Favor %{} in all code instead of (deprecated) {{}} as interpolation syntax for I18n

Signed-off-by: José Valim <jose.valim@gmail.com>

actionpack/lib/action_view/helpers/form_helper.rb

@@ -1179,7 +1179,7 @@ module ActionView
       #     helpers:
       #       submit:
       #         post:
-      #           create: "Add {{model}}"
+      #           create: "Add %{model}"
       #
       def submit(value=nil, options={})
         value, options = nil, value if value.is_a?(Hash)

actionpack/test/template/form_helper_test.rb

@@ -33,11 +33,11 @@ class FormHelperTest < ActionView::TestCase
     I18n.backend.store_translations 'submit', {
       :helpers => {
         :submit => {
-          :create => 'Create {{model}}',
-          :update => 'Confirm {{model}} changes',
+          :create => 'Create %{model}',
+          :update => 'Confirm %{model} changes',
           :submit => 'Save changes',
           :another_post => {
-            :update => 'Update your {{model}}'
+            :update => 'Update your %{model}'
           }
         }
       }

activemodel/lib/active_model/validations/exclusion.rb

@@ -18,7 +18,7 @@ module ActiveModel
       #   class Person < ActiveRecord::Base
       #     validates_exclusion_of :username, :in => %w( admin superuser ), :message => "You don't belong here"
       #     validates_exclusion_of :age, :in => 30..60, :message => "This site is only for under 30 and over 60"
-      #     validates_exclusion_of :format, :in => %w( mov avi ), :message => "extension {{value}} is not allowed"
+      #     validates_exclusion_of :format, :in => %w( mov avi ), :message => "extension %{value} is not allowed"
       #   end
       #
       # Configuration options:

activemodel/lib/active_model/validations/inclusion.rb

@@ -18,7 +18,7 @@ module ActiveModel
       #   class Person < ActiveRecord::Base
       #     validates_inclusion_of :gender, :in => %w( m f )
       #     validates_inclusion_of :age, :in => 0..99
-      #     validates_inclusion_of :format, :in => %w( jpg gif png ), :message => "extension {{value}} is not included in the list"
+      #     validates_inclusion_of :format, :in => %w( jpg gif png ), :message => "extension %{value} is not included in the list"
       #   end
       #
       # Configuration options:

activemodel/lib/active_model/validations/length.rb

@@ -74,9 +74,9 @@ module ActiveModel
       # * <tt>:in</tt> - A synonym(or alias) for <tt>:within</tt>.
       # * <tt>:allow_nil</tt> - Attribute may be +nil+; skip validation.
       # * <tt>:allow_blank</tt> - Attribute may be blank; skip validation.
-      # * <tt>:too_long</tt> - The error message if the attribute goes over the maximum (default is: "is too long (maximum is {{count}} characters)").
-      # * <tt>:too_short</tt> - The error message if the attribute goes under the minimum (default is: "is too short (min is {{count}} characters)").
-      # * <tt>:wrong_length</tt> - The error message if using the <tt>:is</tt> method and the attribute is the wrong size (default is: "is the wrong length (should be {{count}} characters)").
+      # * <tt>:too_long</tt> - The error message if the attribute goes over the maximum (default is: "is too long (maximum is %{count} characters)").
+      # * <tt>:too_short</tt> - The error message if the attribute goes under the minimum (default is: "is too short (min is %{count} characters)").
+      # * <tt>:wrong_length</tt> - The error message if using the <tt>:is</tt> method and the attribute is the wrong size (default is: "is the wrong length (should be %{count} characters)").
       # * <tt>:message</tt> - The error message to use for a <tt>:minimum</tt>, <tt>:maximum</tt>, or <tt>:is</tt> violation.  An alias of the appropriate <tt>too_long</tt>/<tt>too_short</tt>/<tt>wrong_length</tt> message.
       # * <tt>:on</tt> - Specifies when this validation is active (default is <tt>:save</tt>, other options <tt>:create</tt>, <tt>:update</tt>).
       # * <tt>:if</tt> - Specifies a method, proc or string to call to determine if the validation should

