Django and JSON request

Question

In a template I have the following code.

<script>
    var url="/mypjt/my_timer"

    $.post(url, paramarr,
    function callbackHandler(dict)
    {
        alert('got response back');
        if (dict.flag == 2)
        {
            alert('1');
            $.jGrowl("Data could not be saved");
        }
        else if(dict.ret_status == 1)
        {
            alert('2');
            $.jGrowl("Data saved successfully");
            window.location = "/mypjt/display/" + dict.rid;
        }
    },
    "json"
    );
</script>

In views I have the following code,

def my_timer(request):
    dict={}
    try:
        a = timer.objects.get(pk=1)

        dict({'flag':1})
        return HttpResponse(simplejson.dumps(dict), mimetype='application/javascript')

    except:
        dict({'flag':1})
        return HttpResponse(simplejson.dumps(dict), mimetype='application/javascript')

Since we are making a JSON request and in the try block, after setting the flag, can't we return a page directly as

return render_to_response('mypjt/display.html',context_instance=RequestContext(request,{'dict': dict}))

instead of sending the response, because on success again in the HTML page we redirect the code?

Also if there is a exception then only can we return the JSON request.

My only concern is that the interaction between client and server should be minimal.

Answer 1

If you do the response like you said,

return render_to_response('mypjt/display.html',context_instance=RequestContext(request,{'dict': dict}))

the JavaScript code will receive your response, not the navigator. I think you can do somethink like this:

<script>
   $(document).ready(function()
   {
      $('#yourForm').submit();
   });
</script>

<form id="yourForm" action="/mypjt/my_timer" method="post">
...
your fields with data, even they are hidden
...
</form>

So, in Django you can do the response like you said:

 def my_timer(request):
     dict={}
     try:
         a=  timer.objects.get(pk=1)

         dict({'flag':1})
         return render_to_response('mypjt/display.html',context_instance=RequestContext(request,{'dict': dict}))
     except:
         dict({'flag':0})
         return render_to_response('mypjt/error_not_found.html',context_instance=RequestContext(request,{'dict': dict}))

Or, you can do like you were doing but if the query "timer.objects.get(pk=1)" fails, for example, you send back a boolean flag response. So, when it is OK you redirect to the page you prefer.

I hope it could be useful to you!

Answer 2

If I understand rightly, you're sniffing the return code in the JavaScript, and then redirecting depending on the results.

You can do a redirect from Django, so I would do that instead of worrying about return codes. When you've got both a "flag" and a "ret_status", that is a hint you should re-think your design. :)

Also, shadowing the built-in dict object in the Python code should be avoided.