element.jsc

《JavaScript王者归来》examples.rar

# language: jsvm2

/*
 * Copyright (c) 2000 World Wide Web Consortium,
 * (Massachusetts Institute of Technology, Institut National de
 * Recherche en Informatique et en Automatique, Keio University). All
 * Rights Reserved. This program is distributed under the W3C's Software
 * Intellectual Property License. This program 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 W3C License http://www.w3.org/Consortium/Legal/ for more details.
 */

package org.w3c.dom;

import js.util.HashMap;

import org.w3c.dom.Node;
import org.w3c.dom.Attr;
import org.w3c.dom.DOMException;


/**
 * The <code>Element</code> interface represents an element in an HTML or XML 
 * document. Elements may have attributes associated with them; since the 
 * <code>Element</code> interface inherits from <code>Node</code>, the 
 * generic <code>Node</code> interface attribute <code>attributes</code> may 
 * be used to retrieve the set of all attributes for an element. There are 
 * methods on the <code>Element</code> interface to retrieve either an 
 * <code>Attr</code> object by name or an attribute value by name. In XML, 
 * where an attribute value may contain entity references, an 
 * <code>Attr</code> object should be retrieved to examine the possibly 
 * fairly complex sub-tree representing the attribute value. On the other 
 * hand, in HTML, where all attributes have simple string values, methods to 
 * directly access an attribute value can safely be used as a convenience.In 
 * DOM Level 2, the method <code>normalize</code> is inherited from the 
 * <code>Node</code> interface where it was moved.
 * <p>See also the <a href='http://www.w3.org/TR/2000/REC-DOM-Level-2-Core-20001113'>Document Object Model (DOM) Level 2 Core Specification</a>.
 */

class Element extends Node (sName)
{
	super.call(this, Node.ELEMENT_NODE, sName, null);
	this.__tagName = sName;
	this.__attributes = null;
}


/**
  * The name of the element. For example, in: 
  * <pre> &lt;elementExample 
  * id="demo"&gt; ... &lt;/elementExample&gt; , </pre>
  *  <code>tagName</code> has 
  * the value <code>"elementExample"</code>. Note that this is 
  * case-preserving in XML, as are all of the operations of the DOM. The 
  * HTML DOM returns the <code>tagName</code> of an HTML element in the 
  * canonical uppercase form, regardless of the case in the source HTML 
  * document.
  */
Element.prototype.getTagName = function ()
{
	return this.__tagName;
}

/**
 * Retrieves an attribute value by name.
 * @param name The name of the attribute to retrieve.
 * @return The <code>Attr</code> value as a string, or the empty string 
 *   if that attribute does not have a specified or default value.
 */
Element.prototype.getAttribute = function (name)
{
	return (this.__attributes == null || !this.__attributes.containsKey(name))
		? null : this.__attributes.get(name).getValue();
}

/**
 * Adds a new attribute. If an attribute with that name is already present 
 * in the element, its value is changed to be that of the value 
 * parameter. This value is a simple string; it is not parsed as it is 
 * being set. So any markup (such as syntax to be recognized as an 
 * entity reference) is treated as literal text, and needs to be 
 * appropriately escaped by the implementation when it is written out. 
 * In order to assign an attribute value that contains entity 
 * references, the user must create an <code>Attr</code> node plus any 
 * <code>Text</code> and <code>EntityReference</code> nodes, build the 
 * appropriate subtree, and use <code>setAttributeNode</code> to assign 
 * it as the value of an attribute.
 * <br>To set an attribute with a qualified name and namespace URI, use 
 * the <code>setAttributeNS</code> method.
 * @param name The name of the attribute to create or alter.
 * @param value Value to set in string form.
 * @exception DOMException
 *   INVALID_CHARACTER_ERR: Raised if the specified name contains an 
 *   illegal character.
 *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
 */
Element.prototype.setAttribute = function (name, value)
{
	if (this.__attributes == null)
	{
		this.__attributes = new HashMap();
	}
	var attr = new Attr(name, value);
	attr.__ownerElement = this;
	return this.__attributes.put(name, attr);
}