activemodel/test/cases/validations/conditional_validation_test.rb

@@ -13,7 +13,7 @@ class ConditionalValidationTest < ActiveModel::TestCase
   
   def test_if_validation_using_method_true
     # When the method returns true
-    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo {{count}}", :if => :condition_is_true )
+    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo %{count}", :if => :condition_is_true )
     t = Topic.create("title" => "uhohuhoh", "content" => "whatever")
     assert !t.valid?
     assert t.errors[:title].any?
@@ -22,7 +22,7 @@ class ConditionalValidationTest < ActiveModel::TestCase
 
   def test_unless_validation_using_method_true
     # When the method returns true
-    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo {{count}}", :unless => :condition_is_true )
+    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo %{count}", :unless => :condition_is_true )
     t = Topic.create("title" => "uhohuhoh", "content" => "whatever")
     assert t.valid?
     assert !t.errors[:title].any?
@@ -30,7 +30,7 @@ class ConditionalValidationTest < ActiveModel::TestCase
 
   def test_if_validation_using_method_false
     # When the method returns false
-    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo {{count}}", :if => :condition_is_true_but_its_not )
+    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo %{count}", :if => :condition_is_true_but_its_not )
     t = Topic.create("title" => "uhohuhoh", "content" => "whatever")
     assert t.valid?
     assert t.errors[:title].empty?
@@ -38,7 +38,7 @@ class ConditionalValidationTest < ActiveModel::TestCase
 
   def test_unless_validation_using_method_false
     # When the method returns false
-    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo {{count}}", :unless => :condition_is_true_but_its_not )
+    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo %{count}", :unless => :condition_is_true_but_its_not )
     t = Topic.create("title" => "uhohuhoh", "content" => "whatever")
     assert !t.valid?
     assert t.errors[:title].any?
@@ -47,7 +47,7 @@ class ConditionalValidationTest < ActiveModel::TestCase
 
   def test_if_validation_using_string_true
     # When the evaluated string returns true
-    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo {{count}}", :if => "a = 1; a == 1" )
+    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo %{count}", :if => "a = 1; a == 1" )
     t = Topic.create("title" => "uhohuhoh", "content" => "whatever")
     assert !t.valid?
     assert t.errors[:title].any?
@@ -56,7 +56,7 @@ class ConditionalValidationTest < ActiveModel::TestCase
 
   def test_unless_validation_using_string_true
     # When the evaluated string returns true
-    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo {{count}}", :unless => "a = 1; a == 1" )
+    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo %{count}", :unless => "a = 1; a == 1" )
     t = Topic.create("title" => "uhohuhoh", "content" => "whatever")
     assert t.valid?
     assert t.errors[:title].empty?
@@ -64,7 +64,7 @@ class ConditionalValidationTest < ActiveModel::TestCase
 
   def test_if_validation_using_string_false
     # When the evaluated string returns false
-    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo {{count}}", :if => "false")
+    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo %{count}", :if => "false")
     t = Topic.create("title" => "uhohuhoh", "content" => "whatever")
     assert t.valid?
     assert t.errors[:title].empty?
@@ -72,7 +72,7 @@ class ConditionalValidationTest < ActiveModel::TestCase
 
   def test_unless_validation_using_string_false
     # When the evaluated string returns false
-    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo {{count}}", :unless => "false")
+    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo %{count}", :unless => "false")
     t = Topic.create("title" => "uhohuhoh", "content" => "whatever")
     assert !t.valid?
     assert t.errors[:title].any?
@@ -81,7 +81,7 @@ class ConditionalValidationTest < ActiveModel::TestCase
 
   def test_if_validation_using_block_true
     # When the block returns true
-    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo {{count}}",
+    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo %{count}",
       :if => Proc.new { |r| r.content.size > 4 } )
     t = Topic.create("title" => "uhohuhoh", "content" => "whatever")
     assert !t.valid?
@@ -91,7 +91,7 @@ class ConditionalValidationTest < ActiveModel::TestCase
 
   def test_unless_validation_using_block_true
     # When the block returns true
-    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo {{count}}",
+    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo %{count}",
       :unless => Proc.new { |r| r.content.size > 4 } )
     t = Topic.create("title" => "uhohuhoh", "content" => "whatever")
     assert t.valid?
@@ -100,7 +100,7 @@ class ConditionalValidationTest < ActiveModel::TestCase
 
   def test_if_validation_using_block_false
     # When the block returns false
-    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo {{count}}",
+    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo %{count}",
       :if => Proc.new { |r| r.title != "uhohuhoh"} )
     t = Topic.create("title" => "uhohuhoh", "content" => "whatever")
     assert t.valid?
@@ -109,7 +109,7 @@ class ConditionalValidationTest < ActiveModel::TestCase
 
   def test_unless_validation_using_block_false
     # When the block returns false
-    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo {{count}}",
+    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo %{count}",
       :unless => Proc.new { |r| r.title != "uhohuhoh"} )
     t = Topic.create("title" => "uhohuhoh", "content" => "whatever")
     assert !t.valid?

