Attributes


1   // HTMLParser Library $Name: v1_5_20050313 $ - A java-based parser for HTML
2   // http://sourceforge.org/projects/htmlparser
3   // Copyright (C) 2004 Derrick Oswald
4   //
5   // Revision Control Information
6   //
7   // $Source: /cvsroot/htmlparser/htmlparser/src/org/htmlparser/sax/Attributes.java,v $
8   // $Author: derrickoswald $
9   // $Date: 2004/07/14 01:58:02 $
10  // $Revision: 1.1 $
11  //
12  // This library is free software; you can redistribute it and/or
13  // modify it under the terms of the GNU Lesser General Public
14  // License as published by the Free Software Foundation; either
15  // version 2.1 of the License, or (at your option) any later version.
16  //
17  // This library is distributed in the hope that it will be useful,
18  // but WITHOUT ANY WARRANTY; without even the implied warranty of
19  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20  // Lesser General Public License for more details.
21  //
22  // You should have received a copy of the GNU Lesser General Public
23  // License along with this library; if not, write to the Free Software
24  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25  //
26  
27  package org.htmlparser.sax;
28  
29  import java.util.Vector  ;
30  
31  import org.htmlparser.Attribute;
32  import org.htmlparser.Tag;
33  import org.xml.sax.helpers.NamespaceSupport  ;
34  
35  /**
36   * Provides access to the tag attributes.
37   */
38  public class Attributes
39      implements
40          org.xml.sax.Attributes  
41  {
42      /**
43       * The tag from which attributes are exposed.
44       */
45      protected Tag mTag;
46      
47      /**
48       * The utility class that converts namespaces.
49       */
50      protected NamespaceSupport   mSupport;
51  
52      /**
53       * Elements of the qname.
54       * Allocated once for all uses of {@link #mSupport}.
55       */
56      protected String  [] mParts;
57  
58      /**
59       * Create an attibute access object.
60       * @param tag The tag to expose.
61       * @param support The namespace converter.
62       * @param parts The elements of the qualified name.
63       */
64      public Attributes (Tag tag, NamespaceSupport   support, String  [] parts)
65      {
66          mTag = tag;
67          mSupport = support;
68          mParts = parts;
69      }
70      
71  
72      ////////////////////////////////////////////////////////////////////
73      // Indexed access.
74      ////////////////////////////////////////////////////////////////////
75  
76  
77      /**
78       * Return the number of attributes in the list.
79       *
80       * <p>Once you know the number of attributes, you can iterate
81       * through the list.</p>
82       *
83       * @return The number of attributes in the list.
84       * @see #getURI(int)
85       * @see #getLocalName(int)
86       * @see #getQName(int)
87       * @see #getType(int)
88       * @see #getValue(int)
89       */
90      public int getLength ()
91      {
92          return (mTag.getAttributesEx ().size () - 1);
93      }
94  
95  
96      /**
97       * Look up an attribute's Namespace URI by index.
98       *
99       * @param index The attribute index (zero-based).
100      * @return The Namespace URI, or the empty string if none
101      *         is available, or null if the index is out of
102      *         range.
103      * @see #getLength
104      */
105     public String   getURI (int index)
106     {
107         mSupport.processName (getQName (index), mParts, true);
108         return (mParts[0]);
109     }
110 
111 
112     /**
113      * Look up an attribute's local name by index.
114      *
115      * @param index The attribute index (zero-based).
116      * @return The local name, or the empty string if Namespace
117      *         processing is not being performed, or null
118      *         if the index is out of range.
119      * @see #getLength
120      */
121     public String   getLocalName (int index)
122     {
123         mSupport.processName (getQName (index), mParts, true);
124         return (mParts[1]);
125     }
126 
127 
128     /**
129      * Look up an attribute's XML qualified (prefixed) name by index.
130      *
131      * @param index The attribute index (zero-based).
132      * @return The XML qualified name, or the empty string
133      *         if none is available, or null if the index
134      *         is out of range.
135      * @see #getLength
136      */
137     public String   getQName (int index)
138     {
139         Attribute attribute;
140         String   ret;
141         
142         attribute = (Attribute)(mTag.getAttributesEx ().elementAt (index + 1));
143         if (attribute.isWhitespace ())
144             ret = "#text";
145         else
146             ret = attribute.getName ();
147         
148         return (ret);
149     }
150 
151     /**
152      * Look up an attribute's type by index.
153      *
154      * <p>The attribute type is one of the strings "CDATA", "ID",
155      * "IDREF", "IDREFS", "NMTOKEN", "NMTOKENS", "ENTITY", "ENTITIES",
156      * or "NOTATION" (always in upper case).</p>
157      *
158      * <p>If the parser has not read a declaration for the attribute,
159      * or if the parser does not report attribute types, then it must
160      * return the value "CDATA" as stated in the XML 1.0 Recommendation
161      * (clause 3.3.3, "Attribute-Value Normalization").</p>
162      *
163      * <p>For an enumerated attribute that is not a notation, the
164      * parser will report the type as "NMTOKEN".</p>
165      *
166      * @param index The attribute index (zero-based).
