root/Source/core/dom/Attr.cpp

DEFINITIONS

1. m_ignoreChildrenChanged
2. m_ignoreChildrenChanged
3. create
4. create
5. createTextChild
6. setValue
7. setValueInternal
8. valueForBindings
9. setValueForBindings
10. setNodeValue
11. cloneNode
12. childTypeAllowed
13. childrenChanged
14. value
15. elementAttribute
16. detachFromElementWithValue
17. attachToElement

/*
 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
 *           (C) 1999 Antti Koivisto (koivisto@kde.org)
 *           (C) 2001 Peter Kelly (pmk@post.com)
 *           (C) 2001 Dirk Mueller (mueller@kde.org)
 * Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010, 2012 Apple Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */
#include "config.h"
#include "core/dom/Attr.h"

#include "bindings/v8/ExceptionState.h"
#include "bindings/v8/ExceptionStatePlaceholder.h"
#include "core/dom/Element.h"
#include "core/dom/Text.h"
#include "core/events/ScopedEventQueue.h"
#include "core/frame/UseCounter.h"
#include "wtf/text/AtomicString.h"
#include "wtf/text/StringBuilder.h"

namespace WebCore {

using namespace HTMLNames;

Attr::Attr(Element& element, const QualifiedName& name)
    : ContainerNode(&element.document())
    , m_element(&element)
    , m_name(name)
    , m_ignoreChildrenChanged(0)
{
    ScriptWrappable::init(this);
}

Attr::Attr(Document& document, const QualifiedName& name, const AtomicString& standaloneValue)
    : ContainerNode(&document)
    , m_element(0)
    , m_name(name)
    , m_standaloneValue(standaloneValue)
    , m_ignoreChildrenChanged(0)
{
    ScriptWrappable::init(this);
}

PassRefPtr<Attr> Attr::create(Element& element, const QualifiedName& name)
{
    RefPtr<Attr> attr = adoptRef(new Attr(element, name));
    attr->createTextChild();
    return attr.release();
}

PassRefPtr<Attr> Attr::create(Document& document, const QualifiedName& name, const AtomicString& value)
{
    RefPtr<Attr> attr = adoptRef(new Attr(document, name, value));
    attr->createTextChild();
    return attr.release();
}

Attr::~Attr()
{
}

void Attr::createTextChild()
{
    ASSERT(refCount());
    if (!value().isEmpty()) {
        RefPtr<Text> textNode = document().createTextNode(value().string());

        // This does everything appendChild() would do in this situation (assuming m_ignoreChildrenChanged was set),
        // but much more efficiently.
        textNode->setParentOrShadowHostNode(this);
        treeScope().adoptIfNeeded(*textNode);
        setFirstChild(textNode.get());
        setLastChild(textNode.get());
    }
}

void Attr::setValue(const AtomicString& value)
{
    EventQueueScope scope;
    m_ignoreChildrenChanged++;
    removeChildren();
    if (m_element)
        elementAttribute().setValue(value);
    else
        m_standaloneValue = value;
    createTextChild();
    m_ignoreChildrenChanged--;

    invalidateNodeListCachesInAncestors(&m_name, m_element);
}

void Attr::setValueInternal(const AtomicString& value)
{
    if (m_element)
        m_element->willModifyAttribute(qualifiedName(), this->value(), value);

    setValue(value);

    if (m_element)
        m_element->didModifyAttribute(qualifiedName(), value);
}

const AtomicString& Attr::valueForBindings() const
{
    UseCounter::count(document(), UseCounter::AttrGetValue);
    return value();
}

void Attr::setValueForBindings(const AtomicString& value)
{
    UseCounter::count(document(), UseCounter::AttrSetValue);
    if (m_element)
        UseCounter::count(document(), UseCounter::AttrSetValueWithElement);
    setValueInternal(value);
}

void Attr::setNodeValue(const String& v)
{
    // Attr uses AtomicString type for its value to save memory as there
    // is duplication among Elements' attributes values.
    setValueInternal(AtomicString(v));
}

PassRefPtr<Node> Attr::cloneNode(bool /*deep*/)
{
    RefPtr<Attr> clone = adoptRef(new Attr(document(), qualifiedName(), value()));
    cloneChildNodes(clone.get());
    return clone.release();
}

// DOM Section 1.1.1
bool Attr::childTypeAllowed(NodeType type) const
{
    return TEXT_NODE == type;
}

void Attr::childrenChanged(bool, Node*, Node*, int)
{
    if (m_ignoreChildrenChanged > 0)
        return;

    invalidateNodeListCachesInAncestors(&qualifiedName(), m_element);

    StringBuilder valueBuilder;
    for (Node *n = firstChild(); n; n = n->nextSibling()) {
        if (n->isTextNode())
            valueBuilder.append(toText(n)->data());
    }

    AtomicString newValue = valueBuilder.toAtomicString();
    if (m_element)
        m_element->willModifyAttribute(qualifiedName(), value(), newValue);

    if (m_element)
        elementAttribute().setValue(newValue);
    else
        m_standaloneValue = newValue;

    if (m_element)
        m_element->attributeChanged(qualifiedName(), newValue);
}

const AtomicString& Attr::value() const
{
    if (m_element)
        return m_element->getAttribute(qualifiedName());
    return m_standaloneValue;
}

Attribute& Attr::elementAttribute()
{
    ASSERT(m_element);
    ASSERT(m_element->elementData());
    return *m_element->ensureUniqueElementData().getAttributeItem(qualifiedName());
}

void Attr::detachFromElementWithValue(const AtomicString& value)
{
    ASSERT(m_element);
    ASSERT(m_standaloneValue.isNull());
    m_standaloneValue = value;
    m_element = 0;
}

void Attr::attachToElement(Element* element)
{
    ASSERT(!m_element);
    m_element = element;
    m_standaloneValue = nullAtom;
}

}