Strict done!!

overlord/src/app/cost-centre/cost-centre-detail/cost-centre-detail.component.ts

@@ -14,7 +14,7 @@ import { CostCentreService } from '../cost-centre.service';
 export class CostCentreDetailComponent implements OnInit, AfterViewInit {
   @ViewChild('nameElement', { static: true }) nameElement?: ElementRef;
   form: FormGroup;
-  item: CostCentre;
+  item: CostCentre = new CostCentre();
 
   constructor(
     private route: ActivatedRoute,
@@ -45,7 +45,7 @@ export class CostCentreDetailComponent implements OnInit, AfterViewInit {
 
   ngAfterViewInit() {
     setTimeout(() => {
-      this.nameElement.nativeElement.focus();
+      if (this.nameElement) this.nameElement.nativeElement.focus();
     }, 0);
   }
 

overlord/src/app/cost-centre/cost-centre-list/cost-centre-list.component.ts

@@ -15,8 +15,8 @@ import { CostCentreListDataSource } from './cost-centre-list-datasource';
 export class CostCentreListComponent implements OnInit {
   @ViewChild(MatPaginator, { static: true }) paginator?: MatPaginator;
   @ViewChild(MatSort, { static: true }) sort?: MatSort;
-  dataSource: CostCentreListDataSource;
-  list: CostCentre[];
+  list: CostCentre[] = [];
+  dataSource: CostCentreListDataSource = new CostCentreListDataSource(this.list);
   /** Columns displayed in the table. Columns IDs can be added, removed, or reordered. */
   displayedColumns = ['name', 'isFixture'];
 
@@ -28,6 +28,6 @@ export class CostCentreListComponent implements OnInit {
 
       this.list = data.list;
     });
-    this.dataSource = new CostCentreListDataSource(this.paginator, this.sort, this.list);
+    this.dataSource = new CostCentreListDataSource(this.list, this.paginator, this.sort);
   }
 }

overlord/src/app/cost-centre/cost-centre.service.ts

@@ -18,7 +18,7 @@ const serviceName = 'CostCentreService';
 export class CostCentreService {
   constructor(private http: HttpClient, private log: ErrorLoggerService) {}
 
-  get(id: string): Observable<CostCentre> {
+  get(id: string | null): Observable<CostCentre> {
     const getUrl: string = id === null ? `${url}` : `${url}/${id}`;
     return <Observable<CostCentre>>(
       this.http