ImgTag


1   /*
2    * $Id: ImgTag.java 164927 2005-04-27 00:41:05Z niallp $ 
3    *
4    * Copyright 1999-2005 The Apache Software Foundation.
5    * 
6    * Licensed under the Apache License, Version 2.0 (the "License");
7    * you may not use this file except in compliance with the License.
8    * You may obtain a copy of the License at
9    * 
10   *      http://www.apache.org/licenses/LICENSE-2.0
11   * 
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  
19  package org.apache.struts.taglib.html;
20  
21  import java.util.Iterator  ;
22  import java.util.Map  ;
23  
24  import javax.servlet.http.HttpServletRequest  ;
25  import javax.servlet.http.HttpServletResponse  ;
26  import javax.servlet.jsp.JspException  ;
27  
28  import org.apache.struts.Globals;
29  import org.apache.struts.config.ModuleConfig;
30  import org.apache.struts.taglib.TagUtils;
31  import org.apache.struts.util.MessageResources;
32  import org.apache.struts.util.ModuleUtils;
33  
34  /**
35   * Generate an IMG tag to the specified image URI.
36   * <p>
37   * TODO:
38   * <ul>
39   *   <li>Make the <strong>alt</strong>, <strong>src</strong>, and
40   *       <strong>lowsrc</strong> settable from properties (for i18n)</li>
41   * </ul>
42   *
43   * @version $Rev: 164927 $
44   */
45  
46  public class ImgTag extends BaseHandlerTag {
47  
48      // ----------------------------------------------------- Constructor
49  
50      public ImgTag() {
51          super();
52          doDisabled = false;
53      }
54  
55      // ------------------------------------------------------------- Properties
56  
57       /**
58       * The property to specify where to align the image.
59       */
60      protected String   align = null;
61  
62      public String   getAlign() {
63          return (this.align);
64      }
65  
66      public void setAlign(String   align) {
67          this.align = align;
68      }
69  
70      /**
71       * The border size around the image.
72       */
73      protected String   border = null;
74  
75      public String   getBorder() {
76          return (this.border);
77      }
78  
79      public void setBorder(String   border) {
80          this.border = border;
81      }
82  
83      /**
84        * The property to specify how to root the image.
85        * If 'true' or if there is no current module the image is
86        * rooted to the application context path
87        * If 'false' or absent the image is rooted to the current
88        * module's context path.
89        * @deprecated Use module property instead; will be removed in a release after 1.2.0.
90        */
91       protected String   contextRelative = null;
92  
93       /** @deprecated Use module property instead; will be removed in a release after 1.2.0.
94        */
95       public String   getContextRelative() {
96           return (this.contextRelative);
97       }
98  
99      /** @deprecated Use module property instead; will be removed in a release after 1.2.0.
100      */
101      public void setContextRelative(String   contextRelative) {
102          this.contextRelative = contextRelative;
103      }
104 
105 
106     /**
107      * Convenience method to return true if contextRelative set to "true".
108      * @return True if contextRelative set to "true"
109      * @deprecated Use module property instead; will be removed in a release after 1.2.0.
110      */
111     public boolean isContextRelativeSet() {
112         return Boolean.valueOf(this.contextRelative).booleanValue();
113     }
114 
115     /**
116      * The image height.
117      */
118     protected String   height = null;
119 
120     public String   getHeight() {
121         return (this.height);
122     }
123 
124     public void setHeight(String   height) {
125         this.height = height;
126     }
127 
128     /**
129      * The horizontal spacing around the image.
130      */
131     protected String   hspace = null;
132 
133     public String   getHspace() {
134         return (this.hspace);
135     }
136 
137     public void setHspace(String   hspace) {
138         this.hspace = hspace;
139     }
140 
141     /**
142      * The image name for named images.
143      */
144     protected String   imageName = null;
145 
146     public String   getImageName() {
147         return (this.imageName);
148     }
149 
150     public void setImageName(String   imageName) {
151         this.imageName = imageName;
152     }
153 
154     /**
155      * Server-side image map declaration.
156      */
157     protected String   ismap = null;
158 
159     public String   getIsmap() {
160         return (this.ismap);
161     }
162 
163     public void setIsmap(String   ismap) {
164         this.ismap = ismap;
165     }
166 
167     /**
168      * The low resolution image source URI.
169      * @deprecated This is not defined in the HTML 4.01 spec and will be removed in a
170      * future version of Struts.
171      */
172     protected String   lowsrc = null;
173 
174     /**
175      * @deprecated This is not defined in the HTML 4.01 spec and will be removed in a
176      * future version of Struts.
177      */
178     public String   getLowsrc() {
179         return (this.lowsrc);
180     }
181 
182     public void setLowsrc(String   lowsrc) {
183         this.lowsrc = lowsrc;
184     }
185 
186     /**
187      * The message resources for this package.
