Source/WebCore/bindings/js/JSCustomElementInterface.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  * Copyright (C) 2015-2017 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */


 #include "config.h"
 #include "JSCustomElementInterface.h"

 #include "DOMWrapperWorld.h"
 #include "HTMLUnknownElement.h"
 #include "JSDOMBinding.h"
 #include "JSDOMConvertNullable.h"
 #include "JSDOMConvertStrings.h"
 #include "JSDOMWindow.h"
 #include "JSElement.h"
 #include "JSHTMLElement.h"
 #include "JSMainThreadExecState.h"
 #include "JSMainThreadExecStateInstrumentation.h"
 #include "ScriptExecutionContext.h"
 #include <JavaScriptCore/JSLock.h>
 #include <JavaScriptCore/WeakInlines.h>

 namespace WebCore {
 using namespace JSC;

 JSCustomElementInterface::JSCustomElementInterface(const QualifiedName& name, JSObject* constructor, JSDOMGlobalObject* globalObject)
     : ActiveDOMCallback(globalObject->scriptExecutionContext())
     , m_name(name)
     , m_constructor(constructor)
     , m_isolatedWorld(globalObject->world())
 {
 }

 JSCustomElementInterface::~JSCustomElementInterface() = default;

 static RefPtr<Element> constructCustomElementSynchronously(Document&, VM&, ExecState&, JSObject* constructor, const AtomicString& localName);

 Ref<Element> JSCustomElementInterface::constructElementWithFallback(Document& document, const AtomicString& localName)
 {
     if (auto element = tryToConstructCustomElement(document, localName))
         return element.releaseNonNull();

     auto element = HTMLUnknownElement::create(QualifiedName(nullAtom(), localName, HTMLNames::xhtmlNamespaceURI), document);
     element->setIsCustomElementUpgradeCandidate();
     element->setIsFailedCustomElement(*this);

     return WTFMove(element);
 }

 Ref<Element> JSCustomElementInterface::constructElementWithFallback(Document& document, const QualifiedName& name)
 {
     if (auto element = tryToConstructCustomElement(document, name.localName())) {
         if (!name.prefix().isNull())
             element->setPrefix(name.prefix());
         return element.releaseNonNull();
     }

     auto element = HTMLUnknownElement::create(name, document);
     element->setIsCustomElementUpgradeCandidate();
     element->setIsFailedCustomElement(*this);

     return WTFMove(element);
 }

 RefPtr<Element> JSCustomElementInterface::tryToConstructCustomElement(Document& document, const AtomicString& localName)
 {
     if (!canInvokeCallback())
         return nullptr;

     Ref<JSCustomElementInterface> protectedThis(*this);

     VM& vm = m_isolatedWorld->vm();
     JSLockHolder lock(vm);
     auto scope = DECLARE_CATCH_SCOPE(vm);

     if (!m_constructor)
         return nullptr;

     ASSERT(&document == scriptExecutionContext());
     auto& state = *document.execState();
     auto element = constructCustomElementSynchronously(document, vm, state, m_constructor.get(), localName);
     EXCEPTION_ASSERT(!!scope.exception() == !element);
     if (!element) {
         auto* exception = scope.exception();
         scope.clearException();
         reportException(&state, exception);
         return nullptr;
     }

     return element;
 }

 // https://dom.spec.whatwg.org/#concept-create-element
 // 6. 1. If the synchronous custom elements flag is set
 static RefPtr<Element> constructCustomElementSynchronously(Document& document, VM& vm, ExecState& state, JSObject* constructor, const AtomicString& localName)
 {
     auto scope = DECLARE_THROW_SCOPE(vm);
     ConstructData constructData;
     ConstructType constructType = constructor->methodTable(vm)->getConstructData(constructor, constructData);
     if (constructType == ConstructType::None) {
         ASSERT_NOT_REACHED();
         return nullptr;
     }

     InspectorInstrumentationCookie cookie = JSMainThreadExecState::instrumentFunctionConstruct(&document, constructType, constructData);
     MarkedArgumentBuffer args;
     ASSERT(!args.hasOverflowed());
     JSValue newElement = construct(&state, constructor, constructType, constructData, args);
     InspectorInstrumentation::didCallFunction(cookie, &document);
     RETURN_IF_EXCEPTION(scope, nullptr);

