove(mAtom,
 488                                                                   &elements);
 489   MOZ_ASSERT(elements, "There should be a list");
 490
 491   for (const auto& key : *elements) {
 492     nsCOMPtr<Element> elem = do_QueryReferent(key);
 493     if (!elem) {
 494       continue;
 495     }
 496
 497     CustomElementRegistry::Upgrade(elem, definition, er);
 498     MOZ_ASSERT(NS_SUCCEEDED(er.StealNSResult()),
 499                "chrome JavaScript error in custom element construction.");
 500   }
 501
 502   return NS_OK;
 503 }
 504
 505 CustomElementDefinition* CustomElementRegistry::LookupCustomElementDefinition(
 506     nsAtom* aNameAtom, int32_t aNameSpaceID, nsAtom* aTypeAtom) {
 507   CustomElementDefinition* data = mCustomDefinitions.GetWeak(aTypeAtom);
 508
 509   if (!data) {
 510     RefPtr<CustomElementCreationCallback> callback;
 511     mElementCreationCallbacks.Get(aTypeAtom, getter_AddRefs(callback));
 512     if (callback) {
 513       mElementCreationCallbacks.Remove(aTypeAtom);
 514       mElementCreationCallbacksUpgradeCandidatesMap.GetOrInsertNew(aTypeAtom);
 515       RefPtr<Runnable> runnable =
 516           new RunCustomElementCreationCallback(this, aTypeAtom, callback);
 517       nsContentUtils::AddScriptRunner(runnable.forget());
 518       data = mCustomDefinitions.GetWeak(aTypeAtom);
 519     }
 520   }
 521
 522   if (data && data->mLocalName == aNameAtom &&
 523       data->mNamespaceID == aNameSpaceID) {
 524     return data;
 525   }
 526
 527   return nullptr;
 528 }
 529
 530 CustomElementDefinition* CustomElementRegistry::LookupCustomElementDefinition(
 531     JSContext* aCx, JSObject* aConstructor) const {
 532   // We're looking up things that tested true for JS::IsConstructor,
 533   // so doing a CheckedUnwrapStatic is fine here.
 534   JS::Rooted<JSObject*> constructor(aCx, js::CheckedUnwrapStatic(aConstructor));
 535
 536   const auto& ptr = mConstructors.lookup(constructor);
 537   if (!ptr) {
 538     return nullptr;
 539   }
 540
 541   CustomElementDefinition* definition =
 542       mCustomDefinitions.GetWeak(ptr->value());
 543   MOZ_ASSERT(definition, "Definition must be found in mCustomDefinitions");
 544
 545   return definition;
 546 }
 547
 548 void CustomElementRegistry::RegisterUnresolvedElement(Element* aElement,
 549                                                       nsAtom* aTypeName) {
 550   // We don't have a use-case for a Custom Element inside NAC, and continuing
 551   // here causes performance issues for NAC + XBL anonymous content.
 552   if (aElement->IsInNativeAnonymousSubtree()) {
 553     return;
 554   }
 555
 556   mozilla::dom::NodeInfo* info = aElement->NodeInfo();
 557
 558   // Candidate may be a custom element through extension,
 559   // in which case the custom element type name will not
 560   // match the element tag name. e.g. <button is="x-button">.
 561   RefPtr<nsAtom> typeName = aTypeName;
 562   if (!typeName) {
 563     typeName = info->NameAtom();
 564   }
 565
 566   if (mCustomDefinitions.GetWeak(typeName)) {
 567     return;
 568   }
 569
 570   nsTHashSet<RefPtr<nsIWeakReference>>* unresolved =
 571       mCandidatesMap.GetOrInsertNew(typeName);
 572   nsWeakPtr elem = do_GetWeakReference(aElement);
 573   unresolved->Insert(elem);
 574 }
 575
 576 void CustomElementRegistry::UnregisterUnresolvedElement(Element* aElement,
 577                                                         nsAtom* aTypeName) {
 578   nsIWeakReference* weak = aElement->GetExistingWeakReference();
 579   if (!weak) {
 580     return;
 581   }
 582
 583 #ifdef DEBUG
 584   {
 585     nsWeakPtr weakPtr = do_GetWeakReference(aElement);
 586     MOZ_ASSERT(
 587         weak == weakPtr.get(),
 588         "do_GetWeakReference should reuse the existing nsIWeakReference.");
 589   }
 590 #endif
 591
 592   nsTHashSet<RefPtr<nsIWeakReference>>* candidates = nullptr;
 593   if (mCandidatesMap.Get(aTypeName, &candidates)) {
 594     MOZ_ASSERT(candidates);
 595     candidates->Remove(weak);
 596   }
 597 }
 598
 599 // https://html.spec.whatwg.org/commit-snapshots/65f39c6fc0efa92b0b2b23b93197016af6ac0de6/#enqueue-a-custom-element-callback-reaction
 600 /* static */
 601 void CustomElementRegistry::EnqueueLifecycleCallback(
 602     ElementCallbackType aType, Element* aCustomElement,
 603     const LifecycleCallbackArgs& aArgs, CustomElementDefinition* aDefinition) {
 604   CustomElementDefinition* definition = aDefinition;
 605   if (!definition) {
 606     definition = aCustomElement->GetCustomElementDefinition();
 607     if (!definition ||
 608         definition->mLocalName != aCustomElement->NodeInfo()->NameAtom()) {
 609       return;
 610     }
 611
 612     if (!definition->mCallbacks && !definition->mFormAssociatedCallbacks) {
 613       // definition has been unlinked.  Don't try to mess with it.