activemodel/test/cases/validations/exclusion_validation_test.rb

@@ -20,7 +20,7 @@ class ExclusionValidationTest < ActiveModel::TestCase
   end
 
   def test_validates_exclusion_of_with_formatted_message
-    Topic.validates_exclusion_of( :title, :in => %w( abe monkey ), :message => "option {{value}} is restricted" )
+    Topic.validates_exclusion_of( :title, :in => %w( abe monkey ), :message => "option %{value} is restricted" )
 
     assert Topic.create("title" => "something", "content" => "abc")
 

activemodel/test/cases/validations/format_validation_test.rb

@@ -67,7 +67,7 @@ class PresenceValidationTest < ActiveModel::TestCase
   end
 
   def test_validate_format_with_formatted_message
-    Topic.validates_format_of(:title, :with => /^Valid Title$/, :message => "can't be {{value}}")
+    Topic.validates_format_of(:title, :with => /^Valid Title$/, :message => "can't be %{value}")
     t = Topic.create(:title => 'Invalid title')
     assert_equal ["can't be Invalid title"], t.errors[:title]
   end

activemodel/test/cases/validations/i18n_generate_message_validation_test.rb

@@ -15,7 +15,7 @@ class I18nGenerateMessageValidationTest < ActiveModel::TestCase
   end
 
   def test_generate_message_inclusion_with_custom_message
-    assert_equal 'custom message title', @person.errors.generate_message(:title, :inclusion, :default => 'custom message {{value}}', :value => 'title')
+    assert_equal 'custom message title', @person.errors.generate_message(:title, :inclusion, :default => 'custom message %{value}', :value => 'title')
   end
 
   # validates_exclusion_of: generate_message(attr_name, :exclusion, :default => configuration[:message], :value => value)
@@ -24,7 +24,7 @@ class I18nGenerateMessageValidationTest < ActiveModel::TestCase
   end
 
   def test_generate_message_exclusion_with_custom_message
-    assert_equal 'custom message title', @person.errors.generate_message(:title, :exclusion, :default => 'custom message {{value}}', :value => 'title')
+    assert_equal 'custom message title', @person.errors.generate_message(:title, :exclusion, :default => 'custom message %{value}', :value => 'title')
   end
 
   # validates_format_of:  generate_message(attr_name, :invalid, :default => configuration[:message], :value => value)
@@ -33,7 +33,7 @@ class I18nGenerateMessageValidationTest < ActiveModel::TestCase
   end
 
   def test_generate_message_invalid_with_custom_message
-    assert_equal 'custom message title', @person.errors.generate_message(:title, :invalid, :default => 'custom message {{value}}', :value => 'title')
+    assert_equal 'custom message title', @person.errors.generate_message(:title, :invalid, :default => 'custom message %{value}', :value => 'title')
   end
 
   # validates_confirmation_of: generate_message(attr_name, :confirmation, :default => configuration[:message])
@@ -78,7 +78,7 @@ class I18nGenerateMessageValidationTest < ActiveModel::TestCase
   end
 
   def test_generate_message_too_long_with_custom_message
-    assert_equal 'custom message 10', @person.errors.generate_message(:title, :too_long, :default => 'custom message {{count}}', :count => 10)
+    assert_equal 'custom message 10', @person.errors.generate_message(:title, :too_long, :default => 'custom message %{count}', :count => 10)
   end
 
   # validates_length_of: generate_message(attr, :too_short, :default => options[:too_short], :count => option_value.begin)
@@ -87,7 +87,7 @@ class I18nGenerateMessageValidationTest < ActiveModel::TestCase
   end
 
   def test_generate_message_too_short_with_custom_message
-    assert_equal 'custom message 10', @person.errors.generate_message(:title, :too_short, :default => 'custom message {{count}}', :count => 10)
+    assert_equal 'custom message 10', @person.errors.generate_message(:title, :too_short, :default => 'custom message %{count}', :count => 10)
   end
 
