Complex forms + DHH's auto_complete plugin = works!


I’ve been searching for a way to get DHH’s auto_complete plugin to
work with Ryan B.’ complex forms. All I could find was people
asking the same question, but no solutions so I decided to try it
myself. I don’t know if this id 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.
Here’s the code:


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”) +
{ :url => { :action => "auto_complete_for
{sanitized_method}” } }.update(completion_options))

class FormBuilder
  def text_field_with_auto_complete(method, tag_options = {},

completion_options = {})
objectify_options(tag_options), completion_options)

Don’t forget to include the file in your environment.rb of course. I
know some people were looking for a way to get this to work, so I
thought it might be helpful if I post it on the mailing list. If you
see any bugs or know of a better way, please let me know.


Ooh, that code isn’t too readable. Um, I posted it on my website as


Hmm, maybe we could some parts together. I like the one in the second
link, but looking at the code, I think there’s more extra in there. I
would still need to check it out more thoroughly.

One thing I would like to do is extend the autocomplete functionality
to autocomplete for a whole object.

eg: If you have an Address model which contains street, city, region,
zip. In a form you start typing the street and the autocomplete popup
comes up with the full address. When you choose the address, it
automatically fills in all the fields for the address. Has anybody
done that yet and is it possible to do it easily with Prototype?


Hi… I wrote some similar code, and packaged it up into a plugin.

I also know there are a few other forks of the auto_complete plugin
that also solve this same problem, for example:

Or just look through the auto_complete forks on github:

Hope this helps, - pat