Where does related logic go on model creation when working with REST api with Django, Backbone, and Tastypie? - rest

Question

We are trying to move some of our app to use backbone and tastypie. I have the REST api set up and it is working on some basic examples. However, there are a few issues where currently we post an ajax request to a custom url, and in that view do a few things like
make related objects
call a few related functions
However, now that I've switched some of this functionality to using backbone and the REST api, I'm not sure where all of that should go!
For example, I had a view to make a Message, and when I made a Message, I also made a Notification and called a function to add some points to the user. Something like
def ajax_send_message(request):
## ... set up some variables ...
## Make the new message
message = Message(user=user, content=message)
message.save()
## Make the notification
notification = Notification(message=message)
notification.save()
## Give the user points
user.add_points_for_message();
return json_response({"status": "ok"})
Now--am I just supposed to do this all in JavaScript? I have a Message Backbone model as well.
// Create message backbone object
var msg = new Message({content:content, user: user});
// Post to server
msg.save();
// Add to backbone collection
messages.add(msg);
I've looked at different parts of tastypie, and it seems you can create custom URL endpoints, and also do validation, but that doesnt seem like the right spot to call related methods. It seems that calling related methods goes against the REST part of it---but then where are they supposed to go?
If I want to add some logic to backbone only when an object is created, where does that go?

Answer 1

The first thing I would suggest is to switch your mindset to an event-based model, where your code reacts to events. In your example above, you save the model to the server then immediately dd it to the collection. How do you even know that the model was saved correctly? That procedural style of programming works better in a synchronous, server-side style of programming.
In the asynchronous world of client-side programming, you make a request and then set up callbacks which determine what will happen next, depending on the events your are listening for. In your case, you want to react a certain way when the message is saved successfully, correct? You can define a success callback for your save operation like so:
msg.save({
success: function(model, response, options) {
messages.add(model);
// code to add notification
// code to add points
}
});
Basically, you are saying "I would like to save this model, and then listen for a success event. When the event comes in, execute the following code." Notice also that I am adding the model returned from the API to the collection, since this is the exact object that was persisted to the server so it's more appropriate to add than the model you created.