 614       return;
 615     }
 616   }
 617
 618   auto callback =
 619       CustomElementCallback::Create(aType, aCustomElement, aArgs, definition);
 620   if (!callback) {
 621     return;
 622   }
 623
 624   DocGroup* docGroup = aCustomElement->OwnerDoc()->GetDocGroup();
 625   if (!docGroup) {
 626     return;
 627   }
 628
 629   if (aType == ElementCallbackType::eAttributeChanged) {
 630     if (!definition->mObservedAttributes.Contains(aArgs.mName)) {
 631       return;
 632     }
 633   }
 634
 635   CustomElementReactionsStack* reactionsStack =
 636       docGroup->CustomElementReactionsStack();
 637   reactionsStack->EnqueueCallbackReaction(aCustomElement, std::move(callback));
 638 }
 639
 640 namespace {
 641
 642 class CandidateFinder {
 643  public:
 644   CandidateFinder(nsTHashSet<RefPtr<nsIWeakReference>>& aCandidates,
 645                   Document* aDoc);
 646   nsTArray<nsCOMPtr<Element>> OrderedCandidates();
 647
 648  private:
 649   nsCOMPtr<Document> mDoc;
 650   nsInterfaceHashtable<nsPtrHashKey<Element>, Element> mCandidates;
 651 };
 652
 653 CandidateFinder::CandidateFinder(
 654     nsTHashSet<RefPtr<nsIWeakReference>>& aCandidates, Document* aDoc)
 655     : mDoc(aDoc), mCandidates(aCandidates.Count()) {
 656   MOZ_ASSERT(mDoc);
 657   for (const auto& candidate : aCandidates) {
 658     nsCOMPtr<Element> elem = do_QueryReferent(candidate);
 659     if (!elem) {
 660       continue;
 661     }
 662
 663     Element* key = elem.get();
 664     mCandidates.InsertOrUpdate(key, elem.forget());
 665   }
 666 }
 667
 668 nsTArray<nsCOMPtr<Element>> CandidateFinder::OrderedCandidates() {
 669   if (mCandidates.Count() == 1) {
 670     // Fast path for one candidate.
 671     auto iter = mCandidates.Iter();
 672     nsTArray<nsCOMPtr<Element>> rval({std::move(iter.Data())});
 673     iter.Remove();
 674     return rval;
 675   }
 676
 677   nsTArray<nsCOMPtr<Element>> orderedElements(mCandidates.Count());
 678   for (nsINode* node : ShadowIncludingTreeIterator(*mDoc)) {
 679     Element* element = Element::FromNode(node);
 680     if (!element) {
 681       continue;
 682     }
 683
 684     nsCOMPtr<Element> elem;
 685     if (mCandidates.Remove(element, getter_AddRefs(elem))) {
 686       orderedElements.AppendElement(std::move(elem));
 687       if (mCandidates.Count() == 0) {
 688         break;
 689       }
 690     }
 691   }
 692
 693   return orderedElements;
 694 }
 695
 696 }  // namespace
 697
 698 void CustomElementRegistry::UpgradeCandidates(
 699     nsAtom* aKey, CustomElementDefinition* aDefinition, ErrorResult& aRv) {
 700   DocGroup* docGroup = mWindow->GetDocGroup();
 701   if (!docGroup) {
 702     aRv.Throw(NS_ERROR_UNEXPECTED);
 703     return;
 704   }
 705
 706   mozilla::UniquePtr<nsTHashSet<RefPtr<nsIWeakReference>>> candidates;
 707   if (mCandidatesMap.Remove(aKey, &candidates)) {
 708     MOZ_ASSERT(candidates);
 709     CustomElementReactionsStack* reactionsStack =
 710         docGroup->CustomElementReactionsStack();
 711
 712     CandidateFinder finder(*candidates, mWindow->GetExtantDoc());
 713     for (auto& elem : finder.OrderedCandidates()) {
 714       reactionsStack->EnqueueUpgradeReaction(elem, aDefinition);
 715     }
 716   }
 717 }
 718
 719 JSObject* CustomElementRegistry::WrapObject(JSContext* aCx,
 720                                             JS::Handle<JSObject*> aGivenProto) {
 721   return CustomElementRegistry_Binding::Wrap(aCx, this, aGivenProto);
 722 }
 723
 724 nsISupports* CustomElementRegistry::GetParentObject() const { return mWindow; }
 725
 726 DocGroup* CustomElementRegistry::GetDocGroup() const {
 727   return mWindow ? mWindow->GetDocGroup() : nullptr;
 728 }
 729
 730 int32_t CustomElementRegistry::InferNamespace(
 731     JSContext* aCx, JS::Handle<JSObject*> constructor) {
 732   JS::Rooted<JSObject*> XULConstructor(
 733       aCx, XULElement_Binding::GetConstructorObject(aCx));
 734
 735   JS::Rooted<JSObject*> proto(aCx, constructor);
 736   while (proto) {
 737     if (proto == XULConstructor) {
 738       return kNameSpaceID_XUL;
 739     }
 740
 741     JS_GetPrototype(aCx, proto, &proto);
 742   }
 743
 744   return kNameSpaceID_XHTML;
 745 }
 746
 747 bool CustomElementRegistry::JSObjectToAtomArray(
 748     JSContext* aCx, JS::Handle<JSObject*> aConstructor, const nsString& aName,
 749     nsTArray<RefPtr<nsAtom>>& aArray, ErrorResult& aRv) {
 750   JS::Rooted<JS::Value> iterable(aCx, JS::UndefinedValue());
 751   if (!JS_GetUCProperty(aCx, aConstructor, aName.get(), aName.Length(),
 752                         &iterable)) {
 753     aRv.NoteJSContextException(aCx);
 754     return false;
 755   }
 756
 757   if (!iterable.isUndefined()) {
 758     if (!iterable.isObject()) {
 759       aRv.ThrowTypeError<MSG_CONVERSION_ERROR>(NS_ConvertUTF16toUTF8(aName),
 760                                                "sequence");
 761       return false;
 762     }
 763
 764     JS::ForOfIterator iter(aCx);
 765     if (!iter.init(iterable, JS::ForOfIterator::AllowNonIterable)) {
 766       aRv.NoteJSContextException(aCx);
 767       return false;
 768     }
 769
 770     if (!iter.valueIsIterable()) {
 771       aRv.ThrowTypeError<MSG_CONVERSION_ERROR>(NS_ConvertUTF16toUTF8(aName),
 772                                                "sequence");
 773       return false;
 774     }
 775
 776     JS::Rooted<JS::Value> attribute(aCx);
 777     while (true) {
 778       bool done;
 779       if (!iter.next(&attribute, &done)) {
 780         aRv.NoteJSContextException(aCx);
 781         return false;
 782       }
 783       if (done) {
 784         break;
 785       }
 786
 787       nsAutoString attrStr;
 788       if (!ConvertJSValueToString(aCx, attribute, eStringify, eStringify,
 789                                   attrStr)) {
 790         aRv.NoteJSContextException(aCx);
 791         return false;
 792       }
 793
 794       // XXX(Bug 1631371) Check if this should use a fallible operation as it
 795       // pretended earlier.
