Chapter 66. The IDEA Plugin

To completely rewrite existing IDEA files, execute a clean task together with its corresponding generation task, like “gradle cleanIdea idea” (in that order). If you want to make this the default behavior, add “tasks.idea.dependsOn(cleanIdea)” to your build script. This makes it unnecessary to execute the clean task explicitly.

This strategy can also be used for individual files that the plugin would generate. For instance, this can be done for the “.iml” file with “gradle cleanIdeaModule ideaModule”.

A complete rewrite causes all existing content to be discarded, thereby losing any changes made directly in the IDE. The beforeMerged hook makes it possible to overwrite just certain parts of the existing content. The following example removes all existing dependencies from the Module domain object:

idea.module.iml {
    beforeMerged { module ->
        module.dependencies.clear()
    }
}

The resulting module file will only contain Gradle-generated dependency entries, but not any other dependency entries that may have been present in the original file. (In the case of dependency entries, this is also the default behavior.) Other sections of the module file will be either left as-is or merged. The same could be done for the module paths in the project file:

idea.project.ipr {
    beforeMerged { project ->
        project.modulePaths.clear()
    }
}

The whenMerged hook allows you to manipulate the fully populated domain objects. Often this is the preferred way to customize IDEA files. Here is how you would export all the dependencies of an IDEA module:

idea.module.iml {
    whenMerged { module ->
        module.dependencies*.exported = true
    }
}

The withXmlhook allows you to manipulate the in-memory XML representation just before the file gets written to disk. Although Groovy's XML support makes up for a lot, this approach is less convenient than manipulating the domain objects. In return, you get total control over the generated file, including sections not modeled by the domain objects.

idea.project.ipr {
    withXml { provider ->
        provider.node.component
                .find { it.@name == 'VcsDirectoryMappings' }
                .mapping.@vcs = 'Git'
    }
}