Knockout Viewmodel in Typescript

Question

How are we supposed to declare viewmodels in typescript?

As classes, modules or as var/functions?

In the definitelytyped examples they use var and function mostly https://github.com/borisyankov/DefinitelyTyped/blob/master/knockout/tests/knockout-tests.ts

EDIT: Thank you Basarat - in this edit I extend the question: If I use class I suppose it should be like this:

class Player
{
    min:KnockoutObservable<number>;
    constructor(min:number=0)
    {
        this.min=ko.observable(min);
    }
}

BUT how should computed be defined?

Answer 1

You can use computed with generics (latest Typescript 0.9), just define type in declaration and in constructor you will assign value to result of call to ko.computed:

export class Inbox extends vm.BriskIdeaViewModel {

    public rapidEntryText = ko.observable<string>();
    public todosActive: KnockoutComputed<Array<ITodo>>;

    constructor() {
        super();
        this.todosActive = ko.computed(() => {
            return _.filter(this.dataContext.todos(), x => !x.isDone());
        });
    }
}