Spinner

export class DemoUiComponentsComponent extends AppComponentBase implements OnInit {
    constructor(
        injector: Injector
    ) {
        super(injector);
    }
    ngOnInit(): void {
        //show default spinner which cover all page
        this.spinnerService.show();

        setTimeout(() => {
            this.spinnerService.hide();
        }, 1000);
    }
}

 <div class="kt-portlet kt-portlet--height-fluid">   
     ...
     <div class="kt-portlet__body">
		<div [busyIf]="loading">
            
         </div>
     </div>
     ...
</div>

export class MyComponent extends AppComponentBase implements OnInit {
    constructor(
        injector: Injector
    ) {
        super(injector);
    }
    loading = true;
    ngOnInit(): void {
        setTimeout(() => {
            loading = false;
        }, 3000);
    }
}