 796       aArray.AppendElement(NS_Atomize(attrStr));
 797     }
 798   }
 799
 800   return true;
 801 }
 802
 803 // https://html.spec.whatwg.org/commit-snapshots/b48bb2238269d90ea4f455a52cdf29505aff3df0/#dom-customelementregistry-define
 804 void CustomElementRegistry::Define(
 805     JSContext* aCx, const nsAString& aName,
 806     CustomElementConstructor& aFunctionConstructor,
 807     const ElementDefinitionOptions& aOptions, ErrorResult& aRv) {
 808   JS::Rooted<JSObject*> constructor(aCx, aFunctionConstructor.CallableOrNull());
 809
 810   // We need to do a dynamic unwrap in order to throw the right exception.  We
 811   // could probably avoid that if we just threw MSG_NOT_CONSTRUCTOR if unwrap
 812   // fails.
 813   //
 814   // In any case, aCx represents the global we want to be using for the unwrap
 815   // here.
 816   JS::Rooted<JSObject*> constructorUnwrapped(
 817       aCx, js::CheckedUnwrapDynamic(constructor, aCx));
 818   if (!constructorUnwrapped) {
 819     // If the caller's compartment does not have permission to access the
 820     // unwrapped constructor then throw.
 821     aRv.Throw(NS_ERROR_DOM_SECURITY_ERR);
 822     return;
 823   }
 824
 825   /**
 826    * 1. If IsConstructor(constructor) is false, then throw a TypeError and abort
 827    *    these steps.
 828    */
 829   if (!JS::IsConstructor(constructorUnwrapped)) {
 830     aRv.ThrowTypeError<MSG_NOT_CONSTRUCTOR>("Argument 2");
 831     return;
 832   }
 833
 834   int32_t nameSpaceID = InferNamespace(aCx, constructor);
 835
 836   /**
 837    * 2. If name is not a valid custom element name, then throw a "SyntaxError"
 838    *    DOMException and abort these steps.
 839    */
 840   Document* doc = mWindow->GetExtantDoc();
 841   RefPtr<nsAtom> nameAtom(NS_Atomize(aName));
 842   if (!nsContentUtils::IsCustomElementName(nameAtom, nameSpaceID)) {
 843     aRv.ThrowSyntaxError(
 844         nsPrintfCString("'%s' is not a valid custom element name",
 845                         NS_ConvertUTF16toUTF8(aName).get()));
 846     return;
 847   }
 848
 849   /**
 850    * 3. If this CustomElementRegistry contains an entry with name name, then
 851    *    throw a "NotSupportedError" DOMException and abort these steps.
 852    */
 853   if (mCustomDefinitions.GetWeak(nameAtom)) {
 854     aRv.ThrowNotSupportedError(
 855         nsPrintfCString("'%s' has already been defined as a custom element",
 856                         NS_ConvertUTF16toUTF8(aName).get()));
 857     return;
 858   }
 859
 860   /**
 861    * 4. If this CustomElementRegistry contains an entry with constructor
 862    * constructor, then throw a "NotSupportedError" DOMException and abort these
 863    * steps.
 864    */
 865   const auto& ptr = mConstructors.lookup(constructorUnwrapped);
 866   if (ptr) {
 867     MOZ_ASSERT(mCustomDefinitions.GetWeak(ptr->value()),
 868                "Definition must be found in mCustomDefinitions");
 869     nsAutoCString name;
 870     ptr->value()->ToUTF8String(name);
 871     aRv.ThrowNotSupportedError(
 872         nsPrintfCString("'%s' and '%s' have the same constructor",
 873                         NS_ConvertUTF16toUTF8(aName).get(), name.get()));
 874     return;
 875   }
 876
 877   /**
 878    * 5. Let localName be name.
 879    * 6. Let extends be the value of the extends member of options, or null if
 880    *    no such member exists.
 881    * 7. If extends is not null, then:
 882    *    1. If extends is a valid custom element name, then throw a
 883    *       "NotSupportedError" DOMException.
 884    *    2. If the element interface for extends and the HTML namespace is
 885    *       HTMLUnknownElement (e.g., if extends does not indicate an element
 886    *       definition in this specification), then throw a "NotSupportedError"
 887    *       DOMException.
 888    *    3. Set localName to extends.
 889    *
 890    * Special note for XUL elements:
 891    *
 892    * For step 7.1, we'll subject XUL to the same rules as HTML, so that a
 893    * custom built-in element will not be extending from a dashed name.
 894    * Step 7.2 is disregarded. But, we do check if the name is a dashed name
 895    * (i.e. step 2) given that there is no reason for a custom built-in element
 896    * type to take on a non-dashed name.
 897    * This also ensures the name of the built-in custom element type can never
 898    * be the same as the built-in element name, so we don't break the assumption
 899    * elsewhere.
 900    */
 901   nsAutoString localName(aName);
 902   if (aOptions.mExtends.WasPassed()) {
 903     doc->SetUseCounter(eUseCounter_custom_CustomizedBuiltin);
 904
 905     RefPtr<nsAtom> extendsAtom(NS_Atomize(aOptions.mExtends.Value()));
 906     if (nsContentUtils::IsCustomElementName(extendsAtom, kNameSpaceID_XHTML)) {
 907       aRv.ThrowNotSupportedError(
 908           nsPrintfCString("'%s' cannot extend a custom element",
 909                           NS_ConvertUTF16toUTF8(aName).get()));
 910       return;
 911     }
 912
 913     if (nameSpaceID == kNameSpaceID_XHTML) {
 914       // bgsound and multicol are unknown html element.
 915       int32_t tag = nsHTMLTags::CaseSensitiveAtomTagToId(extendsAtom);
 916       if (tag == eHTMLTag_userdefined || tag == eHTMLTag_bgsound ||
 917           tag == eHTMLTag_multicol) {
 918         aRv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
 919         return;
 920       }
 921     } else {  // kNameSpaceID_XUL
 922       // As stated above, ensure the name of the customized built-in element
 923       // (the one that goes to the |is| attribute) is a dashed name.
