WIP

moonmaster9000 · Aug 1, 2012 · f163ed1 · f163ed1
1 parent e9a08f4
commit f163ed1
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Showing 7 changed files with 263 additions and 4 deletions.
diff --git a/ar.rb b/ar.rb
@@ -0,0 +1,65 @@
+require 'active_record'
+require 'sqlite3'
+
+ActiveRecord::Base.establish_connection(
+  adapter: 'sqlite3', 
+  database: 'db/test.db'
+)
+
+%w(posts blogs comments).each do |table|
+  ActiveRecord::Base.connection.execute(
+    %(
+      DROP TABLE 
+        IF EXISTS 
+        #{table}
+    )
+  )
+end
+
+ActiveRecord::Base.connection.execute(
+  %(
+    CREATE TABLE 
+      posts(
+        id INTEGER, 
+        blog_id INTEGER,
+        PRIMARY KEY(id ASC)
+      )
+  )
+)
+
+ActiveRecord::Base.connection.execute(
+  %(
+    CREATE TABLE 
+      blogs(
+        id INTEGER, 
+        name VARCHAR,
+        PRIMARY KEY(id ASC)
+      )
+  )
+)
+
+ActiveRecord::Base.connection.execute(
+  %(
+    CREATE TABLE 
+      comments(
+        id INTEGER, 
+        post_id INTEGER,
+        PRIMARY KEY(id ASC)
+      )
+  )
+)
+
+
+class Post < ActiveRecord::Base
+  belongs_to :blog
+  has_many :comments
+end
+
+class Blog < ActiveRecord::Base
+  has_many :posts
+end
+
+class Comment < ActiveRecord::Base
+  belongs_to :post
+end
+
diff --git a/db/test.db b/db/test.db
diff --git a/lib/frill/active_record/association_decorator.rb b/lib/frill/active_record/association_decorator.rb
@@ -0,0 +1,63 @@
+module Frill
+  module ActiveRecord
+    class AssociationDecorator
+      def self.decorate(object, context)
+        new(object, context).decorate
+      end
+
+      def initialize(object, context)
+        @object  = object
+        @context = context
+      end
+
+      def decorate
+        embed_context_in_object
+        decorate_associations
+      end
+
+      private
+      def embed_context_in_object
+        frill_context = @context
+
+        object.extend(
+          Module.new do 
+            private
+            define_method(:__frill_context) do
+              frill_context
+            end
+          end
+        )
+      end
+
+      def decorate_associations
+        object.class.reflect_on_all_associations.each do |association|
+          if association.collection?
+            object.extend(
+              Module.new.tap do |mod|
+                mod.class_eval <<-EVAL
+                  def #{association.name}
+                    Frill::ActiveRecord::CollectionProxy.new(super, __frill_context)
+                  end
+                EVAL
+              end
+            )
+          else
+            object.extend(
+              Module.new.tap do |mod|
+                mod.class_eval <<-EVAL
+                  def #{association.name}
+                    association = super
+                    return nil unless association
+                    Frill.decorate association, __frill_context
+                  end
+                EVAL
+              end
+            )
+          end
+        end
+      end
+
+      attr_reader :object, :context
+    end
+  end
+end
diff --git a/lib/frill/active_record/association_proxy.rb b/lib/frill/active_record/association_proxy.rb
@@ -0,0 +1,9 @@
+module Frill
+  module ActiveRecord
+    class CollectionProxy
+      def initialize(collection, context)
+      end
+    end
+  end
+end
+
diff --git a/lib/frill/frill.rb b/lib/frill/frill.rb
@@ -13,11 +13,11 @@ def self.reset!
   end
 
   def self.decorate object, context
-   decorators.each do |d|
+    decorators.each do |d|
-     object.extend d if d.frill? object, context
+      object.extend d if d.frill? object, context
-   end
+    end
 
-   object
+    object
   end
 
   module ClassMethods

diff --git a/spec/frill_active_relation_spec.rb b/spec/frill_active_relation_spec.rb
@@ -0,0 +1,113 @@
+require 'active_record'
+require 'sqlite3'
+
+ActiveRecord::Base.establish_connection(
+  adapter: 'sqlite3', 
+  database: 'db/test.db'
+)
+
+%w(posts blogs comments).each do |table|
+  ActiveRecord::Base.connection.execute(
+    %(
+      DROP TABLE 
+        IF EXISTS 
+        #{table}
+    )
+  )
+end
+
+ActiveRecord::Base.connection.execute(
+  %(
+    CREATE TABLE 
+      posts(
+        id INTEGER, 
+        blog_id INTEGER,
+        PRIMARY KEY(id ASC)
+      )
+  )
+)
+
+ActiveRecord::Base.connection.execute(
+  %(
+    CREATE TABLE 
+      blogs(
+        id INTEGER, 
+        name VARCHAR,
+        PRIMARY KEY(id ASC)
+      )
+  )
+)
+
+ActiveRecord::Base.connection.execute(
+  %(
+    CREATE TABLE 
+      comments(
+        id INTEGER, 
+        post_id INTEGER,
+        PRIMARY KEY(id ASC)
+      )
+  )
+)
+
+require_relative '../lib/frill/active_record/association_decorator'
+
+class Post < ActiveRecord::Base
+  belongs_to :blog
+  has_many :comments
+end
+
+class Blog < ActiveRecord::Base
+  has_many :posts
+end
+
+class Comment < ActiveRecord::Base
+  belongs_to :post
+end
+
+describe Frill::ActiveRecord::AssociationDecorator do
+  before { Post.destroy_all; Blog.destroy_all; Comment.destroy_all }
+  before { Frill.reset! }
+
+  let!(:post) do
+    Post.create.tap do |p|
+      p.blog = Blog.create
+      p.save
+    end
+  end
+
+  let!(:decorated_module) do
+    Module.new do
+      include Frill
+
+      def self.frill?(*)
+        true
+      end
+    end
+  end
+
+  describe ".decorate(object, context)" do
+    context "given an ActiveRecord object" do
+      it "should decorate associated objects" do
+        Frill::ActiveRecord::AssociationDecorator.decorate post, double(:context)
+        blog_eigenclass = class << post.blog; self; end
+        blog_eigenclass.included_modules.should include decorated_module
+      end
+
+      it "should not attempt to decorate nil associations" do
+        comment = Comment.create
+        Frill::ActiveRecord::AssociationDecorator.decorate comment, double(:context)
+        post_eigenclass = class << comment.post; self; end
+        post_eigenclass.included_modules.should_not include decorated_module
+      end
+
+      it "should lazily decorate collection associations" do
+        post.comments << Comment.create << Comment.create
+        Frill::ActiveRecord::AssociationDecorator.decorate post, double(:context)
+        comments = post.comments
+        comment = comments.first
+        comment_eigenclass = class << comment; self; end
+        comment_eigenclass.included_modules.should include decorated_module
+      end
+    end
+  end
+end
diff --git a/spec/lib/frill/active_record/association_proxy_spec.rb b/spec/lib/frill/active_record/association_proxy_spec.rb
@@ -0,0 +1,9 @@
+require_relative '../../../../lib/frill/active_record/association_proxy'
+
+module Frill
+  module ActiveRecord
+    describe CollectionProxy do
+
+    end
+  end
+end