     ASSERT(!newElement.isEmpty());
     HTMLElement* wrappedElement = JSHTMLElement::toWrapped(vm, newElement);
     if (!wrappedElement) {
         throwTypeError(&state, scope, ASCIILiteral("The result of constructing a custom element must be a HTMLElement"));
         return nullptr;
     }

     if (wrappedElement->hasAttributes()) {
         throwNotSupportedError(state, scope, ASCIILiteral("A newly constructed custom element must not have attributes"));
         return nullptr;
     }
     if (wrappedElement->hasChildNodes()) {
         throwNotSupportedError(state, scope, ASCIILiteral("A newly constructed custom element must not have child nodes"));
         return nullptr;
     }
     if (wrappedElement->parentNode()) {
         throwNotSupportedError(state, scope, ASCIILiteral("A newly constructed custom element must not have a parent node"));
         return nullptr;
     }
     if (&wrappedElement->document() != &document) {
         throwNotSupportedError(state, scope, ASCIILiteral("A newly constructed custom element belongs to a wrong docuemnt"));
         return nullptr;
     }
     ASSERT(wrappedElement->namespaceURI() == HTMLNames::xhtmlNamespaceURI);
     if (wrappedElement->localName() != localName) {
         throwNotSupportedError(state, scope, ASCIILiteral("A newly constructed custom element belongs to a wrong docuemnt"));
         return nullptr;
     }

     return wrappedElement;
 }

 void JSCustomElementInterface::upgradeElement(Element& element)
 {
     ASSERT(element.tagQName() == name());
     ASSERT(element.isCustomElementUpgradeCandidate());
     if (!canInvokeCallback())
         return;

     Ref<JSCustomElementInterface> protectedThis(*this);
     VM& vm = m_isolatedWorld->vm();
     JSLockHolder lock(vm);
     auto scope = DECLARE_THROW_SCOPE(vm);

     if (!m_constructor)
         return;

     auto* context = scriptExecutionContext();
     if (!context)
         return;
     auto* globalObject = toJSDOMWindow(downcast<Document>(*context).frame(), m_isolatedWorld);
     if (!globalObject)
         return;
     ExecState* state = globalObject->globalExec();

     ConstructData constructData;
     ConstructType constructType = m_constructor->methodTable(vm)->getConstructData(m_constructor.get(), constructData);
     if (constructType == ConstructType::None) {
         ASSERT_NOT_REACHED();
         return;
     }

     CustomElementReactionQueue::enqueuePostUpgradeReactions(element);

     m_constructionStack.append(&element);

     MarkedArgumentBuffer args;
     ASSERT(!args.hasOverflowed());
     InspectorInstrumentationCookie cookie = JSMainThreadExecState::instrumentFunctionConstruct(context, constructType, constructData);
     JSValue returnedElement = construct(state, m_constructor.get(), constructType, constructData, args);
     InspectorInstrumentation::didCallFunction(cookie, context);

     m_constructionStack.removeLast();

     if (UNLIKELY(scope.exception())) {
         element.setIsFailedCustomElement(*this);
         reportException(state, scope.exception());
         return;
     }

     Element* wrappedElement = JSElement::toWrapped(vm, returnedElement);
     if (!wrappedElement || wrappedElement != &element) {
         element.setIsFailedCustomElement(*this);
         reportException(state, createDOMException(state, InvalidStateError, "Custom element constructor failed to upgrade an element"));
         return;
     }
     element.setIsDefinedCustomElement(*this);
 }

 void JSCustomElementInterface::invokeCallback(Element& element, JSObject* callback, const WTF::Function<void(ExecState*, JSDOMGlobalObject*, MarkedArgumentBuffer&)>& addArguments)
 {
     if (!canInvokeCallback())
         return;

     auto* context = scriptExecutionContext();
     if (!context)
         return;

     Ref<JSCustomElementInterface> protectedThis(*this);
     VM& vm = m_isolatedWorld->vm();
     JSLockHolder lock(vm);

     auto* globalObject = toJSDOMWindow(downcast<Document>(*context).frame(), m_isolatedWorld);
     if (!globalObject)
         return;
     ExecState* state = globalObject->globalExec();

     JSObject* jsElement = asObject(toJS(state, globalObject, element));

     CallData callData;
     CallType callType = callback->methodTable(vm)->getCallData(callback, callData);
     ASSERT(callType != CallType::None);

     MarkedArgumentBuffer args;
     addArguments(state, globalObject, args);
     RELEASE_ASSERT(!args.hasOverflowed());

     InspectorInstrumentationCookie cookie = JSMainThreadExecState::instrumentFunctionCall(context, callType, callData);

     NakedPtr<JSC::Exception> exception;
     JSMainThreadExecState::call(state, callback, callType, callData, jsElement, args, exception);

