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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.xerces.dom;
import org.w3c.dom.DocumentFragment;
import org.w3c.dom.Node;
import org.w3c.dom.Text;
/**
* DocumentFragment is a "lightweight" or "minimal" Document
* object. It is very common to want to be able to extract a portion
* of a document's tree or to create a new fragment of a
* document. Imagine implementing a user command like cut or
* rearranging a document by moving fragments around. It is desirable
* to have an object which can hold such fragments and it is quite
* natural to use a Node for this purpose. While it is true that a
* Document object could fulfil this role, a Document object can
* potentially be a heavyweight object, depending on the underlying
* implementation... and in DOM Level 1, nodes aren't allowed to cross
* Document boundaries anyway. What is really needed for this is a
* very lightweight object. DocumentFragment is such an object.
*
* Furthermore, various operations -- such as inserting nodes as
* children of another Node -- may take DocumentFragment objects as
* arguments; this results in all the child nodes of the
* DocumentFragment being moved to the child list of this node.
*
* The children of a DocumentFragment node are zero or more nodes
* representing the tops of any sub-trees defining the structure of
* the document. DocumentFragment do not need to be well-formed XML
* documents (although they do need to follow the rules imposed upon
* well-formed XML parsed entities, which can have multiple top
* nodes). For example, a DocumentFragment might have only one child
* and that child node could be a Text node. Such a structure model
* represents neither an HTML document nor a well-formed XML document.
*
* When a DocumentFragment is inserted into a Document (or indeed any
* other Node that may take children) the children of the
* DocumentFragment and not the DocumentFragment itself are inserted
* into the Node. This makes the DocumentFragment very useful when the
* user wishes to create nodes that are siblings; the DocumentFragment
* acts as the parent of these nodes so that the user can use the
* standard methods from the Node interface, such as insertBefore()
* and appendChild().
*
* @xerces.internal
*
* @version $Id: DocumentFragmentImpl.java 447266 2006-09-18 05:57:49Z mrglavas $
* @since PR-DOM-Level-1-19980818.
*/
public class DocumentFragmentImpl
extends ParentNode
implements DocumentFragment {
//
// Constants
//
/** Serialization version. */
static final long serialVersionUID = -7596449967279236746L;
//
// Constructors
//
/** Factory constructor. */
public DocumentFragmentImpl(CoreDocumentImpl ownerDoc) {
super(ownerDoc);
}
/** Constructor for serialization. */
public DocumentFragmentImpl() {}
//
// Node methods
//
/**
* A short integer indicating what type of node this is. The named
* constants for this value are defined in the org.w3c.dom.Node interface.
*/
public short getNodeType() {
return Node.DOCUMENT_FRAGMENT_NODE;
}
/** Returns the node name. */
public String getNodeName() {
return "#document-fragment";
}
/**
* Override default behavior to call normalize() on this Node's
* children. It is up to implementors or Node to override normalize()
* to take action.
*/
public void normalize() {
// No need to normalize if already normalized.
if (isNormalized()) {
return;
}
if (needsSyncChildren()) {
synchronizeChildren();
}
ChildNode kid, next;
for (kid = firstChild; kid != null; kid = next) {
next = kid.nextSibling;
// If kid is a text node, we need to check for one of two
// conditions:
// 1) There is an adjacent text node
// 2) There is no adjacent text node, but kid is
// an empty text node.
if ( kid.getNodeType() == Node.TEXT_NODE )
{
// If an adjacent text node, merge it with kid
if ( next!=null && next.getNodeType() == Node.TEXT_NODE )
{
((Text)kid).appendData(next.getNodeValue());
removeChild( next );
next = kid; // Don't advance; there might be another.
}
else
{
// If kid is empty, remove it
if ( kid.getNodeValue() == null || kid.getNodeValue().length() == 0 ) {
removeChild( kid );
}
}
}
kid.normalize();
}
isNormalized(true);
}
} // class DocumentFragmentImpl