In my opinion this is something that should be handled purely in JavaScript, you don’t need to get the server involved (beyond the usual form submission/Ajax request), and it’s simpler too.

If you’re using Prototype you just do something like this in the onSuccess callback of your Ajax.request:

$('form_id').remove();

Of course, that assumes you’re comfortable writing a bit of JavaScript, including some unobtrusive code to, say, observe the form’s submit event and send the Ajax request yourself. It’s not the only option but that’s the route I’d recommend.

Ah, I see that we’re talking about different directions of communication. In the case you are talking about, you’re addressing passing the id from Rails to the HTML code (via the :html option of the view code).

In my case I want to communicate the form’s id upon submission to the rails controller. This is so that I can run some JS code to interact with the element (specifically to delete the form from the web page).

I’ve been doing this in the view via the :url option like this:

% form_remote_tag :url=> { :action => ‘remove_element’, :element_id => id } do %

In the controller I then delete the form from the web page:

def remove_element
page.remove element_id
end

What I’m wondering is whether I’m doing unnecessary work? Do I need to manually pass the id of the form to the controller like this or is there some other Rails-magical way that automatically makes information (such as form and element ids) available to the controller?

I don’t see any such data in the params[] hash, but perhaps I’m overlooking something?

I’m not crazy about the way I’m doing it because the element id appears in the URL. Perhaps it should be in a hidden field so it’s passed in the POST data?

What would be the “Rails way” of doing this?

TIA

I’m probably not doing a good job explaining – in your controller action that’s receiving the form submission you can receive a value for each input in the form’s HTML.

So from the controller, the action can assign:

element_id = params[:element_id]

To be able to do that, your HTML might look something like:

<form action="...">
  <input name="element_id" type="...">
  ...
</form>

But with Rails your forms are usually built around creating or editing a model object. This means your form HTML is probably going to look more like this:

<form action="...">
  <input name="element[id]" type="...">
  ...
</form>

In turn, to produce that HTML your view could contain code looking a little like:

<% form_for(@element) do |f| %>
  <%= f.text_field :id ... %>
  ...
  <%= f.submit "Submit" %>


And then in your controller you can just do:

element_like = params[:element]

If you just want the data as some bare object; instead you’ll probably want to instantiate a model object, and probably store it in an instance var too:

@element = Element.new(params[:element])

You might take a look at the Rails API docs for more examples with text_field.

Hope this helps.

% form_remote_tag( :url=> {:action => ‘remove_element’}, :html=> {:element_id => ‘STUFF’} ) do %

%= text_field_tag :answer, ‘Default Answer’ %
%= submit_tag ‘Submit’ %
% end %

\ {:action => ‘remove_element’}, :html=> {:element_id => ‘STUFF’} ) do %\>

\
\
\

{:action => ‘remove_element’}, :html=> {:element_id => ‘STUFF’} ) do %>

Hmmm, please forgive my newbie-ness, perhaps I’m misunderstanding or maybe making a beginner’s error…

Here I’m passing the arbitrary value :element_id via the form as you describe, via the :html hash. I then try to access the value from the controller via params[:element_id]. But the value comes up blank for me when I write it out to the logger. The value for :element_id doesn’t appear in params[] at all..

view:

{:action => ‘remove_element’}, :html=> {:element_id => ‘STUFF’} ) do %>

controller:

def remove_element
element_id = params[:element_id]
logger.info “element_id is #{element_id}”
logger.info( ‘params[]: ‘ + params.to_a.join(‘, ‘) )
end

log:

element_id is
params[]: commit, Submit, answer, Default Answer, authenticity_token, NMX9HWoXEFrz4qDXvx6SpRnM2Z73bapzn1NBRO2JPvc=, action, remove_element, controller, set

Am I misunderstanding something here??

The original post features both form_tag and form_remote_tag, as the :html hash applies to both.

The :yummy => ‘yumminess’ example was only included in the post to point out that you can add any arbitrary attributes (you could potentially interact with some JavaScript frameworks in this way).

To work with a form value in your Rails controller you could use params[:yummy], assuming your form has an input (like a textbox) named “yummy”.

Here’s my question – once you’ve passed the value, say by { :yummy => ‘yumminess’ }, how do you then access the values in the controller?

I’ve tried params[:yummy], but it doesn’t seem to be there. I know it’s hiding in there somewhere…Thanks

With a standard form you can do this:

<%= form_tag({ :action => :create }, { :onsubmit => 'function call' }) %>

However you probably noticed that if you try using :onsubmit with form_remote_tag(), your event handler gets replaced with the Ajax handler set up by Rails.

One option for Ajax may be to use the :before callback, which should allow you to call a function before the request is made. I haven’t tested it, but that may be what you’re looking for.

do you have any thoughts on this? any help would be much appreciated.

thanks,
jen