backbone.projections

backbone.projections is a set of projections for Backbone.Collection

* CappedCollection project underlying collection into a read-only collection
of capped size

{CappedCollection} = require 'backbone.projections'

collection = new Collection [...]
capped = new CappedCollection(collection, cap: 5)

this way capped will contain no more than 5 models and will behave as a
Backbone.Collection and will be in sync with underlying collection.
CappedCollection supports comparator but if no comparator is provided then
capped will have an order induced by underlying collection.

* FilteredCollection project underlying collection into a read-only collection
of models which match some predicate

{FilteredCollection} = require 'backbone.projections'

collection = new Collection [...]
filtered = new FilteredCollection collection,
filter: (model) -> model.get('date').isToday()

this way filtered will contain only models which have "today's date" and
will behave as a Backbone.Collection and will be in sync with underlying
collection. FilteredCollection supports comparator but if no comparator
is provided then capped will have an order induced by underlying
collection.