/**
 * Removes an attribute by name. If the removed attribute is known to have 
 * a default value, an attribute immediately appears containing the 
 * default value as well as the corresponding namespace URI, local name, 
 * and prefix when applicable.
 * <br>To remove an attribute by local name and namespace URI, use the 
 * <code>removeAttributeNS</code> method.
 * @param name The name of the attribute to remove.
 * @exception DOMException
 *   NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
 */
Element.prototype.removeAttribute = function (name)
{
	return (this.__attributes == null) ? null
		: this.__attributes.remove(name);
}


/**
  * Returns <code>true</code> when an attribute with a given name is 
  * specified on this element or has a default value, <code>false</code> 
  * otherwise.
  * @param name The name of the attribute to look for.
  * @return <code>true</code> if an attribute with the given name is 
  *   specified on this element or has a default value, <code>false</code>
  *    otherwise.
  * @since DOM Level 2
  */
Element.prototype.hasAttribute = function (name)
{
	return (this.__attributes == null) ? false
		: this.__attributes.containsKey(name);
}

/**
 * Retrieves an attribute node by name.
 * <br>To retrieve an attribute node by qualified name and namespace URI, 
 * use the <code>getAttributeNodeNS</code> method.
 * @param name The name (<code>nodeName</code>) of the attribute to 
 *   retrieve.
 * @return The <code>Attr</code> node with the specified name (
 *   <code>nodeName</code>) or <code>null</code> if there is no such 
 *   attribute.
 */
Element.prototype.getAttributeNode = function (name)
{
	if (this.__attributes == null)
	{
		return null;
	}
	return this.__attributes.get(name);
}

/**
 * Adds a new attribute node. If an attribute with that name (
 * <code>nodeName</code>) is already present in the element, it is 
 * replaced by the new one.
 * <br>To add a new attribute node with a qualified name and namespace 
 * URI, use the <code>setAttributeNodeNS</code> method.
 * @param newAttr The <code>Attr</code> node to add to the attribute list.
 * @return If the <code>newAttr</code> attribute replaces an existing 
 *   attribute, the replaced <code>Attr</code> node is returned, 
 *   otherwise <code>null</code> is returned.
 * @exception DOMException
 *   WRONG_DOCUMENT_ERR: Raised if <code>newAttr</code> was created from a 
 *   different document than the one that created the element.
 *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
 *   <br>INUSE_ATTRIBUTE_ERR: Raised if <code>newAttr</code> is already an 
 *   attribute of another <code>Element</code> object. The DOM user must 
 *   explicitly clone <code>Attr</code> nodes to re-use them in other 
 *   elements.
 */
Element.prototype.setAttributeNode = function (newAttr)
{
	if (this.__attributes == null)
	{
		this.__attributes = new HashMap();
	}
	var name = newAttr.getName();
	var oldAttr = this.__attributes.get(name);
	if (oldAttr == newAttr)
	{
		return oldAttr;
	}
	if (oldAttr != null &&
		oldAttr.getOwnerElement() == this)
	{
		oldAttr.__ownerElement = null;
	}
	this.__attributes.put(name, newAttr);
	newAttr.__ownerElement = this;
	return oldAttr;
}

/**
 * Removes the specified attribute node. If the removed <code>Attr</code> 
 * has a default value it is immediately replaced. The replacing 
 * attribute has the same namespace URI and local name, as well as the 
 * original prefix, when applicable.
 * @param oldAttr The <code>Attr</code> node to remove from the attribute 
 *   list.
 * @return The <code>Attr</code> node that was removed.
 * @exception DOMException
 *   NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
 *   <br>NOT_FOUND_ERR: Raised if <code>oldAttr</code> is not an attribute 
 *   of the element.
 */
Element.prototype.removeAttributeNode = function (oldAttr)
{
	if (this.__attributes == null
		|| !this.__attributes.containsValue(oldAttr))
	{
		throw new DOMException(this.getClass().getName()
			+ ".removeAttributeNode(oldAttr) error: "
			+ "oldAttr is not an attribute of the element");
	}
	this.__attributes.remove(oldAttr.getName());
	if (oldAttr.getOwnerElement() == this)
	{
		oldAttr.__ownerElement = null;
	}
	return oldAttr;
}