How can I import one Gradle script into another?

Question

Hi all,

I have a complex gradle script that wraps up a load of functionality around building and deploying a number of netbeans projects to a number of environments.

The script works very well, but in essence it is all configured through half a dozen maps holding project and environment information.

I want to abstract the tasks away into another file, so that I can simply define my maps in a simple build file, and import the tasks from the other file. In this way, I can use the same core tasks for a number of projects and configure those projects with a simple set of maps.

Can anyone tell me how I can import one gradle file into another, in a similar manner to Ant's task? I've trawled Gradle's docs to no avail so far.

Additional Info

After Tom's response below, I thought I'd try and clarify exactly what I mean.

Basically I have a gradle script which runs a number of subprojects. However, the subprojects are all Netbeans projects, and come with their own ant build scripts, so I have tasks in gradle to call each of these.

My problem is that I have some configuration at the top of the file, such as:

projects = [
    [name:"MySubproject1", shortname: "sub1", env:"mainEnv", cvs_module="mod1"],
    [name:"MySubproject2", shortname: "sub2", env:"altEnv", cvs_module="mod2"]
]

I then generate tasks such as:

projects.each({
    task "checkout_$it.shortname" << {
         // Code to for example check module out from cvs using config from 'it'.
    }
})

I have many of these sort of task generation snippets, and all of them are generic - they entirely depend on the config in the projects list.

So what I want is a way to put this in a separate script and import it in the following sort of way:

projects = [
    [name:"MySubproject1", shortname: "sub1", env:"mainEnv", cvs_module="mod1"],
    [name:"MySubproject2", shortname: "sub2", env:"altEnv", cvs_module="mod2"]
]

import("tasks.gradle") // This will import and run the script so that all tasks are generated for the projects given above.

So in this example, tasks.gradle will have all the generic task generation code in, and will get run for the projects defined in the main build.gradle file. In this way, tasks.gradle is a file that can be used by all large projects that consist of a number of sub-projects with Netbeans ant build files.

Answer 1

Well, it is hard to tell what serves you best without actually seeing your build file.

I could assume that stetting up your environment as multi-project build should provide you the abstraction you are looking for.

In your project root build.gradle you define all your domain specific stuff as well as the things that apply to all your subprojects:

repositories {
    add(new org.apache.ivy.plugins.resolver.FileSystemResolver()) {
        name = 'destRepo'
        addIvyPattern( file( project.properties['repo.dest.dir']).absolutePath + '/[organisation]/[module]/ivys/ivy(-[revision]).xml')
        addArtifactPattern( file( project.properties['repo.dest.dir']).absolutePath + '/[organisation]/[module]/[type]s/[artifact](-[revision]).[ext]')
        descriptor = 'optional'
        checkmodified = true
    }
    ...
}
...
subprojects {
    sourceCompatibility = 1.5
    targetCompatibility = 1.5
    group = 'my.group'
    version = '1.0'
    uploadArchives {
        uploadDescriptor = true
        repositories {
            add rootProject.repositories.destRepo
        }
    }
    apply{ type my.group.gradle.api.plugins.MyPlugin }
    ...
}

dependsOnChildren()

The project root directory might also contain a gradle.properties file where you define properties used by your projects:

buildDirName=staging
repo.dest.dir=/var/repo
...

Then in an additional file from your project root named settings.gradle you actually point to your subprojects:

include 'my-first-component',
        'my-second-component'
...
project(':my-first-component').projectDir = new File(rootDir, 'path/to/first/component')
project(':my-second-component').projectDir = new File(rootDir, 'path/to/second/component')
...

Each sub-project directory contains a build.gradle file containing the sub-project specific stuff only.

No matter if you invoke gradle from your project root or sub-project directory, gradle will automatically consider all your definitions done in the various files.

Also note that no compile task will be executed for your project root as long as you don't load any plugin beyond the default plugin at the root level.

Answer 2

There is a new feature in 0.9. You can use apply from: 'other.gradle' command.

Read my question about same thing at: http://stackoverflow.com/questions/2566685/is-there-a-way-to-split-factor-out-common-parts-of-gradle-build