The image_url function has to be accessed from within the engine for it to work right in all cases.

lib/compass/sass_extensions/functions/sprites.rb

@@ -1,41 +1,17 @@
 module Compass::SassExtensions::Functions::Sprites
   include Compass::SassExtensions::Functions::ImageSize
-  class SpriteInfo < Sass::Script::Literal
+  class SpriteInfo
     attr_reader :sprite
     attr_reader :sprite_item
     attr_reader :type
 
-    def initialize(type, sprite, sprite_item = nil, position_x = nil, position_y_shift = nil)
-      super(nil)
-      @type = type
+    def initialize(sprite, sprite_item = nil, position_x = nil, position_y_shift = nil)
       @sprite = sprite
       @sprite_item = sprite_item
       @position_x = position_x
       @position_y_shift = position_y_shift
     end
 
-    def to_s(opts = {})
-      case @type
-      when :position
-        position
-      when :url
-        url
-      when :both
-        pos = position
-        if pos == '0 0'
-          url
-        else
-          "#{url} #{pos}"
-        end
-      end
-    end
-
-    def to_sass
-      to_s
-    end
-
-  private
-
     def position
       x = @position_x || 0
       if @sprite_item[:index] == 0 and (@position_y_shift.nil? or @position_y_shift.value == 0)
@@ -47,32 +23,28 @@ module Compass::SassExtensions::Functions::Sprites
       end
     end
 
-    def url
-      if defined?(Compass)
-        compass = Class.new.extend(Compass::SassExtensions::Functions::Urls)
-        compass.image_url(Sass::Script::String.new(@sprite[:file])).to_s
-      else
-        "url('/#{@sprite[:file]}')"
-      end
-    end
-
   end
 
-
   def sprite_url(file)
     dir, name, basename = extract_names(file)
     sprite = sprite_for("#{dir}#{name}")
-    SpriteInfo.new(:url, sprite)
+    image_url(Sass::Script::String.new(sprite[:file]))
   end
 
   def sprite_position(file, position_x = nil, position_y_shift = nil, margin_top_or_both = nil, margin_bottom = nil)
     sprite, sprite_item = sprite_url_and_position(file, position_x, position_y_shift, margin_top_or_both, margin_bottom)
-    SpriteInfo.new(:position, sprite, sprite_item, position_x, position_y_shift)
+    info = SpriteInfo.new(sprite, sprite_item, position_x, position_y_shift)
+    Sass::Script::String.new(info.position)
   end
 
-  def sprite_image(file, position_x = nil, position_y_shift = nil, margin_top_or_both = nil, margin_bottom = nil)
-    sprite, sprite_item = sprite_url_and_position(file, position_x, position_y_shift, margin_top_or_both, margin_bottom)
-    SpriteInfo.new(:both, sprite, sprite_item, position_x, position_y_shift)
+  def sprite_image(file, *args)
+    pos = sprite_position(file, *args)
+    url = sprite_url(file)
+    if pos.value == "0 0"
+      url
+    else
+      url.plus(" ").plus(pos)
+    end
   end
   alias_method :sprite_img, :sprite_image
 

spec/sprite_info_spec.rb

@@ -3,7 +3,7 @@ require File.expand_path(File.dirname(__FILE__) + '/spec_helper')
 describe Compass::SassExtensions::Functions::Sprites::SpriteInfo do
 
   def sprite_info(*args)
-    Compass::SassExtensions::Functions::Sprites::SpriteInfo.new(*args).to_s
+    Compass::SassExtensions::Functions::Sprites::SpriteInfo.new(*args)
   end
 
   ##
@@ -12,14 +12,14 @@ describe Compass::SassExtensions::Functions::Sprites::SpriteInfo do
     sprite = { :file => "sprites.png" }
     sprite_item = { :y => Sass::Script::Number.new(20, ['px']), :index => 0 }
     x = Sass::Script::Number.new(10, ['px'])
-    sprite_info(:position, sprite, sprite_item, x).should == "10px 0"
+    sprite_info(sprite, sprite_item, x).position.should == "10px 0"
   end
 
   it "should output the position for the second+ sprite" do
     sprite = { :file => "sprites.png" }
     sprite_item = { :y => Sass::Script::Number.new(20, ['px']), :index => 1 }
     x = Sass::Script::Number.new(10, ['px'])
-    sprite_info(:position, sprite, sprite_item, x).should == 
+    sprite_info(sprite, sprite_item, x).position.should == 
       "10px <%= Compass::Sprites.sprites['sprites.png'][:images][1][:y].unary_minus %>"
   end
 
@@ -28,7 +28,7 @@ describe Compass::SassExtensions::Functions::Sprites::SpriteInfo do
     sprite_item = { :y => Sass::Script::Number.new(20, ['px']), :index => 1 }
     x = Sass::Script::Number.new(10, ['px'])
     y_shift = Sass::Script::Number.new(3, ['px'])
-    sprite_info(:position, sprite, sprite_item, x, y_shift).should == 
+    sprite_info(sprite, sprite_item, x, y_shift).position.should == 
       "10px <%= Compass::Sprites.sprites['sprites.png'][:images][1][:y].unary_minus.plus(Sass::Script::Number.new(3, ['px'])) %>"
   end
 
@@ -36,14 +36,8 @@ describe Compass::SassExtensions::Functions::Sprites::SpriteInfo do
     sprite = { :file => "sprites.png" }
     sprite_item = { :y => Sass::Script::Number.new(20, ['px']), :index => 2 }
     x = Sass::Script::Number.new(100, ['%'])
-    sprite_info(:position, sprite, sprite_item, x).should == 
+    sprite_info(sprite, sprite_item, x).position.should == 
       "100% <%= Compass::Sprites.sprites['sprites.png'][:images][2][:y].unary_minus %>"
   end
 
-  it "should output the url" do
-    sprite = { :file => "sprites.png" }
-    sprite_item = { }
-    sprite_info(:url, sprite, sprite_item).should == "url('/sprites.png')"
-  end
-
 end