Rails Lighthouse ticket #3768

0001-include-support-for-full_message-option-to-validatio.patch

From 67eb80e72d8d4782334aabf3b120adf6fdca5cda Mon Sep 17 00:00:00 2001
From: Rodrigo Rosenfeld Rosas <[email protected]>
Date: Thu, 25 Feb 2010 00:29:43 -0300
Subject: [PATCH] Include support for :full_message option to validations.

---
 activemodel/lib/active_model/errors.rb             |   54 +++++++++++++------
 .../lib/active_model/validations/acceptance.rb     |    2 +-
 .../lib/active_model/validations/confirmation.rb   |    2 +-
 .../lib/active_model/validations/exclusion.rb      |    2 +-
 activemodel/lib/active_model/validations/format.rb |    4 +-
 .../lib/active_model/validations/inclusion.rb      |    2 +-
 activemodel/lib/active_model/validations/length.rb |    2 +-
 .../lib/active_model/validations/numericality.rb   |    6 +-
 .../lib/active_model/validations/presence.rb       |    2 +-
 activemodel/lib/active_model/validator.rb          |    5 ++
 10 files changed, 53 insertions(+), 28 deletions(-)

diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index d832027..282e201 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -161,20 +161,52 @@ module ActiveModel
       end
     end
 
-    # Adds an error message (+messsage+) to the +attribute+, which will be returned on a call to <tt>on(attribute)</tt>
+    class ErrorMessage < String
+      attr_reader :options, :message
+      def initialize(options=nil)
+        if options.is_a? ErrorMessage
+          @options = options.options
+          return super(options.message)
+        end
+        @options = options.is_a?(Hash) ? options : {:message => options}
+        @message = @options[:full_message] || @options[:message]
+        super(@message.to_s) # in case of symbols...
+      end
+
+      def full_message?
+        !!options[:full_message] rescue false # options could be nil for ErrorMessage.new.sub, for instance
+      end
+    end
+
+    # Adds an error message (+message+) to the +attribute+, which will be returned on a call to <tt>on(attribute)</tt>
     # for the same attribute and ensure that this error object returns false when asked if <tt>empty?</tt>. More than one
     # error can be added to the same +attribute+ in which case an array will be returned on a call to <tt>on(attribute)</tt>.
-    # If no +messsage+ is supplied, :invalid is assumed.
-    # 
+    # If no +message+ is supplied, :invalid is assumed.
+    #
     # If +message+ is a Symbol, it will be translated, using the appropriate scope (see translate_error).
     # If +message+ is a Proc, it will be called, allowing for things like Time.now to be used within an error
     def add(attribute, message = nil, options = {})
       message ||= :invalid
+      full_message = (m=options[:default]).full_message? rescue false
+      options[:default] = m.message rescue m
       message = generate_message(attribute, message, options) if message.is_a?(Symbol)
       message = message.call if message.is_a?(Proc)
+      message = ErrorMessage.new :full_message => message if full_message
       self[attribute] << message
     end
 
+    def generate_full_message(attribute, predicate)
+      predicate = ErrorMessage.new(predicate) unless predicate.is_a? ErrorMessage
+      return (predicate.message.is_a?(Symbol) ? I18n.t(predicate.message) : predicate) if
+        attribute == :base or predicate.full_message?
+
+      attr_name = attribute.to_s.gsub('.', '_').humanize
+      attr_name = @base.class.human_attribute_name(attribute, :default => attr_name)
+      options = { :default => "{{attribute}} {{message}}", :attribute => attr_name }
+
+      I18n.t(:"errors.format", options.merge(:message => predicate))
+    end   
+    
     # Will add an error message to each of the attributes in +attributes+ that is empty.
     def add_on_empty(attributes, custom_message = nil)
       [attributes].flatten.each do |attribute|
@@ -206,20 +238,8 @@ module ActiveModel
       full_messages = []
 
       each do |attribute, messages|
-        messages = Array(messages)
-        next if messages.empty?
-
-        if attribute == :base
-          messages.each {|m| full_messages << m }
-        else
-          attr_name = attribute.to_s.gsub('.', '_').humanize
-          attr_name = @base.class.human_attribute_name(attribute, :default => attr_name)
-          options = { :default => "{{attribute}} {{message}}", :attribute => attr_name }
-
-          messages.each do |m|
-            full_messages << I18n.t(:"errors.format", options.merge(:message => m))
-          end
-        end
+        messages = Array.wrap(messages)
+        messages.each {|m| full_messages << generate_full_message(attribute, m)}
       end
 
       full_messages
diff --git a/activemodel/lib/active_model/validations/acceptance.rb b/activemodel/lib/active_model/validations/acceptance.rb
index 0423fcd..d02a9e3 100644
--- a/activemodel/lib/active_model/validations/acceptance.rb
+++ b/activemodel/lib/active_model/validations/acceptance.rb
@@ -7,7 +7,7 @@ module ActiveModel
 
       def validate_each(record, attribute, value)
         unless value == options[:accept]
-          record.errors.add(attribute, :accepted, :default => options[:message])
+          record.errors.add(attribute, :accepted, :default => message)
         end
       end
       
diff --git a/activemodel/lib/active_model/validations/confirmation.rb b/activemodel/lib/active_model/validations/confirmation.rb
index 8041d4b..37649ee 100644
--- a/activemodel/lib/active_model/validations/confirmation.rb
+++ b/activemodel/lib/active_model/validations/confirmation.rb
@@ -4,7 +4,7 @@ module ActiveModel
       def validate_each(record, attribute, value)
         confirmed = record.send(:"#{attribute}_confirmation")
         return if confirmed.nil? || value == confirmed
-        record.errors.add(attribute, :confirmation, :default => options[:message])
+        record.errors.add(attribute, :confirmation, :default => message)
       end
       
       def setup(klass)
diff --git a/activemodel/lib/active_model/validations/exclusion.rb b/activemodel/lib/active_model/validations/exclusion.rb
index 7ee718c..8bc2cf9 100644
--- a/activemodel/lib/active_model/validations/exclusion.rb
+++ b/activemodel/lib/active_model/validations/exclusion.rb
@@ -8,7 +8,7 @@ module ActiveModel
 
