How it works ?

Since the version 3.8, Jawr provides a way to define which JS engine to use. You can set the default JS engine, with the property jawr.js.engine. The default value for this property is mozilla.rhino. So the default JS engine is Rhino.

Since Java 8, Nashorn JS engine is provided with the JRE. So to use Nashorn, you need to specify in your configuration file :

        # Set Nashorn as default JS engine
        jawr.js.engine=nashorn

You can also specify which JS engine to use per processor or generator, using the dedicated property. (See the processor or generator documentation for more detail)

        # Set Nashorn as default JS engine for the coffescript generator
        jawr.js.generator.coffee.script.js.engine=nashorn

Here is the list of processors which are using a JS engine:

• Uglify [net.jawr.web.resource.bundle.postprocess.impl.js.uglify.UglifyPostProcessor]
• Autoprefixer [net.jawr.web.resource.bundle.postprocess.impl.AutoPrefixerPostProcessor]

Here is the list of generators which are using a JS engine:

• CoffeeScript [net.jawr.web.resource.bundle.generator.js.coffee.CoffeeScriptGenerator]