167      * @return The attribute's type as a string, or null if the
168      *         index is out of range.
169      * @see #getLength
170      */
171     public String   getType (int index)
172     {
173         return ("CDATA");
174     }
175 
176 
177     /**
178      * Look up an attribute's value by index.
179      *
180      * <p>If the attribute value is a list of tokens (IDREFS,
181      * ENTITIES, or NMTOKENS), the tokens will be concatenated
182      * into a single string with each token separated by a
183      * single space.</p>
184      *
185      * @param index The attribute index (zero-based).
186      * @return The attribute's value as a string, or null if the
187      *         index is out of range.
188      * @see #getLength
189      */
190     public String   getValue (int index)
191     {
192         Attribute attribute;
193         String   ret;
194         
195         attribute = (Attribute)(mTag.getAttributesEx ().elementAt (index + 1));
196         ret = attribute.getValue ();
197         if (null == ret)
198             ret = "";
199 
200         return (ret);
201     }
202 
203 
204     ////////////////////////////////////////////////////////////////////
205     // Name-based query.
206     ////////////////////////////////////////////////////////////////////
207 
208 
209     /**
210      * Look up the index of an attribute by Namespace name.
211      *
212      * @param uri The Namespace URI, or the empty string if
213      *        the name has no Namespace URI.
214      * @param localName The attribute's local name.
215      * @return The index of the attribute, or -1 if it does not
216      *         appear in the list.
217      */
218     public int getIndex (String   uri, String   localName)
219     {
220         Vector   attributes;
221         int size;
222         Attribute attribute;
223         String   string;
224         int ret;
225 
226         ret = -1;
227 
228         attributes = mTag.getAttributesEx ();
229         if (null != attributes)
230         {
231             size = attributes.size ();
232             for (int i = 1; i < size; i++)
233             {
234                 attribute = (Attribute)attributes.elementAt (i);
235                 string = attribute.getName ();
236                 if (null != string) // not whitespace
237                 {
238                     mSupport.processName (string, mParts, true);
239                     if (  uri.equals (mParts[0])
240                         & localName.equalsIgnoreCase (mParts[1]))
241                     {
242                         ret = i;
243                         i = size; // exit fast
244                     }
245                 }
246             }
247         }
248 
249         return (ret);
250     }
251 
252 
253     /**
254      * Look up the index of an attribute by XML qualified (prefixed) name.
255      *
256      * @param qName The qualified (prefixed) name.
257      * @return The index of the attribute, or -1 if it does not
258      *         appear in the list.
259      */
260     public int getIndex (String   qName)
261     {
262         mSupport.processName (qName, mParts, true);
263         return (getIndex (mParts[0], mParts[1]));
264     }
265 
266 
267     /**
268      * Look up an attribute's type by Namespace name.
269      *
270      * <p>See {@link #getType(int) getType(int)} for a description
271      * of the possible types.</p>
272      *
273      * @param uri The Namespace URI, or the empty String if the
274      *        name has no Namespace URI.
275      * @param localName The local name of the attribute.
276      * @return The attribute type as a string, or null if the
277      *         attribute is not in the list or if Namespace
278      *         processing is not being performed.
279      */
280     public String   getType (String   uri, String   localName)
281     {
282         return (null);
283     }
284 
285 
286     /**
287      * Look up an attribute's type by XML qualified (prefixed) name.
288      *
289      * <p>See {@link #getType(int) getType(int)} for a description
290      * of the possible types.</p>
291      *
292      * @param qName The XML qualified name.
293      * @return The attribute type as a string, or null if the
294      *         attribute is not in the list or if qualified names
295      *         are not available.
296      */
297     public String   getType (String   qName)
298     {
299         return (null);
300     }
301 
302 
303     /**
304      * Look up an attribute's value by Namespace name.
305      *
306      * <p>See {@link #getValue(int) getValue(int)} for a description
307      * of the possible values.</p>
308      *
309      * @param uri The Namespace URI, or the empty String if the
310      *        name has no Namespace URI.
311      * @param localName The local name of the attribute.
312      * @return The attribute value as a string, or null if the
313      *         attribute is not in the list.
314      */
315     public String   getValue (String   uri, String   localName)
316     {
317         return (mTag.getAttribute (localName));
318     }
319 
320 
321     /**
322      * Look up an attribute's value by XML qualified (prefixed) name.
323      *
324      * <p>See {@link #getValue(int) getValue(int)} for a description
325      * of the possible values.</p>
326      *
327      * @param qName The XML qualified name.
328      * @return The attribute value as a string, or null if the
329      *         attribute is not in the list or if qualified names
330      *         are not available.
331      */
332     public String   getValue (String   qName)
333     {
334         mSupport.processName (qName, mParts, true);
335         return (getValue (mParts[0], mParts[1]));
336     }
337 }
338
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