Ruby on Rails: Complex forms + auto_complete

09 Jan 2009

I haven’t written here in a long time, so as many of you might not know yet, I’ve been learning Ruby on Rails the past 4 or 5 months. I’ll have to say I’ve run into some pretty big challenges, but overall Ruby on Rails is one awesome framework. My latest challenge has been getting DHH’s auto_complete plugin to work with Ryan Bates’ complex forms. It might not be the best way to do it, but the solution was to monkey patch ActionView::FormHelper and FormBuilder which I put in a seperate file in the /lib folder of my project. So without further ado, here’s the code:

## lib/auto_complete_form_helper.rb
module ActionView
  module Helpers
    module FormHelper
      def text_field_with_auto_complete_mod(object, method, tag_options = {}, completion_options = {})
        sanitized_object = object.gsub(/\]\[|[^-a-zA-Z0-9:.]/, "_").sub(/_$/, "")
        sanitized_method = method.to_s.sub(/\?$/,"")
        (completion_options[:skip_style] ? "" : auto_complete_stylesheet) +
        text_field(object, method, tag_options) +
        content_tag("div", "", :id => "#{sanitized_object}_#{sanitized_method}_auto_complete", :class => "auto_complete") +
        auto_complete_field("#{sanitized_object}_#{sanitized_method}", { :url => { :action => "auto_complete_for_#{sanitized_object}_#{sanitized_method}" } }.update(completion_options))
      end
    end

    class FormBuilder
      def text_field_with_auto_complete(method, tag_options = {}, completion_options = {})
        @template.text_field_with_auto_complete_mod(@object_name, method,
          objectify_options(tag_options), completion_options)
      end
    end
  end
end

Don’t forget to include the file in your environment.rb. If you see any bugs or know of a better way (I couldn’t find any solutions on the web), please let me know.

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