Multi-Sort For Backbone Collections

MultiSortCollections extends Backbone.Collection, giving the ability to sort on multiple attributes.

Basic Usage

This is basic usage for the methods. See unit tests for additional examples.

sortBy(sortAttributes)

var models = new MultiSortCollection;
models.add([
	{name : "Charlie",number: 5},
	{name : "Billy", number: 7},
	{name : "Albert",number: 1},
	{name : "Charlie",number: 4}
]);

//collection order is [Charlie 5, Billy 7, Albert 1, Charlie 4]

models.sortBy("name","number");  //collection order is now [Albert 1, Billy 7, Charlie 4, Charlie 5]
models.sortBy("number","name");  //collection order is now [Albert 1, Charlie 4, Charlie 5, Billy 7]

sortIndex(model)

var models = new MultiSortCollection,
		model,
		index;
		
models.add([
	{name : "Charlie",number: 5},
	{name : "Billy", number: 7},
	{name : "Albert",number: 1}
]);

models.sortBy("name","number"); //collection order is now [Albert 1, Billy 7, Charlie 5]

model = new Backbone.Model({name : "Charlie",number: 4})

//determine sort index according to most recent sort
index = models.sortIndex(model)			//returns 2

add(model,[options])

//Backbone.Collection._add has been extended.  First it calls the parent,
//then it moves the new model to correct sort position if the collection is sorted
var models = new MultiSortCollection
		model;
		
models.add([
	{name : "Charlie",number: 5},
	{name : "Billy", number: 7},
	{name : "Albert",number: 1}
]);

models.sortBy("name","number"); //collection order is now [Albert 1, Billy 7, Charlie 5]

model = new Backbone.Model({name : "Charlie",number: 4})

models.add(model);	//collection order is now [Albert 1, Billy 7, Charlie 4, Charlie 5]

Known Issues

MultiSortCollection.sortIndex()does not work with Backbone.Collection.comparator. Avoid using comparator if using this library.

Unit Tests

Jasmine Unit Tests are located at spec/