From 0bbcd19c64710c54e57dcea49e2fb22b1779872e Mon Sep 17 00:00:00 2001
From: Andrew Haines <andrew@haines.org.nz>
Date: Tue, 30 Oct 2012 22:37:09 +0000
Subject: [PATCH] Drop the Utils module

---
 lib/draper.rb                 |  1 -
 lib/draper/decorator.rb       | 31 +++++++++++++++++++++++++------
 lib/draper/utils.rb           | 17 -----------------
 spec/draper/decorator_spec.rb | 16 ++++++++++++++++
 spec/utils_spec.rb            | 14 --------------
 5 files changed, 41 insertions(+), 38 deletions(-)
 delete mode 100644 lib/draper/utils.rb
 delete mode 100644 spec/utils_spec.rb

diff --git a/lib/draper.rb b/lib/draper.rb
index 54fe6acc..74fd1962 100644
--- a/lib/draper.rb
+++ b/lib/draper.rb
@@ -1,7 +1,6 @@
 require 'action_view'
 
 require 'draper/version'
-require 'draper/utils'
 require 'draper/system'
 require 'draper/active_model_support'
 require 'draper/view_helpers'
diff --git a/lib/draper/decorator.rb b/lib/draper/decorator.rb
index 3371e3a4..d0695c4a 100755
--- a/lib/draper/decorator.rb
+++ b/lib/draper/decorator.rb
@@ -25,13 +25,9 @@ class Decorator
     def initialize(input, options = {})
       input.to_a if input.respond_to?(:to_a) # forces evaluation of a lazy query from AR
       self.class.model_class = input.class if model_class.nil?
-      @model = input
-      if input.instance_of?(self.class)
-        @model = input.model
-      elsif Utils.decorators_of(input).include?(self.class)
-        warn "Reapplying #{self.class} decorator to target that is already decorated with it. Call stack:\n#{caller(1).join "\n"}"
-      end
+      self.model = input
       self.options = options
+      handle_multiple_decoration if input.is_a?(Draper::Decorator)
     end
 
     # Proxies to the class specified by `decorates` to automatically
@@ -176,6 +172,21 @@ def self.last(options = {})
       decorate(model_class.last, options)
     end
 
+    # Get the chain of decorators applied to the object.
+    #
+    # @return [Array] list of decorator classes
+    def applied_decorators
+      chain = model.respond_to?(:applied_decorators) ? model.applied_decorators : []
+      chain << self.class
+    end
+
+    # Checks if a given decorator has been applied.
+    #
+    # @param [Class] decorator_class
+    def decorated_with?(decorator_class)
+      applied_decorators.include?(decorator_class)
+    end
+
     # Delegates == to the decorated models
     #
     # @return [Boolean] true if other's model == self's model
@@ -252,6 +263,14 @@ def allow?(method)
       self.class.security.allow?(method)
     end
 
+    def handle_multiple_decoration
+      if model.instance_of?(self.class)
+        self.model = model.model
+      elsif model.decorated_with?(self.class)
+        warn "Reapplying #{self.class} decorator to target that is already decorated with it. Call stack:\n#{caller(1).join("\n")}"
+      end
+    end
+
     def find_association_reflection(association)
       if model.class.respond_to?(:reflect_on_association)
         model.class.reflect_on_association(association)
diff --git a/lib/draper/utils.rb b/lib/draper/utils.rb
deleted file mode 100644
index 39bdc71c..00000000
--- a/lib/draper/utils.rb
+++ /dev/null
@@ -1,17 +0,0 @@
-module Draper
-  # @api private
-  module Utils
-    extend self
-
-    # Returns an array of all decorator classes applied to an instance.
-    def decorators_of(decorated_instance)
-      decorators = []
-      instance = decorated_instance
-      while instance.kind_of?(Draper::Decorator)
-        decorators << instance.class
-        instance = instance.model
-      end
-      decorators
-    end
-  end
-end
diff --git a/spec/draper/decorator_spec.rb b/spec/draper/decorator_spec.rb
index 68bf2601..edac2a61 100755
--- a/spec/draper/decorator_spec.rb
+++ b/spec/draper/decorator_spec.rb
@@ -268,6 +268,22 @@ class CustomDecorator < Draper::Decorator
     end
   end
 
+  describe "#applied_decorators" do
+    it "returns a list of decorators applied to a model" do
+      decorator = ProductDecorator.new(SpecificProductDecorator.new(Product.new))
+      decorator.applied_decorators.should == [SpecificProductDecorator, ProductDecorator]
+    end
+  end
+
+  describe "#decorated_with?" do
+    it "checks if a decorator has been applied to a model" do
+      decorator = ProductDecorator.new(SpecificProductDecorator.new(Product.new))
+      decorator.should be_decorated_with ProductDecorator
+      decorator.should be_decorated_with SpecificProductDecorator
+      decorator.should_not be_decorated_with WidgetDecorator
+    end
+  end
+
   context(".wrapped_object") do
     it "return the wrapped object" do
       subject.wrapped_object.should == source
diff --git a/spec/utils_spec.rb b/spec/utils_spec.rb
deleted file mode 100644
index 19af63fe..00000000
--- a/spec/utils_spec.rb
+++ /dev/null
@@ -1,14 +0,0 @@
-require 'spec_helper'
-
-describe Draper::Utils do
-  describe ".decorators_of" do
-    it "returns a list of decorators applied to a model" do
-      instance = ProductDecorator.new(SpecificProductDecorator.new(Product.new))
-      Draper::Utils.decorators_of(instance).should == [ProductDecorator, SpecificProductDecorator]
-    end
-
-    it "returns an empty array when instance is not decorated" do
-      Draper::Utils.decorators_of(Product.new).should be_empty
-    end
-  end
-end