FormRenderer


1   /*
2    * Copyright 2002-2004 The Apache Software Foundation.
3    * 
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    * 
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    * 
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  
17  package org.apache.struts.faces.renderer;
18  
19  
20  import java.io.IOException  ;
21  import java.util.Map  ;
22  
23  import javax.faces.component.NamingContainer;
24  import javax.faces.component.UIComponent;
25  import javax.faces.context.FacesContext;
26  import javax.faces.context.ResponseWriter;
27  import javax.servlet.http.HttpSession  ;
28  
29  import org.apache.commons.logging.Log;
30  import org.apache.commons.logging.LogFactory;
31  import org.apache.struts.Globals;
32  import org.apache.struts.config.ActionConfig;
33  import org.apache.struts.config.ModuleConfig;
34  import org.apache.struts.faces.component.FormComponent;
35  
36  
37  /**
38   * <p><code>Renderer</code> implementation for the <code>form</code> tag
39   * from the <em>Struts-Faces Integration Library</em>.</p>
40   *
41   * @version $Rev: 55303 $ $Date: 2004-10-22 03:56:53 +0100 (Fri, 22 Oct 2004) $
42   */
43  
44  public class FormRenderer extends AbstractRenderer {
45  
46  
47      // -------------------------------------------------------- Static Variables
48  
49  
50      /**
51       * <p>The <code>Log</code> instance for this class.</p>
52       */
53      private static Log log = LogFactory.getLog(FormRenderer.class);
54  
55  
56      // ---------------------------------------------------------- Public Methods
57  
58  
59      /**
60       * <p>Perform setup processing that will be required for decoding the
61       * incoming request.</p>
62       *
63       * @param context FacesContext for the request we are processing
64       * @param component UIComponent to be processed
65       *
66       * @exception NullPointerException if <code>context</code>
67       *  or <code>component</code> is null
68       */
69      public void decode(FacesContext context, UIComponent component) {
70  
71          if ((context == null) || (component == null)) {
72              throw new NullPointerException  ();
73          }
74          String   clientId = component.getClientId(context);
75      Map   map = context.getExternalContext().getRequestParameterMap();
76          if (log.isDebugEnabled()) {
77              log.debug("decode(" + clientId + ") --> " +
78                        map.containsKey(clientId));
79          }
80          component.getAttributes().put
81              ("submitted",
82               map.containsKey(clientId) ? Boolean.TRUE : Boolean.FALSE);
83  
84      }
85  
86  
87      private static String   passThrough[] =
88      { "enctype", "method", "onreset", "onsubmit", "style", "target", };
89  
90  
91      /**
92       * <p>Render the beginning of an HTML <code>&lt;form&gt;</code>
93       * control.</p>
94       *
95       * @param context FacesContext for the request we are processing
96       * @param component UIComponent to be rendered
97       *
98       * @exception IOException if an input/output error occurs while rendering
99       * @exception NullPointerException if <code>context</code>
100      *  or <code>component</code> is null
101      */
102     public void encodeBegin(FacesContext context, UIComponent component)
103         throws IOException   {
104 
105         if ((context == null) || (component == null)) {
106             throw new NullPointerException  ();
107         }
108 
109         // Calculate and cache the form name
110         FormComponent form = (FormComponent) component;
111         String   action = form.getAction();
112         ModuleConfig moduleConfig = form.lookupModuleConfig(context);
113         ActionConfig actionConfig = moduleConfig.findActionConfig(action);
114         String   beanName = actionConfig.getAttribute();
115         if (beanName != null) {
116             form.getAttributes().put("beanName", beanName);
117         }
118 
119         // Look up attribute values we need
120         String   clientId = component.getClientId(context);
121         if (log.isDebugEnabled()) {
122             log.debug("encodeBegin(" + clientId + ")");
123         }
124         String   styleClass =
125             (String  ) component.getAttributes().get("styleClass");
126 
127         // Render the beginning of this form
128         ResponseWriter writer = context.getResponseWriter();
129         writer.startElement("form", form);
130         writer.writeAttribute("id", clientId, "clientId");
131         if (beanName != null) {
132             writer.writeAttribute("name", beanName, null);
133         }
134         writer.writeAttribute("action", action(context, component), "action");
135         if (styleClass != null) {
136             writer.writeAttribute("class", styleClass, "styleClass");
137         }
138         if (component.getAttributes().get("method") == null) {
139             writer.writeAttribute("method", "post", null);
140         }
141         renderPassThrough(context, component, writer, passThrough);
142         writer.writeText("\n", null);
143 
144         // Add a marker used by our decode() method to note this form is submitted
145         writer.startElement("input", form);
146         writer.writeAttribute("type", "hidden", null);
147         writer.writeAttribute("name", clientId, null);
148         writer.writeAttribute("value", clientId, null);
149         writer.endElement("input");
150         writer.writeText("\n", null);
151 
152         // Add a transaction token if necessary
153         HttpSession   session = (HttpSession  )
154             context.getExternalContext().getSession(false);
155         if (session != null) {
