How to use JQuery and Django (ajax + HttpResponse)?

Question

Suppose I have a AJAX function:

function callpage{
$.ajax({
    method:"get",
    url:"/abc/",
    data:"x="+3
    beforeSend:function() {},
    success:function(html){
       IF HTTPRESPONSE = "1" , ALERT SUCCESS!
    }
    });
    return false;
}
}

When my "View" executes in Django, I want to return HttpResponse('1') or '0'.

How can I know if it was successful, and then make that alert?

Answer 1

The typical workflow is to have the server return a JSON object as text, and then interpret that object in the javascript. In your case you could return the text {"httpresponse":1} from the server, or use the python json libary to generate that for you.

JQuery has a nice json-reader (I just read the docs, so there might be mistakes in my examples)

Javascript:

$.getJSON("/abc/?x="+3,
    function(data){
      if (data["HTTPRESPONSE"] == 1)
      {
          alert("success")
      }
    });

Django

#you might need to easy_install this
import json 

def your_view(request):
    # You can dump a lot of structured data into a json object, such as 
    # lists and touples
    json_data = json.dumps({"HTTPRESPONSE":1})
    # json data is just a JSON string now. 
    return HttpResponse(json_data, mimetype="application/json")

An alternative View suggested by Issy (cute because it follows the DRY principle)

def updates_after_t(request, id): 
    response = HttpResponse() 
    response['Content-Type'] = "text/javascript" 
    response.write(serializers.serialize("json", 
                   TSearch.objects.filter(pk__gt=id))) 
    return response

Answer 2

Rather than do all this messy, low-level ajax and JSON stuff, consider using the taconite plugin for jQuery. You just make the call to the backend and it does the rest. It's well-documented and easy to debug -- especially if you are using Firebug with FF.