 924       if (!nsContentUtils::IsNameWithDash(nameAtom)) {
 925         aRv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
 926         return;
 927       }
 928     }
 929
 930     localName.Assign(aOptions.mExtends.Value());
 931   }
 932
 933   /**
 934    * 8. If this CustomElementRegistry's element definition is running flag is
 935    * set, then throw a "NotSupportedError" DOMException and abort these steps.
 936    */
 937   if (mIsCustomDefinitionRunning) {
 938     aRv.ThrowNotSupportedError(
 939         "Cannot define a custom element while defining another custom element");
 940     return;
 941   }
 942
 943   auto callbacksHolder = MakeUnique<LifecycleCallbacks>();
 944   auto formAssociatedCallbacksHolder =
 945       MakeUnique<FormAssociatedLifecycleCallbacks>();
 946   nsTArray<RefPtr<nsAtom>> observedAttributes;
 947   AutoTArray<RefPtr<nsAtom>, 2> disabledFeatures;
 948   bool formAssociated = false;
 949   bool disableInternals = false;
 950   bool disableShadow = false;
 951   {  // Set mIsCustomDefinitionRunning.
 952     /**
 953      * 9. Set this CustomElementRegistry's element definition is running flag.
 954      */
 955     AutoRestore<bool> restoreRunning(mIsCustomDefinitionRunning);
 956     mIsCustomDefinitionRunning = true;
 957
 958     /**
 959      * 14.1. Let prototype be Get(constructor, "prototype"). Rethrow any
 960      * exceptions.
 961      */
 962     // The .prototype on the constructor passed could be an "expando" of a
 963     // wrapper. So we should get it from wrapper instead of the underlying
 964     // object.
 965     JS::Rooted<JS::Value> prototype(aCx);
 966     if (!JS_GetProperty(aCx, constructor, "prototype", &prototype)) {
 967       aRv.NoteJSContextException(aCx);
 968       return;
 969     }
 970
 971     /**
 972      * 14.2. If Type(prototype) is not Object, then throw a TypeError exception.
 973      */
 974     if (!prototype.isObject()) {
 975       aRv.ThrowTypeError<MSG_NOT_OBJECT>("constructor.prototype");
 976       return;
 977     }
 978
 979     /**
 980      * 14.3. Let lifecycleCallbacks be a map with the four keys
 981      *       "connectedCallback", "disconnectedCallback", "adoptedCallback", and
 982      *       "attributeChangedCallback", each of which belongs to an entry whose
 983      *       value is null. The 'getCustomInterface' callback is also included
 984      *       for chrome usage.
 985      * 14.4. For each of the four keys callbackName in lifecycleCallbacks:
 986      *       1. Let callbackValue be Get(prototype, callbackName). Rethrow any
 987      *          exceptions.
 988      *       2. If callbackValue is not undefined, then set the value of the
 989      *          entry in lifecycleCallbacks with key callbackName to the result
 990      *          of converting callbackValue to the Web IDL Function callback
 991      * type. Rethrow any exceptions from the conversion.
 992      */
 993     if (!callbacksHolder->Init(aCx, prototype)) {
 994       aRv.NoteJSContextException(aCx);
 995       return;
 996     }
 997
 998     /**
 999      * 14.5. If the value of the entry in lifecycleCallbacks with key
1000      *       "attributeChangedCallback" is not null, then:
1001      *       1. Let observedAttributesIterable be Get(constructor,
1002      *          "observedAttributes"). Rethrow any exceptions.
1003      *       2. If observedAttributesIterable is not undefined, then set
1004      *          observedAttributes to the result of converting
1005      *          observedAttributesIterable to a sequence<DOMString>. Rethrow
1006      *          any exceptions from the conversion.
1007      */
1008     if (callbacksHolder->mAttributeChangedCallback.WasPassed()) {
1009       if (!JSObjectToAtomArray(aCx, constructor, u"observedAttributes"_ns,
1010                                observedAttributes, aRv)) {
1011         return;
1012       }
1013     }
1014
1015     /**
1016      * 14.6. Let disabledFeatures be an empty sequence<DOMString>.
1017      * 14.7. Let disabledFeaturesIterable be Get(constructor,
1018      *       "disabledFeatures"). Rethrow any exceptions.
1019      * 14.8. If disabledFeaturesIterable is not undefined, then set
1020      *       disabledFeatures to the result of converting
1021      *       disabledFeaturesIterable to a sequence<DOMString>.
1022      *       Rethrow any exceptions from the conversion.
1023      */
1024     if (!JSObjectToAtomArray(aCx, constructor, u"disabledFeatures"_ns,
1025                              disabledFeatures, aRv)) {
1026       return;
1027     }
1028
1029     // 14.9. Set disableInternals to true if disabledFeaturesSequence contains
1030     //       "internals".
1031     disableInternals = disabledFeatures.Contains(
1032         static_cast<nsStaticAtom*>(nsGkAtoms::internals));
1033
1034     // 14.10. Set disableShadow to true if disabledFeaturesSequence contains
1035     //        "shadow".
1036     disableShadow = disabledFeatures.Contains(
1037         static_cast<nsStaticAtom*>(nsGkAtoms::shadow));
1038
1039     // 14.11. Let formAssociatedValue be Get(constructor, "formAssociated").
1040     //        Rethrow any exceptions.
1041     JS::Rooted<JS::Value> formAssociatedValue(aCx);
1042     if (!JS_GetProperty(aCx, constructor, "formAssociated",
1043                         &formAssociatedValue)) {
1044       aRv.NoteJSContextException(aCx);
1045       return;
1046     }
1047
1048     // 14.12. Set formAssociated to the result of converting
1049     //        formAssociatedValue to a boolean. Rethrow any exceptions from
1050     //        the conversion.
1051     if (!ValueToPrimitive<bool, eDefault>(aCx, formAssociatedValue,
1052                                           "formAssociated", &formAssociated)) {
1053       aRv.NoteJSContextException(aCx);
1054       return;
1055     }
1056
1057     /**
1058      * 14.13. If formAssociated is true, for each of "formAssociatedCallback",
1059      *        "formResetCallback", "formDisabledCallback", and
1060      *        "formStateRestoreCallback" callbackName:
1061      *        1. Let callbackValue be ? Get(prototype, callbackName).
1062      *        2. If callbackValue is not undefined, then set the value of the
1063      *           entry in lifecycleCallbacks with key callbackName to the result
1064      *           of converting callbackValue to the Web IDL Function callback
1065      *           type. Rethrow any exceptions from the conversion.