188      */
189     protected static MessageResources messages =
190         MessageResources.getMessageResources(Constants.Package + ".LocalStrings");
191 
192     /**
193      * The JSP bean name for query parameters.
194      */
195     protected String   name = null;
196 
197     public String   getName() {
198         return (this.name);
199     }
200 
201     public void setName(String   name) {
202         this.name = name;
203     }
204 
205     /**
206      * The module-relative path, starting with a slash character, of the
207      * image to be displayed by this rendered tag.
208      */
209     protected String   page = null;
210 
211     public String   getPage() {
212         return (this.page);
213     }
214 
215     public void setPage(String   page) {
216         this.page = page;
217     }
218 
219     /**
220      * The message resources key under which we should look up the
221      * <code>page</code> attribute for this generated tag, if any.
222      */
223     protected String   pageKey = null;
224 
225     public String   getPageKey() {
226         return (this.pageKey);
227     }
228 
229     public void setPageKey(String   pageKey) {
230         this.pageKey = pageKey;
231     }
232 
233     /**
234      * The module-relative action (beginning with a slash) which will be
235      * used as the source for this image.
236      */
237     protected String   action = null;
238 
239     public String   getAction() {
240         return (this.action);
241     }
242 
243     public void setAction(String   action) {
244         this.action = action;
245     }
246 
247     /**
248      * The module prefix (beginning with a slash) which will be
249      * used to find the action for this link.
250      */
251     protected String   module = null;
252 
253     public String   getModule() {
254         return (this.module);
255     }
256 
257     public void setModule(String   module) {
258         this.module = module;
259     }
260 
261     /**
262      * In situations where an image is dynamically generated (such as to create
263      * a chart graph), this specifies the single-parameter request parameter
264      * name to generate.
265      */
266     protected String   paramId = null;
267 
268     public String   getParamId() {
269         return (this.paramId);
270     }
271 
272     public void setParamId(String   paramId) {
273         this.paramId = paramId;
274     }
275 
276     /**
277      * The single-parameter JSP bean name.
278      */
279     protected String   paramName = null;
280 
281     public String   getParamName() {
282         return (this.paramName);
283     }
284 
285     public void setParamName(String   paramName) {
286         this.paramName = paramName;
287     }
288 
289     /**
290      * The single-parameter JSP bean property.
291      */
292     protected String   paramProperty = null;
293 
294     public String   getParamProperty() {
295         return (this.paramProperty);
296     }
297 
298     public void setParamProperty(String   paramProperty) {
299         this.paramProperty = paramProperty;
300     }
301 
302     /**
303      * The single-parameter JSP bean scope.
304      */
305     protected String   paramScope = null;
306 
307     public String   getParamScope() {
308         return (this.paramScope);
309     }
310 
311     public void setParamScope(String   paramScope) {
312         this.paramScope = paramScope;
313     }
314 
315     /**
316      * The JSP bean property name for query parameters.
317      */
318     protected String   property = null;
319 
320     public String   getProperty() {
321         return (this.property);
322     }
323 
324     public void setProperty(String   property) {
325         this.property = property;
326     }
327 
328     /**
329      * The scope of the bean specified by the name property, if any.
330      */
331     protected String   scope = null;
332 
333     public String   getScope() {
334         return (this.scope);
335     }
336 
337     public void setScope(String   scope) {
338         this.scope = scope;
339     }
340 
341     /**
342      * The image source URI.
343      */
344     protected String   src = null;
345 
346     public String   getSrc() {
347         return (this.src);
348     }
349 
350     public void setSrc(String   src) {
351         this.src = src;
352     }
353 
354     /**
355      * The message resources key under which we should look up the
356      * <code>src</code> attribute for this generated tag, if any.
357      */
358     protected String   srcKey = null;
359 
360     public String   getSrcKey() {
361         return (this.srcKey);
362     }
363 
364     public void setSrcKey(String   srcKey) {
365         this.srcKey = srcKey;
366     }
367 
368     /**
369      * Client-side image map declaration.
370      */
371     protected String   usemap = null;
372 
373     public String   getUsemap() {
374         return (this.usemap);
375     }
376 
377     public void setUsemap(String   usemap) {
378         this.usemap = usemap;
379     }
380 
381     /**
382      * The vertical spacing around the image.
383      */
384     protected String   vspace = null;
385 
386     public String   getVspace() {
387         return (this.vspace);
388     }
389 
390     public void setVspace(String   vspace) {
391         this.vspace = vspace;
392     }
393 
394     /**
395      * The image width.