   # validates_length_of: generate_message(attr, key, :default => custom_message, :count => option_value)
@@ -96,7 +96,7 @@ class I18nGenerateMessageValidationTest < ActiveModel::TestCase
   end
 
   def test_generate_message_wrong_length_with_custom_message
-    assert_equal 'custom message 10', @person.errors.generate_message(:title, :wrong_length, :default => 'custom message {{count}}', :count => 10)
+    assert_equal 'custom message 10', @person.errors.generate_message(:title, :wrong_length, :default => 'custom message %{count}', :count => 10)
   end
 
   # validates_numericality_of: generate_message(attr_name, :not_a_number, :value => raw_value, :default => configuration[:message])
@@ -105,7 +105,7 @@ class I18nGenerateMessageValidationTest < ActiveModel::TestCase
   end
 
   def test_generate_message_not_a_number_with_custom_message
-    assert_equal 'custom message title', @person.errors.generate_message(:title, :not_a_number, :default => 'custom message {{value}}', :value => 'title')
+    assert_equal 'custom message title', @person.errors.generate_message(:title, :not_a_number, :default => 'custom message %{value}', :value => 'title')
   end
 
   # validates_numericality_of: generate_message(attr_name, option, :value => raw_value, :default => configuration[:message])

activemodel/test/cases/validations/i18n_validation_test.rb

@@ -58,7 +58,7 @@ class I18nValidationTest < ActiveModel::TestCase
   end
 
   def test_errors_full_messages_uses_format
-    I18n.backend.store_translations('en', :errors => {:format => "Field {{attribute}} {{message}}"})
+    I18n.backend.store_translations('en', :errors => {:format => "Field %{attribute} %{message}"})
     @person.errors.add('name', 'empty')
     assert_equal ["Field Name empty"], @person.errors.full_messages
   end

activemodel/test/cases/validations/inclusion_validation_test.rb

@@ -44,7 +44,7 @@ class InclusionValidationTest < ActiveModel::TestCase
   end
 
   def test_validates_inclusion_of_with_formatted_message
-    Topic.validates_inclusion_of( :title, :in => %w( a b c d e f g ), :message => "option {{value}} is not in the list" )
+    Topic.validates_inclusion_of( :title, :in => %w( a b c d e f g ), :message => "option %{value} is not in the list" )
 
     assert Topic.create("title" => "a", "content" => "abc").valid?
 

activemodel/test/cases/validations/length_validation_test.rb

@@ -138,7 +138,7 @@ class LengthValidationTest < ActiveModel::TestCase
   end
 
   def test_optionally_validates_length_of_using_within_on_create
-    Topic.validates_length_of :title, :content, :within => 5..10, :on => :create, :too_long => "my string is too long: {{count}}"
+    Topic.validates_length_of :title, :content, :within => 5..10, :on => :create, :too_long => "my string is too long: %{count}"
 
     t = Topic.create("title" => "thisisnotvalid", "content" => "whatever")
     assert !t.save
@@ -159,7 +159,7 @@ class LengthValidationTest < ActiveModel::TestCase
   end
 
   def test_optionally_validates_length_of_using_within_on_update
-    Topic.validates_length_of :title, :content, :within => 5..10, :on => :update, :too_short => "my string is too short: {{count}}"
+    Topic.validates_length_of :title, :content, :within => 5..10, :on => :update, :too_short => "my string is too short: %{count}"
 
     t = Topic.create("title" => "vali", "content" => "whatever")
     assert !t.save
@@ -230,7 +230,7 @@ class LengthValidationTest < ActiveModel::TestCase
   end
 
   def test_validates_length_of_custom_errors_for_minimum_with_message
-    Topic.validates_length_of( :title, :minimum=>5, :message=>"boo {{count}}" )
+    Topic.validates_length_of( :title, :minimum=>5, :message=>"boo %{count}" )
     t = Topic.create("title" => "uhoh", "content" => "whatever")
     assert !t.valid?
     assert t.errors[:title].any?
@@ -238,7 +238,7 @@ class LengthValidationTest < ActiveModel::TestCase
   end
 
