Overview

Polyglot for Maven is a set of extensions for Maven 3.3.1+ that allows the POM model to be written in dialects other than XML. Several of the dialects also allow inlined plugins: the Ruby, Groovy and Scala dialects allow this.

Here's an example POM written in the Ruby dialect:

project 'Polyglot :: Aggregator' do

  model_version '4.0.0'
  id 'io.tesla.polyglot:tesla-polyglot:0.0.1-SNAPSHOT'
  inherit 'io.tesla:tesla:4'
  packaging 'pom'

  properties( 'sisuInjectVersion' => '0.0.0.M2a',
              'teslaVersion' => '3.1.0' )

  modules [ 'tesla-polyglot-common',
            'tesla-polyglot-atom',
            'tesla-polyglot-ruby',
            'tesla-polyglot-groovy',
            'tesla-polyglot-yaml',
            'tesla-polyglot-clojure',
            'tesla-polyglot-scala',
            'tesla-polyglot-cli',
            'tesla-polyglot-maven-plugin' ]

  overrides do
    jar 'org.eclipse.sisu:org.eclipse.sisu.inject:${sisuInjectVersion}'
    jar 'org.eclipse.sisu:org.eclipse.sisu.plexus:${sisuInjectVersion}'
    jar 'org.apache.maven:maven-model-builder:3.1.0'
    jar 'org.apache.maven:maven-embedder:3.1.0'
    jar( 'junit:junit:4.11', :scope => 'test' )

  end

  plugin 'org.codehaus.plexus:plexus-component-metadata:1.5.4' do
    execute_goals 'generate-metadata', 'generate-test-metadata'
  end

  build do
    execute("first", :validate) do |context|
      puts "Hello from JRuby!"
    end
  end
end

Requirements

• Maven 3.3.1+
• Java 7+

Usage

To use Polyglot for Maven you need to edit ${maven.multiModuleProjectDirectory}/.mvn/extensions.xml and add the appropriate language extension.

Available Languages

The available languages, in alphabetical order, with their artifact id are:

Language	Artifact Id
Atom	polyglot-atom
Groovy	polyglot-groovy
Clojure	polyglot-clojure
Ruby	polyglot-ruby
Scala	polyglot-scala
YAML	polyglot-yaml

The groupId value is io.takari.polyglot.

Update extensions.xml

Edit the extensions.xml file and add the following, replacing ARTIFACTID with the artifactId for your chosen language.

<?xml version="1.0" encoding="UTF-8"?>
<extensions>
  <extension>
    <groupId>io.takari.polyglot</groupId>
    <artifactId>ARTIFACTID</artifactId>
    <version>0.2.1</version>
  </extension>
</extensions>

Convert existing POM

We have created a simple Maven plugin that will help you convert any existing pom.xml files:

mvn io.takari.polyglot:polyglot-translate-plugin:translate \
  -Dinput=pom.xml -Doutput=pom.{format}

Where the supported formats are rb, groovy, scala, yaml, atom and of course xml. See here for more info. You can even convert back to xml or cross-convert between all supported formats.

Note of Caution

The whole interoperability story has not been worked out but you can create a XML-formatted POM from the Polyglot version. Currently mixing different dialects within a reactor is not supported.

A pom.xml will currently not be installed or deployed except for the Ruby DSL and the Scala DSL but we are working towards this feature for all DSLs.

Polyglot Maven in Real Life

Despite the warning above, Polyglot Maven is pretty stable right now. Have a look at the integration tests for each dialect in this repository for some examples as well as our dedicated polyglot-maven-examples project.

The following projects are real world usage examples that use Polyglot Maven in their regular development and release work:

Ruby

• https://github.com/jruby - Extensive usage of Polyglot Ruby and contributions to the project from the team, and is recommended when creating java extensions for jruby.
• The ruby-processing project has examples of creating java extensions for jruby (see JRubyArt and propane builds) as well as simpler projects where the polyglot maven is used in creating gem wrappers for processing.org java libraries (eg toxicgem and geomerative gems).

YAML

• http://snakeyaml.org - Extensive usage of Polyglot YAML and contributions to the project from the team.

Scala

• https://github.com/domino-osgi/domino - A simple project using Polyglot Scala.
• https://github.com/woq-blended/blended - A complex mulit-project using Polyglot Scala. It's also an example where the #include feature is heavily used to share common configuration but avoid Maven parent poms, which are often problematic.

Please let us know of your usage by filing an issue so we can add it here.