     InspectorInstrumentation::didCallFunction(cookie, context);

     if (exception)
         reportException(state, exception);
 }

 void JSCustomElementInterface::setConnectedCallback(JSC::JSObject* callback)
 {
     m_connectedCallback = callback;
 }

 void JSCustomElementInterface::invokeConnectedCallback(Element& element)
 {
     invokeCallback(element, m_connectedCallback.get());
 }

 void JSCustomElementInterface::setDisconnectedCallback(JSC::JSObject* callback)
 {
     m_disconnectedCallback = callback;
 }

 void JSCustomElementInterface::invokeDisconnectedCallback(Element& element)
 {
     invokeCallback(element, m_disconnectedCallback.get());
 }

 void JSCustomElementInterface::setAdoptedCallback(JSC::JSObject* callback)
 {
     m_adoptedCallback = callback;
 }

 void JSCustomElementInterface::invokeAdoptedCallback(Element& element, Document& oldDocument, Document& newDocument)
 {
     invokeCallback(element, m_adoptedCallback.get(), [&](ExecState* state, JSDOMGlobalObject* globalObject, MarkedArgumentBuffer& args) {
         args.append(toJS(state, globalObject, oldDocument));
         args.append(toJS(state, globalObject, newDocument));
     });
 }

 void JSCustomElementInterface::setAttributeChangedCallback(JSC::JSObject* callback, const Vector<String>& observedAttributes)
 {
     m_attributeChangedCallback = callback;
     m_observedAttributes.clear();
     for (auto& name : observedAttributes)
         m_observedAttributes.add(name);
 }

 void JSCustomElementInterface::invokeAttributeChangedCallback(Element& element, const QualifiedName& attributeName, const AtomicString& oldValue, const AtomicString& newValue)
 {
     invokeCallback(element, m_attributeChangedCallback.get(), [&](ExecState* state, JSDOMGlobalObject*, MarkedArgumentBuffer& args) {
         args.append(toJS<IDLDOMString>(*state, attributeName.localName()));
         args.append(toJS<IDLNullable<IDLDOMString>>(*state, oldValue));
         args.append(toJS<IDLNullable<IDLDOMString>>(*state, newValue));
         args.append(toJS<IDLNullable<IDLDOMString>>(*state, attributeName.namespaceURI()));
     });
 }

 void JSCustomElementInterface::didUpgradeLastElementInConstructionStack()
 {
     m_constructionStack.last() = nullptr;
 }

 } // namespace WebCore
	/*
	* Copyright (C) 2013 Google Inc. All rights reserved.
	* Copyright (C) 2015-2017 Apple Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
	* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
	* THE POSSIBILITY OF SUCH DAMAGE.
	*/


	#include "config.h"
	#include "JSCustomElementInterface.h"

	#include "DOMWrapperWorld.h"
	#include "HTMLUnknownElement.h"
	#include "JSDOMBinding.h"
	#include "JSDOMConvertNullable.h"
	#include "JSDOMConvertStrings.h"
	#include "JSDOMWindow.h"
	#include "JSElement.h"
	#include "JSHTMLElement.h"
	#include "JSMainThreadExecState.h"
	#include "JSMainThreadExecStateInstrumentation.h"
	#include "ScriptExecutionContext.h"
	#include <JavaScriptCore/JSLock.h>
	#include <JavaScriptCore/WeakInlines.h>

	namespace WebCore {
	using namespace JSC;

	JSCustomElementInterface::JSCustomElementInterface(const QualifiedName& name, JSObject* constructor, JSDOMGlobalObject* globalObject)
	: ActiveDOMCallback(globalObject->scriptExecutionContext())
	, m_name(name)
	, m_constructor(constructor)
	, m_isolatedWorld(globalObject->world())
	{
	}

	JSCustomElementInterface::~JSCustomElementInterface() = default;

	static RefPtr<Element> constructCustomElementSynchronously(Document&, VM&, ExecState&, JSObject* constructor, const AtomicString& localName);

	Ref<Element> JSCustomElementInterface::constructElementWithFallback(Document& document, const AtomicString& localName)
	{
	if (auto element = tryToConstructCustomElement(document, localName))
	return element.releaseNonNull();

	auto element = HTMLUnknownElement::create(QualifiedName(nullAtom(), localName, HTMLNames::xhtmlNamespaceURI), document);
	element->setIsCustomElementUpgradeCandidate();
	element->setIsFailedCustomElement(*this);

	return WTFMove(element);
	}

	Ref<Element> JSCustomElementInterface::constructElementWithFallback(Document& document, const QualifiedName& name)
	{
	if (auto element = tryToConstructCustomElement(document, name.localName())) {
	if (!name.prefix().isNull())
	element->setPrefix(name.prefix());
	return element.releaseNonNull();
	}

	auto element = HTMLUnknownElement::create(name, document);
	element->setIsCustomElementUpgradeCandidate();
	element->setIsFailedCustomElement(*this);

	return WTFMove(element);
	}

	RefPtr<Element> JSCustomElementInterface::tryToConstructCustomElement(Document& document, const AtomicString& localName)
	{
	if (!canInvokeCallback())
	return nullptr;

