Source/core/dom/CustomElementRegistrationContext.cpp

/*
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#include "config.h"
#include "core/dom/CustomElementRegistrationContext.h"

#include "HTMLNames.h"
#include "MathMLNames.h"
#include "SVGNames.h"
#include "core/dom/CustomElement.h"
#include "core/dom/CustomElementDefinition.h"
#include "core/dom/CustomElementRegistry.h"
#include "core/dom/CustomElementUpgradeCandidateMap.h"
#include "core/dom/Element.h"
#include "core/html/HTMLElement.h"
#include "core/html/HTMLUnknownElement.h"
#include "core/svg/SVGElement.h"

namespace WebCore {

// The null registration context is used by documents that do not
// process custom elements. All of its operations are no-ops.
class NullRegistrationContext : public CustomElementRegistrationContext {
public:
    NullRegistrationContext() { }
    virtual ~NullRegistrationContext() { }

    virtual void registerElement(Document*, CustomElementConstructorBuilder*, const AtomicString&, ExceptionCode& ec) OVERRIDE { ec = NotSupportedError; }

    virtual PassRefPtr<Element> createCustomTagElement(Document*, const QualifiedName&) OVERRIDE;
    virtual void didGiveTypeExtension(Element*) OVERRIDE { }
};

PassRefPtr<Element> NullRegistrationContext::createCustomTagElement(Document* document, const QualifiedName& tagName)
{
    ASSERT(isCustomTagName(tagName.localName()));

    if (!document)
        return 0;

    if (HTMLNames::xhtmlNamespaceURI == tagName.namespaceURI())
        return HTMLUnknownElement::create(tagName, document);
    if (SVGNames::svgNamespaceURI == tagName.namespaceURI())
        return SVGElement::create(tagName, document);
    return Element::create(tagName, document);
}

PassRefPtr<CustomElementRegistrationContext> CustomElementRegistrationContext::nullRegistrationContext()
{
    DEFINE_STATIC_LOCAL(RefPtr<NullRegistrationContext>, instance, ());
    if (!instance)
        instance = adoptRef(new NullRegistrationContext());
    return instance.get();
}

// An active registration context is used by documents that are
// processing custom elements.
class ActiveRegistrationContext : public CustomElementRegistrationContext {
public:
    ActiveRegistrationContext() { }
    virtual ~ActiveRegistrationContext() { }

    virtual void registerElement(Document*, CustomElementConstructorBuilder*, const AtomicString& type, ExceptionCode&) OVERRIDE;

    virtual PassRefPtr<Element> createCustomTagElement(Document*, const QualifiedName&) OVERRIDE;
    virtual void didGiveTypeExtension(Element*) OVERRIDE;

    virtual void customElementWasDestroyed(Element*) OVERRIDE;

private:
    void resolve(Element*);
    void didResolveElement(CustomElementDefinition*, Element*);
    void didCreateUnresolvedElement(const CustomElementDescriptor&, Element*);

    CustomElementRegistry m_registry;

    // Element creation
    CustomElementUpgradeCandidateMap m_candidates;
};

void ActiveRegistrationContext::registerElement(Document* document, CustomElementConstructorBuilder* constructorBuilder, const AtomicString& type, ExceptionCode& ec)
{
    CustomElementDefinition* definition = m_registry.registerElement(document, constructorBuilder, type, ec);

    if (!definition)
        return;

    // Upgrade elements that were waiting for this definition.
    const CustomElementUpgradeCandidateMap::ElementSet& upgradeCandidates = m_candidates.takeUpgradeCandidatesFor(definition->descriptor());
    for (CustomElementUpgradeCandidateMap::ElementSet::const_iterator it = upgradeCandidates.begin(); it != upgradeCandidates.end(); ++it)
        didResolveElement(definition, *it);
}

PassRefPtr<Element> ActiveRegistrationContext::createCustomTagElement(Document* document, const QualifiedName& tagName)
{
    ASSERT(isCustomTagName(tagName.localName()));

    if (!document)
        return 0;