       def validate_each(record, attribute, value)
         return unless options[:in].include?(value)
-        record.errors.add(attribute, :exclusion, :default => options[:message], :value => value)
+        record.errors.add(attribute, :exclusion, :default => message, :value => value)
       end
     end
 
diff --git a/activemodel/lib/active_model/validations/format.rb b/activemodel/lib/active_model/validations/format.rb
index 9a9e7ec..f92d51b 100644
--- a/activemodel/lib/active_model/validations/format.rb
+++ b/activemodel/lib/active_model/validations/format.rb
@@ -3,9 +3,9 @@ module ActiveModel
     class FormatValidator < EachValidator
       def validate_each(record, attribute, value)
         if options[:with] && value.to_s !~ options[:with]
-          record.errors.add(attribute, :invalid, :default => options[:message], :value => value)
+          record.errors.add(attribute, :invalid, :default => message, :value => value)
         elsif options[:without] && value.to_s =~ options[:without]
-          record.errors.add(attribute, :invalid, :default => options[:message], :value => value)
+          record.errors.add(attribute, :invalid, :default => message, :value => value)
         end
       end
       
diff --git a/activemodel/lib/active_model/validations/inclusion.rb b/activemodel/lib/active_model/validations/inclusion.rb
index 0c1334f..f8bcf73 100644
--- a/activemodel/lib/active_model/validations/inclusion.rb
+++ b/activemodel/lib/active_model/validations/inclusion.rb
@@ -8,7 +8,7 @@ module ActiveModel
 
       def validate_each(record, attribute, value)
         return if options[:in].include?(value)
-        record.errors.add(attribute, :inclusion, :default => options[:message], :value => value)
+        record.errors.add(attribute, :inclusion, :default => message, :value => value)
       end
     end
 
diff --git a/activemodel/lib/active_model/validations/length.rb b/activemodel/lib/active_model/validations/length.rb
index 9ceb754..c7ea251 100644
--- a/activemodel/lib/active_model/validations/length.rb
+++ b/activemodel/lib/active_model/validations/length.rb
@@ -37,7 +37,7 @@ module ActiveModel
 
         CHECKS.each do |key, validity_check|
           next unless check_value = options[key]
-          custom_message = options[:message] || options[MESSAGES[key]]
+          custom_message = message || options[MESSAGES[key]]
 
           valid_value = if key == :maximum
             value.nil? || value.size.send(validity_check, check_value)
diff --git a/activemodel/lib/active_model/validations/numericality.rb b/activemodel/lib/active_model/validations/numericality.rb
index c6d84c5..95e71b8 100644
--- a/activemodel/lib/active_model/validations/numericality.rb
+++ b/activemodel/lib/active_model/validations/numericality.rb
@@ -26,7 +26,7 @@ module ActiveModel
         return if options[:allow_nil] && raw_value.nil?
 
         unless value = parse_raw_value(raw_value, options)
-          record.errors.add(attr_name, :not_a_number, :value => raw_value, :default => options[:message])
+          record.errors.add(attr_name, :not_a_number, :value => raw_value, :default => message)
           return
         end
 
@@ -34,14 +34,14 @@ module ActiveModel
           case option
           when :odd, :even
             unless value.to_i.send(CHECKS[option])
-              record.errors.add(attr_name, option, :value => value, :default => options[:message])
+              record.errors.add(attr_name, option, :value => value, :default => message)
             end
           else
             option_value = option_value.call(record) if option_value.is_a?(Proc)
             option_value = record.send(option_value) if option_value.is_a?(Symbol)
 
             unless value.send(CHECKS[option], option_value)
-              record.errors.add(attr_name, option, :default => options[:message], :value => value, :count => option_value)
+              record.errors.add(attr_name, option, :default => message, :value => value, :count => option_value)
             end
           end
         end      
diff --git a/activemodel/lib/active_model/validations/presence.rb b/activemodel/lib/active_model/validations/presence.rb
index 4a71cf7..3f4a846 100644
--- a/activemodel/lib/active_model/validations/presence.rb
+++ b/activemodel/lib/active_model/validations/presence.rb
@@ -4,7 +4,7 @@ module ActiveModel
   module Validations
     class PresenceValidator < EachValidator
       def validate(record)
-        record.errors.add_on_blank(attributes, options[:message])
+        record.errors.add_on_blank(attributes, message)
       end
     end
 
diff --git a/activemodel/lib/active_model/validator.rb b/activemodel/lib/active_model/validator.rb
index b61f0cb..48413b8 100644
--- a/activemodel/lib/active_model/validator.rb
+++ b/activemodel/lib/active_model/validator.rb
@@ -158,6 +158,11 @@ module ActiveModel #:nodoc:
     # ArgumentError when invalid options are supplied.
     def check_validity!
     end
+
+    def message
+      return nil unless options[:full_message] || options[:message]
+      @message ||= Errors::ErrorMessage.new(options)
+    end    
   end
 
   # BlockValidator is a special EachValidator which receives a block on initialization
-- 
1.7.0

add-full_messsage.patch

diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 1431228..a2c2554 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -170,6 +170,20 @@ module ActiveModel
       self
     end
 
+    # Represents an error message. Contains the model instance (+base+), the +attribute+ and the +options+
+    # passed to validators.
+    class ErrorMessage < String
+      attr_reader :base, :attribute, :options
+      def initialize(message, base, attribute, options)
+        super(message)
+        @base, @attribute, @options = base, attribute, options
+      end
+
+      def full_message?
+        @full_message ||= options.include? :full_message
+      end
+    end
+
     # Adds +message+ to the error messages on +attribute+, which will be returned on a call to
     # <tt>on(attribute)</tt> for the same attribute. More than one error can be added to the same
     # +attribute+ in which case an array will be returned on a call to <tt>on(attribute)</tt>.
@@ -180,12 +194,17 @@ module ActiveModel
     def add(attribute, message = nil, options = {})
       message ||= :invalid
 
+      fm = options[:full_message]
+      opts = fm ? options.merge(:message => fm) : options
+      opts.delete(:full_message) if fm
+
       if message.is_a?(Symbol)
-        message = generate_message(attribute, message, options.except(*CALLBACKS_OPTIONS))
+        message = generate_message(attribute, message, opts.except(*CALLBACKS_OPTIONS))
       elsif message.is_a?(Proc)
         message = message.call
       end
 
