Helpers

AjaxResponse

AjaxResponse is an extension of Django’s JsonResponse that automatically adds any messages in the Django messages framework store to the response body.

This allows views that are called via XMLHttpRequest requests, that simply return JSON-encoded raw data rather than a rendered template, to still make use of the messages framework and have those messages automatically embedded in the response and removed from the messages store.

The messages are added to the JsonResponse‘s data dictionary using the “messages” key. The messages themselves are dictionaries containing the following:

• message: The message string.
• tags: A string of the tags applied to the message, space separated.

If there are no messages to add, the “messages” key will not be added to the data dictionary at all (i.e. it will not be added as an empty list).

Using AjaxResponse differs from JsonResponse in the following ways:

• The first positional argument should be a Django HttpRequest instance. This argument is required - it is used to retrieve messages from the message framework store.
• The data argument is optional. If provided, it must always be a dict instance, and messages will be added to this dictionary. If not provided, messages will be added to a new dict instance, passing it to the parent JsonResponse. Using the safe argument of JsonResponse to JSON-encode other types is not supported (see the documentation for the safe argument of JsonResponse).
• The optional argument success can be set to add a “success” attribute to the data dictionary. The “success” attribute will always be added as a boolean value, regardless of what was passed to the success argument (though it will not be added at all if nothing was passed). As with messages, this will be added to the data dictionary passed to the parent JsonResponse regardless of whether one was provided to AjaxResponse itself or not.

With the exception of safe, as noted above, AjaxResponse accepts and supports all arguments of JsonResponse.

Usage

This simple example demontrates how AjaxResponse can be used with the messages framework:

from django.contrib import messages
from django_goodies import AjaxResponse

def my_view(request):

    # do something...

    messages.success(request, 'Did something!')

    return AjaxResponse(request)

This will give a JSON-encoded response body that looks like this:

{
    "messages":[{
        "message":"Did something!",
        "tags":"success"
    }]
}

The following is a more complete example, based on the “polls” application created in the Django tutorial. This view records a vote on a given Choice:

from django.contrib import messages
from django_goodies import AjaxResponse

from polls.models import Choice

def vote_on_question(request, choice_id):

    try:
        choice = Choice.objects.get(pk=choice_id)
    except Choice.DoesNotExist:
        messages.error(request, 'Invalid choice.')
        return AjaxResponse(request, success=False)

    choice.votes += 1
    choice.save()

    messages.success(request, 'Vote recorded.')

    return AjaxResponse(request, {'votes': choice.votes}, success=True)