method

error_message_on

v2.2.1 - Show latest stable - 1 note - Class: ActionView::Helpers::ActiveRecordHelper

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What's this?

error_message_on(object, method, *args) public

Returns a string containing the error message attached to the method on the object if one exists. This error message is wrapped in a DIV tag, which can be extended to include a :prepend_text and/or :append_text (to properly explain the error), and a :css_class to style it accordingly. object should either be the name of an instance variable or the actual object. The method can be passed in either as a string or a symbol. As an example, let’s say you have a model @post that has an error message on the title attribute:

  <%= error_message_on "post", "title" %>
  # => <div class="formError">can't be empty</div>

  <%= error_message_on @post, :title %>
  # => <div class="formError">can't be empty</div>

  <%= error_message_on "post", "title",
      :prepend_text => "Title simply ",
      :append_text => " (or it won't work).",
      :css_class => "inputError" %>

Show source

# File actionpack/lib/action_view/helpers/active_record_helper.rb, line 109
      def error_message_on(object, method, *args)
        options = args.extract_options!
        unless args.empty?
          ActiveSupport::Deprecation.warn('error_message_on takes an option hash instead of separate ' +
            'prepend_text, append_text, and css_class arguments', caller)

          options[:prepend_text] = args[0] || ''
          options[:append_text] = args[1] || ''
          options[:css_class] = args[2] || 'formError'
        end
        options.reverse_merge!(:prepend_text => '', :append_text => '', :css_class => 'formError')

        if (obj = (object.respond_to?(:errors) ? object : instance_variable_get("@#{object}"))) &&
          (errors = obj.errors.on(method))
          content_tag("div",
            "#{options[:prepend_text]}#{errors.is_a?(Array) ? errors.first : errors}#{options[:append_text]}",
            :class => options[:css_class]
          )
        else
          ''
        end
      end

August 12, 2008

9 thanks

Overriding the default div class="fieldWithErrors"

By default fields that are invalid are wrapped in:

<div class="fieldWithErrors">
  <input type="text" name="blah">
</div>

To override and wrap in spans instead of divs place the following in your environment.rb:

ActionView::Base.field_error_proc = Proc.new { |html_tag, instance| "<span class=\"fieldWithErrors\">#{html_tag}</span>" }

or to not use wrapping at all:

ActionView::Base.field_error_proc = Proc.new { |html_tag, instance| "#{html_tag}" }

error_message_on

Related methods

Overriding the default div class="fieldWithErrors"