+      message = ErrorMessage.new(message, @base, attribute, options) if message
       self[attribute] << message
     end
 
@@ -245,7 +264,8 @@ module ActiveModel
           options = { :default => "%{attribute} %{message}", :attribute => attr_name }
 
           messages.each do |m|
-            full_messages << I18n.t(:"errors.format", options.merge(:message => m))
+            full_messages << ((m.respond_to?(:full_message?) && m.full_message?) ?
+              m : I18n.t(:"errors.format", options.merge(:message => m)))
           end
         end
       end

add_full_message_support.diff

diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index d832027..7a292d3 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -161,34 +161,58 @@ module ActiveModel
       end
     end
 
-    # Adds an error message (+messsage+) to the +attribute+, which will be returned on a call to <tt>on(attribute)</tt>
+    class FullErrorMessage < String
+      attr_reader :message
+      def initialize(message)
+        super((@message = message).to_s) # in case of symbols...
+      end
+
+      def full_message?
+        true
+      end
+    end
+
+    # Adds an error message (+message+) to the +attribute+, which will be returned on a call to <tt>on(attribute)</tt>
     # for the same attribute and ensure that this error object returns false when asked if <tt>empty?</tt>. More than one
     # error can be added to the same +attribute+ in which case an array will be returned on a call to <tt>on(attribute)</tt>.
-    # If no +messsage+ is supplied, :invalid is assumed.
-    # 
+    # If no +message+ is supplied, :invalid is assumed. Pass +:full_message => true+ in the options for specifying
+    # it is the full message, so that the attribute is not prepended in <tt>full_messages</tt>.
+    #
     # If +message+ is a Symbol, it will be translated, using the appropriate scope (see translate_error).
     # If +message+ is a Proc, it will be called, allowing for things like Time.now to be used within an error
     def add(attribute, message = nil, options = {})
       message ||= :invalid
       message = generate_message(attribute, message, options) if message.is_a?(Symbol)
       message = message.call if message.is_a?(Proc)
+      message = FullErrorMessage.new message if options[:full_message]
       self[attribute] << message
     end
 
+    def generate_full_message(attribute, message)
+      message = message.message if message.respond_to? :message
+      return (message.is_a?(Symbol) ? I18n.t(message) : message) if attribute == :base or (predicate.full_message? rescue false)
+
+      attr_name = attribute.to_s.gsub('.', '_').humanize
+      attr_name = @base.class.human_attribute_name(attribute, :default => attr_name)
+      options = { :default => "{{attribute}} {{message}}", :attribute => attr_name }
+
+      I18n.t(:"errors.format", options.merge(:message => message))
+    end   
+    
     # Will add an error message to each of the attributes in +attributes+ that is empty.
-    def add_on_empty(attributes, custom_message = nil)
+    def add_on_empty(attributes, custom_message = nil, options = {})
       [attributes].flatten.each do |attribute|
         value = @base.send(:read_attribute_for_validation, attribute)
         is_empty = value.respond_to?(:empty?) ? value.empty? : false
-        add(attribute, :empty, :default => custom_message) unless !value.nil? && !is_empty
+        add(attribute, :empty, options.merge(:default => custom_message)) unless !value.nil? && !is_empty
       end
     end
 
     # Will add an error message to each of the attributes in +attributes+ that is blank (using Object#blank?).
-    def add_on_blank(attributes, custom_message = nil)
+    def add_on_blank(attributes, custom_message = nil, options = {})
       [attributes].flatten.each do |attribute|
         value = @base.send(:read_attribute_for_validation, attribute)
-        add(attribute, :blank, :default => custom_message) if value.blank?
+        add(attribute, :blank, options.merge(:default => custom_message)) if value.blank?
       end
     end
 
@@ -206,20 +230,8 @@ module ActiveModel
       full_messages = []
 
       each do |attribute, messages|
-        messages = Array(messages)
-        next if messages.empty?
-
-        if attribute == :base
-          messages.each {|m| full_messages << m }
-        else
-          attr_name = attribute.to_s.gsub('.', '_').humanize
-          attr_name = @base.class.human_attribute_name(attribute, :default => attr_name)
-          options = { :default => "{{attribute}} {{message}}", :attribute => attr_name }
-
-          messages.each do |m|
-            full_messages << I18n.t(:"errors.format", options.merge(:message => m))
-          end
-        end
+        messages = Array.wrap(messages)
+        messages.each {|m| full_messages << generate_full_message(attribute, m)}
       end
 
       full_messages
diff --git a/activemodel/lib/active_model/validations/acceptance.rb b/activemodel/lib/active_model/validations/acceptance.rb
index 0423fcd..dcb8ef5 100644
--- a/activemodel/lib/active_model/validations/acceptance.rb
+++ b/activemodel/lib/active_model/validations/acceptance.rb
@@ -7,7 +7,7 @@ module ActiveModel
 
       def validate_each(record, attribute, value)
         unless value == options[:accept]
-          record.errors.add(attribute, :accepted, :default => options[:message])
+          add_error(record, attribute, :accepted)
         end
       end
       
diff --git a/activemodel/lib/active_model/validations/confirmation.rb b/activemodel/lib/active_model/validations/confirmation.rb
index 8041d4b..aa170f3 100644
--- a/activemodel/lib/active_model/validations/confirmation.rb
+++ b/activemodel/lib/active_model/validations/confirmation.rb
@@ -4,7 +4,7 @@ module ActiveModel
       def validate_each(record, attribute, value)
         confirmed = record.send(:"#{attribute}_confirmation")
         return if confirmed.nil? || value == confirmed
-        record.errors.add(attribute, :confirmation, :default => options[:message])
+        add_error(record, attribute, :confirmation)
       end
       
       def setup(klass)
diff --git a/activemodel/lib/active_model/validations/exclusion.rb b/activemodel/lib/active_model/validations/exclusion.rb
index 7ee718c..ebb67d8 100644
--- a/activemodel/lib/active_model/validations/exclusion.rb
+++ b/activemodel/lib/active_model/validations/exclusion.rb
@@ -8,7 +8,7 @@ module ActiveModel
 