   def test_validates_length_of_custom_errors_for_minimum_with_too_short
-    Topic.validates_length_of( :title, :minimum=>5, :too_short=>"hoo {{count}}" )
+    Topic.validates_length_of( :title, :minimum=>5, :too_short=>"hoo %{count}" )
     t = Topic.create("title" => "uhoh", "content" => "whatever")
     assert !t.valid?
     assert t.errors[:title].any?
@@ -246,7 +246,7 @@ class LengthValidationTest < ActiveModel::TestCase
   end
 
   def test_validates_length_of_custom_errors_for_maximum_with_message
-    Topic.validates_length_of( :title, :maximum=>5, :message=>"boo {{count}}" )
+    Topic.validates_length_of( :title, :maximum=>5, :message=>"boo %{count}" )
     t = Topic.create("title" => "uhohuhoh", "content" => "whatever")
     assert !t.valid?
     assert t.errors[:title].any?
@@ -254,7 +254,7 @@ class LengthValidationTest < ActiveModel::TestCase
   end
 
   def test_validates_length_of_custom_errors_for_in
-    Topic.validates_length_of(:title, :in => 10..20, :message => "hoo {{count}}")
+    Topic.validates_length_of(:title, :in => 10..20, :message => "hoo %{count}")
     t = Topic.create("title" => "uhohuhoh", "content" => "whatever")
     assert !t.valid?
     assert t.errors[:title].any?
@@ -267,7 +267,7 @@ class LengthValidationTest < ActiveModel::TestCase
   end
 
   def test_validates_length_of_custom_errors_for_maximum_with_too_long
-    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo {{count}}" )
+    Topic.validates_length_of( :title, :maximum=>5, :too_long=>"hoo %{count}" )
     t = Topic.create("title" => "uhohuhoh", "content" => "whatever")
     assert !t.valid?
     assert t.errors[:title].any?
@@ -275,7 +275,7 @@ class LengthValidationTest < ActiveModel::TestCase
   end
 
   def test_validates_length_of_custom_errors_for_is_with_message
-    Topic.validates_length_of( :title, :is=>5, :message=>"boo {{count}}" )
+    Topic.validates_length_of( :title, :is=>5, :message=>"boo %{count}" )
     t = Topic.create("title" => "uhohuhoh", "content" => "whatever")
     assert !t.valid?
     assert t.errors[:title].any?
@@ -283,7 +283,7 @@ class LengthValidationTest < ActiveModel::TestCase
   end
 
   def test_validates_length_of_custom_errors_for_is_with_wrong_length
-    Topic.validates_length_of( :title, :is=>5, :wrong_length=>"hoo {{count}}" )
+    Topic.validates_length_of( :title, :is=>5, :wrong_length=>"hoo %{count}" )
     t = Topic.create("title" => "uhohuhoh", "content" => "whatever")
     assert !t.valid?
     assert t.errors[:title].any?
@@ -349,7 +349,7 @@ class LengthValidationTest < ActiveModel::TestCase
 
   def test_optionally_validates_length_of_using_within_on_create_utf8
     with_kcode('UTF8') do
-      Topic.validates_length_of :title, :within => 5..10, :on => :create, :too_long => "長すぎます: {{count}}"
+      Topic.validates_length_of :title, :within => 5..10, :on => :create, :too_long => "長すぎます: %{count}"
 
       t = Topic.create("title" => "一二三四五六七八九十A", "content" => "whatever")
       assert !t.save
@@ -372,7 +372,7 @@ class LengthValidationTest < ActiveModel::TestCase
 
   def test_optionally_validates_length_of_using_within_on_update_utf8
     with_kcode('UTF8') do
-      Topic.validates_length_of :title, :within => 5..10, :on => :update, :too_short => "短すぎます: {{count}}"
+      Topic.validates_length_of :title, :within => 5..10, :on => :update, :too_short => "短すぎます: %{count}"
 
       t = Topic.create("title" => "一二三4", "content" => "whatever")
       assert !t.save
@@ -407,7 +407,7 @@ class LengthValidationTest < ActiveModel::TestCase
   end
 
   def test_validates_length_of_with_block
-    Topic.validates_length_of :content, :minimum => 5, :too_short=>"Your essay must be at least {{count}} words.",
+    Topic.validates_length_of :content, :minimum => 5, :too_short=>"Your essay must be at least %{count} words.",
                                         :tokenizer => lambda {|str| str.scan(/\w+/) }
     t = Topic.create!(:content => "this content should be long enough")
     assert t.valid?

