CODEWITHSUNDEEP
csstypescriptangularangular2-directives
Spencer Bigum
Spencer Bigum

Reputation: 1931

Angular2 get window width onResize

Trying to figure out how to get window width on resizing events in Angular2. Here is my code:

export class SideNav {

    innerWidth: number;

    constructor(private window: Window){

        let getWindow = function(){
          return window.innerWidth;
        };

        window.onresize = function() {
          this.innerWidth = getWindow();
          console.log(getWindow());
        };
}

I am importing window provider globally in the bootstrap.ts file using provide to gain access across my app to window. The problem I am having is this does give me a window size, but on resizing the window - it just repeats the same size over and over even if the window changes size. See image for console.log example: Screenshot image

My overall goal is to be able to set the window number to a variable onresize so I can have access to it in the template. Any ideas on what I am doing wrong here?

Thanks!

Upvotes: 30

Views: 42419

Answers (3)

Günter Zöchbauer
Günter Zöchbauer

Reputation: 657058

<div (window:resize)="onResize($event)"

onResize(event) {
  event.target.innerWidth; 
}

to get notified on scroll events on a child element in a components template

or listen on the components host element itself

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

Upvotes: 54

Pankaj Parkar
Pankaj Parkar

Reputation: 136134

In this case you need to run change detection manually. As you are modifying component variable from outer context of Angular, basically resize event doesn't get monkey patched by Angular2 change detection system.

Code

import {ChangeDetectorRef} from 'angular2/core'

export class SideNav {
    innerWidth: number;

    constructor(private window: Window, private cdr: ChangeDetectorRef){

       let getWindow = () => {
          return window.innerWidth;
       };

      window.onresize = () => {
          this.innerWidth = getWindow();
          this.cdr.detectChanges(); //running change detection manually
      };
    }
}

Rather I'd like to suggest you to go for this answer, which looks more cleaner

Upvotes: 7

Michael Kang
Michael Kang

Reputation: 52837

Use NgZone to trigger change detection:

constructor(ngZone:NgZone) {
    window.onresize = (e) =>
    {
        ngZone.run(() => {
            this.width = window.innerWidth;
            this.height = window.innerHeight;
        });
    };
}

Upvotes: 21

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