       def validate_each(record, attribute, value)
         return unless options[:in].include?(value)
-        record.errors.add(attribute, :exclusion, :default => options[:message], :value => value)
+        add_error(record, attribute, :exclusion, :value => value)
       end
     end
 
diff --git a/activemodel/lib/active_model/validations/format.rb b/activemodel/lib/active_model/validations/format.rb
index 9a9e7ec..b8dc3ff 100644
--- a/activemodel/lib/active_model/validations/format.rb
+++ b/activemodel/lib/active_model/validations/format.rb
@@ -2,11 +2,8 @@ module ActiveModel
   module Validations
     class FormatValidator < EachValidator
       def validate_each(record, attribute, value)
-        if options[:with] && value.to_s !~ options[:with]
-          record.errors.add(attribute, :invalid, :default => options[:message], :value => value)
-        elsif options[:without] && value.to_s =~ options[:without]
-          record.errors.add(attribute, :invalid, :default => options[:message], :value => value)
-        end
+        add_error(record, attribute, :invalid, :value => value) if
+          (options[:with] && value.to_s !~ options[:with]) or (options[:without] && value.to_s =~ options[:without])
       end
       
       def check_validity!
diff --git a/activemodel/lib/active_model/validations/inclusion.rb b/activemodel/lib/active_model/validations/inclusion.rb
index 0c1334f..9f19d36 100644
--- a/activemodel/lib/active_model/validations/inclusion.rb
+++ b/activemodel/lib/active_model/validations/inclusion.rb
@@ -8,7 +8,7 @@ module ActiveModel
 
       def validate_each(record, attribute, value)
         return if options[:in].include?(value)
-        record.errors.add(attribute, :inclusion, :default => options[:message], :value => value)
+        add_error(record, attribute, :inclusion, :value => value)
       end
     end
 
diff --git a/activemodel/lib/active_model/validations/length.rb b/activemodel/lib/active_model/validations/length.rb
index 9ceb754..cdbae7f 100644
--- a/activemodel/lib/active_model/validations/length.rb
+++ b/activemodel/lib/active_model/validations/length.rb
@@ -37,7 +37,7 @@ module ActiveModel
 
         CHECKS.each do |key, validity_check|
           next unless check_value = options[key]
-          custom_message = options[:message] || options[MESSAGES[key]]
+          custom_message = message || options[MESSAGES[key]]
 
           valid_value = if key == :maximum
             value.nil? || value.size.send(validity_check, check_value)
@@ -46,7 +46,7 @@ module ActiveModel
           end
 
           next if valid_value
-          record.errors.add(attribute, MESSAGES[key], :default => custom_message, :count => check_value)
+          add_error(record, attribute, MESSAGES[key], :default => custom_message, :count => check_value)
         end
       end
     end
diff --git a/activemodel/lib/active_model/validations/numericality.rb b/activemodel/lib/active_model/validations/numericality.rb
index c6d84c5..99448b3 100644
--- a/activemodel/lib/active_model/validations/numericality.rb
+++ b/activemodel/lib/active_model/validations/numericality.rb
@@ -26,7 +26,7 @@ module ActiveModel
         return if options[:allow_nil] && raw_value.nil?
 
         unless value = parse_raw_value(raw_value, options)
-          record.errors.add(attr_name, :not_a_number, :value => raw_value, :default => options[:message])
+          add_error(record, attr_name, :not_a_number, :value => raw_value)
           return
         end
 
@@ -34,14 +34,14 @@ module ActiveModel
           case option
           when :odd, :even
             unless value.to_i.send(CHECKS[option])
-              record.errors.add(attr_name, option, :value => value, :default => options[:message])
+              add_error(record, attr_name, option, :value => value)
             end
           else
             option_value = option_value.call(record) if option_value.is_a?(Proc)
             option_value = record.send(option_value) if option_value.is_a?(Symbol)
 
             unless value.send(CHECKS[option], option_value)
-              record.errors.add(attr_name, option, :default => options[:message], :value => value, :count => option_value)
+              add_error(record, attr_name, option, :value => value, :count => option_value)
             end
           end
         end      
diff --git a/activemodel/lib/active_model/validations/presence.rb b/activemodel/lib/active_model/validations/presence.rb
index 4a71cf7..624c88e 100644
--- a/activemodel/lib/active_model/validations/presence.rb
+++ b/activemodel/lib/active_model/validations/presence.rb
@@ -4,7 +4,7 @@ module ActiveModel
   module Validations
     class PresenceValidator < EachValidator
       def validate(record)
-        record.errors.add_on_blank(attributes, options[:message])
+        add_on_blank_error record
       end
     end
 
diff --git a/activemodel/lib/active_model/validator.rb b/activemodel/lib/active_model/validator.rb
index b61f0cb..57452de 100644
--- a/activemodel/lib/active_model/validator.rb
+++ b/activemodel/lib/active_model/validator.rb
@@ -158,6 +158,21 @@ module ActiveModel #:nodoc:
     # ArgumentError when invalid options are supplied.
     def check_validity!
     end
+
+    def message
+      options[:full_message] || options[:message]
+    end
+
+    def add_error(record, attribute, error_message, error_options={})
+      opts = {:default => message}
+      opts.merge! :full_message => !!options[:full_message] if options[:full_message]
+      record.errors.add(attribute, error_message, opts.merge(error_options))
+    end
+
+    def add_on_blank_error(record)
+      opts = options[:full_message] ? {:full_message => true} : {}
+      record.errors.add_on_blank attributes, message, opts
+    end
   end
 
   # BlockValidator is a special EachValidator which receives a block on initialization

full_message-v10.patch

diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 1431228..96015d8 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -170,6 +170,16 @@ module ActiveModel
       self
     end
 
