fix(simple-combo): correct cascading sample clear buttons behavior

Author: georgianastasov

src/app/lists/combo/simple-combo-cascading/simple-combo-cascading.component.ts

@@ -28,15 +28,16 @@ export class SimpleComboCascadingComponent implements OnInit {
             this.regionData = [];
             this.isLoadingRegions = true;
             this.loadingTime = 2000;
+        } else {
+            this.selectedRegion = undefined;
+            this.selectedCity = undefined;
         }
         setTimeout(() => {
             this.regionData = getCitiesByCountry([this.selectedCountry?.name])
             .map(c => ({name: c.region, country: c.country}))
             .filter((v, i, a) => a.findIndex(r => r.name === v.name) === i);
             this.isLoadingRegions = false;
         }, this.loadingTime)
-        this.selectedRegion = null;
-        this.selectedCity = null;
         this.citiesData = [];
         this.loadingTime = 0;
     }
@@ -47,13 +48,14 @@ export class SimpleComboCascadingComponent implements OnInit {
             this.citiesData = [];
             this.isLoadingCities = true;
             this.loadingTime = 2000;
+        } else {
+            this.selectedCity = undefined;
         }
         setTimeout(() => {
             this.citiesData = getCitiesByCountry([this.selectedCountry?.name])
             .filter(c => c.region === this.selectedRegion?.name);
             this.isLoadingCities = false;
         }, this.loadingTime)
-        this.selectedCity = null;
         this.loadingTime = 0;
     }
 }

src/app/lists/lists.module.ts

@@ -89,15 +89,15 @@ import { SimpleComboRemoteComponent } from './combo/simple-combo-remote/simple-c
         IgxButtonModule,
         IgxSliderModule,
         IgxComboModule,
+        IgxSimpleComboModule,
         IgxSwitchModule,
         IgxToastModule,
         IgxButtonGroupModule,
         IgxRippleModule,
         IgxCardModule,
         IgxTreeModule,
         IgxTooltipModule,
-        IgxFinancialChartModule,
-        IgxSimpleComboModule,
         IgxProgressBarModule,
+        IgxFinancialChartModule,
         IgxIconButtonDirective], providers: [provideHttpClient(withInterceptorsFromDi())] })
 export class ListsModule { }