Cannot read property 'nativeElement' of undefined

Ionic Framework Ionic Angular
1

I am using ArcGIS Map using angular and am getting error to render my HTML Div tag and error is “Cannot read property ‘nativeElement’ of undefined”

component.html page : <div  #mapviewnode></div>

component.ts page : below
error

 @ViewChild('mapViewNode') public mapViewEl: ElementRef;
    //@ViewChild("mapViewNode") public searchElement: ElementRef;

    initializeMap(): Promise<any> {
        debugger
        const container = this.mapViewEl.nativeElement;
        const layer = new FeatureLayer({
            url: "https://services6.arcgis.com/KA88lzxweZ86kjDY/arcgis/rest/services/OHaresMap_WFL1/FeatureServer",
            outFields: ["*"]
        });
        const webmap = new WebMap({
            portalItem: {
                id: '6376d7dafbf04761bd460c44dc2d2494',
            },
        });
        const view = new MapView({
            container,
            map: webmap,

        });
        view.when(function () {
            var layerList = new LayerList({
                view: view
            });
            view.ui.add(layerList, "top-right");
        });
        // const bookmarks = new Bookmarks({
        //   view,
        //   // allows bookmarks to be added, edited, or deleted
        //   editingEnabled: true,
        // });

        // const bkExpand = new Expand({
        //   view,
        //   content: bookmarks,
        //   expanded: true,
        // });

        // Add the widget to the top-right corner of the view
        //view.ui.add(bkExpand, 'top-right');

        // bonus - how many bookmarks in the webmap?
        webmap.when(() => {
            if (webmap.bookmarks && webmap.bookmarks.length) {
                console.log('Bookmarks: ', webmap.bookmarks.length);
            } else {
                console.log('No bookmarks in this webmap.');
            }
        });

        this.view = view;
        return this.view.when();
    }
2

When is initializeMap getting called? If it’s getting called too early, like during ngOnInit, the element won’t be ready yet. You’ll need to wait for ngAfterViewInit the child DOM of the component is ready.