autofocus-directive.ts

import { AfterViewInit, Directive, ElementRef } from '@angular/core';

@Directive({ selector: '[ifautofocus]' })
export class IfAutofocus implements AfterViewInit {
    constructor(private elementRef: ElementRef) {}

    ngAfterViewInit() {
        this.elementRef.nativeElement.focus();
    }
}

/*
remember to include it in your module's 'declarations' array, 
then import it into your component.
add it like you would the 'autofocus' tag in your template:

<input formControlName="searchTerm" type="text" placeholder="Search!" ifautofocus />
*/