can.Model.List

Creating a new Model List

To create a new model list, just use new {model_name}.List(ARRAY) like:

var todo1 = new Todo( { name: "Do the dishes" } ),
    todo2 = new Todo( { name: "Wash floors" } )
var todos = new Todo.List( [todo1, todo2] );

Model Lists in can.Model

can.Model.findAll or models will almost always be used to return a can.Model.List object, even though it is possible to create new lists like below:

var todos = Todo.models([
    new Todo( { name: "Do the dishes" } ),
    new Todo( { name: "Wash floors" } )
])

todos.constructor // -> can.Model.List

// the most correct way to get a can.Model.List
Todo.findAll({}, function(todos) {
    todos.constructor // -> can.Model.List
})

Extending can.Model.List

Creating custom can.Model.Lists allows you to extend lists with helper functions for a list of a specific type. So, if you wanted to be able to see how many todos were completed and remaining something could be written like:

Todo.List = can.Model.List({
    completed: function() {
        var completed = 0;
        this.each(function(i, todo) {
            completed += todo.attr('complete') ? 1 : 0
        })
        return completed;
    },
    remaining: function() {
        return this.attr('length') - this.completed();
    }
})

Todo.findAll({}, function(todos) {
    todos.completed() // -> 0
    todos.remaining() // -> 2
});

Removing models from model list

The advantage that can.Model.List has over a traditional can.Observe.List is that when you destroy a model, if it is in that list, it will automatically be removed from the list.

// Listen for when something is removed from the todos list.
todos.bind("remove", function( ev, oldVals, indx ) {
    console.log(oldVals[indx].attr("name") + " removed")
})

todo1.destroy(); // console shows "Do the dishes removed"