Chapter 24. The Groovy Plugin

To use the Groovy plugin, include in your build script:

apply plugin: 'groovy'

The Groovy plugin adds the following tasks to the project.

The Groovy plugin adds the following dependencies to tasks added by the Java plugin.

Figure 24.1. Groovy plugin - tasks

The Groovy plugin assumes the project layout shown in Table 24.3, “Groovy plugin - project layout”. All the Groovy source directories can contain Groovy and Java code. The Java source directories may only contain Java source code. ^[10] None of these directories need exist or have anything in them. The Groovy plugin will compile whatever it finds, and handles anything which is missing.

sourceSets {
    main {
        groovy {
            srcDir 'src/groovy'
        }
    }
}

The Groovy plugin adds a dependency configuration called groovy.

Gradle is written in Groovy and allows you to write your build scripts in Groovy. But this is an internal aspect of Gradle which is strictly separated from building Groovy projects. You are free to choose the Groovy version your project should be build with. This Groovy version is not just used for compiling your code and running your tests. The groovyc compiler and the groovydoc tool are also taken from the Groovy version you provide. As usual, with freedom comes responsibility ;). You are not just free to choose a Groovy version, you have to provide one. Gradle expects that the groovy libraries are assigned to the groovy dependency configuration. Here is an example using the public Maven repository:

repositories {
    mavenCentral()
}

dependencies {
    groovy group: 'org.codehaus.groovy', name: 'groovy', version: '1.7.10'
}

And here is an example using the Groovy JARs checked into the lib directory of the source tree:

repositories {
    flatDir { dirs 'lib' }
}

dependencies {
    groovy module(':groovy:1.6.0') {
        dependency('asm:asm-all:2.2.3')
        dependency('antlr:antlr:2.7.7')
        dependency('commons-cli:commons-cli:1.2')
        module(':ant:1.7.0') {
            dependencies(':ant-junit:1.7.0:jar', ':ant-launcher:1.7.0')
        }
    }
}

The Groovy plugin does not add any convention properties to the project.

The Groovy plugin adds the following convention properties to each source set in the project. You can use these properties in your build script as though they were properties of the source set object (see Section 21.3, “Conventions”).

These properties are provided by a convention object of type GroovySourceSet.

The Groovy plugin also modifies some source set properties:

The Groovy plugin adds a GroovyCompile instance for each source set in the project. The task type extends the Compile task (see Section 23.11, “CompileJava”). The compile task delegates to the Ant Groovyc task to do the compile. Via the compile task you can set most of the properties of Ants Groovyc task.