    RefPtr<Element> element;

    if (HTMLNames::xhtmlNamespaceURI == tagName.namespaceURI()) {
        element = HTMLElement::create(tagName, document);
    } else if (SVGNames::svgNamespaceURI == tagName.namespaceURI()) {
        element = SVGElement::create(tagName, document);
    } else {
        // XML elements are not custom elements, so return early.
        return Element::create(tagName, document);
    }

    resolve(element.get());
    return element.release();
}

void ActiveRegistrationContext::didGiveTypeExtension(Element* element)
{
    resolve(element);
}

void ActiveRegistrationContext::resolve(Element* element)
{
    const CustomElementDescriptor& descriptor = describe(element);
    CustomElementDefinition* definition = m_registry.find(descriptor);
    if (definition)
        didResolveElement(definition, element);
    else
        didCreateUnresolvedElement(descriptor, element);
}

void ActiveRegistrationContext::didResolveElement(CustomElementDefinition* definition, Element* element)
{
    CustomElement::define(element, definition);
}

void ActiveRegistrationContext::didCreateUnresolvedElement(const CustomElementDescriptor& descriptor, Element* element)
{
    element->setCustomElementState(Element::UpgradeCandidate);
    m_candidates.add(descriptor, element);
}

void ActiveRegistrationContext::customElementWasDestroyed(Element* element)
{
    m_candidates.remove(element);
    CustomElementRegistrationContext::customElementWasDestroyed(element);
}

PassRefPtr<CustomElementRegistrationContext> CustomElementRegistrationContext::create()
{
    return adoptRef(new ActiveRegistrationContext());
}

bool CustomElementRegistrationContext::isValidTypeName(const AtomicString& name)
{
    if (notFound == name.find('-'))
        return false;

    DEFINE_STATIC_LOCAL(Vector<AtomicString>, reservedNames, ());
    if (reservedNames.isEmpty()) {
        reservedNames.append(MathMLNames::annotation_xmlTag.localName());
        reservedNames.append(SVGNames::color_profileTag.localName());
        reservedNames.append(SVGNames::font_faceTag.localName());
        reservedNames.append(SVGNames::font_face_srcTag.localName());
        reservedNames.append(SVGNames::font_face_uriTag.localName());
        reservedNames.append(SVGNames::font_face_formatTag.localName());
        reservedNames.append(SVGNames::font_face_nameTag.localName());
        reservedNames.append(SVGNames::missing_glyphTag.localName());
    }

    if (notFound != reservedNames.find(name))
        return false;

    return Document::isValidName(name.string());
}

bool CustomElementRegistrationContext::isCustomTagName(const AtomicString& localName)
{
    return isValidTypeName(localName);
}

CustomElementDescriptor CustomElementRegistrationContext::describe(Element* element)
{
    // If an element has a custom tag name it takes precedence over
    // the "is" attribute (if any).
    const AtomicString& type = isCustomTagName(element->localName())
        ? element->localName()
        : typeExtension(element);

    return CustomElementDescriptor(type, element->namespaceURI(), element->localName());
}

void CustomElementRegistrationContext::setIsAttributeAndTypeExtension(Element* element, const AtomicString& type)
{
    ASSERT(element);
    ASSERT(!type.isEmpty());
    element->setAttribute(HTMLNames::isAttr, type);
    setTypeExtension(element, type);
}

void CustomElementRegistrationContext::setTypeExtension(Element* element, const AtomicString& type)
{
    if (!element->isHTMLElement() && !element->isSVGElement())
        return;

    if (isCustomTagName(element->localName()))
        return; // custom tags take precedence over type extensions

    TypeExtensionMap::AddResult result = typeExtensionMap()->add(element, type);
    ASSERT(result.isNewEntry); // Type extensions should only be set once
    element->document()->registrationContext()->didGiveTypeExtension(element);
}

void CustomElementRegistrationContext::customElementWasDestroyed(Element* element)
{
    ASSERT(element->isCustomElement());
    typeExtensionMap()->remove(element);
}

const AtomicString& CustomElementRegistrationContext::typeExtension(Element* element)
{
    TypeExtensionMap::const_iterator it = typeExtensionMap()->find(element);
    ASSERT(it != typeExtensionMap()->end());
    return it->value;
}

CustomElementRegistrationContext::TypeExtensionMap* CustomElementRegistrationContext::typeExtensionMap()
{
    DEFINE_STATIC_LOCAL(TypeExtensionMap, typeExtensionMap, ());
    return &typeExtensionMap;
}

} // namespace WebCore