validates_each uses a BlockValidator.

activemodel/lib/active_model.rb

@@ -46,6 +46,7 @@ module ActiveModel
   autoload :ValidationsRepairHelper
   autoload :Validator
   autoload :EachValidator, 'active_model/validator'
+  autoload :BlockValidator, 'active_model/validator'
   autoload :VERSION
 
   module Serializers

activemodel/lib/active_model/validations.rb

@@ -12,6 +12,29 @@ module Validations
     end
 
     module ClassMethods
+      # Validates each attribute against a block.
+      #
+      #   class Person < ActiveRecord::Base
+      #     validates_each :first_name, :last_name do |record, attr, value|
+      #       record.errors.add attr, 'starts with z.' if value[0] == ?z
+      #     end
+      #   end
+      #
+      # Options:
+      # * <tt>:on</tt> - Specifies when this validation is active (default is <tt>:save</tt>, other options <tt>:create</tt>, <tt>:update</tt>).
+      # * <tt>:allow_nil</tt> - Skip validation if attribute is +nil+.
+      # * <tt>:allow_blank</tt> - Skip validation if attribute is blank.
+      # * <tt>:if</tt> - Specifies a method, proc or string to call to determine if the validation should
+      #   occur (e.g. <tt>:if => :allow_validation</tt>, or <tt>:if => Proc.new { |user| user.signup_step > 2 }</tt>).  The
+      #   method, proc or string should return or evaluate to a true or false value.
+      # * <tt>:unless</tt> - Specifies a method, proc or string to call to determine if the validation should
+      #   not occur (e.g. <tt>:unless => :skip_validation</tt>, or <tt>:unless => Proc.new { |user| user.signup_step <= 2 }</tt>).  The
+      #   method, proc or string should return or evaluate to a true or false value.
+      def validates_each(*attr_names, &block)
+        options = attr_names.extract_options!.symbolize_keys
+        validates_with BlockValidator, options.merge(:attributes => attr_names.flatten), &block
+      end
+
       # Adds a validation method or block to the class. This is useful when
       # overriding the +validate+ instance method becomes too unwieldly and
       # you're looking for more descriptive declaration of your validations.
@@ -39,39 +62,6 @@ module ClassMethods
       #   end
       #
       # This usage applies to +validate_on_create+ and +validate_on_update as well+.
-
-      # Validates each attribute against a block.
-      #
-      #   class Person < ActiveRecord::Base
-      #     validates_each :first_name, :last_name do |record, attr, value|
-      #       record.errors.add attr, 'starts with z.' if value[0] == ?z
-      #     end
-      #   end
-      #
-      # Options:
-      # * <tt>:on</tt> - Specifies when this validation is active (default is <tt>:save</tt>, other options <tt>:create</tt>, <tt>:update</tt>).
-      # * <tt>:allow_nil</tt> - Skip validation if attribute is +nil+.
-      # * <tt>:allow_blank</tt> - Skip validation if attribute is blank.
-      # * <tt>:if</tt> - Specifies a method, proc or string to call to determine if the validation should
-      #   occur (e.g. <tt>:if => :allow_validation</tt>, or <tt>:if => Proc.new { |user| user.signup_step > 2 }</tt>).  The
-      #   method, proc or string should return or evaluate to a true or false value.
-      # * <tt>:unless</tt> - Specifies a method, proc or string to call to determine if the validation should
-      #   not occur (e.g. <tt>:unless => :skip_validation</tt>, or <tt>:unless => Proc.new { |user| user.signup_step <= 2 }</tt>).  The
-      #   method, proc or string should return or evaluate to a true or false value.
-      def validates_each(*attrs)
-        options = attrs.extract_options!.symbolize_keys
-        attrs   = attrs.flatten
-
-        # Declare the validation.
-        validate options do |record|
-          attrs.each do |attr|
-            value = record.send(:read_attribute_for_validation, attr)
-            next if (value.nil? && options[:allow_nil]) || (value.blank? && options[:allow_blank])
-            yield record, attr, value
-          end
-        end
-      end
-
       def validate(*args, &block)
         options = args.last
         if options.is_a?(Hash) && options.key?(:on)

activemodel/lib/active_model/validations/length.rb

@@ -10,8 +10,8 @@ class LengthValidator < EachValidator
 
       def initialize(options)
         options[:tokenizer] ||= DEFAULT_TOKENIZER
-        super
         @type = (OPTIONS & options.keys).first
+        super
       end
 
       def check_validity!
@@ -108,9 +108,8 @@ module ClassMethods
       #   count words as in above example.)
       #   Defaults to <tt>lambda{ |value| value.split(//) }</tt> which counts individual characters.
       def validates_length_of(*attr_names)
-        options = { :tokenizer => DEFAULT_TOKENIZER }
-        options.update(attr_names.extract_options!)
-        validates_with LengthValidator, options.merge(:attributes => attr_names, :type => type)
+        options = attr_names.extract_options!
+        validates_with LengthValidator, options.merge(:attributes => attr_names)
       end
 
       alias_method :validates_size_of, :validates_length_of

activemodel/lib/active_model/validations/with.rb

@@ -48,9 +48,9 @@ module ClassMethods
       #     end
       #   end
       #
-      def validates_with(*args)
+      def validates_with(*args, &block)
         options = args.extract_options!
-        args.each { |klass| validate(klass.new(options), options) }
+        args.each { |klass| validate(klass.new(options, &block), options) }
       end
     end
   end

activemodel/lib/active_model/validator.rb

@@ -51,7 +51,6 @@ module ActiveModel #:nodoc:
   #       @my_custom_field = options[:field_name] || :first_name
   #     end
   #   end
-  #
   class Validator
     attr_reader :options
 
@@ -64,6 +63,11 @@ def validate(record)
     end
   end
 
+  # EachValidator is a validator which iterates through the attributes given
+  # in the options hash invoking the validate_each method passing in the
+  # record, attribute and value.
+  #
+  # All ActiveModel validations are built on top of this Validator.
   class EachValidator < Validator
     attr_reader :attributes
 
@@ -81,11 +85,25 @@ def validate(record)
       end
     end
 
-    def validate_each(record)
+    def validate_each(record, attribute, value)
       raise NotImplementedError
     end
 
     def check_validity!
     end
   end
+
+  # BlockValidator is a special EachValidator which receives a block on initialization
+  # and call this block for each attribute being validated. +validates_each+ uses this
+  # Validator.
+  class BlockValidator < EachValidator
+    def initialize(options, &block)
+      @block = block
+      super
+    end
+
+    def validate_each(record, attribute, value)
+      @block.call(record, attribute, value)
+    end
+  end
 end