Add svgo worker for optimizing SVG

README.markdown

@@ -1,6 +1,6 @@
 # image_optim
 
-Optimize (lossless compress) images (jpeg, png, gif) using external utilities:
+Optimize (lossless compress) images (jpeg, png, gif, svg) using external utilities:
 
 * [advpng](http://advancemame.sourceforge.net/doc-advpng.html) from [AdvanceCOMP](http://advancemame.sourceforge.net/comp-readme.html)
 * [gifsicle](http://www.lcdf.org/gifsicle/)
@@ -10,6 +10,7 @@ Optimize (lossless compress) images (jpeg, png, gif) using external utilities:
 * [optipng](http://optipng.sourceforge.net/)
 * [pngcrush](http://pmt.sourceforge.net/pngcrush/)
 * [pngout](http://www.advsys.net/ken/util/pngout.htm)
+* [svgo](https://github.com/svg/svgo)
 
 Based on [ImageOptim.app](http://imageoptim.com/).
 
@@ -90,6 +91,14 @@ You can install `pngout` by downloading and installing the [binary versions](htt
 
 _Note: pngout is free to use even in commercial soft, but you can not redistribute, repackage or reuse it without consent and agreement of creator. [license](http://advsys.net/ken/utils.htm#pngoutkziplicense)_
 
+### svgo installation (optional)
+
+svgo is available from NPM.
+
+~~~bash
+npm install -g svgo
+~~~
+
 ## Usage
 
 ### From shell

image_optim.gemspec

@@ -3,7 +3,7 @@
 Gem::Specification.new do |s|
   s.name        = 'image_optim'
   s.version     = '0.10.2'
-  s.summary     = %q{Optimize (lossless compress) images (jpeg, png, gif) using external utilities (advpng, gifsicle, jpegoptim, jpegtran, optipng, pngcrush, pngout)}
+  s.summary     = %q{Optimize (lossless compress) images (jpeg, png, gif, svg) using external utilities (advpng, gifsicle, jpegoptim, jpegtran, optipng, pngcrush, pngout, svgo)}
   s.homepage    = "http://github.com/toy/#{s.name}"
   s.authors     = ['Ivan Kuchin']
   s.license     = 'MIT'

lib/image_optim.rb

@@ -181,7 +181,7 @@ def apply_threading(enum)
 %w[
   pngcrush pngout optipng advpng
   jhead jpegoptim jpegtran
-  gifsicle
+  gifsicle svgo
 ].each do |worker|
   require "image_optim/worker/#{worker}"
 end

lib/image_optim/railtie.rb

@@ -13,6 +13,7 @@ class Railtie < Rails::Railtie
         app.assets.register_preprocessor 'image/gif', :image_optim, &processor
         app.assets.register_preprocessor 'image/jpeg', :image_optim, &processor
         app.assets.register_preprocessor 'image/png', :image_optim, &processor
+        app.assets.register_preprocessor 'image/svg+xml', :image_optim, &processor
       end
     end
   end

lib/image_optim/worker.rb

@@ -52,7 +52,7 @@ def initialize(image_optim, options = {})
 
     # List of formats which worker can optimize
     def image_formats
-      format_from_name = self.class.name.downcase[/gif|jpeg|png/]
+      format_from_name = self.class.name.downcase[/gif|jpeg|png|svg/]
       raise "#{self.class}: can't guess applicable format from worker name" unless format_from_name
       [format_from_name.to_sym]
     end

lib/image_optim/worker/svgo.rb

@@ -0,0 +1,12 @@
+require 'image_optim/worker'
+
+class ImageOptim
+  class Worker
+    class Svgo < Worker
+      def optimize(src, dst)
+        args = %W[-i #{src} -o #{dst}]
+        execute(:svgo, *args) && optimized?(src, dst)
+      end
+    end
+  end
+end