Added Enumerable#pluck to wrap the common pattern of collect(&:method) *DHH*

activesupport/CHANGELOG.md

@@ -1,5 +1,7 @@
 ## Rails 3.2.0 (unreleased) ##
 
+*   Added Enumerable#pluck to wrap the common pattern of collect(&:method) *DHH*
+
 *   Module#synchronize is deprecated with no replacement.  Please use `monitor`
     from ruby's standard library.
 

activesupport/lib/active_support/core_ext/enumerable.rb

@@ -63,6 +63,13 @@ module Enumerable
     end
   end
 
+  # Plucks the value of the passed method for each element and returns the result as an array. Example:
+  #
+  #   people.pluck(:name) # => [ "David Heinemeier Hansson", "Jamie Heinemeier Hansson" ]
+  def pluck(method)
+    collect { |element| element.send(method) }
+  end
+
   # Iterates over a collection, passing the current element *and* the
   # +memo+ to the block. Handy for building up hashes or
   # reducing collections down to one object. Examples:

activesupport/test/core_ext/enumerable_test.rb

@@ -126,4 +126,11 @@ class EnumerableTests < Test::Unit::TestCase
     assert_equal true,  GenericEnumerable.new([ 1 ]).exclude?(2)
     assert_equal false, GenericEnumerable.new([ 1 ]).exclude?(1)
   end
+  
+  def test_pluck_single_method
+    person = Struct.new(:name)
+    people = [ person.new("David"), person.new("Jamie") ]
+    
+    assert_equal [ "David", "Jamie" ], people.pluck(:name)
+  end
 end