Simple buildSrc plugin issue

Help/Discuss
1

Hi,

I’m trying to write a plugin in buildSrc and apply it to the root project. When trying to apply it, I get plugin not found.

Project structure

   build.gradle
+  buildSrc
     build.gradle
   + src
      + main
         + groovy
            CustomPlugin.groovy

Root build.gradle

apply plugin: 'java'
apply plugin: 'groovy'
apply plugin: 'customplugin'

depedencies {
    testCompile 'junit:junit:4.12'
}

buildSrc build.gradle

apply plugin: "groovy"
apply plugin: "java"

dependencies {
    compile localGroovy()
    compile gradleApi()
}

Plugin code

import org.gradle.api.Plugin
import org.gradle.api.Project

class CustomPlugin implements Plugin<Project>
{
    @Override
    void apply(Project target)
    {
        println 'Applying CustomPlugin'
    }
}

gradle clean build gives Plugin with id ‘customplugin’ not found.

Any hints?

Thank you

2

You forgot to add the properties file that tells Gradle about the mapping from plugin ID to implementation class. Have a look at the user guide about plugins.

3

Thanks for your reply, but isn’t that required only for standalone projects? Being in buildSrc, I thought the there’s no need for an extra mapping.

https://docs.gradle.org/current/userguide/custom_plugins.html#sec:custom_plugins_standalone_project

4

You always need a mapping, how else is Gradle going to know what ID your plugin should have?

5

Thanks a lot for the help

6

If you want to implement a plugin into your buildscript, then you have two options.

Option 1
apply plugin: YourCustomPluginClassName

Option 2
plugins { id 'your.custom.plugin.id' }

apply plugin: is used when specifying your plugin by its class name (ex. apply plugin: JavaPlugin)
plugins { } is used when specifying your plugin by its id (ex. plugins { id 'java' })
See Gradle Plugins by tutorialspoint for reference

If you choose Option 1, then your custom plugin will need to be brought into your build script by 1 of 3 ways.

  1. You can code it directly within your Gradle build script.
  2. You can put it under buildSrc (ex. buildSrc/src/main/groovy/MyCustomPlugin).
  3. You can import your custom plugin as a jar in your buildscript method.
    See Gradle Goodness by Mr. Haki for information about the buildscript method.

If you choose Option 2, then you need to create a plugin id. Create the following file buildSrc/src/main/resources/META-INF/gradle-plugins/[desired.plugin.id].properties. Copy and paste implementation-class=desired.plugin.id into your newly created .properties file. Replace ‘desired.plugin.id’ with your desired plugin id.
See Custom Plugins by Gradle for more info.