156             String   token = (String  )
157                 session.getAttribute(Globals.TRANSACTION_TOKEN_KEY);
158             if (token != null) {
159                 writer.startElement("input", form);
160                 writer.writeAttribute("type", "hidden", null);
161                 writer.writeAttribute
162                     ("name", "org.apache.struts.taglib.html.TOKEN", null);
163                 writer.writeAttribute("value", token, null);
164                 writer.endElement("input");
165                 writer.writeText("\n", null);
166             }
167         }
168 
169         // Create an instance of the form bean if necessary
170         if (component instanceof FormComponent) {
171             ((FormComponent) component).createActionForm(context);
172         }
173 
174     }
175 
176 
177     /**
178      * <p>Render the ending of an HTML <code>&lt;form&gt;</code>
179      * control.</p>
180      *
181      * @param context FacesContext for the request we are processing
182      * @param component UIComponent to be rendered
183      *
184      * @exception IOException if an input/output error occurs while rendering
185      * @exception NullPointerException if <code>context</code>
186      *  or <code>component</code> is null
187      */
188     public void encodeEnd(FacesContext context, UIComponent component)
189         throws IOException   {
190 
191         if ((context == null) || (component == null)) {
192             throw new NullPointerException  ();
193         }
194         String   clientId = component.getClientId(context);
195         if (log.isDebugEnabled()) {
196             log.debug("encodeEnd(" + clientId + ")");
197         }
198         ResponseWriter writer = context.getResponseWriter();
199 
200         // Render the hidden variable our decode() method uses to detect submits
201     writer.startElement("input", component);
202     writer.writeAttribute("type", "hidden", null);
203     writer.writeAttribute("name", component.getClientId(context), null);
204     writer.writeAttribute("value", component.getClientId(context), null);
205     writer.endElement("input");
206     writer.write("\n");
207 
208         // Write our state information (if necessary)
209         context.getApplication().getViewHandler().writeState(context);
210 
211         // Render the ending of this form
212         writer.endElement("form");
213         writer.writeText("\n", null);
214 
215         // Render focus JavaScript if requested
216         if (!(component instanceof FormComponent)) {
217             return;
218         }
219         String   focus = (String  ) component.getAttributes().get("focus");
220         if (focus == null) {
221             return;
222         }
223         String   focusIndex =
224             (String  ) component.getAttributes().get("focusIndex");
225         writer.writeText("\n", null);
226         FormComponent form = (FormComponent) component;
227         writer.startElement("script", form);
228         writer.writeAttribute("type", "text/javascript", null);
229         if (!isXhtml(component)) {
230             writer.writeAttribute("language", "JavaScript", null);
231         }
232         writer.writeText("\n", null);
233         if (!isXhtml(component)) {
234             writer.write("<!--\n");
235         }
236 
237         StringBuffer   sb = new StringBuffer  ("document.forms[\"");
238         sb.append(clientId);
239         sb.append("\"].elements[\"");
240         sb.append(component.getClientId(context));
241         sb.append(NamingContainer.SEPARATOR_CHAR);
242         sb.append(focus);
243         sb.append("\"]");
244         String   focusControl = sb.toString();
245 
246         writer.write("  var focusControl = ");
247         writer.write(focusControl);
248         writer.write(";\n");
249         writer.write("  if (focusControl.type != \"hidden\") {\n");
250         writer.write("    ");
251         writer.write(focusControl);
252         if (focusIndex != null) {
253             writer.write("[");
254             writer.write(focusIndex);
255             writer.write("]");
256         }
257         writer.write(".focus();\n");
258         writer.write("  }\n");
259 
260         if (!isXhtml(component)) {
261             writer.write("// -->\n");
262         }
263         writer.endElement("script");
264         writer.writeText("\n", null);
265 
266     }
267 
268 
269     // ------------------------------------------------------- Protected Methods
270 
271 
272     /**
273      * <p>Calculate and return the value to be specifed for the
274      * <code>action</action> attribute on the <code>&lt;form&gt;</code>
275      * element to be rendered.</p>
276      *
277      * @param context FacesContext for the current request
278      * @param component Component being processed
279      */
280     protected String   action(FacesContext context, UIComponent component) {
281 
282         String   actionURL =
283             context.getApplication().getViewHandler().
284             getActionURL(context, context.getViewRoot().getViewId());
285         if (log.isTraceEnabled()) {
286             log.trace("getActionURL(" + context.getViewRoot().getViewId() +
287                       ") --> " + actionURL);
288         }
289         return (context.getExternalContext().encodeActionURL(actionURL));
290 
291     }
292 
293 
294     /**
295      * <p>Return <code>true</code> if we should render as XHTML.</p>
296      *
297      * @param component The component we are rendering
298      */
299     protected boolean isXhtml(UIComponent component) {
300 
301         return (false); // FIXME -- check up the hierarchy
302 
303     }
304 
305 
306 }
307
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