1066      */
1067     if (formAssociated &&
1068         !formAssociatedCallbacksHolder->Init(aCx, prototype)) {
1069       aRv.NoteJSContextException(aCx);
1070       return;
1071     }
1072   }  // Unset mIsCustomDefinitionRunning
1073
1074   /**
1075    * 15. Let definition be a new custom element definition with name name,
1076    *     local name localName, constructor constructor, prototype prototype,
1077    *     observed attributes observedAttributes, and lifecycle callbacks
1078    *     lifecycleCallbacks.
1079    */
1080   // Associate the definition with the custom element.
1081   RefPtr<nsAtom> localNameAtom(NS_Atomize(localName));
1082
1083   /**
1084    * 16. Add definition to this CustomElementRegistry.
1085    */
1086   if (!mConstructors.put(constructorUnwrapped, nameAtom)) {
1087     aRv.Throw(NS_ERROR_FAILURE);
1088     return;
1089   }
1090
1091   RefPtr<CustomElementDefinition> definition = new CustomElementDefinition(
1092       nameAtom, localNameAtom, nameSpaceID, &aFunctionConstructor,
1093       std::move(observedAttributes), std::move(callbacksHolder),
1094       std::move(formAssociatedCallbacksHolder), formAssociated,
1095       disableInternals, disableShadow);
1096
1097   CustomElementDefinition* def = definition.get();
1098   mCustomDefinitions.InsertOrUpdate(nameAtom, std::move(definition));
1099
1100   MOZ_ASSERT(mCustomDefinitions.Count() == mConstructors.count(),
1101              "Number of entries should be the same");
1102
1103   /**
1104    * 17. 18. 19. Upgrade candidates
1105    */
1106   UpgradeCandidates(nameAtom, def, aRv);
1107
1108   /**
1109    * 20. If this CustomElementRegistry's when-defined promise map contains an
1110    *     entry with key name:
1111    *     1. Let promise be the value of that entry.
1112    *     2. Resolve promise with undefined.
1113    *     3. Delete the entry with key name from this CustomElementRegistry's
1114    *        when-defined promise map.
1115    */
1116   RefPtr<Promise> promise;
1117   mWhenDefinedPromiseMap.Remove(nameAtom, getter_AddRefs(promise));
1118   if (promise) {
1119     promise->MaybeResolve(def->mConstructor);
1120   }
1121
1122   // Dispatch a "customelementdefined" event for DevTools.
1123   {
1124     JSString* nameJsStr =
1125         JS_NewUCStringCopyN(aCx, aName.BeginReading(), aName.Length());
1126
1127     JS::Rooted<JS::Value> detail(aCx, JS::StringValue(nameJsStr));
1128     RefPtr<CustomEvent> event = NS_NewDOMCustomEvent(doc, nullptr, nullptr);
1129     event->InitCustomEvent(aCx, u"customelementdefined"_ns,
1130                            /* CanBubble */ true,
1131                            /* Cancelable */ true, detail);
1132     event->SetTrusted(true);
1133
1134     AsyncEventDispatcher* dispatcher =
1135         new AsyncEventDispatcher(doc, event.forget());
1136     dispatcher->mOnlyChromeDispatch = ChromeOnlyDispatch::eYes;
1137
1138     dispatcher->PostDOMEvent();
1139   }
1140
1141   /**
1142    * Clean-up mElementCreationCallbacks (if it exists)
1143    */
1144   mElementCreationCallbacks.Remove(nameAtom);
1145 }
1146
1147 void CustomElementRegistry::SetElementCreationCallback(
1148     const nsAString& aName, CustomElementCreationCallback& aCallback,
1149     ErrorResult& aRv) {
1150   RefPtr<nsAtom> nameAtom(NS_Atomize(aName));
1151   if (mElementCreationCallbacks.GetWeak(nameAtom) ||
1152       mCustomDefinitions.GetWeak(nameAtom)) {
1153     aRv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
1154     return;
1155   }
1156
1157   RefPtr<CustomElementCreationCallback> callback = &aCallback;
1158   mElementCreationCallbacks.InsertOrUpdate(nameAtom, std::move(callback));
1159 }
1160
1161 void CustomElementRegistry::Upgrade(nsINode& aRoot) {
1162   for (nsINode* node : ShadowIncludingTreeIterator(aRoot)) {
1163     Element* element = Element::FromNode(node);
1164     if (!element) {
1165       continue;
1166     }
1167
1168     CustomElementData* ceData = element->GetCustomElementData();
1169     if (ceData) {
1170       NodeInfo* nodeInfo = element->NodeInfo();
1171       nsAtom* typeAtom = ceData->GetCustomElementType();
1172       CustomElementDefinition* definition =
1173           nsContentUtils::LookupCustomElementDefinition(
1174               nodeInfo->GetDocument(), nodeInfo->NameAtom(),
1175               nodeInfo->NamespaceID(), typeAtom);
1176       if (definition) {
1177         nsContentUtils::EnqueueUpgradeReaction(element, definition);
1178       }
1179     }
1180   }
1181 }
1182
1183 void CustomElementRegistry::Get(
1184     const nsAString& aName,
1185     OwningCustomElementConstructorOrUndefined& aRetVal) {
1186   RefPtr<nsAtom> nameAtom(NS_Atomize(aName));
1187   CustomElementDefinition* data = mCustomDefinitions.GetWeak(nameAtom);
1188
1189   if (!data) {
1190     aRetVal.SetUndefined();
1191     return;
1192   }
1193
1194   aRetVal.SetAsCustomElementConstructor() = data->mConstructor;
1195 }
1196
1197 void CustomElementRegistry::GetName(JSContext* aCx,
1198                                     CustomElementConstructor& aConstructor,
1199                                     nsAString& aResult) {
1200   CustomElementDefinition* aDefinition =
1201       LookupCustomElementDefinition(aCx, aConstructor.CallableOrNull());
1202
1203   if (aDefinition) {
1204     aDefinition->mType->ToString(aResult);
1205   } else {
1206     aResult.SetIsVoid(true);
1207   }
1208 }
1209
1210 already_AddRefed<Promise> CustomElementRegistry::WhenDefined(
1211     const nsAString& aName, ErrorResult& aRv) {
1212   // Define a function that lazily creates a Promise and perform some action on
1213   // it when creation succeeded. It's needed in multiple cases below, but not in
1214   // all of them.
