looping through an xml file combining lists in ANT

I have this xml:

<?xml version="1.0" encoding="UTF-8"?>
<projects>
  <project action="D">Project1</project>
  <project action="M">Project2</project>
</projects>

I want to use ant to loop trough the projects and execute a piece of code when the action is D, and an other piece of code when the action is not D.

My progress so far is:

<target name="test">
  <xmlproperty file="changeList.xml"/>
  <for list="${projects.project}" param="project">
    <sequential>
      <echo>The project name is @{project} Action @{project.action}</echo>
    </sequential>
  </for>
</target>

result now is:

 [echo] Project name is Project1 Action is @{project.action}
 [echo] Project name is Project2 Action is @{project.action}

I understand that I have 2 separate lists and that I'm not getting the action in the result. I need to loop trough my xml file having both property's available (project name, and the action) to pass as a parameter to the next target.

Solution

With ant addon task xmltask you have two possibilities.

xmltask with nested action => run all tasks contained in the action task container for every match of the xpath expression (attribute action = D in this example) :

<project>
 <!-- Import XMLTask -->
 <taskdef name="xmltask" classname="com.oopsconsultancy.xmltask.ant.XmlTask"/>

 <!-- loop over all projects with attribute action=D --> 
 <xmltask source="changeList.xml">
  <call path="//projects/project[@action='D']">
   <param path="text()" name="projname"/>
   <!-- define other params if needed .. -->
   <param value="bar" name="foo"/>
   <!-- inside action adress params with @{..} syntax ! -->
    <actions>
      <echo>Action D => @{projname}${line.separator}Param @@{foo} => @{foo}</echo>
   </actions>
  </call>
 </xmltask>

</project>

xmltask calling ant target for every match of the xpath expression (attribute action != D in this example).
In this case you have to use the xmltask from a target (target main in this snippet) otherwise you'll get a BuildFailed => xmltask task at the top level must not invoke its own build file.

<project  default="main">
 <!-- Import XMLTask -->
 <taskdef name="xmltask" classname="com.oopsconsultancy.xmltask.ant.XmlTask"/>

<target name="main">
 <xmltask source="changeList.xml">
  <call path="//projects/project[@action != 'D']" target="foo">
   <param path="text()" name="projname"/>
   <param value="bar" name="foo"/>
  </call>
 </xmltask>
</target>

<!-- you have to use the propertysyntax ${...} in the called target
     for the params ! -->

<target name="foo">
 <echo>
 ${projname} => Action != D
 Param $${foo} is ${foo}
 </echo>
</target>

</project>