documentcloud/backbone — pull request #1039 by dtetto (2012-02-22 23:14:56+00:00)
Title: Collection.addedModels()

Tracks silently added collections to models, with Collection#added and Collection#addedModels analogous to Model#change and Model#changedAttributes.

Not sure about the API nomenclature, but this is something that's important to us… as with a model, you want to queue a bunch of changes before triggering a particular callback.

My real-world case is a "load more" link, where the view needs to know which models are new and which aren't (in our case, to only append the newer models without re-rendering the old).