Creating Gradle Plugins

Annyce Davis - @brwngrldev

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Without Plugins

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With Plugins

Overview• Plugin Skeleton

• Dependencies

• Plugin.groovy

• CustomTask.groovy

• Publishing

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Plugin Skeleton

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Plugin Skeleton

Plugin SkeletonHow Gradle finds the Plugin Implementation

Dependencies

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apply plugin: ‘groovy'

dependencies { compile gradleApi() compile localGroovy() }

Plugin.groovyImplement the Plugin interface and override apply method

class CustomPlugin implements Plugin<Project> {

@Override void apply(Project project) {

} }

QualityChecksPlugin.groovyImplement the Plugin interface and override apply method

Apply Method

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Creates the tasks for the plugin and performs any setup

Project Extension

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Allows the user to customize the behavior of the plugin

Project Extension

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Back in the application’s build.gradle file…

Creating tasks

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Give it a name and a type

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CustomTask.groovy

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class CustomTask extends DefaultTask {

}

CustomTask.groovy

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class CustomTask extends DefaultTask {

@TaskAction def defaultAction() {

} }

CustomTask.groovy

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class CustomTask extends DefaultTask {

@TaskAction def defaultAction() {

< do your cool stuff >

} }

So far…• Plugin Skeleton

• Dependencies

• Plugin.groovy

• CustomTask.groovy

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Questions?

Publishing

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Publishingbuildscript { repositories { maven { url "https://plugins.gradle.org/m2/" } } dependencies { classpath "com.gradle.publish:plugin-publish-plugin:0.9.2" } }

apply plugin: 'com.gradle.plugin-publish'

version = "0.1.3" group = "info.adavis"

version = "0.1.3" group = "info.adavis"

pluginBundle { website = 'https://github.com/adavis/quality-checks' vcsUrl = 'https://github.com/adavis/quality-checks.git' description = 'Gradle Plugin for…’ tags = ['Checkstyle', 'FindBugs', 'PMD']

}

version = "0.1.3" group = "info.adavis"

pluginBundle { website = 'https://github.com/adavis/quality-checks' vcsUrl = 'https://github.com/adavis/quality-checks.git' description = 'Gradle Plugin for…’ tags = ['Checkstyle', 'FindBugs', 'PMD']

plugins { qualityChecksPlugin { id = 'info.adavis.qualitychecks' displayName = 'Quality Checks Plugin' } } }

Publishing

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Once your Plugin is published on the Gradle portal

We’re done…

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WRONG!

We’re done…

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TESTS

Testing

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You can use JUnit and the ProjectBuilder for most testing

Testing

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@Test void shouldBeAbleToCreateTask() { assertTrue(task instanceof WriteConfigFileTask) }

Testing

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@Test void shouldBeAbleToCreateTask() { assertTrue(task instanceof WriteConfigFileTask) }

@Test void pluginShouldBeApplied() { def project = ProjectBuilder.builder().build()

project.apply(plugin: QualityChecksPlugin)

assertNotNull(project.tasks.findByName(‘mytask’)) }

Bonus: README

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Bonus: README

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Summary• Helps avoid copy/paste horror

• Simple project structure

• Extending DefaultTask

• Testing techniques

• Easy to publish

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Next Steps✓Sample: https://git.io/vzJ2w

✓Sample: https://git.io/vzJwS

✓Applaud 😉

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Thanks!

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+AnnyceDavis

www.adavis.info

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