Apache ant does not recognize 'for' task/macro, although I have added ant-contrib via taskdef

Question

I am getting following while doing ant build:

Build\build.xml:247: Problem: failed to create task or type
for
Cause: The name is undefined.
Action: Check the spelling.
Action: Check that any custom tasks/types have been declared.
Action: Check that any <presetdef>/<macrodef> declarations have taken place.

build.xml line 247 is <for param="file">

Already defined <taskdef resource="net/sf/antcontrib/antcontrib.properties"/>, it didn't work. Then I specifically added following but it is still not working.

<taskdef resource="net/sf/antcontrib/antcontrib.properties">
        <classpath>
            <pathelement location="${env.ANT_HOME}/lib/ant-contrib-1.0b3.jar"/>
        </classpath>
    </taskdef>

I have ant-contrib-1.0b3.jar at C:\Softwares\apache-ant-1.8.4\lib directory.
What is missing here?

Solution 1

If you placed the AntContrib jar in $ANT_HOME/lib directory, all you really need to do is this:

<taskdef resource="net/sf/antcontrib/antcontrib.properties"/>

Actually to use the <for/> task, you need to do this:

<taskdef resource="net/sf/antcontrib/antlib.xml"/>

Note you have to use antlib.xml and not antcontrib.properties. Read the Installation directions very carefully. It's easy to miss.

If you are doing this in a group project, I recommend that you put your ant-contrib.jar in your project. THen add them to your project in your version control system. That way, other developers can use your build with the ant-contrib tasks without downloading the ant-contrib jar and installing it in their $ANT_HOME directory themselves.

Let's say you create a directory called ant-contrib.dir and put that in the root of your project, then put the ant-contrib jar in that folder. Just put this in your project:

<taskdef resource="net/sf/antcontrib/antlib.xml">
    <classpath>
          <fileset dir="${basedir}/ant-contrib.dir"/>
    </classpath>
</taskdef>

Solution 2

Ant needs to be aware of the the dependency. The following is a more succinct version of David W's answer. Add the equivalent of the following to your ant project:

<taskdef resource="net/sf/antcontrib/antcontrib.properties" classpath="relative/path/to/ant-contrib-1.0b3.jar"/>
<taskdef resource="net/sf/antcontrib/antlib.xml" classpath="relative/path/to/ant-contrib-1.0b3.jar"/>