First draft of the DSL. Not ready for production yet since JS generation

is somewhat of an issue. Specified the API in a huge data structure for
now.

If you know some better way to do this, let me know.

method_missing is used to check whether a method exists, validate
the arguments and add it to list. The list will be converted to valid
JS calls (based on use_async?) and rendered out for piwik_tracking_tag.

refs #7, #10

app/views/piwik_analytics/piwik_tracking_tag.html.erb

@@ -5,6 +5,7 @@
   </script><script type="text/javascript">
   try {
     var piwikTracker = Piwik.getTracker(pkBaseURL + "piwik.php", <%= id_site %>);
+    <%= tracker %>
     piwikTracker.trackPageView();
     piwikTracker.enableLinkTracking();
   } catch( err ) {}

lib/piwik_analytics.rb

@@ -1,4 +1,5 @@
 require File.join(File.dirname(__FILE__), 'piwik_analytics', 'configuration')
+require File.join(File.dirname(__FILE__), 'piwik_analytics', 'piwik_tracker')
 
 module PiwikAnalytics
   require 'piwik_analytics/engine' if defined?(Rails)
@@ -9,5 +10,9 @@ class <<self
     def configuration
       @configuration ||= PiwikAnalytics::Configuration.new
     end
+
+    def tracker
+      @tracker ||= PiwikAnalytics::PiwikTracker.new
+    end
   end
 end

lib/piwik_analytics/controller_helpers.rb

@@ -0,0 +1,7 @@
+module PiwikAnalytics
+  module ControllerHelpers
+    def piwik_tracking(&block)
+      yield PiwikAnalytics.tracker
+    end
+  end
+end

lib/piwik_analytics/engine.rb

@@ -13,7 +13,8 @@ class Piwik < Rails::Engine
     end
 
     initializer "piwik_analytics.init", :before=> :load_config_initializers do
-      require "piwik_analytics/helpers"
+      require "piwik_analytics/view_helpers"
+      require "piwik_analytics/controller_helpers"
       load "piwik_analytics/init.rb"
     end
   end

lib/piwik_analytics/init.rb

@@ -1 +1,2 @@
-ActionView::Base.send :include, PiwikAnalytics::Helpers
+ActionView::Base.send :include, PiwikAnalytics::ViewHelpers
+ActionController::Base.send :include, PiwikAnalytics::ControllerHelpers

lib/piwik_analytics/piwik_tracker.rb

@@ -0,0 +1,106 @@
+module PiwikAnalytics
+  class PiwikTracker
+
+    def initialize
+      @calls = Array.new
+    end
+
+    def method_missing(meth, *args, &block)
+      name = meth.to_s.camlize(:lower)
+      valid_method? name
+      valid_arguments? args
+      call = { method: name, args: args }
+      @calls.push call
+    end
+
+    def to_s
+      @calls.each do |call|
+
+      end
+    end
+
+  private
+    def valid_method?(name)
+      @@methods.has_key? name
+    end
+
+    def valid_arguments?(name, args)
+      method = @@methods[name]
+      # Check each argument (name, optional)
+      method.each do |arg|
+        unless arg[:optional]
+          return false unless args.has_key? arg[:name]
+        end
+      end
+      # Return in order
+      return true
+    end
+  end
+
+  @@methods = {
+    "setDocumentTitle" => [
+      { name: :title, optional: false }
+    ],  
+    "setCustomUrl" => [
+      { name: :url, optional: false }
+    ],  
+    "setReferrerUrl" => [
+      { name: :url, optional: false }
+    ],
+    "setSiteId" => [
+      { name: :site_id, optional: false }
+    ],
+    "trackGoal" => [
+      { name: :id_goal, optional: false },
+      { name: :custom_revenue, optional: true }
+    ],
+    "trackSiteSearch" => [
+      { name: :keyword, optional: false },
+      { name: :category, optional: true, default: false },
+      { name: :search_count, optional: true, default: false }
+    ],
+    "setCustomVariable" => [
+      { name: :index,  optional: false },
+      { name: :name, optional: false },
+      { name: :value, optional: false },
+      { name: :scope, optional: true, default: "visit" }
+    ],
+    "deleteCustomVariable" => [
+      { name: :index, optional: false },
+      { name: :scope, optional: false }   
+    ],
+    "setCookieDomain" => [
+      { name: :domain, optional: false }
+    ],
+    "setDomains" => [
+      { name: :domains, optional: false }
+    ],
+    "setCookiePath" => [
+      { name: :path, optional: false }
+    ],
+    "setIgnoreClasses" => [
+      { name: :classes, optional: false }
+    ],
+    "setDownloadClasses" => [
+      { name: :classes, optional: false }
+    ],
+    "setLinkClasses" => [
+      { name: :classes, optional: false }
+    ],
+    "setLinkTrackingTimer" => [
+      { name: :time, optional: false }
+    ],
+    "setDownloadExtensions" => [
+      { name: :extensions, optional: false }
+    ],
+    "addDownloadExtensions" => [  
+      { name: :extensions, optional: false }
+    ],
+    "enableLinkTracking" => [
+      { name: :enable, optional: false }
+    ],
+    "setRequestMethod" => [
+      { name: :method, optional: false }
+    ]
+  }
+end

lib/piwik_analytics/helpers.rb → lib/piwik_analytics/view_helpers.rb

@@ -1,17 +1,23 @@
 module PiwikAnalytics
-  module Helpers
-    def piwik_tracking_tag
+  module ViewHelpers
+    def piwik_tracking_tag(&block)
       config = PiwikAnalytics.configuration
       return if config.disabled?
 
+      yield PiwikAnalytics.tracker if block_given?
+
       if config.use_async?
         file = "piwik_analytics/piwik_tracking_tag_async"
       else
         file = "piwik_analytics/piwik_tracking_tag"
       end
       render({
-        :file => file,
-        :locals => {:url => config.url, :id_site => config.id_site}
+        file: file,
+        locals: {
+          url: config.url, 
+          id_site: config.id_site,
+          tracker: PiwikAnalytics.tracker
+        }
       })
     end
   end