jade/support/stylus/docs/import.md

Jade template engine

## Import

 Stylus supports both literal __@import__ for CSS, as well as dynamic importing of other Stylus sheets.

### Literal CSS

  Any filename with the extension `.css` will become a literal, for example:
  
     @import "reset.css"

will render to the literal css __@import__ shown below:

     @import "reset.css"

### Stylus Import

 When using __@import__ without the `.css` extension, it is assumed to be a Stylus sheet, for example `@import "mixins/border-radius"`.

 __@import__ works by iterating an array of directories, and seeing if this file lives in any of them, similar to node's `require.paths`. This array defaults to a single path which is derived from the `filename` option's dirname. So if your filename is `/tmp/testing/stylus/main.styl`, then import will look in `/tmp/testing/stylus/`.
 
 __@import__ also supports index styles, meaning if you `@import blueprint`, it will resolve either `blueprint.styl` or `blueprint/index.styl`, useful for libraries to expose all of their features, but still allow a subset of the library to be imported. For example a common lib structure might be:

    ./tablet
      |-- index.styl 
      |-- vendor.styl 
      |-- buttons.styl 
      |-- images.styl 

 In the example below we set the `paths` options to provide additional paths to Stylus. Within `./test.styl` we could then `@import "mixins/border-radius"` or `@import "border-radius"` since `./mixins` is exposed to Stylus.

      /**
       * Module dependencies.
       */

      var stylus = require('../')
        , str = require('fs').readFileSync(__dirname + '/test.styl', 'utf8');

      var paths = [
          __dirname
        , __dirname + '/mixins'
      ];

      stylus(str)
        .set('filename', __dirname + '/test.styl')
        .set('paths', paths)
        .render(function(err, css){
          if (err) throw err;
          console.log(css);
        });

### JavaScript Import API

 When using the `.import(path)` method, these imports are deferred until evaluation:
 
       var stylus = require('../')
         , str = require('fs').readFileSync(__dirname + '/test.styl', 'utf8');

       stylus(str)
         .set('filename', __dirname + '/test.styl')
         .import('mixins/vendor')
         .render(function(err, css){
         if (err) throw err;
         console.log(css);
       });

 The following are essentially equivalent:
 
     @import 'mixins/vendor'

and
     .import('mixins/vendor')