Adding error_notification helper to show a default message at the top of forms when object has errors

CHANGELOG.rdoc

@@ -1,4 +1,5 @@
 * enhancements
+  * Added error_notification message to form builder
   * Added required by default as configuration option
   * Added label_input as component, allowing boolean to change its order (input appearing first than label)
   * Added error_method to tidy up how errors are exhibited

lib/generators/simple_form/templates/en.yml

@@ -8,3 +8,17 @@ en:
       # You can uncomment the line below if you need to overwrite the whole required html.
       # When using html, text and mark won't be used.
       # html: '<abbr title="required">*</abbr>'
+    error_notification:
+      default_message: "Some errors were found, please take a look:"
+    # Labels and hints examples
+    # labels:
+    #   password: 'Password'
+    #   user:
+    #     new:
+    #       email: 'E-mail para efetuar o sign in.'
+    #     edit:
+    #       email: 'E-mail.'
+    # hints:
+    #   username: 'User name to sign in.'
+    #   password: 'No special characters, please.'
+

lib/generators/simple_form/templates/simple_form.rb

@@ -14,6 +14,9 @@ SimpleForm.setup do |config|
   # Method used to tidy up errors.
   # config.error_method = :first
 
+  # Default tag used for error notification helper.
+  # config.error_notification_tag = :p
+
   # You can wrap all inputs in a pre-defined tag.
   # config.wrapper_tag = :div
 

lib/simple_form.rb

@@ -3,11 +3,12 @@ require 'simple_form/action_view_extensions/form_helper'
 require 'simple_form/action_view_extensions/builder'
 
 module SimpleForm
-  autoload :Components,  'simple_form/components'
-  autoload :FormBuilder, 'simple_form/form_builder'
-  autoload :I18nCache,   'simple_form/i18n_cache'
-  autoload :Inputs,      'simple_form/inputs'
-  autoload :MapType,     'simple_form/map_type'
+  autoload :Components,        'simple_form/components'
+  autoload :ErrorNotification, 'simple_form/error_notification'
+  autoload :FormBuilder,       'simple_form/form_builder'
+  autoload :I18nCache,         'simple_form/i18n_cache'
+  autoload :Inputs,            'simple_form/inputs'
+  autoload :MapType,           'simple_form/map_type'
 
   # Default tag used on hints.
   mattr_accessor :hint_tag
@@ -21,6 +22,10 @@ module SimpleForm
   mattr_accessor :error_method
   @@error_method = :first
 
+  # Default tag used for error notification helper.
+  mattr_accessor :error_notification_tag
+  @@error_notification_tag = :p
+
   # Components used by the form builder.
   mattr_accessor :components
   @@components = [ :label_input, :hint, :error ]

lib/simple_form/components/errors.rb

@@ -2,7 +2,7 @@ module SimpleForm
   module Components
     module Errors
       def error
-        template.content_tag(error_tag, error_text, error_html_options) if object && errors.present?
+        template.content_tag(error_tag, error_text, error_html_options) if has_errors?
       end
 
       def error_tag
@@ -23,6 +23,10 @@ module SimpleForm
 
     protected
 
+      def has_errors?
+        object && errors.present?
+      end
+
       def errors
         @errors ||= (errors_on_attribute + errors_on_association).compact
       end

lib/simple_form/components/wrapper.rb

@@ -23,7 +23,7 @@ module SimpleForm
 
       def wrapper_html_options
         css_classes = input_html_classes.unshift(wrapper_class)
-        css_classes << wrapper_error_class if object && errors.present?
+        css_classes << wrapper_error_class if has_errors?
         html_options_for(:wrapper, css_classes)
       end
     end