1215   auto createPromise = [&](auto&& action) -> already_AddRefed<Promise> {
1216     nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(mWindow);
1217     RefPtr<Promise> promise = Promise::Create(global, aRv);
1218
1219     if (aRv.Failed()) {
1220       return nullptr;
1221     }
1222
1223     action(promise);
1224
1225     return promise.forget();
1226   };
1227
1228   RefPtr<nsAtom> nameAtom(NS_Atomize(aName));
1229   Document* doc = mWindow->GetExtantDoc();
1230   uint32_t nameSpaceID =
1231       doc ? doc->GetDefaultNamespaceID() : kNameSpaceID_XHTML;
1232   if (!nsContentUtils::IsCustomElementName(nameAtom, nameSpaceID)) {
1233     return createPromise([](const RefPtr<Promise>& promise) {
1234       promise->MaybeReject(NS_ERROR_DOM_SYNTAX_ERR);
1235     });
1236   }
1237
1238   if (CustomElementDefinition* definition =
1239           mCustomDefinitions.GetWeak(nameAtom)) {
1240     return createPromise([&](const RefPtr<Promise>& promise) {
1241       promise->MaybeResolve(definition->mConstructor);
1242     });
1243   }
1244
1245   return mWhenDefinedPromiseMap.WithEntryHandle(
1246       nameAtom, [&](auto&& entry) -> already_AddRefed<Promise> {
1247         if (!entry) {
1248           return createPromise([&entry](const RefPtr<Promise>& promise) {
1249             entry.Insert(promise);
1250           });
1251         }
1252         return do_AddRef(entry.Data());
1253       });
1254 }
1255
1256 namespace {
1257
1258 MOZ_CAN_RUN_SCRIPT
1259 static void DoUpgrade(Element* aElement, CustomElementDefinition* aDefinition,
1260                       CustomElementConstructor* aConstructor,
1261                       ErrorResult& aRv) {
1262   if (aDefinition->mDisableShadow && aElement->GetShadowRoot()) {
1263     aRv.ThrowNotSupportedError(nsPrintfCString(
1264         "Custom element upgrade to '%s' is disabled because a shadow root "
1265         "already exists",
1266         NS_ConvertUTF16toUTF8(aDefinition->mType->GetUTF16String()).get()));
1267     return;
1268   }
1269
1270   CustomElementData* data = aElement->GetCustomElementData();
1271   MOZ_ASSERT(data, "CustomElementData should exist");
1272   data->mState = CustomElementData::State::ePrecustomized;
1273
1274   JS::Rooted<JS::Value> constructResult(RootingCx());
1275   // Rethrow the exception since it might actually throw the exception from the
1276   // upgrade steps back out to the caller of document.createElement.
1277   aConstructor->Construct(&constructResult, aRv, "Custom Element Upgrade",
1278                           CallbackFunction::eRethrowExceptions);
1279   if (aRv.Failed()) {
1280     return;
1281   }
1282
1283   Element* element;
1284   // constructResult is an ObjectValue because construction with a callback
1285   // always forms the return value from a JSObject.
1286   if (NS_FAILED(UNWRAP_OBJECT(Element, &constructResult, element)) ||
1287       element != aElement) {
1288     aRv.ThrowTypeError("Custom element constructor returned a wrong element");
1289     return;
1290   }
1291 }
1292
1293 }  // anonymous namespace
1294
1295 // https://html.spec.whatwg.org/commit-snapshots/2793ee4a461c6c39896395f1a45c269ea820c47e/#upgrades
1296 /* static */
1297 void CustomElementRegistry::Upgrade(Element* aElement,
1298                                     CustomElementDefinition* aDefinition,
1299                                     ErrorResult& aRv) {
1300   CustomElementData* data = aElement->GetCustomElementData();
1301   MOZ_ASSERT(data, "CustomElementData should exist");
1302
1303   // Step 1.
1304   if (data->mState != CustomElementData::State::eUndefined) {
1305     return;
1306   }
1307
1308   // Step 2.
1309   aElement->SetCustomElementDefinition(aDefinition);
1310
1311   // Step 3.
1312   data->mState = CustomElementData::State::eFailed;
1313
1314   // Step 4.
1315   if (!aDefinition->mObservedAttributes.IsEmpty()) {
1316     uint32_t count = aElement->GetAttrCount();
1317     for (uint32_t i = 0; i < count; i++) {
1318       mozilla::dom::BorrowedAttrInfo info = aElement->GetAttrInfoAt(i);
1319
1320       const nsAttrName* name = info.mName;
1321       nsAtom* attrName = name->LocalName();
1322
1323       if (aDefinition->IsInObservedAttributeList(attrName)) {
1324         int32_t namespaceID = name->NamespaceID();
1325         nsAutoString attrValue, namespaceURI;
1326         info.mValue->ToString(attrValue);
1327         nsNameSpaceManager::GetInstance()->GetNameSpaceURI(namespaceID,
1328                                                            namespaceURI);
1329
1330         LifecycleCallbackArgs args;
1331         args.mName = attrName;
1332         args.mOldValue = VoidString();
1333         args.mNewValue = attrValue;
1334         args.mNamespaceURI =
1335             (namespaceURI.IsEmpty() ? VoidString() : namespaceURI);
1336
1337         nsContentUtils::EnqueueLifecycleCallback(
1338             ElementCallbackType::eAttributeChanged, aElement, args,
1339             aDefinition);
1340       }
1341     }
1342   }
1343
1344   // Step 5.
1345   if (aElement->IsInComposedDoc()) {
1346     nsContentUtils::EnqueueLifecycleCallback(ElementCallbackType::eConnected,
1347                                              aElement, {}, aDefinition);
1348   }
1349
1350   // Step 6.
1351   AutoConstructionStackEntry acs(aDefinition->mConstructionStack, aElement);
1352
1353   // Step 7 and step 8.
1354   DoUpgrade(aElement, aDefinition, MOZ_KnownLive(aDefinition->mConstructor),
1355             aRv);
1356   if (aRv.Failed()) {
1357     MOZ_ASSERT(data->mState == CustomElementData::State::eFailed ||
1358                data->mState == CustomElementData::State::ePrecustomized);
1359     // Spec doesn't set custom element state to failed here, but without this we
1360     // would have inconsistent state on a custom elemet that is failed to
1361     // upgrade, see https://github.com/whatwg/html/issues/6929, and
1362     // https://github.com/web-platform-tests/wpt/pull/29911 for the test.
