001/*
002 * Copyright (c) 2004 World Wide Web Consortium,
003 *
004 * (Massachusetts Institute of Technology, European Research Consortium for
005 * Informatics and Mathematics, Keio University). All Rights Reserved. This
006 * work is distributed under the W3C(r) Software License [1] in the hope that
007 * it will be useful, but WITHOUT ANY WARRANTY; without even the implied
008 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
009 *
010 * [1] http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231
011 */
012
013package org.w3c.dom;
014
015/**
016 * The <code>Element</code> interface represents an element in an HTML or XML 
017 * document. Elements may have attributes associated with them; since the 
018 * <code>Element</code> interface inherits from <code>Node</code>, the 
019 * generic <code>Node</code> interface attribute <code>attributes</code> may 
020 * be used to retrieve the set of all attributes for an element. There are 
021 * methods on the <code>Element</code> interface to retrieve either an 
022 * <code>Attr</code> object by name or an attribute value by name. In XML, 
023 * where an attribute value may contain entity references, an 
024 * <code>Attr</code> object should be retrieved to examine the possibly 
025 * fairly complex sub-tree representing the attribute value. On the other 
026 * hand, in HTML, where all attributes have simple string values, methods to 
027 * directly access an attribute value can safely be used as a convenience.
028 * <p ><b>Note:</b> In DOM Level 2, the method <code>normalize</code> is 
029 * inherited from the <code>Node</code> interface where it was moved.
030 * <p>See also the <a href='http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407'>Document Object Model (DOM) Level 3 Core Specification</a>.
031 */
032public interface Element extends Node {
033    /**
034     * The name of the element. If <code>Node.localName</code> is different 
035     * from <code>null</code>, this attribute is a qualified name. For 
036     * example, in: 
037     * <pre> &lt;elementExample id="demo"&gt; ... 
038     * &lt;/elementExample&gt; , </pre>
039     *  <code>tagName</code> has the value 
040     * <code>"elementExample"</code>. Note that this is case-preserving in 
041     * XML, as are all of the operations of the DOM. The HTML DOM returns 
042     * the <code>tagName</code> of an HTML element in the canonical 
043     * uppercase form, regardless of the case in the source HTML document.
044     */
045    public String getTagName();
046
047    /**
048     * Retrieves an attribute value by name.
049     * @param name The name of the attribute to retrieve.
050     * @return The <code>Attr</code> value as a string, or the empty string 
051     *   if that attribute does not have a specified or default value.
052     */
053    public String getAttribute(String name);
054
055    /**
056     * Adds a new attribute. If an attribute with that name is already present 
057     * in the element, its value is changed to be that of the value 
058     * parameter. This value is a simple string; it is not parsed as it is 
059     * being set. So any markup (such as syntax to be recognized as an 
060     * entity reference) is treated as literal text, and needs to be 
061     * appropriately escaped by the implementation when it is written out. 
062     * In order to assign an attribute value that contains entity 
063     * references, the user must create an <code>Attr</code> node plus any 
064     * <code>Text</code> and <code>EntityReference</code> nodes, build the 
065     * appropriate subtree, and use <code>setAttributeNode</code> to assign 
066     * it as the value of an attribute.
067     * <br>To set an attribute with a qualified name and namespace URI, use 
068     * the <code>setAttributeNS</code> method.
069     * @param name The name of the attribute to create or alter.
070     * @param value Value to set in string form.
071     * @exception DOMException
072     *   INVALID_CHARACTER_ERR: Raised if the specified name is not an XML 
073     *   name according to the XML version in use specified in the 
074     *   <code>Document.xmlVersion</code> attribute.
075     *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
076     */
077    public void setAttribute(String name, 
078                             String value)
079                             throws DOMException;
080
081    /**
082     * Removes an attribute by name. If a default value for the removed 
083     * attribute is defined in the DTD, a new attribute immediately appears 
084     * with the default value as well as the corresponding namespace URI, 
085     * local name, and prefix when applicable. The implementation may handle 
086     * default values from other schemas similarly but applications should 
087     * use <code>Document.normalizeDocument()</code> to guarantee this 
088     * information is up-to-date.
089     * <br>If no attribute with this name is found, this method has no effect.
090     * <br>To remove an attribute by local name and namespace URI, use the 
091     * <code>removeAttributeNS</code> method.
092     * @param name The name of the attribute to remove.
