Deprecate ivars in view.

Deprecate use of @logger and @action_name instance variables inside
views. Please use instance methods logger and action_name instead.

actionpack/lib/action_view/base.rb

@@ -157,6 +157,8 @@ class Base
     attr_reader :logger, :response, :headers
     attr_internal :cookies, :flash, :headers, :params, :request, :response, :session
 
+    delegate :logger, :action_name, :to => :controller
+
     attr_writer :template_format
 
     # Specify trim mode for the ERB compiler. Defaults to '-'.
@@ -524,10 +526,18 @@ def delegate_compile(handler, template)
       def template_handler_is_compilable?(handler)
         handler.new(self).respond_to?(:compile)
       end
-
+      
       # Assigns instance variables from the controller to the view.
       def assign_variables_from_controller
-        @assigns.each { |key, value| instance_variable_set("@#{key}", value) }
+        @assigns.each do |key, value|
+          if ['logger'].include?(key)
+            instance_variable_set("@#{key}", ActiveSupport::Deprecation::DeprecatedInstanceVariableProxy.new(self, key.to_sym))
+          elsif ['action_name'].include?(key)
+            instance_variable_set("@#{key}", ActiveSupport::Deprecation::DeprecatedInstanceVariable.new(value, key))
+          else
+            instance_variable_set("@#{key}", value)
+          end
+        end
       end
 
 

actionpack/test/template/deprecate_ivars_test.rb

@@ -0,0 +1,51 @@
+require File.dirname(__FILE__) + '/../abstract_unit'
+
+class DeprecateIvars < ActionController::Base
+  def use_logger
+    render :inline => "<%= logger.class -%>"
+  end
+
+  def use_old_logger
+    render :inline => "<%= @logger.class -%>"
+  end
+
+  def use_action_name
+    render :inline => "<%= action_name -%>"
+  end
+
+  def use_old_action_name
+    render :inline => "<%= @action_name -%>"
+  end
+end
+
+class DeprecateIvarsTest < Test::Unit::TestCase
+  def setup
+    @request    = ActionController::TestRequest.new
+    @response   = ActionController::TestResponse.new
+
+    @controller = DeprecateIvars.new
+    @controller.logger = Logger.new(nil)
+
+    @request.host = "rubyonrails.com"
+  end
+
+  def test_logger
+    assert_not_deprecated { get :use_logger }
+    assert_equal "Logger", @response.body
+  end
+
+  def test_deprecated_logger
+    assert_deprecated { get :use_old_logger }
+    assert_equal "Logger", @response.body
+  end
+
+  def test_action_name
+    assert_not_deprecated { get :use_action_name }
+    assert_equal "use_action_name", @response.body
+  end
+
+  def test_deprecated_action_name
+    assert_deprecated { get :use_old_action_name }
+    assert_equal "use_old_action_name", @response.body
+  end
+end

activesupport/lib/active_support/deprecation.rb

@@ -1,4 +1,5 @@
 require 'yaml'
+require 'delegate'
 
 module ActiveSupport
   module Deprecation #:nodoc:
@@ -175,6 +176,20 @@ def warn(callstack, called, args)
           ActiveSupport::Deprecation.warn("#{@var} is deprecated! Call #{@method}.#{called} instead of #{@var}.#{called}. Args: #{args.inspect}", callstack)
         end
     end
+
+    class DeprecatedInstanceVariable < Delegator
+      def initialize(value, method)
+        super(value)
+        @method = method
+        @value = value
+      end
+
+      def __getobj__
+        ActiveSupport::Deprecation.warn("Instance variable @#{@method} is deprecated! Call instance method #{@method} instead.")
+        @value
+      end
+    end
+
   end
 end
 

activesupport/test/deprecation_test.rb

@@ -1,6 +1,7 @@
 require File.dirname(__FILE__) + '/abstract_unit'
 
 class Deprecatee
+
   def initialize
     @request = ActiveSupport::Deprecation::DeprecatedInstanceVariableProxy.new(self, :request)
     @_request = 'there we go'
@@ -148,4 +149,15 @@ def message
     assert_not_deprecated { error.message }
     assert_nil @last_message
   end
+
+end
+
+class DeprecatedIvarTest < Test::Unit::TestCase
+
+  def test_deprecated_ivar
+    @action = ActiveSupport::Deprecation::DeprecatedInstanceVariable.new("fubar", :foobar)
+
+    assert_deprecated(/Instance variable @foobar is deprecated! Call instance method foobar instead/) { assert_equal "fubar", @action }
+  end
+
 end