Tidy up ActiveSupport::Callbacks::CallbackChain instance API.

actionpack/lib/action_controller/dispatcher.rb

@@ -22,7 +22,7 @@ module ActionController
       def to_prepare(identifier = nil, &block)
         @prepare_dispatch_callbacks ||= ActiveSupport::Callbacks::CallbackChain.new
         callback = ActiveSupport::Callbacks::Callback.new(:prepare_dispatch, block, :identifier => identifier)
-        @prepare_dispatch_callbacks.replace_or_append_callback(callback)
+        @prepare_dispatch_callbacks | callback
       end
 
       # If the block raises, send status code as a last-ditch response.

actionpack/lib/action_controller/filters.rb

@@ -265,7 +265,7 @@ module ActionController #:nodoc:
       def skip_filter_in_chain(*filters, &test)
         filters, conditions = extract_options(filters)
         filters.each do |filter|
-          if callback = find_callback(filter) then delete(callback) end
+          if callback = find(filter) then delete(callback) end
         end if conditions.empty?
         update_filter_in_chain(filters, :skip => conditions, &test)
       end
@@ -302,7 +302,7 @@ module ActionController #:nodoc:
         def find_or_create_filter(filter, filter_type, options = {})
           update_filter_in_chain([filter], options)
 
-          if found_filter = find_callback(filter) { |f| f.type == filter_type }
+          if found_filter = find(filter) { |f| f.type == filter_type }
             found_filter
           else
             filter_kind = case
@@ -326,7 +326,7 @@ module ActionController #:nodoc:
         end
 
         def update_filter_in_chain(filters, options, &test)
-          filters.map! { |f| block_given? ? find_callback(f, &test) : find_callback(f) }
+          filters.map! { |f| block_given? ? find(f, &test) : find(f) }
           filters.compact!
 
           map! do |filter|

activemodel/lib/active_model/validations.rb

@@ -7,8 +7,7 @@ module ActiveModel
       %w( validate validate_on_create validate_on_update ).each do |validation_method|
         base.class_eval <<-"end_eval"
           def self.#{validation_method}(*methods, &block)
-            methods = CallbackChain.build(:#{validation_method}, *methods, &block)
-            self.#{validation_method}_callback_chain.replace(#{validation_method}_callback_chain | methods)
+            self.#{validation_method}_callback_chain | CallbackChain.build(:#{validation_method}, *methods, &block)
           end
 
           def self.#{validation_method}_callback_chain

activerecord/lib/active_record/validations.rb

@@ -285,8 +285,7 @@ module ActiveRecord
       VALIDATIONS.each do |validation_method|
         base.class_eval <<-"end_eval"
           def self.#{validation_method}(*methods, &block)
-            methods = CallbackChain.build(:#{validation_method}, *methods, &block)
-            self.#{validation_method}_callback_chain.replace(#{validation_method}_callback_chain | methods)
+            self.#{validation_method}_callback_chain | CallbackChain.build(:#{validation_method}, *methods, &block)
           end
 
           def self.#{validation_method}_callback_chain

activesupport/lib/active_support/callbacks.rb

@@ -96,17 +96,26 @@ module ActiveSupport
         end
       end
 
-      def find_callback(callback, &block)
+      def |(chain)
+        if chain.is_a?(Callback)
+          if found_callback = find(chain)
+            index = index(found_callback)
+            self[index] = chain
+          else
+            self << chain
+          end
+        else
+          chain.each { |callback| self | callback }
+        end
+        self
+      end
+
+      def find(callback, &block)
         select { |c| c == callback && (!block_given? || yield(c)) }.first
       end
 
-      def replace_or_append_callback(callback)
-        if found_callback = find_callback(callback)
-          index = index(found_callback)
-          self[index] = callback
-        else
-          self << callback
-        end
+      def delete(callback)
+        super(find(callback))
       end
 
       private

activesupport/test/callbacks_test.rb

@@ -96,6 +96,8 @@ class ConditionalCallbackTest < Test::Unit::TestCase
 end
 
 class CallbackTest < Test::Unit::TestCase
+  include ActiveSupport::Callbacks
+
   def test_eql
     callback = Callback.new(:before, :save, :identifier => :lifesaver)
     assert callback.eql?(Callback.new(:before, :save, :identifier => :lifesaver))
@@ -115,3 +117,32 @@ class CallbackTest < Test::Unit::TestCase
     assert_equal({}, a.options)
   end
 end
+
+class CallbackChainTest < Test::Unit::TestCase
+  include ActiveSupport::Callbacks
+
+  def setup
+    @chain = CallbackChain.build(:make, :bacon, :lettuce, :tomato)
+  end
+
+  def test_build
+    assert_equal 3, @chain.size
+    assert_equal [:bacon, :lettuce, :tomato], @chain.map(&:method)
+  end
+
+  def test_find
+    assert_equal :bacon, @chain.find(:bacon).method
+  end
+
+  def test_union
+    assert_equal [:bacon, :lettuce, :tomato], (@chain | Callback.new(:make, :bacon)).map(&:method)
+    assert_equal [:bacon, :lettuce, :tomato, :turkey], (@chain | CallbackChain.build(:make, :bacon, :lettuce, :tomato, :turkey)).map(&:method)
+    assert_equal [:bacon, :lettuce, :tomato, :turkey, :mayo], (@chain | Callback.new(:make, :mayo)).map(&:method)
+  end
+
+  def test_delete
+    assert_equal [:bacon, :lettuce, :tomato], @chain.map(&:method)
+    @chain.delete(:bacon)
+    assert_equal [:lettuce, :tomato], @chain.map(&:method)
+  end
+end