// https://html.spec.whatwg.org/multipage/scripting.html#dom-customelementsregistry-get
ScriptValue CustomElementRegistry::get(const AtomicString& name) {
CustomElementDefinition* definition = definitionForName(name);
if (!definition) {
// Binding layer converts |ScriptValue()| to script specific value,
// e.g. |undefined| for v8.
return ScriptValue();
}
return definition->getConstructorForScript();
}
CustomElementDefinition* CustomElementRegistry::definitionFor(
const CustomElementDescriptor& desc) const {
CustomElementDefinition* definition = definitionForName(desc.name());
if (!definition)
return nullptr;
// The definition for a customized built-in element, such as
// <button is="my-button"> should not be provided for an
// autonomous element, such as <my-button>, even though the
// name "my-button" matches.
return definition->descriptor() == desc ? definition : nullptr;
}
HTMLElement* CustomElement::createCustomElementAsync(Document& document, const QualifiedName& tagName)
{
CHECK(shouldCreateCustomElement(document, tagName));
// To create an element:
// https://dom.spec.whatwg.org/#concept-create-element
// 6. If definition is non-null, then:
// 6.2. If the synchronous custom elements flag is not set:
if (CustomElementDefinition* definition = definitionForName(document, tagName))
return definition->createElementAsync(document, tagName);
return createUndefinedElement(document, tagName);
}
HTMLElement* CustomElement::createCustomElementSync(Document& document, const QualifiedName& tagName)
{
CHECK(shouldCreateCustomElement(document, tagName));
// When invoked from "create an element for a token":
// https://html.spec.whatwg.org/multipage/syntax.html#create-an-element-for-the-token
// 7. If this step throws an exception, then report the exception,
// and let element be instead a new element that implements
// HTMLUnknownElement.
if (CustomElementDefinition* definition = definitionForName(document, tagName))
return definition->createElementSync(document, tagName);
return createUndefinedElement(document, tagName);
}
// https://html.spec.whatwg.org/multipage/scripting.html#dom-customelementsregistry-whendefined
ScriptPromise CustomElementRegistry::whenDefined(
ScriptState* scriptState,
const AtomicString& name,
ExceptionState& exceptionState) {
if (throwIfInvalidName(name, exceptionState))
return ScriptPromise();
CustomElementDefinition* definition = definitionForName(name);
if (definition)
return ScriptPromise::castUndefined(scriptState);
ScriptPromiseResolver* resolver = m_whenDefinedPromiseMap.get(name);
if (resolver)
return resolver->promise();
ScriptPromiseResolver* newResolver =
ScriptPromiseResolver::create(scriptState);
m_whenDefinedPromiseMap.add(name, newResolver);
return newResolver->promise();
}