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| <head> |
| <link rel="stylesheet" type="text/css" href="stylesheets/style.css"/> |
| <title>If and Unless on all tasks/nested elements</title> |
| </head> |
| |
| <body> |
| <h1 id="if_and_unless">If And Unless</h1> |
| |
| <p><em>Since Ant 1.9.1</em>, it is possible to add <var>if</var> and <var>unless</var> attributes on all tasks and nested elements using special namespaces.</p> |
| |
| <p>In order to use this feature you need to add the following namespace declarations</p> |
| <pre> |
| xmlns:if="ant:if" |
| xmlns:unless="ant:unless"</pre> |
| |
| <p>The <code>if</code> and <code>unless</code> namespaces support the following 3 conditions:</p> |
| <dl> |
| <dt><q>true</q></dt><dd>true if the value of the attribute evaluates to true</dd> |
| <dt><q>blank</q></dt><dd>true if the value of the attribute is null or empty</dd> |
| <dt><q>set</q></dt><dd>true if the specified property is set</dd> |
| </dl> |
| <pre> |
| <project name="tryit" |
| xmlns:if="ant:if" |
| xmlns:unless="ant:unless"> |
| <exec executable="java"> |
| <arg line="-X" if:true="${showextendedparams}"/> |
| <arg line="-version" unless:true="${showextendedparams}"/> |
| </exec> |
| <condition property="onmac"> |
| <os family="mac"/> |
| </condition> |
| <echo if:set="onmac">running on MacOS</echo> |
| <echo unless:set="onmac">not running on MacOS</echo> |
| </project></pre> |
| |
| </body> |
| </html> |