ember-cli-css-preprocess

ember-cli-css-preprocess

Preprocess your stylesheets with multiple preprocessors.

Currently supported preprocessors:

• postcss
• node-sass
• less

Please feel free to fork in order to add more processors!

You can determine in which order the stylesheets are processed!

Installation

ember install ember-cli-css-preprocess

Usage

Basic configuration

All the configuration for this plugin is stored in the ember-cli-build.js in the root-directory of your ember application.

Search for the following lines:

    var app = new EmberApp(defaults, {
        // Add options here
    ...

And add the the basic options:

    var app = new EmberApp(defaults, {
        // Add options here
        styleProcessorOptions: {
            processors: [],
            extension: 'css'
        }
    ...

Adding a preprocessor

Currently there a two available preprocessors which you can chain in any order (even multiple times if you want).

Supported processors:

• node-sass
• postcss
• less

To add on simply pass in an object to the processors-Array containing a type-Property with the processor title. Furthermore you have to install the corresponding npm-module with the same name (e.g. npm install autoprefixer --save-dev).

Adding a Sass Preprocessor:

    var app = new EmberApp(defaults, {
        // Add options here
        styleProcessorOptions: {
            processors: [
                {
                    type: 'node-sass',
                    sourcemaps: true,  // enables sourcemaps
                    options: {}
                }
            ],
            extension: 'scss'
        }
    ...

By changing the extension-property you can specify the extension of your stylesheets. Because we are only processing our sheets with Sass we set the extension to scss.

Annotation: You can also pass all setting you could pass to node-sass by setting the options-object in the processor object. By default the only settings are the includePath which is set to your styles-folder and the sourcemap settings if sourcemaps is set to true. This allows you to include any stylesheet in your folder with the @import-rule

Adding a PostCSS Preprocessor:

    var app = new EmberApp(defaults, {
        // Add options here
        styleProcessorOptions: {
            processors: [
                {
                    type: 'postcss',
                    plugins: [
                        {
                            module: require('autoprefixer'),
                            options: {
                                browsers: [
                                    'last 2 versions'
                                ]
                            }
                        }
                    ]
                }
            ],
            extension: 'css'
        }
    ...

This is a basic postcss implementation using the autoprefixer plugin.

The plugin-array is filled with objects with the module and the options properties. The latter obviously contains the options which are passed into the module/plugin when processing your stylesheets.

Annotation: Before requiring any postcss-plugin you have to install it via npm (e.g. npm install autoprefixer --save).

You can also add a custom parser or syntax by adding it to the processor object. Here is an example which uses the postcss-scss parser (for adding a syntax, use the syntax property):

    var app = new EmberApp(defaults, {
        // Add options here
        styleProcessorOptions: {
            processors: [
                {
                    type: 'postcss',
                    parser: require('postcss-scss'),
                    //syntax: require('postcss-scss'),
                    plugins: [
                        {
                            module: require('autoprefixer'),
                            options: {
                                browsers: [
                                    'last 2 versions'
                                ]
                            }
                        }
                    ]
                }
            ],
            extension: 'css'
        }
    ...

Adding a less Preprocessor:

    var app = new EmberApp(defaults, {
        // Add options here
        styleProcessorOptions: {
            processors: [
                {
                    type: 'less'
                }
            ],
            extension: 'css'
        }
    ...

To include any less plugin you can make use of the plugins-array, it is handled like the postcss-plugin array.

Using multiple processors:

    var app = new EmberApp(defaults, {
        // Add options here
        styleProcessorOptions: {
            processors: [
                {
                    type: 'node-sass'
                },
                {
                    type: 'postcss',
                    plugins: [
                        {
                            module: require('autoprefixer'),
                            options: {
                                browsers: [
                                    'last 2 versions'
                                ]
                            }
                        }
                    ]
                }
            ],
            extension: 'css'
        }
    ...

This example should clarify how to chain preprocessors. The position inside the processors-array determines the order in which the stylesheets are processed by each preprocessors (from top to bottom).

Using multiple input stylesheets

Multiple stylesheets are added by using the outputPaths-property (, which is not part of the styleProcessorOptions-property).

Configuring Output Paths (Ember CLI Reference)

In addition to the default configuration you can add an extension to your css-value.

... // styleProcessorOptions
            extension: 'scss' // specified extension, overrides default: css
        },
        outputPaths: {
            app: {
                css: {
                    'app': 'assets/lel.css', // will parse app/styles/app.scss
                    'amk.css': 'assets/toll.css', //will parse app/styles/amk.css
                    'hippo.less': 'assets/eichhorn.css', //will parse app/styles/amk.less
                    'trolol/bars': 'assets/foo.css' //will parse app/trolol/bars.scss
                }
            }
        }

Setup processor to parse specific files only (Filter):

    var app = new EmberApp(defaults, {
        // Add options here
        styleProcessorOptions: {
            processors: [
                {
                    type: 'postcss',
                    filter: ['test.css'],
                    plugins: [
                        {
                            module: require('autoprefixer'),
                            options: {
                                browsers: [
                                    'last 2 versions'
                                ]
                            }
                        }
                    ]
                },
                {
                    type: 'node-sass'
                }
            ],
            extension: 'css'
        }
    ...

With this setup the postcss processor will only process the file test.css. The filter property can either be a string or an array of strings.

An example for using the glob pattern:

    var app = new EmberApp(defaults, {
        // Add options here
        styleProcessorOptions: {
            processors: [
                {
                    type: 'node-sass',
                    filter: ['*.scss']
                },
                {
                    type: 'less',
                    filter: ['*.less']
                }
            ],
            extension: 'css'
        },
        outputPaths: {
            app: {
                css: {
                    'app': 'assets/lel.css', // input file contents will equal input file contents
                    'amk.css': 'assets/toll.css', // input file contents will equal input file contents
                    'hippo.less': 'assets/eichhorn.css', // will only be processed by less processor
                    'trolol.scss': 'assets/foo.css' // will only be processed by less processor
                }
            }
        }
    ...

Resources

Github: BroccoliCachingWriter