HtmlTag


1   /*
2    * $Id: HtmlTag.java 54929 2004-10-16 16:38:42Z germuska $ 
3    *
4    * Copyright 1999-2004 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.Locale  ;
22  
23  import javax.servlet.http.HttpServletRequest  ;
24  import javax.servlet.http.HttpSession  ;
25  import javax.servlet.jsp.JspException  ;
26  import javax.servlet.jsp.PageContext  ;
27  import javax.servlet.jsp.tagext.TagSupport  ;
28  
29  import org.apache.struts.Globals;
30  import org.apache.struts.taglib.TagUtils;
31  import org.apache.struts.util.MessageResources;
32  
33  /**
34   * Renders an HTML <html> element with appropriate language attributes if
35   * there is a current Locale available in the user's session.
36   *
37   * @version $Rev: 54929 $ $Date: 2004-10-16 17:38:42 +0100 (Sat, 16 Oct 2004) $
38   */
39  public class HtmlTag extends TagSupport   {
40    
41  
42      // ------------------------------------------------------------- Properties
43  
44  
45      /**
46       * The message resources for this package.
47       */
48      protected static MessageResources messages =
49       MessageResources.getMessageResources(Constants.Package + ".LocalStrings");
50  
51  
52      /**
53       * Should we set the current Locale for this user if needed?
54       * @deprecated This will be removed after Struts 1.2.
55       */
56      protected boolean locale = false;
57  
58      /**
59       * @deprecated This will be removed after Struts 1.2.
60       */
61      public boolean getLocale() {
62          return (locale);
63      }
64  
65      /**
66       * @deprecated This will be removed after Struts 1.2.
67       */
68      public void setLocale(boolean locale) {
69          this.locale = locale;
70      }
71  
72      /**
73       * Are we rendering an xhtml page?
74       */
75      protected boolean xhtml = false;
76      
77      /**
78       * Are we rendering a lang attribute?
79       * @since Struts 1.2
80       */
81      protected boolean lang = false;
82  
83      public boolean getXhtml() {
84          return this.xhtml;
85      }
86  
87      public void setXhtml(boolean xhtml) {
88          this.xhtml = xhtml;
89      }
90      
91      /**
92       * Returns true if the tag should render a lang attribute.
93       * @since Struts 1.2
94       */
95      public boolean getLang() {
96          return this.lang;
97      }
98  
99      /**
100      * Sets whether the tag should render a lang attribute.
101      * @since Struts 1.2
102      */
103     public void setLang(boolean lang) {
104         this.lang = lang;
105     }
106 
107     /**
108      * Process the start of this tag.
109      *
110      * @exception JspException if a JSP exception has occurred
111      */
112     public int doStartTag() throws JspException   {
113 
114         TagUtils.getInstance().write(this.pageContext, this.renderHtmlStartElement());
115 
116         return EVAL_BODY_INCLUDE;
117     }
118 
119     /**
120      * Renders an &lt;html&gt; element with appropriate language attributes.
121      * @since Struts 1.2
122      */
123     protected String   renderHtmlStartElement() {
124         StringBuffer   sb = new StringBuffer  ("<html");
125 
126         String   language = null;
127         String   country = "";
128                 
129         if (this.locale) {
130             // provided for 1.1 backward compatibility, remove after 1.2
131             language = this.getCurrentLocale().getLanguage();
132         } else {
133             Locale   currentLocale =
134                 TagUtils.getInstance().getUserLocale(pageContext, Globals.LOCALE_KEY);
135 
136             language = currentLocale.getLanguage();
137             country = currentLocale.getCountry();
138         }
139 
140         boolean validLanguage = ((language != null) && (language.length() > 0));
141         boolean validCountry = country.length() > 0;
142 
143         if (this.xhtml) {
144             this.pageContext.setAttribute(
145                 Globals.XHTML_KEY,
146                 "true",
147                 PageContext.PAGE_SCOPE);
148                 
149             sb.append(" xmlns=\"http://www.w3.org/1999/xhtml\"");
150         }
151 
152         if ((this.lang || this.locale || this.xhtml) && validLanguage) {
153             sb.append(" lang=\"");
154             sb.append(language);
155             if (validCountry) {
156                 sb.append("-");
157                 sb.append(country);
158             }
159             sb.append("\"");
160         }
161 
162         if (this.xhtml && validLanguage) {
163             sb.append(" xml:lang=\"");
164             sb.append(language);
165             if (validCountry) {
166                 sb.append("-");
167                 sb.append(country);
168             }
169             sb.append("\"");
170         }
171 
172         sb.append(">");
173 
174         return sb.toString();
175     }
176 
177 
178     /**
179      * Process the end of this tag.
180      *
181      * @exception JspException if a JSP exception has occurred
182      */
183     public int doEndTag() throws JspException   {
184 
185         TagUtils.getInstance().write(pageContext, "</html>");
186 
187         // Evaluate the remainder of this page
188         return (EVAL_PAGE);
189 
190     }
191 
192     /**
193      * Release any acquired resources.
194      */
195     public void release() {
196         this.locale = false;
197         this.xhtml = false;
198         this.lang=false;
199     }
200 
201 
202     // ------------------------------------------------------ Protected Methods
203 
204 
205     /**
206      * Return the current Locale for this request.  If there is no locale in the session and
207      * the locale attribute is set to "true", this method will create a Locale based on the 
208      * client's Accept-Language header or the server's default locale and store it in the 
209      * session.  This will always return a Locale and never null.
210      * @since Struts 1.1
211      * @deprecated This will be removed after Struts 1.2.
212      */
213     protected Locale   getCurrentLocale() {
214 
215         Locale   userLocale = TagUtils.getInstance().getUserLocale(pageContext, Globals.LOCALE_KEY);
216 
217         // Store a new current Locale, if requested
218         if (this.locale) {
219             HttpSession   session = ((HttpServletRequest  ) this.pageContext.getRequest()).getSession();
220             session.setAttribute(Globals.LOCALE_KEY, userLocale);
221         }
222 
223         return userLocale;
224     }
225 
226 
227 
228 }
229
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags