Manage dependencies between your CSS files.

This plugin requires Grunt ~0.4.2

If you haven't used Grunt before, be sure to check out the Getting Started guide.

To install the module:

npm install grunt-csstree --save-dev

Include the task in your Gruntfile:

grunt.loadNpmTasks('grunt-csstree');

Csstree allows you to fragment and mutualise your CSS, manage the inclusions of them but without writing any @import. It doesn't add anything to the syntax, it's fully compliant and compatible with all different tools around CSS.

Basically, Csstree writes @import for you, based on the files/directories structure of your project. Because of the use of @import rules, Csstree should always be combined with some kind of minification in order to not slow down page load.

Csstree generates a file branch.gen.css in every directory contained in a given root. Each file will have @import declarations of

1. ../branch.gen.css
2. All files within this directory, but not subdirectories

The structure is recursive! Inclusions are going upward.

Take a moment to think of it ;)

index.html
css
+-- index
|   +-- index.css
+-- articles
|   +-- templates.css
|   +-- edit
|       +-- edit.css
+-- menus.css
+-- reset.css

By adding <link rel="stylesheet" href="css/index/branch.gen.css"> to index.html, you will import menus.css, reset.css and index.css.

You get it, css/acticles/branch.gen.css would import menus.css, reset.css and templates.css but not edit.css.

css/acticles/edit/branch.gen.css would import menus.css, reset.css, templates.css and edit.css.

This is a very convenient way to organise CSS. Note that the order of imports matters, CSS overriding becomes much clearer because only subdirectories can override.

As mentionned above, using branch.gen.css directly is practial for developing but should be replaced in production. We are going to minify our branch.gen.css into branch.gen.min.css. We let you figure out how to do the switch because it depends a lot on how you manage deployment, configurations etc ...

grunt.initConfig({
  csstree: {
    clientProject: {
      src: 'css/' // The root of your css tree
    }
  },
  cssmin: {
    minifyBranches: {
      expand: true,
      src: ['css/**/branch.gen.css'],
      ext: '.min.css',
      extDot: 'last'
    }
  }
});

src must be a single directory. Csstree is a multi-task, so if you want to build several trees, then define several targets.

Csstree excludes file names that contain .gen, so please keep .gen on minified files so they won't be processed by further Csstree executions.

Generated files should not be commited and should be included in a clean task:

clean: ['css/**/*.gen.*']

Given that your less (or css) files are in styles/

Less doesn't resolve @import on regular css files (more details here), we revolve this simply by changing the extension of branch files:

grunt.initConfig({
  csstree: {
    lessTree: {
      options: {
        ext: '.less'
      },
      src: 'styles'
    }
  },
  less: {
    compileTree: {
      expand: true,
      src: ['styles/**/branch.gen.less'],
      ext: '.min.css',
      extDot: 'last'
    }
  }
});

Type: String
Default: .css

Extension of generated files branch.gen(+ext)

Type: Function(file)
Default: return '@import "' + filename +'";'

Define the import format used in branch.gen.css. Csstree redefine it itself when using ext: '.less'

Type: String
Default: utf-8

Encoding of generated files

In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. We care about clean git history as well.

• 2014-04-07 v0.1.0 First version of Csstree