	Ref<JSCustomElementInterface> protectedThis(*this);

	VM& vm = m_isolatedWorld->vm();
	JSLockHolder lock(vm);
	auto scope = DECLARE_CATCH_SCOPE(vm);

	if (!m_constructor)
	return nullptr;

	ASSERT(&document == scriptExecutionContext());
	auto& state = *document.execState();
	auto element = constructCustomElementSynchronously(document, vm, state, m_constructor.get(), localName);
	EXCEPTION_ASSERT(!!scope.exception() == !element);
	if (!element) {
	auto* exception = scope.exception();
	scope.clearException();
	reportException(&state, exception);
	return nullptr;
	}

	return element;
	}

	// https://dom.spec.whatwg.org/#concept-create-element
	// 6. 1. If the synchronous custom elements flag is set
	static RefPtr<Element> constructCustomElementSynchronously(Document& document, VM& vm, ExecState& state, JSObject* constructor, const AtomicString& localName)
	{
	auto scope = DECLARE_THROW_SCOPE(vm);
	ConstructData constructData;
	ConstructType constructType = constructor->methodTable(vm)->getConstructData(constructor, constructData);
	if (constructType == ConstructType::None) {
	ASSERT_NOT_REACHED();
	return nullptr;
	}

	InspectorInstrumentationCookie cookie = JSMainThreadExecState::instrumentFunctionConstruct(&document, constructType, constructData);
	MarkedArgumentBuffer args;
	ASSERT(!args.hasOverflowed());
	JSValue newElement = construct(&state, constructor, constructType, constructData, args);
	InspectorInstrumentation::didCallFunction(cookie, &document);
	RETURN_IF_EXCEPTION(scope, nullptr);

	ASSERT(!newElement.isEmpty());
	HTMLElement* wrappedElement = JSHTMLElement::toWrapped(vm, newElement);
	if (!wrappedElement) {
	throwTypeError(&state, scope, ASCIILiteral("The result of constructing a custom element must be a HTMLElement"));
	return nullptr;
	}

	if (wrappedElement->hasAttributes()) {
	throwNotSupportedError(state, scope, ASCIILiteral("A newly constructed custom element must not have attributes"));
	return nullptr;
	}
	if (wrappedElement->hasChildNodes()) {
	throwNotSupportedError(state, scope, ASCIILiteral("A newly constructed custom element must not have child nodes"));
	return nullptr;
	}
	if (wrappedElement->parentNode()) {
	throwNotSupportedError(state, scope, ASCIILiteral("A newly constructed custom element must not have a parent node"));
	return nullptr;
	}
	if (&wrappedElement->document() != &document) {
	throwNotSupportedError(state, scope, ASCIILiteral("A newly constructed custom element belongs to a wrong docuemnt"));
	return nullptr;
	}
	ASSERT(wrappedElement->namespaceURI() == HTMLNames::xhtmlNamespaceURI);
	if (wrappedElement->localName() != localName) {
	throwNotSupportedError(state, scope, ASCIILiteral("A newly constructed custom element belongs to a wrong docuemnt"));
	return nullptr;
	}

	return wrappedElement;
	}

	void JSCustomElementInterface::upgradeElement(Element& element)
	{
	ASSERT(element.tagQName() == name());
	ASSERT(element.isCustomElementUpgradeCandidate());
	if (!canInvokeCallback())
	return;

	Ref<JSCustomElementInterface> protectedThis(*this);
	VM& vm = m_isolatedWorld->vm();
	JSLockHolder lock(vm);
	auto scope = DECLARE_THROW_SCOPE(vm);

	if (!m_constructor)
	return;

	auto* context = scriptExecutionContext();
	if (!context)
	return;
	auto* globalObject = toJSDOMWindow(downcast<Document>(*context).frame(), m_isolatedWorld);
	if (!globalObject)
	return;
	ExecState* state = globalObject->globalExec();

	ConstructData constructData;
	ConstructType constructType = m_constructor->methodTable(vm)->getConstructData(m_constructor.get(), constructData);
	if (constructType == ConstructType::None) {
	ASSERT_NOT_REACHED();
	return;
	}

	CustomElementReactionQueue::enqueuePostUpgradeReactions(element);

	m_constructionStack.append(&element);

