Add the `full_error` component.

With this wrapper, it will call full_messages_for the attribute.

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## master
 
 ### enhancements
+  * Add the `full_error` component. [@laurocaetano](https://github.com/laurocaetano)
   * Add support to `scope` to be used on associations. [@laurocaetano](https://github.com/laurocaetano)
   * Execute the association `condition` in the object context. [@laurocaetano](https://github.com/laurocaetano)
   * Check if the given association responds to `order` before calling it. [@laurocaetano](https://github.com/laurocaetano)

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

@@ -43,6 +43,12 @@ SimpleForm.setup do |config|
     b.use :label_input
     b.use :hint,  wrap_with: { tag: :span, class: :hint }
     b.use :error, wrap_with: { tag: :span, class: :error }
+
+    ## full_messages_for
+    # If you want to display the full error message for the attribute, you can
+    # use the component :full_error, like:
+    #
+    # b.use :full_error, wrap_with: { tag: :span, class: :error }
   end
 
   # The default wrapper to be used by the FormBuilder.

lib/simple_form/components/errors.rb

@@ -5,6 +5,10 @@ module SimpleForm
         error_text if has_errors?
       end
 
+      def full_error(wrapper_options = nil)
+        full_error_text if has_errors?
+      end
+
       def has_errors?
         object && object.respond_to?(:errors) && errors.present?
       end
@@ -15,6 +19,10 @@ module SimpleForm
         "#{html_escape(options[:error_prefix])} #{errors.send(error_method)}".lstrip.html_safe
       end
 
+      def full_error_text
+        "#{html_escape(options[:error_prefix])} #{full_errors.send(error_method)}".lstrip.html_safe
+      end
+
       def error_method
         options[:error_method] || SimpleForm.error_method
       end
@@ -23,13 +31,25 @@ module SimpleForm
         @errors ||= (errors_on_attribute + errors_on_association).compact
       end
 
+      def full_errors
+        @full_errors ||= (full_errors_on_attribute + full_errors_on_association).compact
+      end
+
       def errors_on_attribute
         object.errors[attribute_name]
       end
 
+      def full_errors_on_attribute
+        object.errors.full_messages_for(attribute_name)
+      end
+
       def errors_on_association
         reflection ? object.errors[reflection.name] : []
       end
+
+      def full_errors_on_association
+        reflection ? object.full_messages_for(reflection.name) : []
+      end
     end
   end
 end

test/form_builder/error_test.rb

@@ -123,4 +123,13 @@ class ErrorTest < ActionView::TestCase
       assert_select 'span.omg_error', "can't be blank"
     end
   end
+
+  # FULL_ERROR_WRAPPER
+
+  test 'full error should find errors on association' do
+    swap_wrapper :default, self.custom_wrapper_with_full_error do
+      with_form_for @user, :company_id, as: :select
+      assert_select 'span.error', 'Company must be valid'
+    end
+  end
 end

test/form_builder/wrapper_test.rb

@@ -136,6 +136,13 @@ class WrapperTest < ActionView::TestCase
     end
   end
 
+  test 'custom wrappers can have full error message on attributes' do
+    swap_wrapper :default, self.custom_wrapper_with_full_error do
+      with_form_for @user, :name
+      assert_select 'span.error', "Name can't be blank"
+    end
+  end
+
   test 'custom wrappers on a form basis' do
     swap_wrapper :another do
       with_concat_form_for(@user) do |f|

test/support/misc_helpers.rb

@@ -144,6 +144,12 @@ module MiscHelpers
     end
   end
 
+  def custom_wrapper_with_full_error
+    SimpleForm.build tag: :div, class: 'custom_wrapper' do |b|
+      b.use :full_error,  wrap_with: { tag: :span, class: :error }
+    end
+  end
+
   def custom_wrapper_with_label_text
     SimpleForm.build :label_text => proc { |label, required| "**#{label}**" } do |b|
       b.use :label_input