+    # Represents a full error message
+    class ErrorMessage < String
+      attr_reader :full_message
+      
+      def initialize(message, full_message)
+        super(message || full_message)
+        @full_message = full_message
+      end
+    end
+
     # Adds +message+ to the error messages on +attribute+, which will be returned on a call to
     # <tt>on(attribute)</tt> for the same attribute. More than one error can be added to the same
     # +attribute+ in which case an array will be returned on a call to <tt>on(attribute)</tt>.
@@ -178,15 +188,19 @@ module ActiveModel
     # If +message+ is a symbol, it will be translated using the appropriate scope (see +translate_error+).
     # If +message+ is a proc, it will be called, allowing for things like <tt>Time.now</tt> to be used within an error.
     def add(attribute, message = nil, options = {})
-      message ||= :invalid
-
-      if message.is_a?(Symbol)
-        message = generate_message(attribute, message, options.except(*CALLBACKS_OPTIONS))
-      elsif message.is_a?(Proc)
-        message = message.call
+      messages = {:message => message || :invalid, :full_message => options[:full_message]}
+      options = options.except(*CALLBACKS_OPTIONS)
+
+      messages.each do |type, message|
+        if message.is_a? Symbol
+          messages[type] = generate_message(attribute, message, options)
+        elsif message.is_a? Proc
+          messages[type] = message.call
+        end
       end
 
-      self[attribute] << message
+      self[attribute] << (!messages[:full_message] ? messages[:message] :
+        ErrorMessage.new(messages[:message], messages[:full_message]))
     end
 
     # Will add an error message to each of the attributes in +attributes+ that is empty.
@@ -245,7 +259,8 @@ module ActiveModel
           options = { :default => "%{attribute} %{message}", :attribute => attr_name }
 
           messages.each do |m|
-            full_messages << I18n.t(:"errors.format", options.merge(:message => m))
+            full_messages << ((m.respond_to?(:full_message) && m.full_message) ?
+              m.full_message : I18n.t(:"errors.format", options.merge(:message => m)))
           end
         end
       end
@@ -280,6 +295,7 @@ module ActiveModel
     # </ol>
     def generate_message(attribute, type = :invalid, options = {})
       type = options.delete(:message) if options[:message].is_a?(Symbol)
+      full_message = options.delete(:full_message)
 
       if options[:default]
         ActiveSupport::Deprecation.warn \
@@ -296,7 +312,7 @@ module ActiveModel
       defaults << options.delete(:message)
       defaults << :"#{@base.class.i18n_scope}.errors.messages.#{type}"
       defaults << :"errors.attributes.#{attribute}.#{type}"
-      defaults << :"errors.messages.#{type}"
+      defaults << :"errors.#{full_message ? 'full_' : ''}messages.#{type}"
 
       defaults.compact!
       defaults.flatten!

full_message-v11.patch

diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 1431228..efc7eb5 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -170,23 +170,58 @@ module ActiveModel
       self
     end
 
+    # Represents a full error message. The full_message is available in <tt>full_message</tt>
+    # and <tt>to_s</tt> returns the +message+ given to constructor, or +full_message+ if +message+ is nil.
+    class ErrorMessage < String
+      attr_reader :full_message
+      
+      def initialize(message, full_message)
+        super(message || full_message)
+        @full_message = full_message
+      end
+    end
+
     # Adds +message+ to the error messages on +attribute+, which will be returned on a call to
     # <tt>on(attribute)</tt> for the same attribute. More than one error can be added to the same
     # +attribute+ in which case an array will be returned on a call to <tt>on(attribute)</tt>.
     # If no +message+ is supplied, <tt>:invalid</tt> is assumed.
     #
+    # If a <tt>:full_message</tt> option is specified, an ErrorMessage instance will be added to errors,
+    # which will be processed by <tt>full_messages</tt> as a full message (no concatenation with attribute names).
+    #
     # If +message+ is a symbol, it will be translated using the appropriate scope (see +translate_error+).
-    # If +message+ is a proc, it will be called, allowing for things like <tt>Time.now</tt> to be used within an error.
+    # If +message+ or +options[:message/:full_message]+ is a proc, it will be called with optional parameters,
+    # depending on proc arity, in the following order: instance (@base), +attribute+, +options+.
     def add(attribute, message = nil, options = {})
       message ||= :invalid
+      proc_args = [@base, attribute, options]
 
-      if message.is_a?(Symbol)
-        message = generate_message(attribute, message, options.except(*CALLBACKS_OPTIONS))
-      elsif message.is_a?(Proc)
-        message = message.call
+      if message.is_a? Proc
+        options = options.merge(:message => message)
+        ActiveSupport::Deprecation.warn \
+          "ActiveModel::Errors#add(attributes, proc, options) has been deprecated.\n" +
+          "Instead of passing the proc to message, add it to options[:message] or options[:full_message] instead."
+      end
+
+      message_options = options.except(:full_message, *CALLBACKS_OPTIONS)
+      messages = {}.tap{|m| m.merge! :message => message unless message.is_a? Symbol}
+      [:message, :full_message].each do |key|
+        messages[key] ||= options[key]
+        if (msg_proc = messages[key]).is_a?(Proc)
+          messages[key] = case msg_proc.arity
+            when  0: msg_proc.call
+            when -1: msg_proc.call(*proc_args)
+            else msg_proc.call(*proc_args[0..msg_proc.arity-1])
+          end
+        elsif message.is_a?(Symbol) && ((key == :message) || messages[:full_message])
+          opts = message_options
+          opts.merge! :message => messages[key] if messages[key]
+          messages[key] = generate_message attribute, message, opts #, key (temporarily disabled, to avoid changing the tests for now)
+        end
       end
 
-      self[attribute] << message
+      self[attribute] << (!messages[:full_message] ? messages[:message] :
+        ErrorMessage.new(messages[:message], messages[:full_message]))
     end
 
     # Will add an error message to each of the attributes in +attributes+ that is empty.
@@ -224,12 +259,12 @@ module ActiveModel
     #
     #   class Company
     #     validates_presence_of :name, :address, :email
-    #     validates_length_of :name, :in => 5..30
+    #     validates_length_of :name, :in => 5..30, :full_message => 'You should specify a name between 5 and 30 characters'
     #   end
     #
     #   company = Company.create(:address => '123 First St.')
     #   company.errors.full_messages # =>
-    #     ["Name is too short (minimum is 5 characters)", "Name can't be blank", "Address can't be blank"]
+    #     ["You should specify a name between 5 and 30 characters", "Name can't be blank", "Address can't be blank"]
     def full_messages
       full_messages = []
 
