compass/doc-src/content/help/tutorials/extending.markdown

title	layout	crumb	classnames
Extending Compass	tutorial	Extending Compass	tutorial

Extending Compass

Sprite engine

The sprite engine is the work horse of sprite generation it's the interface for assembling and writing the image file to disk.

Requirments

A sprite engine requires only one method and that is construct_sprite which must return an object that responds to save(filepath)

Once inside this method you have access to images which is a collection of Compass::SassExtensions::Sprites::Image

Since the Engine module extends base you also have access to all methods in Compass::SassExtensions::Sprites::Base

Configuration

To enable your sprite engine from the config file set

sprite_engine = :<engine name>

The example below will load Compass::SassExtension::Sprites::ChunkyPngEngine

sprite_engine = :chunky_png

Class Definition

module Compass
  module SassExtensions
    module Sprites
      module <engine name>Engine

        # Returns an object
        def construct_sprite
          #must return a image object that responds to save(filename)
        end

      end
    end
  end
end