fix backend services calling 2x times postProcess

Author: Ghislain Beaulac

src/app/modules/angular-slickgrid/components/angular-slickgrid.component.ts

@@ -94,8 +94,9 @@ export class AngularSlickgridComponent implements AfterViewInit, OnDestroy, OnIn
 
   ngOnDestroy(): void {
     this._dataView = [];
+    this._gridOptions = {};
     this.controlAndPluginService.destroy();
-    this.filterService.clearFilters();
+    this.filterService.destroyFilters();
     this.resizer.destroy();
     this.grid.destroy();
   }

src/app/modules/angular-slickgrid/services/filter.service.ts

@@ -110,6 +110,16 @@ export class FilterService {
     }
   }
 
+  destroyFilters() {
+    // we need to loop through all columnFilters and delete them 1 by 1
+    // only trying to make columnFilter an empty (without looping) would not trigger a dataset change
+    for (const columnId in this._columnFilters) {
+      if (columnId && this._columnFilters[columnId]) {
+        delete this._columnFilters[columnId];
+      }
+    }
+  }
+
   testFilterCondition(operator: string, value1: any, value2: any): boolean {
     switch (operator) {
       case '<': return (value1 < value2) ? true : false;