How do I append data to a jquery-ujs post request in Rails?

Question

I have an Ajax form with a data-remote=\"true\" attribute which I\'m submitting to a controller in rails.

What I\'d like to do is to use the jquery-ujs even

Answer 1

I figured this one out myself in the end. It appears that despite what the docs say, the ajax:beforeSend hook actually takes three arguments. According to this helpful blog post they are event, xhr and settingsin that order.

The form data I was looking for is in the in the data attribute of the settings argument.

So basically, I can now add data to the request with the function

$("#my_form").bind('ajax:beforeSend', function(event, xhr, settings){
  settings.data += "&serialized=data";
});

And the extra paramaters will be available on the server.