Why isn't this "ajax:success" event firing? - ruby-on-rails

Question

I have a view with several "Invite" buttons like this:
<div class = "fbinvite_form" id = "<%= friend[:identifier] %>" name = "fb">
<div class = "btn btn-small">
Invite
</div>
</div>
When one of these buttons are clicked an AJAX function is called (invite_friend) :
$('.fbinvite_form').click(function() {
invite_friend();
});
Here's invite_friend (some values are hard-coded as I debug):
function invite_friend() {
$.post('/groups/7/invitations',
{
"recipient_email": "facebook#meetcody.com",
"commit" : "fb",
"fb" : "fb"
},
function(response) {
});
}
Here's the relevant line that is returned from the controller:
render :json => {
:url => signup_with_token_url(#invitation.token),
:id => #invitation.id
},
:status => :created
I can confirm that this json is being rendered correctly. At this point I'm expecting an ajax:success event to fire. I have the following code at the top of my page:
$('.fbinvite_form').bind("ajax:success", function(evt, data, status, xhr) {
...
});
But it's not firing. Any clue what might be going wrong or how to better troubleshoot (I'm a bit of a noob)?
Additional Context
I wanted to add a little bit more as it might help. I had originally built this to work with a form and it worked fine. For some performance reasons I decided to switch to buttons with AJAX. Here's the original form:
<%= form_for([#group, #invitation], :remote => true, :html => { :'data-type' => 'html', :class => 'fbinvite_form', :id => friend[:identifier]}) do |f| %>
<%= f.hidden_field :recipient_email, :value => "facebook#meetcody.com" %>
<div class = "fbinvite btn_list_right" id = "<%= friend[:identifier] %>">
<%= f.submit "Invite", :class => "btn btn-medium btn-primary", :name => "fb" %>
</div>
<% end %>
This has since been replace with all the code you see above the controller snippet.
UPDATE 1
Per Vince's suggestion I have moved the "ajax:success" code into the success function. Here is the original "ajax:success" function:
$('.fbinvite_form').bind("ajax:success", function(evt, data, status, xhr){
var fb_id = $(this).attr('id');
var response = eval("(" + xhr.responseText + ")");
var link_url = response.url;
var id = response.id;
var inv_url = <%= raw('"' + group_url(#group) + '/invitations/"') %> + id;
var picture_url = "https://www.example.com.com/assets/cody_130by130.png";
var desc = <%= raw('"' + first_name(current_user) + " is working with Cody on fitness. Join " + genderizer(current_user, "his") + " group to start tracking your workouts. Cody and the other group members will keep you motivated!" + '"') %>;
send_invite(fb_id, link_url, picture_url, desc, inv_url); return false;
});
And here is what I've done to move the code into the success function. The issue is that I don't seem to have access to "xhr"
$.ajax({
type: "POST",
url: "/groups/7/invitations",
data: {recipient_email: "facebook#meetcody.com", commit : "fb", fb : "fb" },
dataType: "json",
success: function(evt, data, status, xhr) {
var fb_id = $(this).attr('id');
var response = eval("(" + xhr.responseText + ")");
var link_url = response.url;
var id = response.id;
var inv_url = <%= raw('"' + group_url(#group) + '/invitations/"') %> + id;
var picture_url = "https://www.meetcody.com/assets/cody_130by130.png";
var desc = <%= raw('"' + first_name(current_user) + " is working with Cody on fitness. Join " + genderizer(current_user, "his") + " group to start tracking your workouts. Cody and the other group members will keep you motivated!" + '"') %>;
send_invite(fb_id, link_url, picture_url, desc, inv_url); return false;
}
});

Answer 1

Add error handler like this and log the error, this should help diagnose the issue.
error: function(xhr, status, error) {
console.log(error);
}
EDIT
Sorry you need to use .ajax instead of .post.
$.ajax({
type: "POST",
url: "/groups/7/invitations",
data: "name=John&location=Boston",
success: function(msg){
alert( "Data Saved: " + msg );
},
error(xhr, status, error) {
console.log(error);
}
});