activemodel/test/cases/validations/numericality_validation_test.rb

@@ -126,13 +126,13 @@ class NumericalityValidationTest < ActiveModel::TestCase
   end
 
   def test_validates_numericality_with_numeric_message
-    Topic.validates_numericality_of :approved, :less_than => 4, :message => "smaller than {{count}}"
+    Topic.validates_numericality_of :approved, :less_than => 4, :message => "smaller than %{count}"
     topic = Topic.new("title" => "numeric test", "approved" => 10)
 
     assert !topic.valid?
     assert_equal ["smaller than 4"], topic.errors[:approved]
 
-    Topic.validates_numericality_of :approved, :greater_than => 4, :message => "greater than {{count}}"
+    Topic.validates_numericality_of :approved, :greater_than => 4, :message => "greater than %{count}"
     topic = Topic.new("title" => "numeric test", "approved" => 1)
 
     assert !topic.valid?

activerecord/test/cases/validations/i18n_generate_message_validation_test.rb

@@ -15,7 +15,7 @@ class I18nGenerateMessageValidationTest < ActiveRecord::TestCase
   end
 
   def test_generate_message_invalid_with_custom_message
-    assert_equal 'custom message title', @topic.errors.generate_message(:title, :invalid, :default => 'custom message {{value}}', :value => 'title')
+    assert_equal 'custom message title', @topic.errors.generate_message(:title, :invalid, :default => 'custom message %{value}', :value => 'title')
   end
 
   # validates_uniqueness_of: generate_message(attr_name, :taken, :default => configuration[:message])
@@ -24,7 +24,7 @@ class I18nGenerateMessageValidationTest < ActiveRecord::TestCase
   end
 
   def test_generate_message_taken_with_custom_message
-    assert_equal 'custom message title', @topic.errors.generate_message(:title, :taken, :default => 'custom message {{value}}', :value => 'title')
+    assert_equal 'custom message title', @topic.errors.generate_message(:title, :taken, :default => 'custom message %{value}', :value => 'title')
   end
 
   # ActiveRecord#RecordInvalid exception

railties/guides/source/activerecord_validations_callbacks.textile

@@ -234,7 +234,7 @@ This helper validates that the attributes' values are not included in a given se
 <ruby>
 class Account < ActiveRecord::Base
   validates_exclusion_of :subdomain, :in => %w(www),
-    :message => "Subdomain {{value}} is reserved."
+    :message => "Subdomain %{value} is reserved."
 end
 </ruby>
 
@@ -262,7 +262,7 @@ This helper validates that the attributes' values are included in a given set. I
 <ruby>
 class Coffee < ActiveRecord::Base
   validates_inclusion_of :size, :in => %w(small medium large),
-    :message => "{{value}} is not a valid size"
+    :message => "%{value} is not a valid size"
 end
 </ruby>
 
@@ -290,12 +290,12 @@ The possible length constraint options are:
 * +:in+ (or +:within+) - The attribute length must be included in a given interval. The value for this option must be a range.
 * +:is+ - The attribute length must be equal to the given value.
 
-The default error messages depend on the type of length validation being performed. You can personalize these messages using the +:wrong_length+, +:too_long+, and +:too_short+ options and <tt>{{count}}</tt> as a placeholder for the number corresponding to the length constraint being used. You can still use the +:message+ option to specify an error message.
+The default error messages depend on the type of length validation being performed. You can personalize these messages using the +:wrong_length+, +:too_long+, and +:too_short+ options and <tt>%{count}</tt> as a placeholder for the number corresponding to the length constraint being used. You can still use the +:message+ option to specify an error message.
 
