Coffee Sprites

CoffeeSprites is a plugin for Node.js CoffeeStylesheets which allows you to use functions like sprite_position(), sprite_height(), image_width(), sprite_map(), etc. within your *.css.coffee markup to automatically fetch images and generate css sprites at render time.

If you come from the Ruby on Rails community, you will immediately recognize conventions from Spriting with Compass/SASS, originally Lemonade.

Install

sudo apt-get install libgd2-xpm-dev # on ubuntu; a libgd dependency
npm install coffee-sprites

Use

CoffeeStylesheets = require 'coffee-stylesheets'
engine = new CoffeeStylesheets format: true

CoffeeSprites = require __dirname + 'coffee-sprites'
engine.use new CoffeeSprites
  image_path: __dirname + '/precompile/assets/sprites/'
  sprite_path: __dirname + '/static/public/assets/'
  sprite_url:  'assets/'

  stylesheet = ->
    body ->
      background '#eee'
      color '#333'
      margin '20px'
    wigi = sprite_map 'wigi',
      spacing: 10
    s '#wigi', ->
      background "url(#{sprite_url wigi}) no-repeat"
      height sprite_height wigi, 'fly-3'
      width sprite_width wigi, 'fly-3'
    for i, v of 'walk-1 walk-2 walk-3 run-1 run-2 run-3 fly-1 fly-2 fly-3 fall jump'.split ' '
      s '#wigi.wigi-'+i, ->
        background_position sprite_position wigi, v

css = engine.render stylesheet, (err, css) ->
  fs.writeFileSync __dirname + '/static/public/assets/application.css', css

Will output CSS like this:

#wigi {
  background: url(./wigi-2e192be7fd.png) no-repeat;
  height: 112px;
  width: 96px;
}
#wigi.wigi-0 {
  background-position: 0 -122px;
}
#wigi.wigi-1 {
  background-position: 0 -244px;
}
#wigi.wigi-2 {
  background-position: 0 -366px;
}
#wigi.wigi-3 {
  background-position: 0 -484px;
}
#wigi.wigi-4 {
  background-position: 0 -606px;
}
#wigi.wigi-5 {
  background-position: 0 -728px;
}
#wigi.wigi-6 {
  background-position: 0 -850px;
}
#wigi.wigi-7 {
  background-position: 0 -968px;
}
#wigi.wigi-8 {
  background-position: 0 0;
}
#wigi.wigi-9 {
  background-position: 0 -1086px;
}
#wigi.wigi-10 {
  background-position: 0 -1208px;
}

And the sprite image(s) will turn out like this:

• test/fixtures/static/public/assets/wigi-2e192be7fd.png

For the very latest and most comprehensive example, see test/fixtures/precompile/assets/stylesheets/application.css.coffee.

Test

npm test # build coffee, run mocha unit test, run chrome browser integration test

TODO

• sprites that repeat-x and repeat-y are left to be implemented (coming soon!)
• add validation to ensure no function can be called with invalid input to avoid semi-cryptic errors
• could probably simplify by calculating x, y, width, height using gd directly and once during render() rather than as-we-go