1363     data->mState = CustomElementData::State::eFailed;
1364     aElement->SetCustomElementDefinition(nullptr);
1365     // Empty element's custom element reaction queue.
1366     data->mReactionQueue.Clear();
1367     return;
1368   }
1369
1370   // Step 9.
1371   if (data->IsFormAssociated()) {
1372     ElementInternals* internals = data->GetElementInternals();
1373     MOZ_ASSERT(internals);
1374     MOZ_ASSERT(aElement->IsHTMLElement());
1375     MOZ_ASSERT(!aDefinition->IsCustomBuiltIn());
1376
1377     internals->UpdateFormOwner();
1378   }
1379
1380   // Step 10.
1381   data->mState = CustomElementData::State::eCustom;
1382   aElement->SetDefined(true);
1383 }
1384
1385 already_AddRefed<nsISupports> CustomElementRegistry::CallGetCustomInterface(
1386     Element* aElement, const nsIID& aIID) {
1387   MOZ_ASSERT(aElement);
1388
1389   if (!nsContentUtils::IsChromeDoc(aElement->OwnerDoc())) {
1390     return nullptr;
1391   }
1392
1393   // Try to get our GetCustomInterfaceCallback callback.
1394   CustomElementDefinition* definition = aElement->GetCustomElementDefinition();
1395   if (!definition || !definition->mCallbacks ||
1396       !definition->mCallbacks->mGetCustomInterfaceCallback.WasPassed() ||
1397       (definition->mLocalName != aElement->NodeInfo()->NameAtom())) {
1398     return nullptr;
1399   }
1400   LifecycleGetCustomInterfaceCallback* func =
1401       definition->mCallbacks->mGetCustomInterfaceCallback.Value();
1402
1403   // Initialize a AutoJSAPI to enter the compartment of the callback.
1404   AutoJSAPI jsapi;
1405   JS::Rooted<JSObject*> funcGlobal(RootingCx(), func->CallbackGlobalOrNull());
1406   if (!funcGlobal || !jsapi.Init(funcGlobal)) {
1407     return nullptr;
1408   }
1409
1410   // Grab our JSContext.
1411   JSContext* cx = jsapi.cx();
1412
1413   // Convert our IID to a JSValue to call our callback.
1414   JS::Rooted<JS::Value> jsiid(cx);
1415   if (!xpc::ID2JSValue(cx, aIID, &jsiid)) {
1416     return nullptr;
1417   }
1418
1419   JS::Rooted<JSObject*> customInterface(cx);
1420   func->Call(aElement, jsiid, &customInterface);
1421   if (!customInterface) {
1422     return nullptr;
1423   }
1424
1425   // Wrap our JSObject into a nsISupports through XPConnect
1426   nsCOMPtr<nsISupports> wrapper;
1427   nsresult rv = nsContentUtils::XPConnect()->WrapJSAggregatedToNative(
1428       aElement, cx, customInterface, aIID, getter_AddRefs(wrapper));
1429   if (NS_WARN_IF(NS_FAILED(rv))) {
1430     return nullptr;
1431   }
1432
1433   return wrapper.forget();
1434 }
1435
1436 void CustomElementRegistry::TraceDefinitions(JSTracer* aTrc) {
1437   for (const RefPtr<CustomElementDefinition>& definition :
1438        mCustomDefinitions.Values()) {
1439     if (definition && definition->mConstructor) {
1440       mozilla::TraceScriptHolder(definition->mConstructor, aTrc);
1441     }
1442   }
1443 }
1444
1445 //-----------------------------------------------------
1446 // CustomElementReactionsStack
1447
1448 void CustomElementReactionsStack::CreateAndPushElementQueue() {
1449   MOZ_ASSERT(mRecursionDepth);
1450   MOZ_ASSERT(!mIsElementQueuePushedForCurrentRecursionDepth);
1451
1452   // Push a new element queue onto the custom element reactions stack.
1453   mReactionsStack.AppendElement(MakeUnique<ElementQueue>());
1454   mIsElementQueuePushedForCurrentRecursionDepth = true;
1455 }
1456
1457 void CustomElementReactionsStack::PopAndInvokeElementQueue() {
1458   MOZ_ASSERT(mRecursionDepth);
1459   MOZ_ASSERT(mIsElementQueuePushedForCurrentRecursionDepth);
1460   MOZ_ASSERT(!mReactionsStack.IsEmpty(), "Reaction stack shouldn't be empty");
1461
1462   // Pop the element queue from the custom element reactions stack,
1463   // and invoke custom element reactions in that queue.
1464   const uint32_t lastIndex = mReactionsStack.Length() - 1;
1465   ElementQueue* elementQueue = mReactionsStack.ElementAt(lastIndex).get();
1466   // Check element queue size in order to reduce function call overhead.
1467   if (!elementQueue->IsEmpty()) {
1468     // It is still not clear what error reporting will look like in custom
1469     // element, see https://github.com/w3c/webcomponents/issues/635.
1470     // We usually report the error to entry global in gecko, so just follow the
1471     // same behavior here.
1472     // This may be null if it's called from parser, see the case of
1473     // attributeChangedCallback in
1474     // https://html.spec.whatwg.org/multipage/parsing.html#create-an-element-for-the-token
1475     // In that case, the exception of callback reactions will be automatically
1476     // reported in CallSetup.
1477     nsIGlobalObject* global = GetEntryGlobal();
1478     InvokeReactions(elementQueue, MOZ_KnownLive(global));
1479   }
1480
1481   // InvokeReactions() might create other custom element reactions, but those
1482   // new reactions should be already consumed and removed at this point.