093     * @exception DOMException
094     *   NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
095     */
096    public void removeAttribute(String name)
097                                throws DOMException;
098
099    /**
100     * Retrieves an attribute node by name.
101     * <br>To retrieve an attribute node by qualified name and namespace URI, 
102     * use the <code>getAttributeNodeNS</code> method.
103     * @param name The name (<code>nodeName</code>) of the attribute to 
104     *   retrieve.
105     * @return The <code>Attr</code> node with the specified name (
106     *   <code>nodeName</code>) or <code>null</code> if there is no such 
107     *   attribute.
108     */
109    public Attr getAttributeNode(String name);
110
111    /**
112     * Adds a new attribute node. If an attribute with that name (
113     * <code>nodeName</code>) is already present in the element, it is 
114     * replaced by the new one. Replacing an attribute node by itself has no 
115     * effect.
116     * <br>To add a new attribute node with a qualified name and namespace 
117     * URI, use the <code>setAttributeNodeNS</code> method.
118     * @param newAttr The <code>Attr</code> node to add to the attribute list.
119     * @return If the <code>newAttr</code> attribute replaces an existing 
120     *   attribute, the replaced <code>Attr</code> node is returned, 
121     *   otherwise <code>null</code> is returned.
122     * @exception DOMException
123     *   WRONG_DOCUMENT_ERR: Raised if <code>newAttr</code> was created from a 
124     *   different document than the one that created the element.
125     *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
126     *   <br>INUSE_ATTRIBUTE_ERR: Raised if <code>newAttr</code> is already an 
127     *   attribute of another <code>Element</code> object. The DOM user must 
128     *   explicitly clone <code>Attr</code> nodes to re-use them in other 
129     *   elements.
130     */
131    public Attr setAttributeNode(Attr newAttr)
132                                 throws DOMException;
133
134    /**
135     * Removes the specified attribute node. If a default value for the 
136     * removed <code>Attr</code> node is defined in the DTD, a new node 
137     * immediately appears with the default value as well as the 
138     * corresponding namespace URI, local name, and prefix when applicable. 
139     * The implementation may handle default values from other schemas 
140     * similarly but applications should use 
141     * <code>Document.normalizeDocument()</code> to guarantee this 
142     * information is up-to-date.
143     * @param oldAttr The <code>Attr</code> node to remove from the attribute 
144     *   list.
145     * @return The <code>Attr</code> node that was removed.
146     * @exception DOMException
147     *   NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
148     *   <br>NOT_FOUND_ERR: Raised if <code>oldAttr</code> is not an attribute 
149     *   of the element.
150     */
151    public Attr removeAttributeNode(Attr oldAttr)
152                                    throws DOMException;
153
154    /**
155     * Returns a <code>NodeList</code> of all descendant <code>Elements</code> 
156     * with a given tag name, in document order.
157     * @param name The name of the tag to match on. The special value "*" 
158     *   matches all tags.
159     * @return A list of matching <code>Element</code> nodes.
160     */
161    public NodeList getElementsByTagName(String name);
162
163    /**
164     * Retrieves an attribute value by local name and namespace URI.
165     * <br>Per [<a href='http://www.w3.org/TR/1999/REC-xml-names-19990114/'>XML Namespaces</a>]
166     * , applications must use the value <code>null</code> as the 
167     * <code>namespaceURI</code> parameter for methods if they wish to have 
168     * no namespace.
169     * @param namespaceURI The namespace URI of the attribute to retrieve.
170     * @param localName The local name of the attribute to retrieve.
171     * @return The <code>Attr</code> value as a string, or the empty string 
172     *   if that attribute does not have a specified or default value.
173     * @exception DOMException
174     *   NOT_SUPPORTED_ERR: May be raised if the implementation does not 
175     *   support the feature <code>"XML"</code> and the language exposed 
176     *   through the Document does not support XML Namespaces (such as [<a href='http://www.w3.org/TR/1999/REC-html401-19991224/'>HTML 4.01</a>]). 
