sbt-closurec

Google Closure Compiler plugin for SBT

This plugin is helping to work with Google Closure Compiler of your JavaScripts during development and packaging.

Install

val verClosurec = "0.1.3"

lazy val closurecPlugin = uri(s"https://github.com/hitsoft/sbt-closurec.git#$verClosurec")

lazy val root = project.in(file("."))
	.dependsOn(closurecPlugin)

NOTE this plugin is targeting the release of sbt, 0.13.7

You will need to add the following to your project/build.properties file if you have multiple versions of sbt installed

sbt.version=0.13.7

Be sure to use the latest launcher.

Usage

Out of the box

Add the following to your build.sbt file

seq(closureSettings:_*)

Default configuration suppose you have following files structure

src/main/javascript - the place where your JavaScript files will be looked for

In Developer mode

This mode suppose you do just compile action and use xsbt-web plugin to run Jetty with your webapp.

In this case plugin will copy all your src/main/javascript .js files to the target/resource-managed/js and create the deps.js file according to your goog.require and goog.provide.

In this mode you should make reference in your html to js/deps.js and your root js file like js/app.entry.js

SUMMARY In developer mode no real closure compilation performed, plugin just refreshes deps.js file and you work with raw sources js files

In Package mode

In this mode SIMPLE_OPTIMIZATIONS google closure compilation will be used. This will be called with package action.

How it supposed to work:

Plugin searches for the *.entry.js files. Those files will be compiled with dependencies using goog.provide, goog.require functions and packaged to js/*.min.js files. For example if you have app.entry.js in src/main/javascript you will have js/app.min.js in your final webapp packaged folder.

Externs are searched in externs/*.js anywhere inside your src/main/javascript folder.

SUMMARY In Package mode (when you call package in sbt), your JavaScripts will be compiled with google closure compiler and packaged to WAR without sources, just compiled version.

Customization

Here is the list of options (keys) that can be adjusted in your build.sbt script

// Turn on ADVANCED optimizations instead of SIMPLE
(ClosureKeys.compilationLevel in Compile) := CompilationLevel.ADVANCED_OPTIMIZATIONS

// Turn on JavaScript strict mode
(ClosureKeys.strictMode in Compile) := true

// Turn on pretty printing of compiled JavaScript
(ClosureKeys.prettyPrint in Compile) := true

// Specify the compiled file name suffix. app.entry.js -> app-suffix.min.js
(ClosureKeys.suffix in Compile) := "suffix"