Chapter 27. The Eclipse Plugin

If you want Gradle to completely overwrite existing Eclipse files you can specify this on the command line by executing something like gradle cleanEclipse eclipse or gradle cleanEclipseClasspath eclipseClasspath. You can specify this also in the build script. Just make the generating tasks depending on the deleting tasks. You can tailor this to your needs. You could make the eclipse task dependent on the cleanEclipse task. If you only want to overwrite for example the classpath files you simply make the eclipseClasspath task dependent on the cleanEclipseClasspath task.

Doing a complete overwrite removes all your manual customizations. This might be not what you want. Therefore Gradle provides the option for a partial overwrite. You can hook into the phase just after the existing Eclipse files have populated the domain objects. You could then for example remove all the dependencies from the classpath object.

eclipseClasspath {
    beforeConfigured { classpath ->
        classpath.entries.removeAll { entry -> entry.kind == 'lib' || entry.kind == 'var' }
    }
}

The generated XML will have all sections of the existing Eclipse classpath file, except for the dependencies, where only the information of the build script is used. You could do something similar for the project file.

eclipseProject {
    beforeConfigured { project ->
        project.natures.clear()
    }
}

You can also hook into the phase after the existing Eclipse files and the build script metadata have populated the domain objects. You could then for example disable export of all the dependencies of the module object.

eclipseClasspath {
    whenConfigured { classpath ->
        classpath.entries.findAll { entry -> entry.kind == 'lib' }*.exported = false
    }
}

You can also hook into the phase after the XML DOM is fully populated but not written to disk. That hook provides total control over what is generated.

eclipseWtp {
    withXml { files ->
        files.'org.eclipse.wst.commons.project.facet.core'.fixed.find { it.@facet == 'jst.java' }.@facet = 'jst2.java'
    }
}