Rails 2 to Rails 3 upgrade issues

Hi All,

I'm very new to RoR development and am working through the developer.apple.com tutorials to try to get a good enough working knowledge to be able to start my own project. Unfortunately, i'm using Rails 3 and the tutorials are aimed at a Rails 2 environment.

I've been able to get a fair way through the tutorials, working out some of the simpler changes myself (changes to the routing API were interesting), but i've hit a point where i'm stuck and google hasn't been able to help me.

I'm currently working through the "Spicing it up with Ajax" section of http://developer.apple.com/tools/customizeonrailsleopard.html but am unable to successfully convert the Rails 2 link_to_remote syntax into Rails 3. I understand that the method is depreciated and that i should use link_to with a :remote => true option specified, but the arguments that i'm supplying don't seem to be being picked up as a Javascript link. Instead, when i click one of the links, the whole page is refreshed and the arguments appear in the address bar (instead of an Ajax call). E.g. http://localhost:3000/events/4?remote=true&method=delete&confirm=Are+you+sure%3F&url=http%3A%2F%2Flocalhost%3A3000%2Fevents%2F4%2Fexpenses%2F6

My _expenses.erb event looks like so:

...<% for expense in expenses -%>   <tr id="<%= dom_id(expense) %>">     <td>       <%= link_to expense.vendor.name, expense.vendor %>     </td>     <td align="right">       <%= number_to_currency(expense.amount, :unit => "£") %>     </td>     <td>       <%= link_to 'delete',         :url => event_expense_url(event, expense),         :confirm => 'Are you sure?',         :method => :delete,         :remote => true %>     </td>   </tr> <% end -%>...

and my application.html.erb file:

<!DOCTYPE html> <html> <head>   <title>Expenses</title>   <%= stylesheet_link_tag :all %>   <%= javascript_include_tag :defaults %>   <%= csrf_meta_tag %> </head> <body>

<%= yield %>

</body> </html>

I'd be very grateful if anyone could offer some advice. Apologies if the source code is too long for the forum.

Thanks, Dave.

if the rails.js file in public/javascripts? Is it being loaded? That is the file that :remote => true is going to try to call. I seem to remember that this is one of the major gotchas on a 2 to 3 conversion.


Thanks for the quick response, Steve. The rails.js file is in the public/javascripts and it can be seen in the source of my page:

<script src="/javascripts/rails.js?1285525822" type="text/javascript"></script>

The link that is generated by the call to link_to is:

<a href="/events/4?remote=true&amp;method=delete&amp;confirm=Are+you+sure%3F&amp;url=http%3A%2F%2Flocalhost%3A3000%2Fevents%2F4%2Fexpenses%2F6">delete</a>

Which mentions remote=true, but doesn't appear to make any reference to javascript.

I made a successful Ajax call in the prior part of the tutorial, only this time with the following syntax:

<%= form_for [@event, @expense], :remote => true do |f| -%>

The standard delete link created by scaffold is

        <%= link_to 'Destroy', question, :confirm => 'Are you sure?', :method => :delete %>

There is no reference to remote. Delete is not an ajax call, it is just a javascript call that hides all the build a delete form stuff that happened in Rails 2.x. By putting in :remote, it was probably trying to do an Unobtrusive Javascript call to an unknown method. I think!!!

If you are just trying to replace the delete link on the Apple demo, try the above line.


Rather than trying to learn rails 2 and 3 at once you might be better to use a Rails 3 tutorial such as railstutorial.org. This is available online free though initially it looks as if you have to pay.