angular ssr处理服务器不存在对象处理方式

• document 
  export class ExampleComponent { constructor(@Inject(DOCUMENT) document: any) { console.dir(document) } }

• window 
  const WINDOW = new InjectionToken('window', { providedIn: 'root', factory: () => window }); 
  
  or 
  
  export class ExampleComponent { constructor(@Inject(WINDOW) window: any) { console.dir(window) } }

  Location 
  
  import { Location } from '@angular/common';
  
  export class AbmNavbarComponent implements OnInit{
  
    // ctor 中注入 Location
  
    constructor(private _location:Location){
  
      //...
  
    }
  
    ngOnInit() {
  
      // 打印当前地址
  
      console.log(this._location.path(true));
  
    }
  
  }