177     * @since DOM Level 2
178     */
179    public String getAttributeNS(String namespaceURI, 
180                                 String localName)
181                                 throws DOMException;
182
183    /**
184     * Adds a new attribute. If an attribute with the same local name and 
185     * namespace URI is already present on the element, its prefix is 
186     * changed to be the prefix part of the <code>qualifiedName</code>, and 
187     * its value is changed to be the <code>value</code> parameter. This 
188     * value is a simple string; it is not parsed as it is being set. So any 
189     * markup (such as syntax to be recognized as an entity reference) is 
190     * treated as literal text, and needs to be appropriately escaped by the 
191     * implementation when it is written out. In order to assign an 
192     * attribute value that contains entity references, the user must create 
193     * an <code>Attr</code> node plus any <code>Text</code> and 
194     * <code>EntityReference</code> nodes, build the appropriate subtree, 
195     * and use <code>setAttributeNodeNS</code> or 
196     * <code>setAttributeNode</code> to assign it as the value of an 
197     * attribute.
198     * <br>Per [<a href='http://www.w3.org/TR/1999/REC-xml-names-19990114/'>XML Namespaces</a>]
199     * , applications must use the value <code>null</code> as the 
200     * <code>namespaceURI</code> parameter for methods if they wish to have 
201     * no namespace.
202     * @param namespaceURI The namespace URI of the attribute to create or 
203     *   alter.
204     * @param qualifiedName The qualified name of the attribute to create or 
205     *   alter.
206     * @param value The value to set in string form.
207     * @exception DOMException
208     *   INVALID_CHARACTER_ERR: Raised if the specified qualified name is not 
209     *   an XML name according to the XML version in use specified in the 
210     *   <code>Document.xmlVersion</code> attribute.
211     *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
212     *   <br>NAMESPACE_ERR: Raised if the <code>qualifiedName</code> is 
213     *   malformed per the Namespaces in XML specification, if the 
214     *   <code>qualifiedName</code> has a prefix and the 
215     *   <code>namespaceURI</code> is <code>null</code>, if the 
216     *   <code>qualifiedName</code> has a prefix that is "xml" and the 
217     *   <code>namespaceURI</code> is different from "<a href='http://www.w3.org/XML/1998/namespace'>
218     *   http://www.w3.org/XML/1998/namespace</a>", if the <code>qualifiedName</code> or its prefix is "xmlns" and the 
219     *   <code>namespaceURI</code> is different from "<a href='http://www.w3.org/2000/xmlns/'>http://www.w3.org/2000/xmlns/</a>", or if the <code>namespaceURI</code> is "<a href='http://www.w3.org/2000/xmlns/'>http://www.w3.org/2000/xmlns/</a>" and neither the <code>qualifiedName</code> nor its prefix is "xmlns".
220     *   <br>NOT_SUPPORTED_ERR: May be raised if the implementation does not 
221     *   support the feature <code>"XML"</code> and the language exposed 
222     *   through the Document does not support XML Namespaces (such as [<a href='http://www.w3.org/TR/1999/REC-html401-19991224/'>HTML 4.01</a>]). 
223     * @since DOM Level 2
224     */
225    public void setAttributeNS(String namespaceURI, 
226                               String qualifiedName, 
227                               String value)
228                               throws DOMException;
229
230    /**
231     * Removes an attribute by local name and namespace URI. If a default 
232     * value for the removed attribute is defined in the DTD, a new 
233     * attribute immediately appears with the default value as well as the 
234     * corresponding namespace URI, local name, and prefix when applicable. 
235     * The implementation may handle default values from other schemas 
236     * similarly but applications should use 
237     * <code>Document.normalizeDocument()</code> to guarantee this 
238     * information is up-to-date.
239     * <br>If no attribute with this local name and namespace URI is found, 
240     * this method has no effect.
241     * <br>Per [<a href='http://www.w3.org/TR/1999/REC-xml-names-19990114/'>XML Namespaces</a>]
242     * , applications must use the value <code>null</code> as the 
243     * <code>namespaceURI</code> parameter for methods if they wish to have 
244     * no namespace.
245     * @param namespaceURI The namespace URI of the attribute to remove.
246     * @param localName The local name of the attribute to remove.
247     * @exception DOMException
248     *   NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
249     *   <br>NOT_SUPPORTED_ERR: May be raised if the implementation does not 
250     *   support the feature <code>"XML"</code> and the language exposed 
251     *   through the Document does not support XML Namespaces (such as [<a href='http://www.w3.org/TR/1999/REC-html401-19991224/'>HTML 4.01</a>]). 
252     * @since DOM Level 2
253     */
254    public void removeAttributeNS(String namespaceURI, 
255                                  String localName)
256                                  throws DOMException;
257
258    /**
259     * Retrieves an <code>Attr</code> node by local name and namespace URI.