lib/simple_form/error_notification.rb

@@ -0,0 +1,36 @@
+module SimpleForm
+  class ErrorNotification
+    delegate :object, :object_name, :template, :to => :@builder
+
+    def initialize(builder, options)
+      @builder = builder
+      @options = options
+    end
+
+    def render
+      if has_errors?
+        error_message = @options.delete(:message) || translate_error_notification
+        @options[:class] = "error_notification #{@options[:class]}".strip
+        template.content_tag(error_notification_tag, error_message, @options)
+      end
+    end
+
+    protected
+
+    def error_notification_tag
+      SimpleForm.error_notification_tag
+    end
+
+    def has_errors?
+      object && object.respond_to?(:errors) && object.errors.present?
+    end
+
+    def translate_error_notification
+      lookups = []
+      lookups << :"#{object_name}"
+      lookups << :default_message
+      lookups << "Some errors were found, please take a look:"
+      I18n.t(lookups.shift, :scope => :"simple_form.error_notification", :default => lookups)
+    end
+  end
+end

lib/simple_form/form_builder.rb

@@ -216,6 +216,21 @@ module SimpleForm
       SimpleForm::Inputs::Base.new(self).label
     end
 
+    # Creates an error notification message that only appears when the form object
+    # has some error. You can give a specific message with the :message option,
+    # otherwise it will look for a message using I18n. All other options given are
+    # passed straight as html options to the html tag.
+    #
+    # == Examples
+    #
+    #    f.error_notification
+    #    f.error_notification :message => 'Something went wrong'
+    #    f.error_notification :id => 'user_error_message', :class => 'form_error'
+    #
+    def error_notification(options={})
+      SimpleForm::ErrorNotification.new(self, options).render
+    end
+
   private
 
     # Setup default simple form attributes.

test/error_notification_test.rb

@@ -0,0 +1,63 @@
+require 'test_helper'
+
+class ErrorNotificationTest < ActionView::TestCase
+
+  def with_error_notification_for(object, options={}, &block)
+    concat(simple_form_for(object) do |f|
+      concat(f.error_notification(options))
+    end)
+  end
+
+  test 'error notification is not generated when the form has no error' do
+    valid_user = ValidatingUser.new
+    valid_user.name = 'Carlos'
+    assert valid_user.valid?
+    with_error_notification_for valid_user
+    assert_no_select 'p.error_notification'
+  end
+
+  test 'error notification is not generated for forms without objects' do
+    with_error_notification_for :user
+    assert_no_select 'p.error_notification'
+  end
+
+  test 'error notification is generated when the form has some error' do
+    with_error_notification_for @user
+    assert_select 'p.error_notification', 'Some errors were found, please take a look:'
+  end
+
+  test 'error notification uses I18n based on model to generate the notification message' do
+    store_translations(:en, :simple_form => { :error_notification => { :user =>
+      'Alguns erros foram encontrados para o usuário:'
+    } }) do
+      with_error_notification_for @user
+      assert_select 'p.error_notification', 'Alguns erros foram encontrados para o usuário:'
+    end
+  end
+
+  test 'error notification uses I18n fallbacking to default message' do
+    store_translations(:en, :simple_form => { :error_notification => {
+      :default_message => 'Opa! Alguns erros foram encontrados, poderia verificar?'
+    } }) do
+      with_error_notification_for @user
+      assert_select 'p.error_notification', 'Opa! Alguns erros foram encontrados, poderia verificar?'
+    end
+  end
+
+  test 'error notification allows passing the notification message' do
+    with_error_notification_for @user, :message => 'Erro encontrado ao criar usuario'
+    assert_select 'p.error_notification', 'Erro encontrado ao criar usuario'
+  end
+
+  test 'error notification accepts other html options' do
+    with_error_notification_for @user, :id => 'user_error_message', :class => 'form_error'
+    assert_select 'p#user_error_message.form_error.error_notification'
+  end
+
+  test 'error notification allows configuring the wrapper element' do
+    swap SimpleForm, :error_notification_tag => :div do
+      with_error_notification_for @user
+      assert_select 'div.error_notification'
+    end
+  end
+end