How to focus on a field?

Question

I updated from Angular 2 to Angular 4 and in the docs it's written to use the Renderer2 instead of Renderer which is deprecated.

Now am looking into the Renderer source, but cannot find a way to invoke the focus() method as I used to.

Old method:

this.renderer.invokeElementMethod(element, 'focus', []);

What is the new aproach?

EDIT

What if the element i am focusing onto is obtained via QuerySelector?

For instance:

let inputField = document.querySelectorAll('.dialog input');
if ( inputField[0] ) {
   inputField[0].focus();
}

Since its obtained via QuerySelector, the focus() method doesn't exist on it.

Answer 1

If you declare the correct type of your inputField var, you can use any JS query selector.

For instances declaring:
let inputField: HTMLInputElement = document.querySelector('.dialog input');
enables you to call
inputField.focus();
that it will work and no TS error will be thrown.