gistfile1.txt

class Activity
  module FactoryMethods
    
    %w[
      project_created
      lab_created
      
      person_joined_project
      person_left_project
      
      person_created_message
      person_published_message
      person_created_discussion
      person_created_discussion_reply_in_discussion
      
      person_started_following_another_person
      person_stopped_following_another_person
    ].each do |name|
      
      #extract object, action and subjects 
      object, subjects = name.split("_", 2)
      action, *subjects = subjects.split(/_?(?:in_)?((?:another|starting|started)?_?[^_]+(?:_(?:reply|category|comment))?)/).reject{|i| i.blank?}
      subject = subjects.first
      
      #there are only 2 arguments - object and subject.
      args = [object, subject].compact * ", "
      
      #remove me if DM bug is ever fixed. this soloely is a bug workaround
      subjects.each_with_index do |thing, i| 
        subjects[i] = \
        if i == 0
          thing
        else
          "#{thing}_id"
        end
      end
      
      
      #other subjects are gotten from first subject, e.g. project = subject.project
      getters = (subjects[1, 10] || []).map {|i| "#{i} = #{subject}.#{i}"} * "\n"
      
      project = "project ||= " + \
      if subject
        subjects << "project"
        "#{subject}.respond_to?(:project) ? #{subject}.project : nil"
      else
        "nil"
      end
      
      everything = [object, *subjects]
      hash = everything.map{|i| ":#{i} => #{i}"} * ", "   
      
      recipients = {
        :public => everything.grep(/project$|lab$/),
        :members => everything.grep(/project$|lab$/),
        :followers => everything.grep(/person$/),
        :people => everything.grep(/person$/)
      }
      
      {
        "" => recipients.map{|group, subjects| ":#{group} => [#{subjects * ', '}]"} * ", ",   
        "!" => recipients.only(:public, :people).map{|group, subjects| ":#{group} => [#{subjects * ', '}]"} * ", "
      }.each do |excl, recipients|
        class_eval %{
          def #{name}#{excl}(#{args})
            #{getters}
            #{project}
            activity = create(:type => "#{name}", #{hash})

            self.deliver activity, #{recipients}
            
            activity
          end
        }
      end
    end
    
    
      def deliver(activity, options = {})
        recipients = []
        recipients += [*options[:members]].compact.map{|i| i.members} if options[:members]
        recipients += [*options[:followers]].compact.map{|i| i.followed_by_people} if options[:followers]
        recipients -= [*options[:people]].compact if options[:person]
        
        recipients.flatten.uniq.compact.each do |recipient|
          recipient.private_activity!(activity)
        end
        
        if options[:public]
          [options[:public], options[:people]].flatten.uniq.compact.each do |recipient|
            recipient.public_activity!(activity)
          end
        end
        
        activity
      end
  end # ActivityHooks
end