<dx-data-grid [dataSource]="priorities">
<dxi-column dataField="Priority"></dxi-column>
</dx-data-grid>

ngOnInit() {

this.ds.list('priority').valueChanges().subscribe(
  data => {
    console.dir(data)
    for(var k = 0; k<data.length; k++){
      var prior = new priority();
      prior.Prioritie = data[k].toString();
      this.priorities.push(prior);
    }
    console.dir(this.priorities);}