device-screen-size.directive.ts

import { Directive, HostListener } from '@angular/core';
import { DevicesService } from './devices.service';

@Directive({
  selector: '[cesDeviceScreenSize]'
})
export class DeviceScreenSizeDirective {
  constructor(
    private devices: DevicesService
  ) { }

  @HostListener('window:load', ['$event']) onLoad(event) {
    this.sendSize(event.currentTarget.innerWidth);
  }

  @HostListener('window:resize', ['$event']) onResize(event) {
      this.sendSize(event.currentTarget.innerWidth);
  }

  sendSize(width: number) {
    this.devices.setSize(width);
  }
}