CollectionTagsHandler


1   /*
2    * Copyright (c) 2001, 2002 The XDoclet team
3    * All rights reserved.
4    */
5   package xdoclet.modules.util;
6   
7   import java.util.*;
8   
9   import xdoclet.*;
10  import xdoclet.util.Translator;
11  
12  /**
13   * This taghandler puts together some utility tags useful during template processing. For now, contains only a mechanism
14   * to manage collections of strings
15   *
16   * @author               Marcus Brito (pazu@animegaiden.com.br)
17   * @created              25 Jun 2002
18   * @xdoclet.taghandler   namespace="Collection"
19   * @version              $Revision: 1.2 $
20   */
21  public class CollectionTagsHandler extends XDocletTagSupport
22  {
23      // This will be a map of collections
24      private Map     collections = new HashMap();
25  
26      /**
27       * Obtains one value contained in the collection. This tag only apply to map valued collections, and an xdoclet
28       * exception will be throw if the specified collection is not a map.
29       *
30       * @param attributes         The attributes of the template tag
31       * @return                   The requested value or null if no such value exists.
32       * @throws XDocletException  if something goes wrong
33       * @doc.tag                  type="content"
34       * @doc.param                name="key" optional="false" description="The collection to operate on."
35       * @doc.param                name="name" optional="false" description="The key to retrive."
36       */
37      public String   get(Properties attributes) throws XDocletException
38      {
39          String   name = attributes.getProperty("name");
40          String   key = attributes.getProperty("key");
41  
42          // Makes sure name is specified
43          if (name == null || name.length() == 0) {
44              throw new XDocletException(Translator.getString(XDocletMessages.class,
45                  XDocletMessages.PARAMETER_MISSING_OR_EMPTY, new String  []{"name"}));
46          }
47  
48          // Makes key is specified
49          if (key == null || key.length() == 0) {
50              throw new XDocletException(Translator.getString(XDocletMessages.class,
51                  XDocletMessages.PARAMETER_MISSING_OR_EMPTY, new String  []{"key"}));
52          }
53  
54          // Makes sure the name exists
55          if (!collections.containsKey(name)) {
56              throw new XDocletException(Translator.getString(CollectionMessages.class,
57                  CollectionMessages.COLLECTION_NOT_DEFINED, new String  []{name}));
58          }
59  
60          // Make sure the name is a map
61          if (!(collections.get(name) instanceof Map)) {
62              throw new XDocletException(Translator.getString(CollectionMessages.class,
63                  CollectionMessages.COLLECTION_IS_NOT_MAP, new String  []{name}));
64          }
65  
66          return (String  ) ((Map) collections.get(name)).get(key);
67      }
68  
69  
70      /**
71       * Creates a new utility collection that will store template data. If a collection with the specified name already
72       * exists, an XDocletException will be thrown.
73       *
74       * @param attributes         The attributes of the template tag
75       * @throws XDocletException  if something goes wrong
76       * @doc.tag                  type="content"
77       * @doc.param                name="name" optional="false" description="The name for the newly created collection"
78       * @doc.param                name="type" optional="true" values="map,set" description="The type of the collection to
79       *      create. Default value is set"
80       */
81      public void create(Properties attributes) throws XDocletException
82      {
83          String   name = attributes.getProperty("name");
84          String   type = attributes.getProperty("type");
85  
86          // Make sure name is specified
87          if (name == null || name.length() == 0) {
88              throw new XDocletException(Translator.getString(XDocletMessages.class,
89                  XDocletMessages.PARAMETER_MISSING_OR_EMPTY, new String  []{"name"}));
90          }
91  
92          // Prevent collection overwriting
93          if (collections.containsKey(name)) {
94              throw new XDocletException(Translator.getString(CollectionMessages.class,
95                  CollectionMessages.COLLECTION_ALREADY_EXISTS, new String  []{name}));
96          }
97  
98          // Creates a new map or set, as requested
99          if ("map".equals(type))
100             collections.put(name, new HashMap());
101         else
102             collections.put(name, new HashSet());
103     }
104 
105     /**
106      * Puts a new element into the specified collection. If the collection is a set, only the 'name' and 'value'
107      * attributes should be specified. If the collection is a map, the 'key' value should also be specified. If the
108      * 'key' is specified and the collection is a set, or if 'key' is not specified and the collection is a map, an
109      * XDocletException will be thrown.
110      *
111      * @param attributes         The attributes of the template tag
112      * @throws XDocletException  if something goes wrong
113      * @doc.tag                  type="content"
114      * @doc.param                name="name" optional="false" description="The name of the collection to operate on. If
115      *      the collection does not exists, an execption will be thrown."
