collection.create should return the request object

[iros]

Right now the current create call returns the model that was created, but that is inconsistent with the way save, destroy and fetch work. Those all return the xhr object, allowing the use of deferreds in a consistent fashion. Since create is also a networked operation, it should return the xhr object as well.

Is there a reason why create returns the model itself? I realize that you can provide a json object at which point you'd need to capture the model instance in the callback, but you could also pass a model directly to create (thus already having the model). At present, I believe create is the only api call that requires use of the success callback if you want to capture the result of the operation.

Happy to make a pull req if this is a desired change.

[tgriesser]

I agree, the model returned from create isn't too useful since you don't really know what the deal is with it until you hear from the server, and it'd be more consistent to get the xhr object for the promise chaining, etc... but #1155 and #2220 have some info about the reasoning for it.

[iros]

So far the reasoning I see is that "it's intended to return a model" which isn't really a reason in it of itself. Is there a specific use case that necessitates it behaving differently from the others?

[jashkenas]

create is a shortcut for "new model", plus "add to collection and save". If create returned the XHR, you'd have no reference to the model you just made. If you want the XHR, use new, and then save it later.

[iros]

but @jashkenas, you could pass a model to create that has been created elsewhere. Additionally, you could:

var myModel = null;
collection.create({ bla: 12 }).then(function(model) {
  myModel = model;
});

An empty non-initialized model is worse than no model, because someone not realizing there is a network operation happening could start using the model before it's actually saved, which may not be the desired behavior.

[jashkenas]

you could pass a model to create that has been created elsewhere

You could, but that's not the intended use case.

Your code example makes sense, but it's noticeably awkward compared to:

var model = collection.create({bla: 12})

someone not realizing there is a network operation happening could start using the model before it's actually saved

... that's exactly how optimistic models are supposed to be used. If you're worried about the save failing, or the model being invalidated by the server, and so on, then you'll want to wait for the save to complete.

create is just a shortcut — think create in Rails.