Question

A Backbone.Model object maintains a ‘collection’ attribute.
In the Backbone source code, we have :

var Model = Backbone.Model = function(attributes, options) {
   ...    
   if (options && options.collection) this.collection = options.collection;
   ...
}

The annotated source says nothing about that, and the documentation references only functions.
I guess it’s mainly used when deleting the model : the collection removes this model.

But what if the model belongs to many collections ? Is there a danger to use/override this collection attribute ?

Answer 1

It’s used in two places (look a bit further down in the annotated source).

• As you note, it’s used when a model is destroyed, to remove the model from the collection.

Optimistically removes the model from its collection, if it has one.

• In the url function, if the collection exists with a URL scheme, it uses that to construct a URL for the model.

if you’re using Backbone’s restful methods, override this to change the endpoint that will be called.