Hidden


1   /*
2    * Copyright 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   * $Header:$
17   */
18  package org.apache.beehive.netui.tags.html;
19  
20  import org.apache.beehive.netui.util.internal.InternalStringBuilder;
21  
22  import org.apache.beehive.netui.tags.ByRef;
23  import org.apache.beehive.netui.tags.HtmlUtils;
24  import org.apache.beehive.netui.tags.rendering.*;
25  import org.apache.beehive.netui.util.Bundle;
26  
27  import javax.servlet.ServletRequest  ;
28  import javax.servlet.jsp.JspException  ;
29  
30  
31  /**
32   * Generates a hidden tag with a given value.  Hidden ignores its body content.
33   * @jsptagref.tagdescription Generates an HTML hidden tag with a given value.
34   *
35   * <p>The <code>dataInput</code> attribute overrides the <code>dataSource</code> attribute
36   * for the input of the value.
37   * It allows a &lt;netui:hidden> tag to read it's value from one place (whatever is referenced by
38   * the <code>dataInput</code> attribute) and submit the value to a new destination
39   * (whatever is referenced by the <code>dataSource</code> attribute).
40   * The <code>dataInput</code> attribute may take a String literal or a data binding expression.
41   * @example In this sample, the Hidden tag is written using the value from the form bean's status property.
42   * <pre>&lt;netui:hidden dataSource="actionForm.status"  /></pre>
43   * @netui:tag name="hidden" description="Generates a hidden tag with a given value."
44   */
45  public class Hidden
46          extends HtmlDataSourceTag
47  {
48      private InputHiddenTag.State _state = new InputHiddenTag.State();
49  
50      private String   _value;
51      private Object   _dataInput;
52  
53      /**
54       * Return the name of the Tag.
55       */
56      public String   getTagName()
57      {
58          return "Hidden";
59      }
60  
61      /**
62       * This method will return the state associated with the tag.  This is used by this
63       * base class to access the individual state objects created by the tags.
64       * @return a subclass of the <code>AbstractHtmlState</code> class.
65       */
66      protected AbstractHtmlState getState()
67      {
68          return _state;
69      }
70  
71      /**
72       * Base support for the attribute tag.  This is overridden to prevent setting the <code>type</code>
73       * or <code>value</code> attributes.
74       * @param name  The name of the attribute
75       * @param value The value of the attribute
76       */
77      public void setAttribute(String   name, String   value, String   facet)
78              throws JspException  
79      {
80          if (name == null)
81              return;
82  
83          if (name.equals(TYPE) || name.equals(VALUE)) {
84              String   s = Bundle.getString("Tags_AttributeMayNotBeSet", new Object  []{name});
85              registerTagError(s, null);
86          }
87          super.setAttribute(name, value, facet);
88      }
89  
90      /**
91       * Set the data input.  This value will override the <code>
92       * dataSource</code> and provide the input value on the select box.
93       * @param dataInput the value of the input to the page.  This value
94       *                  may contain an expression.
95       * @jsptagref.attributedescription The dataInput attribute overrides the dataSource attribute for the input of the value.
96       * It allows a &lt;netui:hidden> tag to read it's value from one place (whatever is referenced by
97       * the <code>dataInput</code> attribute) and return the value to a new destination (whatever is
98       * referenced by the <code>dataSource</code> attribute).
99       * This attribute may take a String literal or a data binding expression.
100      * @jsptagref.databindable true
101      * @jsptagref.attributesyntaxvalue <i>string_or_expression_dataInput</i>
102      * @netui:attribute required="false" rtexprvalue="true" type="java.lang.Object"
103      * description="The dataInput attribute overrides the dataSource attribute for the input of the value. "
104      */
105     public void setDataInput(Object   dataInput)
106     {
107         _dataInput = dataInput;
108     }
109 
110     /**
111      * Render the Hidden tag
112      * @throws JspException if a JSP exception has occurred
113      */
114     public int doStartTag() throws JspException  
115     {
116         return EVAL_BODY_BUFFERED;
117     }
118 
119     /**
120      * Save the body content of the Hidden.
121      * @throws JspException if a JSP exception has occurred
122      */
123     public int doAfterBody() throws JspException  
124     {
125 
126         if (bodyContent != null) {
127             bodyContent.clearBody();
128         }
129         return SKIP_BODY;
130     }
131 
132     /**
133      * Generate the hidden input tag.
134      * @throws JspException if a JSP exception has occurred
135      */
136     public int doEndTag() throws JspException  
137     {
138         Object   val = evaluateDataSource();
139 
140         ServletRequest   req = pageContext.getRequest();
141 
142         if (_dataInput != null) {
143             val = _dataInput.toString();
144         }
145 
146         // if there were expression errors report them
147         if (hasErrors())
148             return reportAndExit(SKIP_BODY);
149 
150         if (val != null) {
151             _value = val.toString();
152         }
153 
154         // Create an appropriate "input" element based on our parameters
155         ByRef ref = new ByRef();
156         nameHtmlControl(_state, ref);
157 
158         if (_value != null) {
159             InternalStringBuilder sb = new InternalStringBuilder(_value.length() + 16);
160             StringBuilderRenderAppender sbAppend = new StringBuilderRenderAppender(sb);
161             HtmlUtils.filter(_value, sbAppend);
162             _state.value = sb.toString();
163         }
164 
165         // correct for null text here
166         if (_state.value == null)
167             _state.value = "";
168 
169         WriteRenderAppender writer = new WriteRenderAppender(pageContext);
170         TagRenderingBase hiddenTag = TagRenderingBase.Factory.getRendering(TagRenderingBase.INPUT_HIDDEN_TAG, req);
171 
172         hiddenTag.doStartTag(writer, _state);
173         hiddenTag.doEndTag(writer);
174 
175         if (!ref.isNull())
176             write((String  ) ref.getRef());
177 
178         // Continue processing this page
179         localRelease();
180         return SKIP_BODY;
181     }
182 
183     /**
184      * Release any acquired resources.
185      */
186     protected void localRelease()
187     {
188         super.localRelease();
189 
190         _state.clear();
191         _value = null;
192         _dataInput = null;
193     }
194 
195     /* ==================================================================
196      *
197      * This tag's publically exposed HTML, CSS, and JavaScript attributes
198      *
199      * ==================================================================
200      */
201     /**
202      * Sets the tabIndex of the rendered html tag.
203      * @param tabindex the tab index.
204      * @jsptagref.attributedescription The tabIndex of the rendered HTML tag.  This attribute determines the position of the
205      * rendered HTML tag in the sequence of tags that the user may advance through by pressing the TAB key.
206      * @jsptagref.databindable false
207      * @jsptagref.attributesyntaxvalue <i>string_tabIndex</i>
208      * @netui:attribute required="false" rtexprvalue="true" type="int"
209      * description="The tabIndex of the rendered HTML tag.  This attribute determines the position of the
210      * rendered HTML tag in the sequence of tags that the user may advance through by pressing the TAB key."
211      */
212     public void setTabindex(int tabindex)
213     {
214         _state.registerAttribute(AbstractHtmlState.ATTR_GENERAL, HtmlConstants.TABINDEX, Integer.toString(tabindex));
215     }
216 }
217
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