Rails - Feb 2006 - Best practice for showing errors AND updating list

Morning/Afternoon/Evening All,

   This is my first post to the ruby message board so if my request is 
better suited to another location just let me know,

   The problem I keep coming up against is with a listing of objects and 
updating that list via AJAX (for arguments we are talking about a list 
of users).

   As it stands I can currently submit a form, and update the list 
(using :update => ''list_div_name'' and generating the whole
list again or
generating a partial of a single row and using Insertion.Top) and I can 
also display the errors for a form using the same method and updating a 
notification div above my form,

   However, my problem occurs when I want to update a list on success 
and display errors on failure,

   I have figured the best way up until now would be to always update 
the forms notification and either display the errors or generate a 
hidden div and copy its contents to the top of the list if successful 
but this seems far from efficient,

   What I am essentially asking is there a standard / more efficient way 
of doing this that I have missed completely or is my current method 
suitable?

- Michael

-- 
Posted via http://www.ruby-forum.com/.

Michael Bryne wrote:
>    However, my problem occurs when I want to update a list on success 
> and display errors on failure,
Look at the :success and :failure parameters of link_to_remote,
which can also be inside the :update parameter. Also available in
submit_to_remote, form_remote_tag, periodically_call_remote,
remote_function, observe_field, and observe_form:

http://api.rubyonrails.com/classes/ActionView/Helpers/JavaScriptHelper.html#M000433

Set the reponse status in your controller using the :status parameter
to render:

http://api.rubyonrails.com/classes/ActionController/Base.html#M000178

-- 
We develop, watch us RoR, in numbers too big to ignore.

Using RJS (requires rails trunk) is probably the simplest way, you can 
then control which parts of the page are updated. Your action may 
become...

  def add_user
    @user = User.create(params[:user])
  end

And add_user.rjs:

  if @user.valid?
    page.insert_html :top, ''user_list'', :partial =>
''user'', :object =>
@user
  else
    page.replace_html ''errors'', :partial =>
''errors'', :object =>
@user.errors
  end

Make sure you remove the :update => bit from your helper call as well. 
You can actually now put the RJS in the controller if you like...

  def add_user
    ...
    render :update do |page|
      if @user....
        page.replace_html
    end
  end

Whatever takes your fancy :)

Cheers, -Jonny.

-- 
Posted via http://www.ruby-forum.com/.

Thanks guys :) that told me exactly what I was after

-- 
Posted via http://www.ruby-forum.com/.

Quick note, there is actually a plugin to allow you to use RJS outside
of the Trunk release. Can''t remember the site, but do a quick google
for it and you''ll run across it. Works great for me.

On 2/17/06, Jonathan Viney <jviney@spreydon.org.nz>
wrote:
> Using RJS (requires rails trunk) is probably the simplest way, you can
> then control which parts of the page are updated. Your action may
> become...
>