396      */
397     protected String   width = null;
398 
399     public String   getWidth() {
400         return (this.width);
401     }
402 
403     public void setWidth(String   width) {
404         this.width = width;
405     }
406 
407     protected boolean useLocalEncoding = false;
408     
409     public boolean isUseLocalEncoding() {
410        return useLocalEncoding;
411     }
412 
413     public void setUseLocalEncoding(boolean b) {
414        useLocalEncoding = b;
415     }
416    
417    // --------------------------------------------------------- Public Methods
418 
419     /**
420      * Render the beginning of the IMG tag.
421      *
422      * @exception JspException if a JSP exception has occurred
423      */
424     public int doStartTag() throws JspException   {
425 
426         // Evaluate the body of this tag
427         return (EVAL_BODY_TAG);
428 
429     }
430 
431     /**
432      * Render the end of the IMG tag.
433      *
434      * @exception JspException if a JSP exception has occurred
435      */
436     public int doEndTag() throws JspException   {
437 
438         // Generate the name definition or image element
439         HttpServletResponse   response = (HttpServletResponse  ) pageContext.getResponse();
440         StringBuffer   results = new StringBuffer  ("<img");
441         String   tmp = src();
442         String   srcurl = url(tmp);
443         if (srcurl != null) {
444             prepareAttribute(results, "src", response.encodeURL(srcurl));
445         }
446         String   lowsrcurl = url(this.lowsrc);
447         if (lowsrcurl != null) {
448             prepareAttribute(results, "lowsrcurl", response.encodeURL(lowsrcurl));
449         }
450 
451         prepareAttribute(results, "name", getImageName());
452         prepareAttribute(results, "height", getHeight());
453         prepareAttribute(results, "width", getWidth());
454         prepareAttribute(results, "align", getAlign());
455         prepareAttribute(results, "border", getBorder());
456         prepareAttribute(results, "hspace", getHspace());
457         prepareAttribute(results, "vspace", getVspace());
458         prepareAttribute(results, "ismap", getIsmap());
459         prepareAttribute(results, "usemap", getUsemap());
460         results.append(prepareStyles());
461         results.append(prepareEventHandlers());
462         prepareOtherAttributes(results);
463         results.append(getElementClose());
464 
465         TagUtils.getInstance().write(pageContext, results.toString());
466 
467         return (EVAL_PAGE);
468 
469     }
470 
471     /**
472      * Release any acquired resources.
473      */
474     public void release() {
475 
476         super.release();
477 
478         border = null;
479         height = null;
480         hspace = null;
481         imageName = null;
482         ismap = null;
483         lowsrc = null;
484         name = null;
485         page = null;
486         pageKey = null;
487         action = null;
488         paramId = null;
489         paramName = null;
490         paramProperty = null;
491         paramScope = null;
492         property = null;
493         scope = null;
494         src = null;
495         srcKey = null;
496         usemap = null;
497         vspace = null;
498         width = null;
499 
500     }
501 
502     // ------------------------------------------------------ Protected Methods
503 
504     /**
505      * Convenience method to throw a "imgTag.src" exception.
506      * @throws JspException
507      */
508     private void throwImgTagSrcException() throws JspException   {
509         JspException   e = new JspException  (messages.getMessage("imgTag.src"));
510         TagUtils.getInstance().saveException(pageContext, e);
511         throw e;
512     }
513 
514     /**
515      * Convenience method to test whether this is the default module
516      * or if contestRelative has been set.
517      * @param config Our Moduleconfig
518      * @return True if this is the default module or contextRelative is set
519      */
520     private boolean srcDefaultReference(ModuleConfig config) {
521        return (config == null || isContextRelativeSet());
522     }
523 
524     /**
525      * Return the base source URL that will be rendered in the <code>src</code>
526      * property for this generated element, or <code>null</code> if there is
527      * no such URL.
