QElement


1   /*
2    * Copyright (c) 1998-2006 Caucho Technology -- all rights reserved
3    *
4    * This file is part of Resin(R) Open Source
5    *
6    * Each copy or derived work must preserve the copyright notice and this
7    * notice unmodified.
8    *
9    * Resin Open Source is free software; you can redistribute it and/or modify
10   * it under the terms of the GNU General Public License as published by
11   * the Free Software Foundation; either version 2 of the License, or
12   * (at your option) any later version.
13   *
14   * Resin Open Source is distributed in the hope that it will be useful,
15   * but WITHOUT ANY WARRANTY; without even the implied warranty of
16   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
17   * of NON-INFRINGEMENT.  See the GNU General Public License for more
18   * details.
19   *
20   * You should have received a copy of the GNU General Public License
21   * along with Resin Open Source; if not, write to the
22   *   Free SoftwareFoundation, Inc.
23   *   59 Temple Place, Suite 330
24   *   Boston, MA 02111-1307  USA
25   *
26   * @author Scott Ferguson
27   */
28  
29  package com.caucho.xml2;
30  
31  import com.caucho.util.CharBuffer;
32  
33  import org.w3c.dom.*;
34  
35  import java.io.IOException  ;
36  import java.util.HashMap  ;
37  import javax.xml.namespace.QName  ;
38  
39  /**
40   * Resin's implementation of the DOM element.
41   */
42  public class QElement extends QAttributedNode implements CauchoElement {
43    private QName   _name;
44  
45    /**
46     * Create a new element.
47     */
48    public QElement()
49    {
50    }
51  
52    /**
53     * Create a new named element.
54     *
55     * @param name the element's name.
56     */
57    public QElement(String   name)
58    {
59      _name = new QName  (name);
60    }
61  
62    /**
63     * Create a new named element.
64     *
65     * @param name the element's name.
66     */
67    public QElement(String   name, String   namespace)
68    {
69      _name = new QName  (name, namespace);
70    }
71  
72    /**
73     * Create a new named element.
74     *
75     * @param name the element's name.
76     */
77    public QElement(QName   name)
78    { 
79      _name = name; 
80    }
81  
82    protected QElement(QDocument owner, QName   name)
83    {
84      _owner = owner;
85      _name = name;
86    }
87  
88    /**
89     * Create a new named element with initial parameters.
90     *
91     * @param name the element's name.
92     * @param attributes the element's attributes.
93     */
94    QElement(QName   name, HashMap   attributes)
95    { 
96      _name = name; 
97    }
98  
99    /**
100    * Assign a name to the element.  Not normally called by external
101    * API.
102    *
103    * @param name the element's name.
104    */
105   public void setName(QName   name)
106   {
107     _name = name;
108   }
109 
110   /**
111    * Returns the qname
112    */
113   public QName   getQName()
114   {
115     return _name;
116   }
117 
118   /**
119    * Returns the element's qualified-name as the node name.
120    */
121   public String   getNodeName()
122   {
123     return _name.getLocalPart();
124   }
125 
126   /**
127    * Returns the element's qualified-name as the node name.
128    */
129   public String   getTagName()
130   {
131     return _name.getLocalPart();
132   }
133 
134   /**
135    * Returns the local part of the element's name.
136    */
137   public String   getLocalName()
138   {
139     return _name.getLocalPart();
140   }
141 
142   /**
143    * Returns the namespace prefix for the element.
144    */
145   public String   getPrefix()
146   {
147     return _name.getPrefix();
148   }
149 
150   /**
151    * Returns the canonical name of the element.
152    */
153   public String   getCanonicalName()
154   {
155     return _name.toString();
156   }
157 
158   /**
159    * Returns the namespace of the element.
160    */
161   public String   getNamespaceURI()
162   {
163     return _name.getNamespaceURI();
164   }
165 
166   /**
167    * Given a prefix, returns the namespace in effect at this element.
168    *
169    * @param prefix the prefix to test.
170    * @return the namespace URL matching the prefix or null.
171    */
172   public String   getNamespace(String   prefix)
173   {
174     if (prefix == null)
175       return getNamespace("", "xmlns");
176     else
177       return getNamespace(prefix, "xmlns:" + prefix);
178   }
179 
180   private String   getNamespace(String   prefix, String   xmlns)
181   {
182     Attr namespace = getAttributeNode(xmlns);
183 
184     if (namespace != null)
185       return namespace.getNodeValue();
186 
187     if (_parent instanceof QElement)
188       return ((QElement) _parent).getNamespace(prefix, xmlns);
189 
190     return _owner.getNamespace(prefix);
191   }
192 
193   /**
194    * Returns the DOM NodeType, ELEMENT_NODE.
195    */
196   public short getNodeType()
197   {
198     return ELEMENT_NODE;
199   }
200 
201   /**
202    * Returns the schema type.
203    */
204   public TypeInfo getSchemaTypeInfo()
205   {
206     return null;
207   }
208 
209   /**
210    * Returns a list of elements, given a tag name.
