Question

I am making a post via Jquery ajax that looks like this:

$.ajax({
    type: 'POST',
    url: "/sandbox/read_demands/",
    data: {
        "partner_ref": "PH",
        "return_field": ["summary", "details"]
    },
    success: [read_demands_response],
    dataType: 'json'
});

I then recieve the data on the server-side with a simple Django view that only prints request.POST into a log. The data then looks like this:

{u'return_field[]': [u'summary', u'details'], u'partner_ref': [u'PH']}

As you can see, the key ‘return_field’ has become ‘return_field[]’ and the value for ‘partner_ref’ is now a list. What on earth is going on? Am I missing something complected obvious in the jquery post that causes my data to be malformed or is do you think this error comes from somewhere else? I am trying to rule-out different possibilities until I can find the cause of the problem.

This is jquery 1.8.2 and Django 1.4 btw.

Answer 1

The first one is just jQuery being jQuery. For reasons best known to themselves, the makers of jQuery believe that PHP is the only way to write server-side applications, and PHP expects fields that have more than one value to have the [] suffix – so if you don’t provide one, it’ll add it. You just have to use it like that in Django.

However, the second one is not an error. It’s just how a Django QueryDict works: any value can have multiple items, so they’ll always be represented as a list. However, request.POST['partner_ref'] will correctly give the single value. And in fact to access both values of the other key, you’ll need to do request.POST.getlist('return_field[]').

Edit: as pointed out in the comments, $.ajaxSettings.traditional = true; fixes the jQuery issue.