528      *
529      * @exception JspException if an error occurs
530      */
531     protected String   src() throws JspException   {
532 
533         // Deal with a direct context-relative page that has been specified
534         if (this.page != null) {
535             if ((this.src != null) || (this.srcKey != null) || (this.pageKey != null)) {
536                 throwImgTagSrcException();
537             }
538             ModuleConfig config = 
539                 ModuleUtils.getInstance().getModuleConfig(
540                         this.module,
541                         (HttpServletRequest  ) pageContext.getRequest(),
542                         pageContext.getServletContext());                
543             
544             HttpServletRequest   request = (HttpServletRequest  ) pageContext.getRequest();
545             String   pageValue = this.page;
546             if (!srcDefaultReference(config)) {
547                 pageValue = TagUtils.getInstance().pageURL(request,
548                                                            this.page,
549                                                            config);
550             }
551             return (request.getContextPath() + pageValue);
552         }
553 
554         // Deal with an indirect context-relative page that has been specified
555         if (this.pageKey != null) {
556             if ((this.src != null) || (this.srcKey != null)) {
557                 throwImgTagSrcException();
558             }
559             ModuleConfig config =
560                 ModuleUtils.getInstance().getModuleConfig(
561                         this.module,
562                         (HttpServletRequest  ) pageContext.getRequest(),
563                         pageContext.getServletContext());
564             
565             HttpServletRequest   request = (HttpServletRequest  ) pageContext.getRequest();
566             String   pageValue = TagUtils.getInstance().message(
567                                           pageContext,
568                                           getBundle(),
569                                           getLocale(),
570                                           this.pageKey);
571             if (!srcDefaultReference(config)) {
572                 pageValue = TagUtils.getInstance().pageURL(request,
573                                                            pageValue,
574                                                            config);
575             }
576             return (request.getContextPath() + pageValue);
577         }
578 
579         if (this.action != null) {
580             if ((this.src != null) || (this.srcKey != null)) {
581                 throwImgTagSrcException();
582             }
583             return TagUtils.getInstance().getActionMappingURL(action, module, pageContext, isContextRelativeSet());
584         }
585 
586         // Deal with an absolute source that has been specified
587         if (this.src != null) {
588             if (this.srcKey != null) {
589                 throwImgTagSrcException();
590             }
591             return (this.src);
592         }
593 
594         // Deal with an indirect source that has been specified
595         if (this.srcKey == null) {
596             throwImgTagSrcException();
597         }
598         
599         return TagUtils.getInstance().message(
600             pageContext,
601             getBundle(),
602             getLocale(),
603             this.srcKey);
604 
605     }
606 
607     /**
608      * Return the specified src URL, modified as necessary with optional
609      * request parameters.
610      *
611      * @param url The URL to be modified (or null if this url will not be used)
612      *
613      * @exception JspException if an error occurs preparing the URL
614      */
615     protected String   url(String   url) throws JspException   {
616 
617         if (url == null) {
618             return (url);
619         }
620 
621         String   charEncoding = "UTF-8";
622         if(useLocalEncoding){
623             charEncoding = pageContext.getResponse().getCharacterEncoding();
624         }
625         
626         // Start with an unadorned URL as specified
627         StringBuffer   src = new StringBuffer  (url);
628 
629         // Append a single-parameter name and value, if requested
630         if ((paramId != null) && (paramName != null)) {
631             if (src.toString().indexOf('?') < 0) {
632                 src.append('?');
633             } else {
634                 src.append("&amp;");
635             }
636             src.append(paramId);
637             src.append('=');
638             Object   value = TagUtils.getInstance().lookup(pageContext, paramName, paramProperty, paramScope);
639             if (value != null)
640                 src.append(TagUtils.getInstance().encodeURL(value.toString(), charEncoding));
641         }
642 
643         // Just return the URL if there is no bean to look up
644         if ((property != null) && (name == null)) {
645             JspException   e = new JspException  (messages.getMessage("getter.name"));
646             TagUtils.getInstance().saveException(pageContext, e);
647             throw e;
648         }
649 
650         if (name == null) {
651             return (src.toString());
652         }
653 
654         // Look up the map we will be using
655         Object   mapObject = TagUtils.getInstance().lookup(pageContext, name, property, scope);
656         Map   map = null;
657         try {
658             map = (Map  ) mapObject;
659         } catch (ClassCastException   e) {
660             TagUtils.getInstance().saveException(pageContext, e);
661             throw new JspException  (messages.getMessage("imgTag.type"));
662         }
663 
664         // Append the required query parameters
665         boolean question = (src.toString().indexOf("?") >= 0);
666         Iterator   keys = map.keySet().iterator();
667         while (keys.hasNext()) {
668             String   key = (String  ) keys.next();
669             Object   value = map.get(key);
670             if (value == null) {
671                 if (question) {
672                     src.append("&amp;");
673                 } else {
674                     src.append('?');
675                     question = true;
676                 }
677                 src.append(key);
678                 src.append('=');
679                 // Interpret null as "no value specified"
680             } else if (value instanceof String  []) {
681                 String   values[] = (String  []) value;
682                 for (int i = 0; i < values.length; i++) {
683                     if (question) {
684                         src.append("&amp;");
685                     } else {
686                         src.append('?');
687                         question = true;
688                     }
689                     src.append(key);
690                     src.append('=');
691                     src.append(TagUtils.getInstance().encodeURL(values[i], charEncoding));
692                 }
693             } else {
694 
695                 if (question) {
696                     src.append("&amp;");
697                 } else {
698                     src.append('?');
699                     question = true;
700                 }
701                 src.append(key);
702                 src.append('=');
703                 src.append(TagUtils.getInstance().encodeURL(value.toString(), charEncoding));
704             }
705         }
706 
707         // Return the final result
708         return (src.toString());
709 
710     }
711 
712 }
713
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