1 files changed, 32 insertions, 22 deletions

diff --git a/activesupport/lib/active_support/callbacks.rb b/activesupport/lib/active_support/callbacks.rb
index 85b7669353..5c738572a8 100644
--- a/activesupport/lib/active_support/callbacks.rb
+++ b/activesupport/lib/active_support/callbacks.rb
@@ -1,5 +1,6 @@
 require 'active_support/concern'
 require 'active_support/descendants_tracker'
+require 'active_support/core_ext/array/extract_options'
 require 'active_support/core_ext/class/attribute'
 require 'active_support/core_ext/kernel/reporting'
 require 'active_support/core_ext/kernel/singleton_class'
@@ -94,6 +95,15 @@ module ActiveSupport
     def halted_callback_hook(filter)
     end
 
+    module Conditionals # :nodoc:
+      class Value
+        def initialize(&block)
+          @block = block
+        end
+        def call(target, value); @block.call(value); end
+      end
+    end
+
     module Filters
       Environment = Struct.new(:target, :halted, :value, :run_block)
 
@@ -403,8 +413,8 @@ module ActiveSupport
       # the same after this point:
       #
       #   Symbols:: Already methods.
-      #   Strings:: class_eval'ed into methods.
-      #   Procs::   define_method'ed into methods.
+      #   Strings:: class_eval'd into methods.
+      #   Procs::   using define_method compiled into methods.
       #   Objects::
       #     a method is created that calls the before_foo method
       #     on the object.
@@ -415,6 +425,7 @@ module ActiveSupport
         when String
           l = eval "lambda { |value| #{filter} }"
           lambda { |target, value| target.instance_exec(value, &l) }
+        when Conditionals::Value then filter
         when ::Proc
           if filter.arity > 1
             return lambda { |target, _, &block|
@@ -532,14 +543,12 @@ module ActiveSupport
         @callbacks = nil
         @chain.delete_if { |c| callback.duplicates?(c) }
       end
-
     end
 
     module ClassMethods
-
       def normalize_callback_params(filters, block) # :nodoc:
         type = CALLBACK_FILTER_TYPES.include?(filters.first) ? filters.shift : :before
-        options = filters.last.is_a?(Hash) ? filters.pop : {}
+        options = filters.extract_options!
         filters.unshift(block) if block
         [type, filters, options.dup]
       end
@@ -627,16 +636,16 @@ module ActiveSupport
       end
 
       # Remove all set callbacks for the given event.
-      def reset_callbacks(symbol)
-        callbacks = get_callbacks symbol
+      def reset_callbacks(name)
+        callbacks = get_callbacks name
 
         ActiveSupport::DescendantsTracker.descendants(self).each do |target|
-          chain = target.get_callbacks(symbol).dup
+          chain = target.get_callbacks(name).dup
           callbacks.each { |c| chain.delete(c) }
-          target.set_callbacks symbol, chain
+          target.set_callbacks name, chain
         end
 
-        self.set_callbacks symbol, callbacks.dup.clear
+        self.set_callbacks name, callbacks.dup.clear
       end
 
       # Define sets of events in the object lifecycle that support callbacks.
@@ -648,10 +657,11 @@ module ActiveSupport
       #
       # * <tt>:terminator</tt> - Determines when a before filter will halt the
       #   callback chain, preventing following callbacks from being called and
-      #   the event from being triggered. This is a string to be eval'ed. The
-      #   result of the callback is available in the +result+ variable.
+      #   the event from being triggered. This should be a lambda to be executed.
+      #   The current object and the return result of the callback will be called
+      #   with the lambda.
       #
-      #     define_callbacks :validate, terminator: 'result == false'
+      #     define_callbacks :validate, terminator: ->(target, result) { result == false }
       #
       #   In this example, if any before validate callbacks returns +false+,
       #   other callbacks are not executed. Defaults to +false+, meaning no value
@@ -706,18 +716,18 @@ module ActiveSupport
       #     define_callbacks :save, scope: [:name]
       #
       #   would call <tt>Audit#save</tt>.
-      def define_callbacks(*callbacks)
-        config = callbacks.last.is_a?(Hash) ? callbacks.pop : {}
-        if config.key?(:terminator) && String === config[:terminator]
+      def define_callbacks(*names)
+        options = names.extract_options!
+        if options.key?(:terminator) && String === options[:terminator]
           ActiveSupport::Deprecation.warn "String based terminators are deprecated, please use a lambda"
-          value = config[:terminator]
-          l = class_eval "lambda { |result| #{value} }", __FILE__, __LINE__
-          config[:terminator] = lambda { |target, result| target.instance_exec(result, &l) }
+          value = options[:terminator]
+          line = class_eval "lambda { |result| #{value} }", __FILE__, __LINE__
+          options[:terminator] = lambda { |target, result| target.instance_exec(result, &line) }
         end
 
-        callbacks.each do |callback|
-          class_attribute "_#{callback}_callbacks"
-          set_callbacks callback, CallbackChain.new(callback, config)
+        names.each do |name|
+          class_attribute "_#{name}_callbacks"
+          set_callbacks name, CallbackChain.new(name, options)
         end
       end