Add support for maxlenght to text area inputs. Closes #232

CHANGELOG.rdoc

@@ -6,6 +6,7 @@
   * Change form css class handling to only add the dom class when one is not given to the form call (by github.com/patrick99e99)
   * Support for required attributs when action validations are present (by github.com/csegura)
   * Don't generate `size` attribute for numeric input (by github.com/jasonmp85)
+  * Support for `maxlength` on text area inputs inferred from validation
 
 * bug fix
   * Fix bug when simple_fields_for is used with a hash like models and Rails 3.1

lib/generators/simple_form/templates/config/initializers/simple_form.rb

@@ -2,7 +2,7 @@
 SimpleForm.setup do |config|
   # Components used by the form builder to generate a complete input. You can remove
   # any of them, change the order, or even add your own components to the stack.
-  # config.components = [ :placeholder, :label_input, :hint, :error ]
+  # config.components = [ :placeholder, :maxlength, :label_input, :hint, :error ]
 
   # Default tag used on hints.
   # config.hint_tag = :span

lib/simple_form.rb

@@ -45,7 +45,7 @@ module SimpleForm
 
   # Components used by the form builder.
   mattr_accessor :components
-  @@components = [ :placeholder, :label_input, :hint, :error ]
+  @@components = [ :placeholder, :maxlength, :label_input, :hint, :error ]
 
   # Series of attemps to detect a default label method for collection.
   mattr_accessor :collection_label_methods

lib/simple_form/components.rb

@@ -6,5 +6,6 @@ module SimpleForm
     autoload :Labels,       'simple_form/components/labels'
     autoload :Placeholders, 'simple_form/components/placeholders'
     autoload :Wrapper,      'simple_form/components/wrapper'
+    autoload :Maxlength,    'simple_form/components/maxlength'
   end
-end
+end

lib/simple_form/components/maxlength.rb

@@ -0,0 +1,32 @@
+module SimpleForm
+  module Components
+    module Maxlength
+      def maxlength
+        if has_maxlength?
+          input_html_options[:maxlength] ||= maximum_length_from_validation
+          input_html_options[:maxlength] ||= limit if limit && SimpleForm.html5
+        end
+        nil
+      end
+
+      def has_maxlength?
+        false
+      end
+
+      def limit
+        column && column.limit
+      end
+
+      def maximum_length_from_validation
+        return unless has_validators?
+
+        length_validator = find_length_validator or return
+        length_validator.options[:maximum]
+      end
+
+      def find_length_validator
+        attribute_validators.find { |v| ActiveModel::Validations::LengthValidator === v }
+      end
+    end
+  end
+end

lib/simple_form/inputs/base.rb

@@ -14,6 +14,7 @@ module SimpleForm
       include SimpleForm::Components::LabelInput
       include SimpleForm::Components::Placeholders
       include SimpleForm::Components::Wrapper
+      include SimpleForm::Components::Maxlength
 
       attr_reader :attribute_name, :column, :input_type, :reflection,
                   :options, :input_html_options

lib/simple_form/inputs/mapping_input.rb

@@ -13,6 +13,10 @@ module SimpleForm
 
     private
 
+      def has_maxlength?
+        text?
+      end
+
       def has_placeholder?
         (text? || password?) && placeholder_present?
       end

lib/simple_form/inputs/string_input.rb

@@ -8,8 +8,6 @@ module SimpleForm
 
       def input
         input_html_options[:size]      ||= [limit, SimpleForm.default_input_size].compact.min
-        input_html_options[:maxlength] ||= maximum_length_from_validation
-        input_html_options[:maxlength] ||= limit if limit && SimpleForm.html5
         if password? || SimpleForm.html5
           input_html_options[:type]    ||= input_type unless string?
         end
@@ -22,8 +20,8 @@ module SimpleForm
 
     protected
 
-      def limit
-        column && column.limit
+      def has_maxlength?
+        true
       end
 
       def has_placeholder?
@@ -37,17 +35,6 @@ module SimpleForm
       def password?
         input_type == :password
       end
-
-      def maximum_length_from_validation
-        return unless has_validators?
-
-        length_validator = find_length_validator or return
-        length_validator.options[:maximum]
-      end
-
-      def find_length_validator
-        attribute_validators.find { |v| ActiveModel::Validations::LengthValidator === v }
-      end
     end
   end
 end

test/inputs_test.rb

@@ -398,6 +398,23 @@ class InputTest < ActionView::TestCase
     assert_select 'textarea.text[placeholder=Put in some text]'
   end
 
+  test 'input should get maxlength from column definition for text attributes' do
+    with_input_for @user, :description, :text
+    assert_select 'textarea.text[maxlength=200]'
+  end
+
+  test 'input should infer maxlength column definition from validation when present for text attributes' do
+    with_input_for @validating_user, :description, :text
+    assert_select 'textarea.text[maxlength=50]'
+  end
+
+  test 'when not using HTML5, does not show maxlength attribute for text attributes' do
+    swap SimpleForm, :html5 => false do
+      with_input_for @user, :description, :text
+      assert_no_select 'textarea.text[maxlength]'
+    end
+  end
+
   test 'input should generate a file field' do
     with_input_for @user, :name, :file
     assert_select 'input#user_name[type=file]'

test/support/models.rb

@@ -67,7 +67,7 @@ class User
   def column_for_attribute(attribute)
     column_type, limit = case attribute.to_sym
       when :name, :status, :password then [:string, 100]
-      when :description   then :text
+      when :description   then [:text, 200]
       when :age           then :integer
       when :credit_limit  then [:decimal, 15]
       when :active        then :boolean
@@ -144,6 +144,7 @@ class ValidatingUser < User
     :less_than_or_equal_to => :max_attempts,
     :only_integer => true
   validates_length_of :name, :maximum => 25
+  validates_length_of :description, :maximum => 50
 
   def min_amount
     10