Added documentation for the <antstructure> task.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@267919 13f79535-47bb-0310-9956-ffa450edef68

WHATSNEW

@@ -28,7 +28,7 @@ beahvior has been dropped.
 Other changes:
 --------------
 
-* New tasks: sql, genkey, cab, ftp, junit.
+* New tasks: antstructure, cab, ftp, genkey, junit, sql.
 
 * New tasks mparse, execon. All pending documentation, most of
 them pending review.

docs/index.html

@@ -743,6 +743,7 @@ same patterns as the example before.</p>
 <h2><a name="tasks">Built in tasks</a></h2>
 <ul>
   <li><a href="#ant">Ant</a></li>
+  <li><a href="#antstructure">AntStructure</a></li>
   <li><a href="#available">Available</a></li>
   <li><a href="#chmod">Chmod</a></li>
   <li><a href="#copydir">Copydir</a></li>
@@ -835,6 +836,35 @@ allows you to parameterize your subprojects.</p>
   &lt;/ant&gt;
 </pre>
 <hr>
+<h2><a name="antstructure">AntStructure</a></h2>
+<h3><b>Description:</b></h3> 
+<p>Generates a DTD for Ant build files which contains informations
+about all tasks currently known to Ant.</p> 
+<p>Note that the DTD generated by this task is incomplete, you can
+always add XML entities using <a
+href="#taskdef"><code>&lt;taskdef&gt;</code></a>. See <a
+href="http://www.sdv.fr/pages/casa/html/ant-dtd.en.html">here</a> for
+a way to get around this problem.</p>
+<p>This task doesn't know about required attributes, all will be
+listed as <code>#IMPLIED</code>.</p>
+<h3>Parameters:</h3>
+<table border="1" cellpadding="2" cellspacing="0">
+  <tr>
+    <td valign="top"><b>Attribute</b></td>
+    <td valign="top"><b>Description</b></td>
+    <td align="center" valign="top"><b>Required</b></td>
+  </tr>
+  <tr>
+    <td valign="top">output</td>
+    <td valign="top">file to write the DTD to.</td>
+    <td valign="top" align="center">Yes</td>
+  </tr>
+</table>
+<h3>Examples</h3>
+<blockquote><pre>
+&lt;antstructure output=&quot;project.dtd&quot; /&gt;
+</pre></blockquote>
+<hr>
 <h2><a name="available">Available</a></h2>
 <h3>Description</h3>
 <p>Sets a property if a resource is available at runtime. This resource can be a