SASS, LESS, and SCSS code is not processed by browsers that work with CSS code. Therefore to be executed, SASS, LESS, or SCSS code has to be translated into CSS. This operation is referred to as transpilation and the tools that perform it are called transpilers.
IntelliJ IDEA supports integration with transpiler tools that translate SASS, LESS, and SCSS code into CSS.
In IntelliJ IDEA, transpiler configurations are called File Watchers. For each supported transpiler, IntelliJ IDEA provides a predefined File Watcher template. Predefined File Watcher templates are available at the IntelliJ IDEA level. To run a transpiler against your project files, you need to create a project-specific File Watcher based on the relevant template, at least, specify the path to the transpiler to use on your machine.
On this page:
- Installing the SASS/SCSS transpiler
- Installing the LESS transpiler
- Creating a File Watcher
- Transpiling the code
SASS and SCSS transpilers are managed through the Ruby Gem manager.
- Download and install Ruby.
- Specify a path variable for the folder where the Ruby executable file and the gem.bat file are stored. This lets you launch Ruby and Gem Manager from any folder and ensures that Ruby is successfully launched during transpilation.
Type one of the following commands at the command line prompt:
gem install sass
gem install scss
The tool is installed to the folder where Ruby executable file and the gem.bat file are stored.
Download and install the Node.js framework. The framework is required for two reasons:
- The LESS transpiler is started through Node.js.
- The Node Package Manager (npm), which is a part of the framework, is also the easiest way to download the transpiler.
For details on using Node.js in IntelliJ IDEA, see the section Node.js
Make sure the following paths are added to the PATH variable:
- The path to the parent folder of the Node.js executable file.
- The path to the Node Package Manager folder (npm).
Install and enable the NodeJS repository plugin.
The plugin is not bundled with IntelliJ IDEA, but it is available from the JetBrains plugin repository. Once enabled, the plugin is available at the IDE level, that is, you can use it in all your IntelliJ IDEA projects.
Download and install the LESS transpiler. The easiest way is to use the Node Package Manager (npm), which is a part of Node.js.
- Switch to the directory where the Node Package Manager (npm) is stored or define a path variable for it so it is available from any folder.
Type the following command at the command line prompt:
npm install less
IntelliJ IDEA provides a common procedure and user interface for creating File Watchers of all types. The only difference is in the predefined templates you choose in each case.
Install and enable the File Watchers repository plugin.
The plugin is not bundled with IntelliJ IDEA, but it is available from the IntelliJ IDEA plugin repository. Once enabled, the plugin is available at the IDE level, that is, you can use it in all your IntelliJ IDEA projects.
- To start creating a File Watcher, open the Project Settings and click File Watchers. The File Watchers page that opens, shows the list of File Watchers that are already configured in the project.
Click the Add button or press Alt+InsertAlt+InsertAlt+InsertAlt+InsertAlt+InsertAlt+InsertAlt+InsertAlt+Insert or Ctrl+NAlt+InsertCommand N or Control EnterControl N or Control EnterCommand N or Control Enter.
Depending on the tool you are going to use, choose the appropriate predefined template from the pop-up list:
In the Program text box, specify the path to the compiler executable file or archive depending on the chosen predefined template.
- lessc.cmd for LESS If you installed the tool through the Node Package Manager, IntelliJ IDEA locates the required file itself at <node.js_home>/node_modules/bin/lessc.cmd and fills in the field automatically. Otherwise, type the path manually or click the Browse button and choose the file location in the dialog box that opens.
- sass.bat for SASS
- scss.bat for SCSS
If you installed the SASS and SCSS tools through Ruby, IntelliJ IDEA locates the required files itself at <ruby_home>/bin/sass.bat <ruby_home>/bin/scss.bat respectively and fills in the field automatically. Otherwise, type the path manually or click the Browse button and choose the file location in the dialog box that opens.
- Proceed as described on page Using File Watchers.
Transpiling the code
When you open a TypeScript file, IntelliJ IDEA checks whether an applicable file watcher is available in the current project. If such file watcher is configured but disabled, IntelliJ IDEA displays a pop-up window that informs you about the configured file watcher and suggests to enable it.
If an applicable file watcher is configured and enabled in the current project, IntelliJ IDEA starts it automatically upon the event specified in the New Watcher dialog.
- If the Immediate file synchronization check box is selected, the File Watcher is invoked as soon as any changes are made to the source code.
- If the Immediate file synchronization check box is cleared, the File Watcher is started upon save ( , Ctrl+SCtrl+SCtrl+SCtrl+SCtrl+X, Ctrl+SCtrl+S or Ctrl+Shift+ACtrl+SCtrl+S or Ctrl+Shift+SCtrl+SCommand SCommand SCommand S) or when you move focus from IntelliJ IDEA (upon frame deactivation).
IntelliJ IDEA creates a separate file with the generated output. The file has the name of the source SASS, LESS, or SCSS file and the extension css. The location of the generated files is defined in the Output paths to refresh text box of the New Watcher dialog. However, in the Project Tree, they are shown under the source file which is now displayed as a node.