Minification or compression means removing all unnecessary characters, such as spaces, new lines, comments without changing the functionality of the source code. During development and debugging, these characters make code easier to read. At the production stage they only increase the size of code to be transferred.
Before you start
Download and install Node.js.
If you are going to use YUI Compressor or Closure Compiler, download and install Java Runtime Environment (JRE):
JRE version 1.4 or later for YUI Compressor.
JRE version 7 for Closure Compiler.
Installing a minification tool
To install UglifyJS, open the built-in IntelliJ IDEA Terminal Alt+F12 and type
npm install uglify-jsor
npm install uglify-js@<version>. Learn more from the UglifyJS official website.
To install YUI Compressor, follow the instructions on YUI Compressor official website.
To install Closure Compiler, follow the instructions on Closure Compiler official website.
Compressing the code
To compress your code on the fly, you need to configure the minification tool as a IntelliJ IDEA File Watcher.
To create a File Watcher
In the Settings/Preferences dialog (Ctrl+Alt+S), and click File Watchers under Tools. The File Watchers page opens.
Click and choose the relevant File Watcher template from the list.
In the New Watcher dialog that opens, specify the path to the relevant executable file or jar archive in the Program field:
compiler.jarfor Closure Compiler.
yuicompressor-<version>.jarfor YUI Compressor JS.
Optionally, customize the behaviour of the File Watcher.
Make sure the checkbox next to the File Watcher is selected, which indicates that the File Watcher is enabled.
Running a compressor