Angular 2 ngOnInit is not called when routerlink changes

Question

i have a menu bar that contain a list of menus loaded from express api and every menu is referenced to a page that have an alias wich will be the URL of tha

Answer 1

Well it fixed thanks to @Günter Zöchbauer and @DeborahK I changed the Page Component code from this

@Component({
selector: 'page',
templateUrl: './page.component.html'
    })
    export class PageComponent implements OnInit {
        alias: string;
        page:Page;

        constructor(private router:Router,
                    private route: ActivatedRoute,
                    private pageService:PageService) {

            this.route.params.subscribe(
                (params : Params) => {
                    this.alias = params["alias"];
                    console.log(this.alias)
                }
            );
        }

    ngOnInit():void {
            debugger;
            this.pageService.getPage(this.alias).subscribe(page => {
                this.page = page;
                console.log(this.page);
            });
        }
    }

to this one

@Component({
selector: 'page',
templateUrl: './page.component.html'
    })
    export class PageComponent implements OnInit {
        alias:string;
        page:Page;

        constructor(private router:Router,
                    private route:ActivatedRoute,
                    private pageService:PageService) {

            this.route.params.subscribe(
                (params:Params) => {
                    this.alias = params["alias"];
                    this.pageService.getPage(this.alias).subscribe(page => {
                        this.page = page;
                        console.log(this.page);
                    });
                    console.log(this.alias)
                }
            );
        }
         ngOnInit():void {
            this.pageService.getPage(this.alias).subscribe(page => {
                this.page = page;
                console.log(this.page);
            });
        }
    }