Implemented new relationship between Snippets and PageParts. It is

going to replace the one between Snippets and Pages.

Added some scopes to find all the Pages for an Snippet and all the
Snippets for a Page.

app/models/snippet.rb

@@ -1,19 +1,27 @@
 class Snippet < ActiveRecord::Base
-  
+
   acts_as_indexed :fields => [:title, :body]
 
   validates :title, :presence => true, :uniqueness => true
 
   translates :body
 
-  has_many :snippet_page, :dependent => :destroy
-  has_many :pages, :through => :snippet_page
+  has_many :snippet_page_parts, :dependent => :destroy
+  has_many :page_parts, :through => :snippet_page_parts
+
+  named_scope :for_page, lambda{ |page|
+    raise RuntimeError.new("Couldn't find Snippet for a nil Page") if page.blank?
+    {
+      :joins => {:page_parts, :page},
+      :conditions => {:pages => {:id => page.id}}
+    }
+  }
 
   def self.inactive(page)
-      @page = page
-      snippets = scoped      
-      snippets = snippets.where('id NOT IN (?)', @page.snippets) unless @page.snippets.empty?
-      snippets
+    @page = page
+    snippets = scoped
+    snippets = snippets.where('id NOT IN (?)', @page.snippets) unless @page.snippets.empty?
+    snippets
   end
 
   # rejects any page that has not been translated to the current locale.
@@ -22,6 +30,6 @@ def self.inactive(page)
     translations = Arel::Table.new(Snippet.translations_table_name)
 
     includes(:translations).where(
-      translations[:locale].eq(Globalize.locale)).where(pages[:id].eq(translations[:snippet_id]))
+                                  translations[:locale].eq(Globalize.locale)).where(pages[:id].eq(translations[:snippet_id]))
   }
 end

app/models/snippet_page_part.rb

@@ -0,0 +1,12 @@
+class SnippetPagePart < ActiveRecord::Base
+
+  set_table_name 'snippets_page_parts'
+
+  belongs_to :snippet, :foreign_key => :snippet_id
+  belongs_to :page_part, :foreign_key => :page_part_id
+
+  before_save do |snippet_page_part|
+    snippet_page_part.position = (SnippetPagePart.where('page_part_id = ?', snippet_page_part.page_part_id).maximum(:position) || -1) + 1
+  end
+
+end

db/migrate/4_create_snippets_page_parts.rb

@@ -0,0 +1,19 @@
+class CreateSnippetsPageParts < ActiveRecord::Migration
+
+  def self.up
+    create_table :snippets_page_parts do |t|
+      t.integer :snippet_id, :null => false, :references => [:snippets, :id]
+      t.integer :page_part_id, :null => false, :references => [:page_parts, :id]
+      t.integer :position, :null => false, :default => 0
+      t.boolean :before_body, :null => false, :default => false
+    end
+
+    add_index :snippets_page_parts, :snippet_id
+    add_index :snippets_page_parts, :page_part_id
+  end
+
+  def self.down
+    drop_table :snippet_page_parts
+  end
+
+end

lib/extensions/page_extensions.rb

@@ -0,0 +1,30 @@
+module Extensions
+
+  module Page
+
+    # Accessor method to get a page part from a page.
+    # Example:
+    #
+    #    Page.first.content_for(:body)
+    #
+    # Will return the body page part of the first page wrap with its
+    # attached snippets.
+    def content_for(part_title)
+      part = self.parts.detect do |part|
+        part.title.present? and #protecting against the problem that occurs when have nil title
+          part.title == part_title.to_s or
+          part.title.downcase.gsub(" ", "_") == part_title.to_s.downcase.gsub(" ", "_")
+      end
+
+      content = part.snippets.before.each{|snippet| snippet.try(:body)}
+      content = part.try(:body)
+      content = part.snippets.after.each{|snippet| snippet.try(:body)}
+    end
+
+    def self.included(base)
+      alias_method :content_without_snippets_for, :content_for
+    end
+
+  end
+
+end

lib/refinerycms-snippets.rb

@@ -3,19 +3,37 @@
 module Refinery
   module Snippets
     class Engine < Rails::Engine
+
+      config.before_initialize do
+        require 'extensions/page_extensions'
+      end
+
       initializer "static assets" do |app|
         app.middleware.insert_after ::ActionDispatch::Static, ::ActionDispatch::Static, "#{root}/public"
       end
-      
+
       config.to_prepare do
+        PagePart.module_eval do
+          has_many :snippet_page_parts, :dependent => :destroy
+          has_many :snippets, :through => :snippet_page_parts, :order => 'position ASC'
+        end
         Page.module_eval do
-          has_many :snippet_page, :dependent => :destroy
-          has_many :snippets, :through => :snippet_page, :order => 'position ASC'
+          # TODO: eliminar
+          # has_many :snippet_page, :dependent => :destroy
+          # has_many :snippets, :through => :snippet_page, :order => 'position ASC'
+          named_scope :for_snippet, lambda{ |snippet|
+            raise RuntimeError.new("Couldn't find Pages for a nil Snippet") if snippet.blank? 
+            {
+              :joins => {:parts, :snippets},
+              :conditions => {:snippets_page_parts => {:snippet_id => snippet.id}}
+            }
+          }
         end
+        Page.send :included, Extensions::Page
       end
 
       config.after_initialize do
-       ::Refinery::Pages::Tab.register do |tab|
+        ::Refinery::Pages::Tab.register do |tab|
           tab.name = "snippets"
           tab.partial = "/admin/pages/tabs/snippets"
         end
@@ -24,10 +42,10 @@ class Engine < Rails::Engine
           plugin.url = {:controller => '/admin/snippets'}
           plugin.menu_match = /^\/?(admin|refinery)\/snippets/
           plugin.activity = [{
-            :class => Snippet
-          }, {
-            :class => SnippetPage
-          }]
+                               :class => Snippet
+                             }, {
+                               :class => SnippetPage
+                             }]
         end
       end
     end