@@ -245,7 +280,8 @@ module ActiveModel
           options = { :default => "%{attribute} %{message}", :attribute => attr_name }
 
           messages.each do |m|
-            full_messages << I18n.t(:"errors.format", options.merge(:message => m))
+            full_messages << ((m.respond_to?(:full_message) && m.full_message) ?
+              m.full_message : I18n.t(:"errors.format", options.merge(:message => m)))
           end
         end
       end
@@ -259,8 +295,9 @@ module ActiveModel
     # Error messages are first looked up in <tt>models.MODEL.attributes.ATTRIBUTE.MESSAGE</tt>,
     # if it's not there, it's looked up in <tt>models.MODEL.MESSAGE</tt> and if that is not
     # there also, it returns the translation of the default message
-    # (e.g. <tt>activemodel.errors.messages.MESSAGE</tt>). The translated model name,
-    # translated attribute name and the value are available for interpolation.
+    # (e.g. <tt>activemodel.errors.messages.MESSAGE</tt> or <tt>activemodel.errors.full_messages.MESSAGE</tt>,
+    # depending on the +translation_key+ param, which should be :message or :full_message).
+    # The translated model name, translated attribute name and the value are available for interpolation.
     #
     # When using inheritance in your models, it will check all the inherited
     # models too, but only if the model itself hasn't been found. Say you have
@@ -278,7 +315,7 @@ module ActiveModel
     # <li><tt>errors.attributes.title.blank</tt></li>
     # <li><tt>errors.messages.blank</tt></li>
     # </ol>
-    def generate_message(attribute, type = :invalid, options = {})
+    def generate_message(attribute, type = :invalid, options = {}, translation_key = :message)
       type = options.delete(:message) if options[:message].is_a?(Symbol)
 
       if options[:default]
@@ -296,7 +333,7 @@ module ActiveModel
       defaults << options.delete(:message)
       defaults << :"#{@base.class.i18n_scope}.errors.messages.#{type}"
       defaults << :"errors.attributes.#{attribute}.#{type}"
-      defaults << :"errors.messages.#{type}"
+      defaults << :"errors.#{translation_key}s.#{type}"
 
       defaults.compact!
       defaults.flatten!

full_message-v3.patch

diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 1431228..e2277fc 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -170,6 +170,17 @@ module ActiveModel
       self
     end
 
+    # Represents an error message. Contains the model instance (+base+), the +attribute+ and the +options+
+    # passed to validators.
+    class ErrorMessage < String
+      attr_reader :full_message
+      
+      def initialize(message, full_message)
+        super(message || full_message)
+        @full_message = full_message
+      end
+    end
+
     # Adds +message+ to the error messages on +attribute+, which will be returned on a call to
     # <tt>on(attribute)</tt> for the same attribute. More than one error can be added to the same
     # +attribute+ in which case an array will be returned on a call to <tt>on(attribute)</tt>.
@@ -179,13 +190,17 @@ module ActiveModel
     # If +message+ is a proc, it will be called, allowing for things like <tt>Time.now</tt> to be used within an error.
     def add(attribute, message = nil, options = {})
       message ||= :invalid
+      full_message = options[:full_message]
 
       if message.is_a?(Symbol)
-        message = generate_message(attribute, message, options.except(*CALLBACKS_OPTIONS))
+        options = options.except(*CALLBACKS_OPTIONS)
+        options[:message] = options.delete(:full_message) if full_message
+        message = generate_message(attribute, message, options)
       elsif message.is_a?(Proc)
         message = message.call
       end
 
+      message = ErrorMessage.new(message, full_message) if message && full_message
       self[attribute] << message
     end
 
@@ -245,7 +260,8 @@ module ActiveModel
           options = { :default => "%{attribute} %{message}", :attribute => attr_name }
 
           messages.each do |m|
-            full_messages << I18n.t(:"errors.format", options.merge(:message => m))
+            full_messages << ((m.respond_to?(:full_message) && m.full_message) ?
+              m : I18n.t(:"errors.format", options.merge(:message => m)))
           end
         end
       end

full_message-v4.patch

diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 1431228..8c71a5a 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -170,6 +170,17 @@ module ActiveModel
       self
     end
 
+    # Represents an error message. Contains the model instance (+base+), the +attribute+ and the +options+
+    # passed to validators.
+    class ErrorMessage < String
+      attr_reader :full_message
+      
+      def initialize(message, full_message)
+        super(message || full_message)
+        @full_message = full_message
+      end
+    end
+
     # Adds +message+ to the error messages on +attribute+, which will be returned on a call to
     # <tt>on(attribute)</tt> for the same attribute. More than one error can be added to the same
     # +attribute+ in which case an array will be returned on a call to <tt>on(attribute)</tt>.
@@ -179,13 +190,18 @@ module ActiveModel
     # If +message+ is a proc, it will be called, allowing for things like <tt>Time.now</tt> to be used within an error.
     def add(attribute, message = nil, options = {})
       message ||= :invalid
-
+      full_message = options[:full_message]
+      message = full_message if full_message.is_a? Proc
+      
       if message.is_a?(Symbol)
-        message = generate_message(attribute, message, options.except(*CALLBACKS_OPTIONS))
+        options = options.except(*CALLBACKS_OPTIONS)
+        options[:message] = options.delete(:full_message) if full_message
+        message = generate_message(attribute, message, options)
       elsif message.is_a?(Proc)
         message = message.call
       end
 
+      message = ErrorMessage.new(message, full_message) if message && full_message
       self[attribute] << message
     end
 
@@ -245,7 +261,8 @@ module ActiveModel
           options = { :default => "%{attribute} %{message}", :attribute => attr_name }
 
           messages.each do |m|
-            full_messages << I18n.t(:"errors.format", options.merge(:message => m))
+            full_messages << ((m.respond_to?(:full_message) && m.full_message) ?
+              m : I18n.t(:"errors.format", options.merge(:message => m)))
           end
         end
       end

full_message-v5.patch

diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 1431228..ecedd79 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -170,6 +170,17 @@ module ActiveModel
       self
     end
 
