Get an entry of a Manifest file with ant - ant

Question

I am trying to develope an Ant macrodef which gets the values separated by commas of the Require-Bundle property in a Manifest file passed as parameter. What I want to obtain is something like this:
Require-Bundle=org.eclipse.ui,org.eclipse.ui.ide,org.eclipse.ui.views...
The problem I am facing in my code is that it doesn't take into account if the property has multiple values in multiple lines, here is my code:
<macrodef name="getDependencies">
<attribute name="file" />
<attribute name="prefix" default="ant-mf." />
<sequential>
<loadproperties>
<file file="#{file}" />
<filterchain>
<linecontains>
<contains value="Require-Bundle" />
</linecontains>
<prefixlines prefix="#{prefix}" />
</filterchain>
</loadproperties>
</sequential>
</macrodef>
But this is what I get:
[echoproperties] ant-mf.Require-Bundle=org.eclipse.ui,
Any help will be appreciated.

Answer 1

Most likely, your Manifest file looks like this:
Require-Bundle: org.eclipse.ui,
org.eclipse.ui.ide,
org.eclipse.ui.views,
...
Unfortunately, Java Manifest files aren't quite Java Properties files. Manifest files can have attributes that span multiple lines whereas Property files can't have multi-line values. The <loadproperties> task can't handle multi-line attributes.
Instead, you'll need an Ant task that knows about Manifest files. In another question, Richard Steele provides Ant script that loads a Manifest file from a Jar file. You can adapt the example to get just the Require-Bundle attribute.

Answer 2

Thanks to Chad Nouis I have changed the macrodef approach to scriptdef. I have debugged and adapted the Richard Steele script to fit my needs:
<!--
Loads entries from a manifest file.
#manifest A manifest file to read
#entry The name of the manifest entry to load (optional)
#prefix A prefix to prepend (optional)
-->
<scriptdef name="getDependencies" language="javascript" description="Gets all entries or a specified one of a manifest file">
<attribute name="manifest" />
<attribute name="entry" />
<attribute name="prefix" />
<![CDATA[
var filename = attributes.get("manifest");
var entry = attributes.get("entry");
if (entry == null) {
entry = "";
}
var prefix = attributes.get("prefix");
if (prefix == null) {
prefix = "";
}
var manifest;
if (filename != null) {
manifest = new java.util.jar.Manifest(new java.io.FileInputStream(new java.io.File(filename)));
} else {
self.fail("File is required");
}
if (manifest == null) {
self.log("Problem loading the Manifest");
} else {
var attributes = manifest.getMainAttributes();
if (attributes != null) {
if (entry != "") {
project.setProperty(prefix + entry, attributes.getValue(entry));
} else {
var it = attributes.keySet().iterator();
while (it.hasNext()) {
var key = it.next();
project.setProperty(prefix + key, attributes.getValue(key));
}
}
}
}
]]>
</scriptdef>