	MarkedArgumentBuffer args;
	ASSERT(!args.hasOverflowed());
	InspectorInstrumentationCookie cookie = JSMainThreadExecState::instrumentFunctionConstruct(context, constructType, constructData);
	JSValue returnedElement = construct(state, m_constructor.get(), constructType, constructData, args);
	InspectorInstrumentation::didCallFunction(cookie, context);

	m_constructionStack.removeLast();

	if (UNLIKELY(scope.exception())) {
	element.setIsFailedCustomElement(*this);
	reportException(state, scope.exception());
	return;
	}

	Element* wrappedElement = JSElement::toWrapped(vm, returnedElement);
	if (!wrappedElement \|\| wrappedElement != &element) {
	element.setIsFailedCustomElement(*this);
	reportException(state, createDOMException(state, InvalidStateError, "Custom element constructor failed to upgrade an element"));
	return;
	}
	element.setIsDefinedCustomElement(*this);
	}

	void JSCustomElementInterface::invokeCallback(Element& element, JSObject* callback, const WTF::Function<void(ExecState, JSDOMGlobalObject, MarkedArgumentBuffer&)>& addArguments)
	{
	if (!canInvokeCallback())
	return;

	auto* context = scriptExecutionContext();
	if (!context)
	return;

	Ref<JSCustomElementInterface> protectedThis(*this);
	VM& vm = m_isolatedWorld->vm();
	JSLockHolder lock(vm);

	auto* globalObject = toJSDOMWindow(downcast<Document>(*context).frame(), m_isolatedWorld);
	if (!globalObject)
	return;
	ExecState* state = globalObject->globalExec();

	JSObject* jsElement = asObject(toJS(state, globalObject, element));

	CallData callData;
	CallType callType = callback->methodTable(vm)->getCallData(callback, callData);
	ASSERT(callType != CallType::None);

	MarkedArgumentBuffer args;
	addArguments(state, globalObject, args);
	RELEASE_ASSERT(!args.hasOverflowed());

	InspectorInstrumentationCookie cookie = JSMainThreadExecState::instrumentFunctionCall(context, callType, callData);

	NakedPtr<JSC::Exception> exception;
	JSMainThreadExecState::call(state, callback, callType, callData, jsElement, args, exception);

	InspectorInstrumentation::didCallFunction(cookie, context);

	if (exception)
	reportException(state, exception);
	}

	void JSCustomElementInterface::setConnectedCallback(JSC::JSObject* callback)
	{
	m_connectedCallback = callback;
	}

	void JSCustomElementInterface::invokeConnectedCallback(Element& element)
	{
	invokeCallback(element, m_connectedCallback.get());
	}

	void JSCustomElementInterface::setDisconnectedCallback(JSC::JSObject* callback)
	{
	m_disconnectedCallback = callback;
	}

	void JSCustomElementInterface::invokeDisconnectedCallback(Element& element)
	{
	invokeCallback(element, m_disconnectedCallback.get());
	}

	void JSCustomElementInterface::setAdoptedCallback(JSC::JSObject* callback)
	{
	m_adoptedCallback = callback;
	}

	void JSCustomElementInterface::invokeAdoptedCallback(Element& element, Document& oldDocument, Document& newDocument)
	{
	invokeCallback(element, m_adoptedCallback.get(), [&](ExecState* state, JSDOMGlobalObject* globalObject, MarkedArgumentBuffer& args) {
	args.append(toJS(state, globalObject, oldDocument));
	args.append(toJS(state, globalObject, newDocument));
	});
	}

	void JSCustomElementInterface::setAttributeChangedCallback(JSC::JSObject* callback, const Vector<String>& observedAttributes)
	{
	m_attributeChangedCallback = callback;
	m_observedAttributes.clear();
	for (auto& name : observedAttributes)
	m_observedAttributes.add(name);
	}

	void JSCustomElementInterface::invokeAttributeChangedCallback(Element& element, const QualifiedName& attributeName, const AtomicString& oldValue, const AtomicString& newValue)
	{
	invokeCallback(element, m_attributeChangedCallback.get(), [&](ExecState* state, JSDOMGlobalObject*, MarkedArgumentBuffer& args) {
	args.append(toJS<IDLDOMString>(*state, attributeName.localName()));
	args.append(toJS<IDLNullable<IDLDOMString>>(*state, oldValue));
	args.append(toJS<IDLNullable<IDLDOMString>>(*state, newValue));
	args.append(toJS<IDLNullable<IDLDOMString>>(*state, attributeName.namespaceURI()));
	});
	}

	void JSCustomElementInterface::didUpgradeLastElementInConstructionStack()
	{
	m_constructionStack.last() = nullptr;
	}

	} // namespace WebCore