1483   MOZ_ASSERT(
1484       lastIndex == mReactionsStack.Length() - 1,
1485       "reactions created by InvokeReactions() should be consumed and removed");
1486
1487   mReactionsStack.RemoveLastElement();
1488   mIsElementQueuePushedForCurrentRecursionDepth = false;
1489 }
1490
1491 void CustomElementReactionsStack::EnqueueUpgradeReaction(
1492     Element* aElement, CustomElementDefinition* aDefinition) {
1493   Enqueue(aElement, new CustomElementUpgradeReaction(aDefinition));
1494 }
1495
1496 void CustomElementReactionsStack::EnqueueCallbackReaction(
1497     Element* aElement,
1498     UniquePtr<CustomElementCallback> aCustomElementCallback) {
1499   Enqueue(aElement,
1500           new CustomElementCallbackReaction(std::move(aCustomElementCallback)));
1501 }
1502
1503 void CustomElementReactionsStack::Enqueue(Element* aElement,
1504                                           CustomElementReaction* aReaction) {
1505   CustomElementData* elementData = aElement->GetCustomElementData();
1506   MOZ_ASSERT(elementData, "CustomElementData should exist");
1507
1508   if (mRecursionDepth) {
1509     // If the element queue is not created for current recursion depth, create
1510     // and push an element queue to reactions stack first.
1511     if (!mIsElementQueuePushedForCurrentRecursionDepth) {
1512       CreateAndPushElementQueue();
1513     }
1514
1515     MOZ_ASSERT(!mReactionsStack.IsEmpty());
1516     // Add element to the current element queue.
1517     mReactionsStack.LastElement()->AppendElement(aElement);
1518     elementData->mReactionQueue.AppendElement(aReaction);
1519     return;
1520   }
1521
1522   // If the custom element reactions stack is empty, then:
1523   // Add element to the backup element queue.
1524   MOZ_ASSERT(mReactionsStack.IsEmpty(),
1525              "custom element reactions stack should be empty");
1526   mBackupQueue.AppendElement(aElement);
1527   elementData->mReactionQueue.AppendElement(aReaction);
1528
1529   if (mIsBackupQueueProcessing) {
1530     return;
1531   }
1532
1533   CycleCollectedJSContext* context = CycleCollectedJSContext::Get();
1534   RefPtr<BackupQueueMicroTask> bqmt = new BackupQueueMicroTask(this);
1535   context->DispatchToMicroTask(bqmt.forget());
1536 }
1537
1538 void CustomElementReactionsStack::InvokeBackupQueue() {
1539   // Check backup queue size in order to reduce function call overhead.
1540   if (!mBackupQueue.IsEmpty()) {
1541     // Upgrade reactions won't be scheduled in backup queue and the exception of
1542     // callback reactions will be automatically reported in CallSetup.
1543     // If the reactions are invoked from backup queue (in microtask check
1544     // point), we don't need to pass global object for error reporting.
1545     InvokeReactions(&mBackupQueue, nullptr);
1546   }
1547   MOZ_ASSERT(
1548       mBackupQueue.IsEmpty(),
1549       "There are still some reactions in BackupQueue not being consumed!?!");
1550 }
1551
1552 void CustomElementReactionsStack::InvokeReactions(ElementQueue* aElementQueue,
1553                                                   nsIGlobalObject* aGlobal) {
1554   // This is used for error reporting.
1555   Maybe<AutoEntryScript> aes;
1556   if (aGlobal) {
1557     aes.emplace(aGlobal, "custom elements reaction invocation");
1558   }
1559
1560   // Note: It's possible to re-enter this method.
1561   for (uint32_t i = 0; i < aElementQueue->Length(); ++i) {
1562     Element* element = aElementQueue->ElementAt(i);
1563     // ElementQueue hold a element's strong reference, it should not be a
1564     // nullptr.
1565     MOZ_ASSERT(element);
1566
1567     CustomElementData* elementData = element->GetCustomElementData();
1568     if (!elementData || !element->GetOwnerGlobal()) {
1569       // This happens when the document is destroyed and the element is already
1570       // unlinked, no need to fire the callbacks in this case.
1571       continue;
1572     }
1573
1574     auto& reactions = elementData->mReactionQueue;
1575     for (uint32_t j = 0; j < reactions.Length(); ++j) {
1576       // Transfer the ownership of the entry due to reentrant invocation of
1577       // this function.
1578       auto reaction(std::move(reactions.ElementAt(j)));
1579       if (reaction) {
1580         if (!aGlobal && reaction->IsUpgradeReaction()) {
1581           nsIGlobalObject* global = element->GetOwnerGlobal();
1582           MOZ_ASSERT(!aes);
1583           aes.emplace(global, "custom elements reaction invocation");
1584         }
1585         ErrorResult rv;
1586         reaction->Invoke(MOZ_KnownLive(element), rv);
1587         if (aes) {
1588           JSContext* cx = aes->cx();
1589           if (rv.MaybeSetPendingException(cx)) {
1590             aes->ReportException();
1591           }
1592           MOZ_ASSERT(!JS_IsExceptionPending(cx));
1593           if (!aGlobal && reaction->IsUpgradeReaction()) {
1594             aes.reset();
1595           }
1596         }
1597         MOZ_ASSERT(!rv.Failed());
1598       }
1599     }
1600     reactions.Clear();
1601   }
1602   aElementQueue->Clear();
1603 }
1604
1605 //-----------------------------------------------------
1606 // CustomElementDefinition
1607
1608 NS_IMPL_CYCLE_COLLECTION(CustomElementDefinition, mConstructor, mCallbacks,
1609                          mFormAssociatedCallbacks, mConstructionStack)
1610
1611 CustomElementDefinition::CustomElementDefinition(
1612     nsAtom* aType, nsAtom* aLocalName, int32_t aNamespaceID,
1613     CustomElementConstructor* aConstructor,
1614     nsTArray<RefPtr<nsAtom>>&& aObservedAttributes,
1615     UniquePtr<LifecycleCallbacks>&& aCallbacks,
1616     UniquePtr<FormAssociatedLifecycleCallbacks>&& aFormAssociatedCallbacks,
1617     bool aFormAssociated, bool aDisableInternals, bool aDisableShadow)
1618     : mType(aType),
1619       mLocalName(aLocalName),
1620       mNamespaceID(aNamespaceID),
1621       mConstructor(aConstructor),
1622       mObservedAttributes(std::move(aObservedAttributes)),
1623       mCallbacks(std::move(aCallbacks)),
1624       mFormAssociatedCallbacks(std::move(aFormAssociatedCallbacks)),
1625       mFormAssociated(aFormAssociated),
1626       mDisableInternals(aDisableInternals),
1627       mDisableShadow(aDisableShadow) {}
1628
1629 }  // namespace mozilla::dom