116      * @doc.param                name="key" optional="true" description="The key to the new value. Should only be
117      *      specified if the collection is a map."
118      * @doc.param                name="value" optional="false" description="The value to put into the collection."
119      */
120     public void put(Properties attributes) throws XDocletException
121     {
122         String   name = attributes.getProperty("name");
123         String   key = attributes.getProperty("key");
124         String   value = attributes.getProperty("value");
125 
126         // Makes sure name is specified
127         if (name == null || name.length() == 0) {
128             throw new XDocletException(Translator.getString(XDocletMessages.class,
129                 XDocletMessages.PARAMETER_MISSING_OR_EMPTY, new String  []{"name"}));
130         }
131 
132         // Makes sure value is specified
133         if (value == null || value.length() == 0) {
134             throw new XDocletException(Translator.getString(XDocletMessages.class,
135                 XDocletMessages.PARAMETER_MISSING_OR_EMPTY, new String  []{"value"}));
136         }
137 
138         // Make sure the collection exists
139         if (!collections.containsKey(name)) {
140             throw new XDocletException(Translator.getString(CollectionMessages.class,
141                 CollectionMessages.COLLECTION_NOT_DEFINED, new String  []{name}));
142         }
143 
144         // Puts the value into the collection, as requested
145         if (collections.get(name) instanceof Map) {
146             if (key == null || key.length() == 0) {
147                 throw new XDocletException(Translator.getString(XDocletMessages.class,
148                     XDocletMessages.PARAMETER_MISSING_OR_EMPTY, new String  []{"key"}));
149             }
150 
151             ((Map) collections.get(name)).put(key, value);
152         }
153         else {
154             // Throws an exception if key is specified
155             if (key != null) {
156                 throw new XDocletException(Translator.getString(CollectionMessages.class,
157                     CollectionMessages.COLLECTION_IS_NOT_MAP, new String  []{name}));
158             }
159 
160             ((Set) collections.get(name)).add(value);
161         }
162     }
163 
164 
165     /**
166      * Removes an element from the specified collection. One of 'key' or 'value' attributes should be specified,
167      * depending if the collection is a map or a set.
168      *
169      * @param attributes         The attributes of the template tag
170      * @throws XDocletException  if something goes wrong
171      * @doc.tag                  type="content"
172      * @doc.param                name="name" optional="false" description="The name of the collection to operate on. If
173      *      the collection does not exists, an execption will be thrown."
174      * @doc.param                name="key" optional="true" description="The key to remove from the map. Invalid if the
175      *      collection is a set."
176      * @doc.param                name="value" optional="true" description="The value to remove from the set. Invalid if
177      *      the collection is a map."
178      */
179     public void remove(Properties attributes) throws XDocletException
180     {
181         String   name = attributes.getProperty("name");
182         String   key = attributes.getProperty("key");
183         String   value = attributes.getProperty("value");
184 
185         // Makes sure name is specified
186         if (name == null || name.length() == 0) {
187             throw new XDocletException(Translator.getString(XDocletMessages.class,
188                 XDocletMessages.PARAMETER_MISSING_OR_EMPTY, new String  []{"name"}));
189         }
190 
191         // Make sure name exists
192         if (!collections.containsKey(name)) {
193             throw new XDocletException(Translator.getString(CollectionMessages.class,
194                 CollectionMessages.COLLECTION_NOT_DEFINED, new String  []{name}));
195         }
196 
197         // Removes the key from the name, as requested
198         if (collections.get(name) instanceof Map) {
199             // Makes sure key is specified
200             if (key == null || key.length() == 0) {
201                 throw new XDocletException(Translator.getString(XDocletMessages.class,
202                     XDocletMessages.PARAMETER_MISSING_OR_EMPTY, new String  []{"key"}));
203             }
204 
205             ((Map) collections.get(name)).remove(key);
206         }
207         else {
208             // Makes sure value is specified
209             if (value == null || value.length() == 0) {
210                 throw new XDocletException(Translator.getString(XDocletMessages.class,
211                     XDocletMessages.PARAMETER_MISSING_OR_EMPTY, new String  []{"value"}));
212             }
213 
214             ((Set) collections.get(name)).remove(key);
215         }
216     }
217 
218     /**
219      * Generates the contained template code if the specified collection contains the key or value passed as attributes.
220      * If the collection is a set, only the 'value' attribute should be specified. If the collection is a map, the 'key'
221      * attribute should be specifed and if the 'value' attribute is also specified, an additional check for equality
222      * will be made.
