Move CSS file path into the YAML config as well

Author: michael-misshore

.rubocop_todo.yml

@@ -1,12 +1,12 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2015-10-03 13:02:27 -0500 using RuboCop version 0.34.1.
+# on 2015-10-03 13:56:01 -0500 using RuboCop version 0.34.1.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
 # versions of RuboCop, may require this file to be generated again.
 
-# Offense count: 1
+# Offense count: 2
 # Configuration parameters: AllowURI, URISchemes.
 Metrics/LineLength:
-  Max: 90
+  Max: 86

lib/config/critical_path_css.yml

@@ -1,4 +1,8 @@
 defaults: &defaults
+  # If using the asset pipeline, provide the manifest name
+  manifest_name: application
+  # Else provide the relative path of your CSS file from the /public directory
+  # css_path: /path/to/css/from/public/main.css
   routes:
     - /
 

lib/critical_path_css/configuration.rb

@@ -6,18 +6,33 @@ def initialize
       @configurations = YAML.load_file(configuration_file_path)[Rails.env]
     end
 
-    def routes
-      @routes ||= @configurations['routes']
+    def base_url
+      @configurations['base_url']
     end
 
-    def base_url
-      @base_url ||= @configurations['base_url']
+    def css_path
+      @css_path ||= begin
+        relative_path = @configurations['css_path'] || manifest_path
+        "#{Rails.root}/public#{relative_path}"
+      end
+    end
+
+    def manifest_name
+      @configurations['manifest_name']
+    end
+
+    def routes
+      @configurations['routes']
     end
 
     private
 
     def configuration_file_path
-      Rails.root.join('config', CONFIGURATION_FILENAME)
+      @configuration_file_path ||= Rails.root.join('config', CONFIGURATION_FILENAME)
+    end
+
+    def manifest_path
+      @manifest_path ||= ActionController::Base.helpers.stylesheet_path(manifest_name)
     end
   end
 end

lib/critical_path_css/css_fetcher.rb

@@ -5,8 +5,7 @@ class CssFetcher
 
     PENTHOUSE_PATH = "#{File.dirname(__FILE__)}/../penthouse/penthouse.js"
 
-    def initialize(main_css_relative_path)
-      @main_css_path = "#{Rails.root}/public#{main_css_relative_path}"
+    def initialize
       @config = Configuration.new
     end
 
@@ -17,7 +16,7 @@ def fetch
     private
 
     def css_for_route(route)
-      Phantomjs.run(PENTHOUSE_PATH, @config.base_url + route, @main_css_path)
+      Phantomjs.run(PENTHOUSE_PATH, @config.base_url + route, @config.css_path)
     end
   end
 end

lib/critical_path_css_rails.rb

@@ -3,8 +3,8 @@ module CriticalPathCss
 
   CACHE_NAMESPACE = 'critical-path-css'
 
-  def self.generate(main_css_relative_path)
-    CssFetcher.new(main_css_relative_path).fetch.each do |route, css|
+  def self.generate
+    CssFetcher.new.fetch.each do |route, css|
       Rails.cache.write(route, css, namespace: CACHE_NAMESPACE)
     end
   end

lib/tasks/critical_path_css.rake

@@ -3,8 +3,6 @@ require 'critical_path_css_rails'
 namespace :critical_path_css do
   desc 'Generate critical CSS for the routes defined'
   task generate: :environment do
-    main_css_path = ActionController::Base.helpers.stylesheet_path('application.css').to_s
-
-    CriticalPathCss.generate(main_css_path)
+    CriticalPathCss.generate
   end
 end