ant: string manipulation on variable - string

Question

I have a question based from this question
Replacing characters in Ant property
I want to build a variable (i can't use a property because i'm in a loop) that is pretty much StringA - StringB.
(maybe this is a misunderstanding of properties on my part but they can only be assigned once correct?)
I guess I could build a script function to calculate that, but my guess is that it must be possible to do it in an already existing function, probably something i'm missing.
this would be an example of the code
<for param="file">
<path>
<fileset dir="${mydir}" >
<include name="*.war"/>
</fileset>
</path>
<sequential>
<var name="undeploy_name" value="#{file} function_here ${mydir}" />
<JBossCLI port="${jboss.port.management-native}">
<undeploy namePattern="${undeploy_name}" />
</JBossCLI>
<deployToLiferay file="#{file}" />
</sequential>
</for>
in general I want to deploy several wars. this works fine when I run it once but if I want to make it re-runnable I need to undeploy them first.
I'm just a consumer of this interfaces, Ideally deployToLiferay would auto undeploy but it does not.
thanks for an feedback
edit: if I use something similar to what is define on the linked page i get:
<loadresource property="file-to-deploy">
<propertyresource name="#{file}"/>
<filterchain>
<tokenfilter>
<filetokenizer/>
<replacestring from="${mydir}" to=""/>
</tokenfilter>
</filterchain>
</loadresource>
10:52:49.541: * /data/contribution.xml:171: The following error occurred while executing this line:
10:52:49.541: * /data/contribution.xml:178: null doesn't exist
line 178 is my loadresource part

Answer 1

ANT is not a programming language. Personally I'd recommend embedding a scripting language like Groovy to process a group of files:
<target name="process-files" depends="resolve">
<taskdef name="groovy" classname="org.codehaus.groovy.ant.Groovy" classpathref="build.path"/>
<fileset id="wars" dir="src/wars" includes="*.war"/>
<groovy>
project.references.wars.each {
ant.echo(message: "I want to do something with this ${it} file")
}
</groovy>
</target>
Example
├── build.xml
└── src
└── wars
├── app1.war
├── app2.war
└── app3.war
Example
process-files:
[echo] I want to do something with this /../src/wars/app1.war file
[echo] I want to do something with this /../src/wars/app2.war file
[echo] I want to do something with this /../src/wars/app3.war file
Update
The following working example shows how Apache ivy can be used to manage build dependencies. This is a capability that exists in other Java build tools like Maven.
<project name="demo" default="process-files" xmlns:ivy="antlib:org.apache.ivy.ant">
<available classname="org.apache.ivy.Main" property="ivy.installed"/>
<!--
==================
Normal ANT targets
==================
-->
<target name="process-files" depends="resolve">
<taskdef name="groovy" classname="org.codehaus.groovy.ant.Groovy" classpathref="build.path"/>
<fileset id="wars" dir="src/wars" includes="*.war"/>
<groovy>
project.references.wars.each {
ant.echo(message: "I want to do something with this ${it} file")
}
</groovy>
</target>
<!--
=============================
Dependency management targets
=============================
-->
<target name="resolve" depends="install-ivy">
<ivy:cachepath pathid="build.path">
<dependency org="org.codehaus.groovy" name="groovy-all" rev="2.4.7" conf="default"/>
</ivy:cachepath>
</target>
<target name="install-ivy" unless="ivy.installed">
<mkdir dir="${user.home}/.ant/lib"/>
<get dest="${user.home}/.ant/lib/ivy.jar" src="http://search.maven.org/remotecontent?filepath=org/apache/ivy/ivy/2.4.0/ivy-2.4.0.jar"/>
<fail message="Ivy has been installed. Run the build again"/>
</target>
</project>