223      *
224      * @param template              The block tag contents
225      * @param attributes            The attributes of the tag template
226      * @exception XDocletException
227      * @doc.tag                     type="block"
228      * @doc.param                   name="name" optional="false" description="The collection to operate on."
229      * @doc.param                   name="key" optional="true" description="The key to check, if the collection is a
230      *      map."
231      * @doc.param                   name="value" optional="true" description="The valu to check, if the collection is a
232      *      set. If the collection is a map, the value to check for equality."
233      */
234     public void ifContains(String   template, Properties attributes) throws XDocletException
235     {
236         if (contains(attributes))
237             generate(template);
238     }
239 
240     /**
241      * Generates the contained template code if the specified collection doesn't contain the key or value passed as
242      * attributes. If the collection is a set, only the 'value' attribute should be specified. If the collection is a
243      * map, the 'key' attribute should be specifed and if the 'value' attribute is also specified, an additional check
244      * for equality will be made.
245      *
246      * @param template              The block tag contents
247      * @param attributes            The attributes of the tag template
248      * @exception XDocletException
249      * @doc.tag                     type="block"
250      * @doc.param                   name="name" optional="false" description="The collection to operate on."
251      * @doc.param                   name="key" optional="true" description="The key to check, if the collection is a
252      *      map."
253      * @doc.param                   name="value" optional="true" description="The valu to check, if the collection is a
254      *      set. If the collection is a map, the value to check for equality."
255      */
256     public void ifDoesntContain(String   template, Properties attributes) throws XDocletException
257     {
258         if (!contains(attributes))
259             generate(template);
260     }
261 
262     /**
263      * Destroys the specified collection. The collection must exists or an exception will be thrown.
264      *
265      * @param attributes         The attributes of the tag template
266      * @throws XDocletException  if something goes wrong
267      * @doc.tag                  type="content"
268      * @doc.param                name="name" description="The collection to destroy."
269      */
270     public void destroy(Properties attributes) throws XDocletException
271     {
272         String   name = attributes.getProperty("name");
273 
274         // Makes sure name is specified
275         if (name == null || name.length() == 0) {
276             throw new XDocletException(Translator.getString(XDocletMessages.class,
277                 XDocletMessages.PARAMETER_MISSING_OR_EMPTY, new String  []{"name"}));
278         }
279 
280         // Makes sure name exists
281         if (!collections.containsKey(name)) {
282             throw new XDocletException(Translator.getString(CollectionMessages.class,
283                 CollectionMessages.COLLECTION_NOT_DEFINED, new String  []{name}));
284         }
285 
286         collections.remove(name);
287     }
288 
289 
290     /**
291      * Checks if the specified collection contains a certain key/value. If the collection is a set, only the 'value'
292      * attribute should be specified. If the collection is a map, the 'key' value should be specified and if the 'value'
293      * attribute is also specified, an additional check for equality will be made.
294      *
295      * @param attributes            The attributes of the template tag
296      * @return
297      * @exception XDocletException
298      */
299     private boolean contains(Properties attributes) throws XDocletException
300     {
301         String   name = attributes.getProperty("name");
302         String   key = attributes.getProperty("key");
303         String   value = attributes.getProperty("value");
304 
305         // Makes sure name is specified
306         if (name == null || name.length() == 0) {
307             throw new XDocletException(Translator.getString(XDocletMessages.class,
308                 XDocletMessages.PARAMETER_MISSING_OR_EMPTY, new String  []{"name"}));
309         }
310 
311         // Make sure name exists
312         if (!collections.containsKey(name)) {
313             throw new XDocletException(Translator.getString(CollectionMessages.class,
314                 CollectionMessages.COLLECTION_NOT_DEFINED, new String  []{name}));
315         }
316 
317         // Checks if the collection contains the key/value specified
318         if (collections.get(name) instanceof Map) {
319             // Makes sure key is specified
320             if (key == null || key.length() == 0) {
321                 throw new XDocletException(Translator.getString(XDocletMessages.class,
322                     XDocletMessages.PARAMETER_MISSING_OR_EMPTY, new String  []{"key"}));
323             }
324 
325             // If value is specified, checks for equality
326             if (value == null)
327                 return ((Map) collections.get(name)).containsKey(key);
328             else
329                 return value.equals(((Map) collections.get(name)).get(key));
330         }
331         else {
332             // Makes sure value is specified
333             if (value == null || value.length() == 0) {
334                 throw new XDocletException(Translator.getString(XDocletMessages.class,
335                     XDocletMessages.PARAMETER_MISSING_OR_EMPTY, new String  []{"value"}));
336             }
337 
338             return ((Set) collections.get(name)).contains(value);
339         }
340     }
341 }
342
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