Property set to false, but target still executed

Here's a simple Ant build file:

<?xml version="1.0" encoding="UTF-8"?>
<project name="Project" default="build" basedir=".">
    <property name="compressAssets" value="false"/>

    <target name="build" depends="compress-assets"/>
    <target name="compress-assets" if="compressAssets">
        <echo message="executed"/>
    </target>
</project>

compressAssets is set to false, so how come the compress-assets target is executed every time? Note the if property on the targ开发者_运维技巧et.

if does not check for the value of the property, it checks if the property has been set.

From the documentation:

<target name="build-module-A" if="module-A-present"/>

[...] if the module-A-present property is set (to any value, e.g. false), the target will be run.

In Ant 1.8, if now does check that the value is true (unless checks for false), so you can do:

<target name="blah" if="${do-blah}">
    .
    .
    .
</target>