211    */
212   public NodeList getElementsByTagName(String   tagName)
213   {
214     QAbstractNode child = (QAbstractNode) getFirstChild();
215     
216     if (child != null)
217       return new QDeepNodeList(this, child, new TagPredicate(tagName));
218     else
219       return new QDeepNodeList(this, null, new TagPredicate(tagName));
220   }
221   
222   /**
223    * Returns a list of elements, given a namespace and a local name.
224    */
225   public NodeList getElementsByTagNameNS(String   uri, String   name)
226   {
227     QAbstractNode child = (QAbstractNode) getFirstChild();
228     
229     if (child != null)
230       return new QDeepNodeList(this, child, new NSTagPredicate(uri, name));
231     else
232       return new QDeepNodeList(this, null, new NSTagPredicate(uri, name));
233   }
234 
235   /**
236    * Appends a new node as the last child of the element.
237    *
238    * @param child the new child.
239    * @return the child.
240    */
241   public Node appendChild(Node child)
242     throws DOMException
243   {
244     Node result = super.appendChild(child);
245 
246     if (child instanceof QElement) {
247       QElement elt = (QElement) child;
248       QName   name = elt._name;
249 
250       if (name.getNamespaceURI() != "") {
251         addNamespace(name);
252       }
253 
254       for (QAttr attr = (QAttr) elt.getFirstAttribute();
255        attr != null;
256        attr = (QAttr) attr.getNextSibling()) {
257     name = attr._name;
258 
259     if (name.getNamespaceURI() != "") {
260       addNamespace(name);
261     }
262       }
263     }
264 
265     return result;
266   }
267 
268   /**
269    * Adds the name to the global namespace, if possible.
270    */
271   void addNamespace(QName   name)
272   {
273     _owner.addNamespace(name.getPrefix(), name.getNamespaceURI());
274   }
275 
276   /**
277    * Normalize the element, i.e. smash all neighboring text nodes together.
278    */
279   public void normalize()
280   {
281     Node node = _firstChild;
282 
283     while (node != null) {
284       if (node.getNodeType() == TEXT_NODE &&
285       node.getNextSibling() != null &&
286       node.getNextSibling().getNodeType() == TEXT_NODE) {
287     Text text = (Text) node;
288     Text next = (Text) node.getNextSibling();
289     text.appendData(next.getData());
290     removeChild(next);
291       } else if (node.getNodeType() == ELEMENT_NODE) {
292     Element elt = (Element) node;
293     elt.normalize();
294     node = node.getNextSibling();
295       } else
296     node = node.getNextSibling();
297     }
298   }
299 
300   public boolean hasContent() 
301   {
302     return true;
303   }
304 
305   public boolean equals(Object   arg)
306   {
307     return this == arg;
308   }
309 
310   public boolean equals(Node arg, boolean deep)
311   {
312     return this == arg;
313   }
314 
315   /**
316    * Returns the text value of the element.  For an element, the text
317    * value is the smashing together of all the child text nodes.
318    */
319   public String   getTextValue()
320   {
321     CharBuffer cb = CharBuffer.allocate();
322 
323     for (QAbstractNode node = _firstChild; node != null; node = node._next) {
324       cb.append(node.getTextValue());
325     }
326 
327     return cb.close();
328   }
329 
330   void print(XmlPrinter out) throws IOException  
331   {
332     out.startElement(getNamespaceURI(), getLocalName(), getNodeName());
333     for (QAbstractNode node = (QAbstractNode) getFirstAttribute();
334          node != null;
335          node = (QAbstractNode) node.getNextSibling()) {
336       out.attribute(node.getNamespaceURI(),
337                     node.getLocalName(),
338                     node.getNodeName(),
339                     node.getNodeValue());
340     }
341     for (Node node = getFirstChild();
342          node != null;
343          node = node.getNextSibling()) {
344       ((QAbstractNode) node).print(out);
345     }
346     out.endElement(getNamespaceURI(), getLocalName(), getNodeName());
347   }
348 
349   public String   toString()
350   {
351     CharBuffer cb = CharBuffer.allocate();
352 
353     cb.append("Element[" + _name);
354 
355     for (QAttr attr = (QAttr) getFirstAttribute();
356          attr != null;
357          attr = (QAttr) attr.getNextSibling())
358       cb.append(" " + attr);
359     cb.append("]");
360 
361     return cb.close();
362   }
363 
364   private Object   writeReplace()
365   {
366     return new SerializedXml(this);
367   }
368 
369   static class TagPredicate implements QNodePredicate  {
370     String   _name;
371 
372     TagPredicate(String   name)
373     {
374       if (name == null)
375         name = "*";
376       
377       _name = name;
378     }
379 
380     public boolean isMatch(QAbstractNode node)
381     {
382       return (node.getNodeName().equals(_name) ||
383               _name.equals("*") && node instanceof Element);
384     }
385   }
386 
387   static class NSTagPredicate implements QNodePredicate  {
388     String   _uri;
389     String   _local;
390 
391     NSTagPredicate(String   uri, String   local)
392     {
393       _uri = uri;
394       _local = local;
395     }
396 
397     public boolean isMatch(QAbstractNode node)
398     {
399       return (_local.equals(node.getLocalName()) &&
400               _uri.equals(node.getNamespaceURI()));
401     }
402   }
403 }
404
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