Still we're supporting legacy Ruby that doesn't have Module#prepend...

Author: amatsuda

lib/html5_validators.rb

@@ -23,7 +23,11 @@ class Railtie < ::Rails::Railtie #:nodoc:
       end
       ActiveSupport.on_load(:action_view) do
         if ActionPack::VERSION::STRING >= '4'
-          require 'html5_validators/action_view/form_helpers'
+          if RUBY_VERSION > '2'
+            require 'html5_validators/action_view/form_helpers'
+          else
+            require 'html5_validators/action_view/form_helpers_ruby1'
+          end
         else
           require 'html5_validators/action_view/form_helpers_rails3'
         end

lib/html5_validators/action_view/form_helpers_ruby1.rb

@@ -0,0 +1,78 @@
+# Legacy Ruby 1.x on Rails 4.x support
+module Html5Validators
+  module ActionViewExtension
+    def inject_required_attribute
+      if object.class.ancestors.include?(ActiveModel::Validations) && (object.auto_html5_validation != false) && (object.class.auto_html5_validation != false)
+        @options["required"] ||= @options[:required] || object.class.attribute_required?(@method_name)
+      end
+    end
+
+    def inject_maxlength_attribute
+      if object.class.ancestors.include?(ActiveModel::Validations) && (object.auto_html5_validation != false) && (object.class.auto_html5_validation != false)
+        @options["maxlength"] ||= @options[:maxlength] || object.class.attribute_maxlength(@method_name)
+      end
+    end
+
+    def inject_numericality_attributes
+      if object.class.ancestors.include?(ActiveModel::Validations) && (object.auto_html5_validation != false) && (object.class.auto_html5_validation != false)
+        @options["max"] ||= @options["max"] || @options[:max] || object.class.attribute_max(@method_name)
+        @options["min"] ||= @options["min"] || @options[:min] || object.class.attribute_min(@method_name)
+      end
+    end
+  end
+end
+
+
+module ActionView
+  module Helpers
+    module FormHelper
+      def form_for_with_auto_html5_validation_option(record, options = {}, &proc)
+        if record.respond_to?(:auto_html5_validation=)
+          if !Html5Validators.enabled || (options[:auto_html5_validation] == false)
+            record.auto_html5_validation = false
+          end
+        end
+        form_for_without_auto_html5_validation_option record, options, &proc
+      end
+      alias_method_chain :form_for, :auto_html5_validation_option
+    end
+
+    module Tags
+      class Base #:nodoc:
+        include Html5Validators::ActionViewExtension
+      end
+
+      class TextField
+        def render_with_html5_attributes
+          inject_required_attribute
+          inject_maxlength_attribute
+          inject_numericality_attributes
+
+          render_without_html5_attributes
+        end
+        alias_method_chain :render, :html5_attributes
+      end
+
+      class TextArea
+        def render_with_html5_attributes
+          inject_required_attribute
+          inject_maxlength_attribute
+
+          render_without_html5_attributes
+        end
+        alias_method_chain :render, :html5_attributes
+      end
+
+      #TODO probably I have to add some more classes here
+      [RadioButton, CheckBox, Select, DateSelect, TimeZoneSelect].each do |kls|
+        kls.class_eval do
+          def render_with_html5_attributes
+            inject_required_attribute
+            render_without_html5_attributes
+          end
+          alias_method_chain :render, :html5_attributes
+        end
+      end
+    end
+  end
+end