Pass multiple form element values with link_to_remote?

rubyonrails-talk
#1

Let me preface this by noting that I'm new to Rails and hardly know
anything about Javascript...hence why I need help. :slight_smile:

That said, I have a form which contains three text fields: site_id,
start_date, and end_date. I have a link_to_remote link which needs to
pass these three values to an action when I click it, but I can't for
the life of me figure out how to access / pass the three text field
values on so that I can use them.

Any help for me?

#2

you probably should make it a link_to_function instead which calls
form.submit() (where form is the id of your form). Then turn your form
into a remote_form_tag or remote_form_for. I think this would work
because you are triggering the onsubmit handler of the form which will
contain the AJAX request.

e.g. (approximately)

<%= link_to_function('save','my_form.submit();') %>
<%= image_tag('/images/spinner.gif', :alt => 'Loading'), :id =>
'spinner' %>
<%= form_remote_tag(:url => {:controller => 'sites', :action =>
'create'}, :before => "Element.show('spinner')", :after =>
"Element.hide('spinner')", :html => {:id => 'my_form'}) do %>
<%= text_field_tag(:site_id) %>
<%= text_field_tag(:start_date) %>
<%= text_field_tag(:end_date) %>
<% end %>

Not too familiar with the exact syntax for form_remote_tag, but it is
along those lines. Try gotapi.com/rubyrails for the full reference.
I've added the image there for a loading spinner but you could equally
write some text or whatever, just make sure there is an element with
id='spinner', or change the :before and :after calls (or remove them).

You can also use remote_form_for if you are changing a model directly.
I prefer this way. Finally, you can use restful or named routes in
place of the {:controller => ... :action => ...} hash

If you want to know more about selecting elements from the DOM using
prototype's $ helpers check that out on the prototype webiste
http://www.prototypejs.org/

Hope this assists.

Joe

#3

I actually got what I wanted using the link_to_remote. I'm not sure
the form_remote_tag was exactly what I wanted, but I appreciate the
help because I will certainly need that later on with what I'm doing.
The solution was this:

In my view:

<p><%= link_to_remote("Calculate Invoice",
  :url => { :action => :calculate_invoice },
  :method => 'get',
   :with => 'serialize_fields()',
  :update => 'invoice-div' )%>

<h2>Invoice Amount</h2>
<p>
  <div id="invoice-div" name="invoice-div">Pending selection...</div>

In application.js: (code stolen from another post in the group)

function serialize_fields(){
  var fields = new Array();
  fields.push(Form.Element.serialize('reservation_site_id'));
  fields.push(Form.Element.serialize('reservation_start_date'));
  fields.push(Form.Element.serialize('reservation_end_date'));
  return fields.join('&');
}

In my controller (this is ugly as sin and there are probably a ton of
better ways to do this:

  def calculate_invoice
    @site = Site.find(params[:reservation][:site_id].to_s)
    nightly_rate = @site.default_rate
    start_date = params[:reservation][:start_date].to_date
    end_date = params[:reservation][:end_date].to_date
    total_nights = end_date - start_date
    invoice_total = nightly_rate * total_nights
    render :partial => 'invoice', :locals => { :nightly_rate =>
nightly_rate.to_s, :total_nights => total_nights.to_s, :invoice_total
=> invoice_total.to_s }
  end

And then my _invoice.rhtml:

<table>
  <tr>
    <th>Total Nights</th>
    <th>Nightly Rate</th>
    <th>Invoice Total</th>
  </tr>
  <tr>
    <td><%= total_nights %></td>
    <td><%= nightly_rate %></td>
    <td><%= invoice_total %></td>
  </tr>
</table>

<input type="hidden" value="<%= invoice_total %>"
id="reservation_invoice_amount" name="reservation[invoice_amount]">

Anybody feel free to advise me where I could have done things better
because I'm still very very new to coding in general, and especially
new to Rails.

Thanks!

#4

You can pass any params you wish in the :url hash

In this case:
<%= link_to_remote("Calculate Invoice",
         :url => { :action => :calculate_invoice, :start_date =>
params[:reservation][:start_date], :end_date => params[:reservation]
[:end_date] },
         :method => 'get',
         :update => 'invoice-div' )%>

Then find total_nights in the calculate_invoice controller action.

#5

Oops, I mixed up information. Really, what you wanted to use was a
remote_form, though, as wildtangent suggested.

Use a form for multiple values that are entered on the page after the
page loads.
Use a link/button for any action using params that were already
available from the controller action.

#6

Just reading this thread made me wonder. I thought serialize was a
standard function.

Having looked, and, yes serialize is in the Scriptaculous library, so
you don't need to write the function.

Of course you may have written your own because you only want to
include a subset of the fields.

Also noticed this thread which included a subset function - which you
may already have seen.

http://groups.google.ca/group/rubyonrails-talk/msg/3df638d6c271d8c0

Tonypm

#7

thanks, It helped me. My problem solved.