+    # Represents an error message. Contains the model instance (+base+), the +attribute+ and the +options+
+    # passed to validators.
+    class ErrorMessage < String
+      attr_reader :full_message
+      
+      def initialize(message, full_message)
+        super(message || full_message)
+        @full_message = full_message
+      end
+    end
+
     # Adds +message+ to the error messages on +attribute+, which will be returned on a call to
     # <tt>on(attribute)</tt> for the same attribute. More than one error can be added to the same
     # +attribute+ in which case an array will be returned on a call to <tt>on(attribute)</tt>.
@@ -180,12 +191,19 @@ module ActiveModel
     def add(attribute, message = nil, options = {})
       message ||= :invalid
 
+      full_message = options[:full_message]
+      message = full_message if full_message.is_a? Proc
+      
       if message.is_a?(Symbol)
-        message = generate_message(attribute, message, options.except(*CALLBACKS_OPTIONS))
+        options = options.except(*(CALLBACKS_OPTIONS + [:full_message]))
+        full_message = generate_message(attribute, message, options.merge(:message => full_message)) if full_message
+        message = generate_message(attribute, message, options)
       elsif message.is_a?(Proc)
         message = message.call
+        full_message = message if full_message
       end
 
+      message = ErrorMessage.new(message, full_message) if (message && full_message)
       self[attribute] << message
     end
 
@@ -245,7 +263,8 @@ module ActiveModel
           options = { :default => "%{attribute} %{message}", :attribute => attr_name }
 
           messages.each do |m|
-            full_messages << I18n.t(:"errors.format", options.merge(:message => m))
+            full_messages << ((m.respond_to?(:full_message) && m.full_message) ?
+              m.full_message : I18n.t(:"errors.format", options.merge(:message => m)))
           end
         end
       end

full_message-v6.patch

diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 1431228..abcf15c 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -170,6 +170,17 @@ module ActiveModel
       self
     end
 
+    # Represents an error message. Contains the model instance (+base+), the +attribute+ and the +options+
+    # passed to validators.
+    class ErrorMessage < String
+      attr_reader :full_message
+      
+      def initialize(message, full_message)
+        super(message || full_message)
+        @full_message = full_message
+      end
+    end
+
     # Adds +message+ to the error messages on +attribute+, which will be returned on a call to
     # <tt>on(attribute)</tt> for the same attribute. More than one error can be added to the same
     # +attribute+ in which case an array will be returned on a call to <tt>on(attribute)</tt>.
@@ -180,12 +191,17 @@ module ActiveModel
     def add(attribute, message = nil, options = {})
       message ||= :invalid
 
+      full_message = options[:full_message]
+      message = full_message if full_message.is_a? Proc
+      
       if message.is_a?(Symbol)
-        message = generate_message(attribute, message, options.except(*CALLBACKS_OPTIONS))
+        message = generate_message(attribute, message, options.except(*(CALLBACKS_OPTIONS + [:full_message])))
       elsif message.is_a?(Proc)
         message = message.call
+        full_message &&= message
       end
 
+      message &&= ErrorMessage.new(message, full_message) if full_message
       self[attribute] << message
     end
 
@@ -245,7 +261,8 @@ module ActiveModel
           options = { :default => "%{attribute} %{message}", :attribute => attr_name }
 
           messages.each do |m|
-            full_messages << I18n.t(:"errors.format", options.merge(:message => m))
+            full_messages << ((m.respond_to?(:full_message) && m.full_message) ?
+              m.full_message : I18n.t(:"errors.format", options.merge(:message => m)))
           end
         end
       end

full_message-v7.patch

diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 1431228..46b6a15 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -170,6 +170,17 @@ module ActiveModel
       self
     end
 
+    # Represents an error message. Contains the model instance (+base+), the +attribute+ and the +options+
+    # passed to validators.
+    class ErrorMessage < String
+      attr_reader :full_message
+      
+      def initialize(message, full_message)
+        super(message || full_message)
+        @full_message = full_message
+      end
+    end
+
     # Adds +message+ to the error messages on +attribute+, which will be returned on a call to
     # <tt>on(attribute)</tt> for the same attribute. More than one error can be added to the same
     # +attribute+ in which case an array will be returned on a call to <tt>on(attribute)</tt>.
@@ -180,12 +191,17 @@ module ActiveModel
     def add(attribute, message = nil, options = {})
       message ||= :invalid
 
+      full_message = options[:full_message]
+      message = full_message if full_message.is_a? Proc
+      
       if message.is_a?(Symbol)
-        message = generate_message(attribute, message, options.except(*CALLBACKS_OPTIONS))
+        message = generate_message(attribute, message, options.except(:full_message, *CALLBACKS_OPTIONS))
       elsif message.is_a?(Proc)
         message = message.call
+        full_message &&= message
       end
 
+      message &&= ErrorMessage.new(message, full_message) if full_message
       self[attribute] << message
     end
 
@@ -245,7 +261,8 @@ module ActiveModel
           options = { :default => "%{attribute} %{message}", :attribute => attr_name }
 
           messages.each do |m|
-            full_messages << I18n.t(:"errors.format", options.merge(:message => m))
+            full_messages << ((m.respond_to?(:full_message) && m.full_message) ?
+              m.full_message : I18n.t(:"errors.format", options.merge(:message => m)))
           end
         end
       end

full_message-v8.patch

diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 1431228..304a010 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -170,6 +170,16 @@ module ActiveModel
       self
     end
 
+    # Represents a full error message
+    class ErrorMessage < String
+      attr_reader :full_message
+      
+      def initialize(message, full_message)
+        super(message || full_message)
+        @full_message = full_message
+      end
+    end
+
     # Adds +message+ to the error messages on +attribute+, which will be returned on a call to
     # <tt>on(attribute)</tt> for the same attribute. More than one error can be added to the same
     # +attribute+ in which case an array will be returned on a call to <tt>on(attribute)</tt>.
@@ -180,12 +190,17 @@ module ActiveModel
     def add(attribute, message = nil, options = {})
       message ||= :invalid
 
+      full_message = options[:full_message]
+      message = full_message if full_message.is_a? Proc
+      
       if message.is_a?(Symbol)
-        message = generate_message(attribute, message, options.except(*CALLBACKS_OPTIONS))
+        message = generate_message(attribute, message, options.except(:full_message, *CALLBACKS_OPTIONS))
       elsif message.is_a?(Proc)
         message = message.call
+        full_message &&= message
       end
 