260     * <br>Per [<a href='http://www.w3.org/TR/1999/REC-xml-names-19990114/'>XML Namespaces</a>]
261     * , applications must use the value <code>null</code> as the 
262     * <code>namespaceURI</code> parameter for methods if they wish to have 
263     * no namespace.
264     * @param namespaceURI The namespace URI of the attribute to retrieve.
265     * @param localName The local name of the attribute to retrieve.
266     * @return The <code>Attr</code> node with the specified attribute local 
267     *   name and namespace URI or <code>null</code> if there is no such 
268     *   attribute.
269     * @exception DOMException
270     *   NOT_SUPPORTED_ERR: May be raised if the implementation does not 
271     *   support the feature <code>"XML"</code> and the language exposed 
272     *   through the Document does not support XML Namespaces (such as [<a href='http://www.w3.org/TR/1999/REC-html401-19991224/'>HTML 4.01</a>]). 
273     * @since DOM Level 2
274     */
275    public Attr getAttributeNodeNS(String namespaceURI, 
276                                   String localName)
277                                   throws DOMException;
278
279    /**
280     * Adds a new attribute. If an attribute with that local name and that 
281     * namespace URI is already present in the element, it is replaced by 
282     * the new one. Replacing an attribute node by itself has no effect.
283     * <br>Per [<a href='http://www.w3.org/TR/1999/REC-xml-names-19990114/'>XML Namespaces</a>]
284     * , applications must use the value <code>null</code> as the 
285     * <code>namespaceURI</code> parameter for methods if they wish to have 
286     * no namespace.
287     * @param newAttr The <code>Attr</code> node to add to the attribute list.
288     * @return If the <code>newAttr</code> attribute replaces an existing 
289     *   attribute with the same local name and namespace URI, the replaced 
290     *   <code>Attr</code> node is returned, otherwise <code>null</code> is 
291     *   returned.
292     * @exception DOMException
293     *   WRONG_DOCUMENT_ERR: Raised if <code>newAttr</code> was created from a 
294     *   different document than the one that created the element.
295     *   <br>NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
296     *   <br>INUSE_ATTRIBUTE_ERR: Raised if <code>newAttr</code> is already an 
297     *   attribute of another <code>Element</code> object. The DOM user must 
298     *   explicitly clone <code>Attr</code> nodes to re-use them in other 
299     *   elements.
300     *   <br>NOT_SUPPORTED_ERR: May be raised if the implementation does not 
301     *   support the feature <code>"XML"</code> and the language exposed 
302     *   through the Document does not support XML Namespaces (such as [<a href='http://www.w3.org/TR/1999/REC-html401-19991224/'>HTML 4.01</a>]). 
303     * @since DOM Level 2
304     */
305    public Attr setAttributeNodeNS(Attr newAttr)
306                                   throws DOMException;
307
308    /**
309     * Returns a <code>NodeList</code> of all the descendant 
310     * <code>Elements</code> with a given local name and namespace URI in 
311     * document order.
312     * @param namespaceURI The namespace URI of the elements to match on. The 
313     *   special value "*" matches all namespaces.
314     * @param localName The local name of the elements to match on. The 
315     *   special value "*" matches all local names.
316     * @return A new <code>NodeList</code> object containing all the matched 
317     *   <code>Elements</code>.
318     * @exception DOMException
319     *   NOT_SUPPORTED_ERR: May be raised if the implementation does not 
320     *   support the feature <code>"XML"</code> and the language exposed 
321     *   through the Document does not support XML Namespaces (such as [<a href='http://www.w3.org/TR/1999/REC-html401-19991224/'>HTML 4.01</a>]). 
322     * @since DOM Level 2
323     */
324    public NodeList getElementsByTagNameNS(String namespaceURI, 
325                                           String localName)
326                                           throws DOMException;
327
328    /**
329     * Returns <code>true</code> when an attribute with a given name is 
330     * specified on this element or has a default value, <code>false</code> 
331     * otherwise.
332     * @param name The name of the attribute to look for.
333     * @return <code>true</code> if an attribute with the given name is 
334     *   specified on this element or has a default value, <code>false</code>
335     *    otherwise.
336     * @since DOM Level 2
337     */
338    public boolean hasAttribute(String name);
339
340    /**
341     * Returns <code>true</code> when an attribute with a given local name and 
342     * namespace URI is specified on this element or has a default value, 
343     * <code>false</code> otherwise.
