Question

I’ve been trying to get some Ajax stuff to work in my Django application, but it has been difficult because for some reason syntax and type errors are not causing a server crash and are failing silently. How could this be?

JavaScript (jQuery):

 add_foo = function() {
   var numfoos = $("div#foos_container > div.foo").length + 1;
   var foo_id = numfoos + "-foo";
   var div = $("<div></div>").attr("id",foo_id).addClass("foo");
   div.load("http://localhost:8000/ajax/get/url/");
   div.appendTo("div#foos_container");
    };

Python:

def ajax_add_foo(request):     
  print request.session['editing_foos'].keys()
  keys = request.session['editing_foos'].keys()
  if len(keys) == 0:
    next_key = 1
  else:
    next_key = max([ id_from_prefix(key) for key in keys ])
  print next_key

  form = FooForm(prefix=next_key)
  print next_key
  request.session['editing_foos'].update( {create_prefix(FooForm, next_key) : -1 } ) # This foo is new and has no pkey
  print request.session['editing_foos']
  return render_to_response( 'bar/foo_fragment.html',
        {'fooform' : fooform, },
        context_instance=RequestContext(request))

Answer 1

This is probably because server returns error code (500) and your jQuery cod doesn’t do anything on error. Could you post $.get or $.post code you are using?

EDIT: If you are using $.load, there is a place for a callback function, that you can create to display errors. It’s pretty simple, you need to define a function similar to this:

function (responseText, textStatus, XMLHttpRequest){
    if (textStatus < 200 || textStatus >= 299){
        $(document).html(responseText);
    }
}

This way you will put error message into the whole document and see it. I don’t exactly know, if the above works, because I can’t test it, but you should be able to construct something working on this.