+      message &&= ErrorMessage.new(message, full_message) if full_message
       self[attribute] << message
     end
 
@@ -245,7 +260,8 @@ module ActiveModel
           options = { :default => "%{attribute} %{message}", :attribute => attr_name }
 
           messages.each do |m|
-            full_messages << I18n.t(:"errors.format", options.merge(:message => m))
+            full_messages << ((m.respond_to?(:full_message) && m.full_message) ?
+              m.full_message : I18n.t(:"errors.format", options.merge(:message => m)))
           end
         end
       end

full_message-v9.patch

diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 1431228..d76fd2e 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -170,6 +170,16 @@ module ActiveModel
       self
     end
 
+    # Represents a full error message
+    class ErrorMessage < String
+      attr_reader :full_message
+      
+      def initialize(message, full_message)
+        super(message || full_message)
+        @full_message = full_message
+      end
+    end
+
     # Adds +message+ to the error messages on +attribute+, which will be returned on a call to
     # <tt>on(attribute)</tt> for the same attribute. More than one error can be added to the same
     # +attribute+ in which case an array will be returned on a call to <tt>on(attribute)</tt>.
@@ -180,12 +190,17 @@ module ActiveModel
     def add(attribute, message = nil, options = {})
       message ||= :invalid
 
+      full_message = options[:full_message]
+      message = full_message if full_message.is_a? Proc
+      
       if message.is_a?(Symbol)
         message = generate_message(attribute, message, options.except(*CALLBACKS_OPTIONS))
       elsif message.is_a?(Proc)
         message = message.call
+        full_message &&= message
       end
 
+      message &&= ErrorMessage.new(message, full_message) if full_message
       self[attribute] << message
     end
 
@@ -245,7 +260,8 @@ module ActiveModel
           options = { :default => "%{attribute} %{message}", :attribute => attr_name }
 
           messages.each do |m|
-            full_messages << I18n.t(:"errors.format", options.merge(:message => m))
+            full_messages << ((m.respond_to?(:full_message) && m.full_message) ?
+              m.full_message : I18n.t(:"errors.format", options.merge(:message => m)))
           end
         end
       end
@@ -280,6 +296,7 @@ module ActiveModel
     # </ol>
     def generate_message(attribute, type = :invalid, options = {})
       type = options.delete(:message) if options[:message].is_a?(Symbol)
+      full_message = options.delete(:full_message)
 
       if options[:default]
         ActiveSupport::Deprecation.warn \
@@ -296,7 +313,7 @@ module ActiveModel
       defaults << options.delete(:message)
       defaults << :"#{@base.class.i18n_scope}.errors.messages.#{type}"
       defaults << :"errors.attributes.#{attribute}.#{type}"
-      defaults << :"errors.messages.#{type}"
+      defaults << :"errors.#{full_message ? 'full_' : ''}messages.#{type}"
 
       defaults.compact!
       defaults.flatten!

third_attempt-v2.patch

diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 1431228..d8c8588 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -170,6 +170,17 @@ module ActiveModel
       self
     end
 
+    # Represents an error message. Contains the model instance (+base+), the +attribute+ and the +options+
+    # passed to validators.
+    class ErrorMessage < String
+      attr_reader :full_message
+      
+      def initialize(message, full_message)
+        super(message || full_message)
+        @full_message = full_message
+      end
+    end
+
     # Adds +message+ to the error messages on +attribute+, which will be returned on a call to
     # <tt>on(attribute)</tt> for the same attribute. More than one error can be added to the same
     # +attribute+ in which case an array will be returned on a call to <tt>on(attribute)</tt>.
@@ -181,7 +192,10 @@ module ActiveModel
       message ||= :invalid
 
       if message.is_a?(Symbol)
-        message = generate_message(attribute, message, options.except(*CALLBACKS_OPTIONS))
+        options = options.except(*CALLBACKS_OPTIONS)
+        options[:message] = options.delete(:full_message) if full_message = options[:full_message]
+        message = generate_message(attribute, message, options)
+        message = ErrorMessage.new(message, full_message) if full_message
       elsif message.is_a?(Proc)
         message = message.call
       end
@@ -245,7 +259,8 @@ module ActiveModel
           options = { :default => "%{attribute} %{message}", :attribute => attr_name }
 
           messages.each do |m|
-            full_messages << I18n.t(:"errors.format", options.merge(:message => m))
+            full_messages << ((m.respond_to?(:full_message) && m.full_message) ?
+              m : I18n.t(:"errors.format", options.merge(:message => m)))
           end
         end
       end

third_attempt.patch

diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 1431228..38549f5 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -170,6 +170,17 @@ module ActiveModel
       self
     end
 
+    # Represents an error message. Contains the model instance (+base+), the +attribute+ and the +options+
+    # passed to validators.
+    class ErrorMessage < String
+      attr_reader :full_message
+      
+      def initialize(message, full_message)
+        super(message)
+        @full_message = full_message
+      end
+    end
+
     # Adds +message+ to the error messages on +attribute+, which will be returned on a call to
     # <tt>on(attribute)</tt> for the same attribute. More than one error can be added to the same
     # +attribute+ in which case an array will be returned on a call to <tt>on(attribute)</tt>.
@@ -181,7 +192,10 @@ module ActiveModel
       message ||= :invalid
 
       if message.is_a?(Symbol)
-        message = generate_message(attribute, message, options.except(*CALLBACKS_OPTIONS))
+        options = options.except(*CALLBACKS_OPTIONS)
+        options[:message] = options.delete(:full_message) if full_message = options[:full_message]
+        message = generate_message(attribute, message, options)
+        message = ErrorMessage.new(message, full_message) if full_message
       elsif message.is_a?(Proc)
         message = message.call
       end
@@ -245,7 +259,8 @@ module ActiveModel
           options = { :default => "%{attribute} %{message}", :attribute => attr_name }
 
           messages.each do |m|
-            full_messages << I18n.t(:"errors.format", options.merge(:message => m))
+            full_messages << ((m.respond_to?(:full_message) && m.full_message) ?
+              m : I18n.t(:"errors.format", options.merge(:message => m)))
           end
         end
       end