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| distributed under the License is distributed on an "AS IS" BASIS, |
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| <document> |
| <properties> |
| <title>Hidden</title> |
| </properties> |
| <body> |
| |
| <section name="Hidden"> |
| |
| <p> |
| Adds a hidden HTML <code><input type="hidden"></code> field to a |
| <a href="form.html">Form</a> |
| . This is often used to synchronize data when the form is submitted with values |
| known when the page was rendered. |
| </p> |
| |
| <p> |
| <strong> |
| See also: |
| <a href="form.html">Form</a> |
| </strong> |
| </p> |
| |
| <section name="Parameters"> |
| |
| |
| <table> |
| <tr> |
| <th>Name</th> |
| <th>Type</th> |
| <th>Required</th> |
| <th>Default</th> |
| <th>Description</th> |
| </tr> |
| <tr> |
| <td>value</td> |
| <td>Object</td> |
| <td>yes</td> |
| <td></td> |
| <td> |
| The value to be stored in the the hidden field. The parameter is read |
| when the HTML response is generated, and then written when the form is |
| submitted. A |
| <a |
| href="../../apidocs/org/apache/tapestry/services/DataSqueezer.html"> |
| DataSqueezer |
| </a> |
| is used to convert the value between an arbitrary type and a String. |
| </td> |
| </tr> |
| |
| <tr> |
| <td>id</td> |
| <td>Object</td> |
| <td>no</td> |
| <td>undefined in HTML presentation.</td> |
| <td> |
| ID parameter of HTML hidden object. The parameter is read when the HTML |
| response is generated and if there is a specific value the component |
| generate parameter id with passed value in its HTML presentation. |
| </td> |
| </tr> |
| <tr> |
| <td>listener</td> |
| <td> |
| <a |
| href="../../apidocs/org/apache/tapestry/IActionListener.html"> |
| IActionListener |
| </a> |
| </td> |
| <td>no</td> |
| <td></td> |
| <td> |
| <p> |
| A listener that is informed after the value parameter is updated. |
| This allows the data set operated on by the rest of the |
| <a href="form.html">Form</a> |
| components to be synchronized to the value stored in the hidden |
| field. |
| </p> |
| <p> |
| A typical use is to encode the primary key of an entity as a Hidden; |
| when the form is submitted, the Hidden's listener re-reads the |
| corresponding entity from the database. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td>encode</td> |
| <td>boolean</td> |
| <td>no</td> |
| <td>true</td> |
| <td> |
| <p> |
| If true (the default) a |
| <a |
| href="../../apidocs/org/apache/tapestry/services/DataSqueezer.html"> |
| DataSqueezer |
| </a> |
| is used to transform the value Object into the HTML value string, |
| and (on submit) to convert the string back into an Object. |
| </p> |
| <p> |
| If false, then the value must be a String. This is most likely used |
| when the hidden field is used to communicate with client-side logic |
| in JavaScript (which is not able to interpret even Strings encoded |
| by |
| <a |
| href="../../apidocs/org/apache/tapestry/services/DataSqueezer.html"> |
| DataSqueezer |
| </a> |
| ). If you find yourself getting strange errors during the form |
| rewind it could easily be Tapestry trying to interpret a value |
| you've set via JavaScript. |
| </p> |
| </td> |
| |
| </tr> |
| </table> |
| |
| <p> |
| Body: |
| <strong>removed</strong> |
| </p> |
| |
| <p> |
| Informal parameters: |
| <strong>forbidden</strong> |
| </p> |
| |
| <p> |
| Reserved parameters: |
| <em>name</em> |
| </p> |
| |
| </section> |
| |
| </section> |
| |
| </body> |
| </document> |
