Disabled column sort for alarm widget for details key

@@ -78,7 +78,9 @@
           </mat-cell>
           </mat-cell>
         </ng-container>
         </ng-container>
         <ng-container [matColumnDef]="column.def" *ngFor="let column of columns; trackBy: trackByColumnDef;">
         <ng-container [matColumnDef]="column.def" *ngFor="let column of columns; trackBy: trackByColumnDef;">
-          <mat-header-cell [ngStyle]="headerStyle(column)" *matHeaderCellDef mat-sort-header> {{ column.title }} </mat-header-cell>
+          <mat-header-cell [ngStyle]="headerStyle(column)" *matHeaderCellDef mat-sort-header [disabled]="isSorting(column)">
+            {{ column.title }}
+          </mat-header-cell>
           <mat-cell *matCellDef="let alarm;"
           <mat-cell *matCellDef="let alarm;"
                     [innerHTML]="cellContent(alarm, column)"
                     [innerHTML]="cellContent(alarm, column)"
                     [ngStyle]="cellStyle(alarm, column)">
                     [ngStyle]="cellStyle(alarm, column)">

@@ -840,6 +840,9 @@ export class AlarmsTableWidgetComponent extends PageComponent implements OnInit,
     }
     }
   }
   }
 
 
+  isSorting(column: EntityColumn): boolean {
+    return column.type === DataKeyType.alarm && column.name.startsWith('details.');
+  }
 }
 }
 
 
 class AlarmsDatasource implements DataSource<AlarmDataInfo> {
 class AlarmsDatasource implements DataSource<AlarmDataInfo> {