Question

In Typescript, how would I use a getter/setter for all the properties of an object? For example, I can have the following code:

class Div {
    private _container: HTMLDivElement;
    public get container() {
        return this._container;
    }
    public set container(value) {
        alert("Updated!");
        this._container = value;
    }

    testDiv() {
        this.container = <HTMLDivElement>document.createElement('div');
        this.container.style.width = "100px";
    }
}
var newDiv: Div = new Div();
newDiv.testDiv();

“Updated!” is alerted only once – when the div is first set (which, I guess, is really what it should be), but I want it to alert “Updated!” even when I’m setting a property on that object. Is there a way to do this, or should I come up with some kind of workaround?

Answer 1

Create an event system that triggers when your objects state changes. Do not allow direct access to properties. Funnel all activity through a controller that triggers state change as necessary.

Or look into using a framework that already does this. Backbone, Knockout, Angularjs etc.