WindowRef

@bespunky/angular-zen - Official Docs

TLDR Summary
Use WindowRef to safely access the window object and/or mock it with a simple to use class and syntax.

The window object is necessary many times when working with the web, and normally we would summon it directly in our code. However, window doesn't always exist when working with angular.

Why?

Angular serves for many purposes other than web development:

• Mobile development
• Server Side development
• Testing

Basically, this means that our application might be run in different environments, others than the normal browser, hence will not have the window object.

What do we do?

The WindowRef service acts as an injectable angular wrapper for the javascript window object.

WindowRef will automatically detect if it is running on a browser platform and will return an empty object otherwise. This allows DI and unit testing and prevents "window is undefined" on non-browser platforms.

The default implementation for WindowRef depends on the WINDOW token which provides the actual native object.

This eventually gives you the ability to use the WindowRef service in your apps and, when needed, mock or provide a different implementation for the service, the WINDOW token, or both.

How to use

1. Import CoreModule into your app:

   import { BrowserModule } from '@angular/platform-browser';
   import { NgModule } from '@angular/core';
   
   import { CoreModule } from '@bespunky/angular-zen/core'; // 1. Import core module
   
   import { AppComponent } from './app.component';
   
   @NgModule({
       declarations: [
           AppComponent
       ],
       imports: [
           BrowserModule,
           CoreModule // 2. Include module in your app
       ],
       providers: [], 
       bootstrap: [AppComponent]
   })
   export class AppModule { }

2. Inject WindowRef in your components and use .nativeWindow to access the window object:

   import { Component, OnInit } from '@angular/core';
   import { WindowRef } from '@bespunky/angular-zen/core';
   
   @Component({
       selector: 'zen-window-ref-demo',
       templateUrl: './window-ref-demo.component.html',
       styleUrls: ['./window-ref-demo.component.css']
   })
   export class WindowRefDemoComponent implements OnInit
   {
       public screen: Screen;
   
       constructor(private windowRef: WindowRef) { }
   
       ngOnInit()
       {
           this.screen = this.windowRef.nativeWindow.screen;
       }
   }

See also

Mocking and replacing implementation

WindowRef internals