3 files changed, 23 insertions, 1 deletions
diff --git a/activemodel/CHANGELOG.md b/activemodel/CHANGELOG.md
index fb7ab5cb40..7be8b2e522 100644
--- a/activemodel/CHANGELOG.md
+++ b/activemodel/CHANGELOG.md
@@ -1,3 +1,8 @@
+*   Allow passing record being validated to the message proc to generate
+    customized error messages for that object using I18n helper.
+
+    *Prathamesh Sonpatki*
+
 ## Rails 5.0.0.beta3 (February 24, 2016) ##
 
 *   No changes.
diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 836201535f..d925960b41 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -486,7 +486,8 @@ module ActiveModel
         default: defaults,
         model: @base.model_name.human,
         attribute: @base.class.human_attribute_name(attribute),
-        value: value
+        value: value,
+        object: @base
       }.merge!(options)
 
       I18n.translate(key, options)
diff --git a/activemodel/test/cases/validations_test.rb b/activemodel/test/cases/validations_test.rb
index f0317ad219..2a4e9f842f 100644
--- a/activemodel/test/cases/validations_test.rb
+++ b/activemodel/test/cases/validations_test.rb
@@ -444,4 +444,20 @@ class ValidationsTest < ActiveModel::TestCase
     assert topic.invalid?
     assert duped.valid?
   end
+
+  def test_validation_with_message_as_proc_that_takes_a_record_as_a_parameter
+    Topic.validates_presence_of(:title, message: proc { |record| "You have failed me for the last time, #{record.author_name}." })
+
+    t = Topic.new(author_name: 'Admiral')
+    assert t.invalid?
+    assert_equal ["You have failed me for the last time, Admiral."], t.errors[:title]
+  end
+
+  def test_validation_with_message_as_proc_that_takes_record_and_data_as_a_parameters
+    Topic.validates_presence_of(:title, message: proc { |record, data| "#{data[:attribute]} is missing. You have failed me for the last time, #{record.author_name}." })
+
+    t = Topic.new(author_name: 'Admiral')
+    assert t.invalid?
+    assert_equal ["Title is missing. You have failed me for the last time, Admiral."], t.errors[:title]
+  end
 end