 <ruby>
 class Person < ActiveRecord::Base
   validates_length_of :bio, :maximum => 1000,
-    :too_long => "{{count}} characters is the maximum allowed"
+    :too_long => "%{count} characters is the maximum allowed"
 end
 </ruby>
 
@@ -307,8 +307,8 @@ class Essay < ActiveRecord::Base
     :minimum   => 300,
     :maximum   => 400,
     :tokenizer => lambda { |str| str.scan(/\w+/) },
-    :too_short => "must have at least {{count}} words",
-    :too_long  => "must have at most {{count}} words"
+    :too_short => "must have at least %{count} words",
+    :too_long  => "must have at most %{count} words"
 end
 </ruby>
 
@@ -337,11 +337,11 @@ end
 
 Besides +:only_integer+, the +validates_numericality_of+ helper also accepts the following options to add constraints to acceptable values:
 
-* +:greater_than+ - Specifies the value must be greater than the supplied value. The default error message for this option is "_must be greater than {{count}}_".
-* +:greater_than_or_equal_to+ - Specifies the value must be greater than or equal to the supplied value. The default error message for this option is "_must be greater than or equal to {{count}}_".
-* +:equal_to+ - Specifies the value must be equal to the supplied value. The default error message for this option is "_must be equal to {{count}}_".
-* +:less_than+ - Specifies the value must be less than the supplied value. The default error message for this option is "_must be less than {{count}}_".
-* +:less_than_or_equal_to+ - Specifies the value must be less than or equal the supplied value. The default error message for this option is "_must be less or equal to {{count}}_".
+* +:greater_than+ - Specifies the value must be greater than the supplied value. The default error message for this option is "_must be greater than %{count}_".
+* +:greater_than_or_equal_to+ - Specifies the value must be greater than or equal to the supplied value. The default error message for this option is "_must be greater than or equal to %{count}_".
+* +:equal_to+ - Specifies the value must be equal to the supplied value. The default error message for this option is "_must be equal to %{count}_".
+* +:less_than+ - Specifies the value must be less than the supplied value. The default error message for this option is "_must be less than %{count}_".
+* +:less_than_or_equal_to+ - Specifies the value must be less than or equal the supplied value. The default error message for this option is "_must be less or equal to %{count}_".
 * +:odd+ - Specifies the value must be an odd number if set to true. The default error message for this option is "_must be odd_".
 * +:even+ - Specifies the value must be an even number if set to true. The default error message for this option is "_must be even_".
 
@@ -469,7 +469,7 @@ The +:allow_nil+ option skips the validation when the value being validated is +
 <ruby>
 class Coffee < ActiveRecord::Base
   validates_inclusion_of :size, :in => %w(small medium large),
-    :message => "{{value}} is not a valid size", :allow_nil => true
+    :message => "%{value} is not a valid size", :allow_nil => true
 end
 </ruby>
 

railties/guides/source/i18n.textile

@@ -531,7 +531,7 @@ In many cases you want to abstract your translations so that *variables can be i
 All options besides +:default+ and +:scope+ that are passed to +#translate+ will be interpolated to the translation:
 
 <ruby>
-I18n.backend.store_translations :en, :thanks => 'Thanks {{name}}!'
+I18n.backend.store_translations :en, :thanks => 'Thanks %{name}!'
 I18n.translate :thanks, :name => 'Jeremy'
 # => 'Thanks Jeremy!'
 </ruby>
@@ -547,7 +547,7 @@ The +:count+ interpolation variable has a special role in that it both is interp
 <ruby>
 I18n.backend.store_translations :en, :inbox => {
   :one => '1 message',
-  :other => '{{count}} messages'
+  :other => '%{count} messages'
 }
 I18n.translate :inbox, :count => 2
 # => '2 messages'
@@ -711,7 +711,7 @@ h5. Error Message Interpolation
 
 The translated model name, translated attribute name, and value are always available for interpolation.
 
-So, for example, instead of the default error message +"can not be blank"+ you could use the attribute name like this : +"Please fill in your {{attribute}}"+.
+So, for example, instead of the default error message +"can not be blank"+ you could use the attribute name like this : +"Please fill in your %{attribute}"+.
 
 * +count+, where available, can be used for pluralization if present:
 
@@ -750,8 +750,8 @@ en:
     errors:
       template:
         header:
-          one:   "1 error prohibited this {{model}} from being saved"
-          other: "{{count}} errors prohibited this {{model}} from being saved"
+          one:   "1 error prohibited this %{model} from being saved"
+          other: "%{count} errors prohibited this %{model} from being saved"
         body:    "There were problems with the following fields:"
 </yaml>