344     * <br>Per [<a href='http://www.w3.org/TR/1999/REC-xml-names-19990114/'>XML Namespaces</a>]
345     * , applications must use the value <code>null</code> as the 
346     * <code>namespaceURI</code> parameter for methods if they wish to have 
347     * no namespace.
348     * @param namespaceURI The namespace URI of the attribute to look for.
349     * @param localName The local name of the attribute to look for.
350     * @return <code>true</code> if an attribute with the given local name 
351     *   and namespace URI is specified or has a default value on this 
352     *   element, <code>false</code> otherwise.
353     * @exception DOMException
354     *   NOT_SUPPORTED_ERR: May be raised if the implementation does not 
355     *   support the feature <code>"XML"</code> and the language exposed 
356     *   through the Document does not support XML Namespaces (such as [<a href='http://www.w3.org/TR/1999/REC-html401-19991224/'>HTML 4.01</a>]). 
357     * @since DOM Level 2
358     */
359    public boolean hasAttributeNS(String namespaceURI, 
360                                  String localName)
361                                  throws DOMException;
362
363    /**
364     *  The type information associated with this element. 
365     * @since DOM Level 3
366     */
367    public TypeInfo getSchemaTypeInfo();
368
369    /**
370     *  If the parameter <code>isId</code> is <code>true</code>, this method 
371     * declares the specified attribute to be a user-determined ID attribute
372     * . This affects the value of <code>Attr.isId</code> and the behavior 
373     * of <code>Document.getElementById</code>, but does not change any 
374     * schema that may be in use, in particular this does not affect the 
375     * <code>Attr.schemaTypeInfo</code> of the specified <code>Attr</code> 
376     * node. Use the value <code>false</code> for the parameter 
377     * <code>isId</code> to undeclare an attribute for being a 
378     * user-determined ID attribute. 
379     * <br> To specify an attribute by local name and namespace URI, use the 
380     * <code>setIdAttributeNS</code> method. 
381     * @param name The name of the attribute.
382     * @param isId Whether the attribute is a of type ID.
383     * @exception DOMException
384     *   NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
385     *   <br>NOT_FOUND_ERR: Raised if the specified node is not an attribute 
386     *   of this element.
387     * @since DOM Level 3
388     */
389    public void setIdAttribute(String name, 
390                               boolean isId)
391                               throws DOMException;
392
393    /**
394     *  If the parameter <code>isId</code> is <code>true</code>, this method 
395     * declares the specified attribute to be a user-determined ID attribute
396     * . This affects the value of <code>Attr.isId</code> and the behavior 
397     * of <code>Document.getElementById</code>, but does not change any 
398     * schema that may be in use, in particular this does not affect the 
399     * <code>Attr.schemaTypeInfo</code> of the specified <code>Attr</code> 
400     * node. Use the value <code>false</code> for the parameter 
401     * <code>isId</code> to undeclare an attribute for being a 
402     * user-determined ID attribute. 
403     * @param namespaceURI The namespace URI of the attribute.
404     * @param localName The local name of the attribute.
405     * @param isId Whether the attribute is a of type ID.
406     * @exception DOMException
407     *   NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
408     *   <br>NOT_FOUND_ERR: Raised if the specified node is not an attribute 
409     *   of this element.
410     * @since DOM Level 3
411     */
412    public void setIdAttributeNS(String namespaceURI, 
413                                 String localName, 
414                                 boolean isId)
415                                 throws DOMException;
416
417    /**
418     *  If the parameter <code>isId</code> is <code>true</code>, this method 
419     * declares the specified attribute to be a user-determined ID attribute
420     * . This affects the value of <code>Attr.isId</code> and the behavior 
421     * of <code>Document.getElementById</code>, but does not change any 
422     * schema that may be in use, in particular this does not affect the 
423     * <code>Attr.schemaTypeInfo</code> of the specified <code>Attr</code> 
424     * node. Use the value <code>false</code> for the parameter 
425     * <code>isId</code> to undeclare an attribute for being a 
426     * user-determined ID attribute. 
427     * @param idAttr The attribute node.
428     * @param isId Whether the attribute is a of type ID.
429     * @exception DOMException
430     *   NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
431     *   <br>NOT_FOUND_ERR: Raised if the specified node is not an attribute 
432     *   of this element.
433     * @since DOM Level 3
434     */
435    public void setIdAttributeNode(Attr idAttr, 
436                                   boolean isId)
437                                   throws DOMException;
438
439}