Merge pull request #7766 from IgniteUI/PMiteva/cancellable_onSearchInput_10.1

Make onSearchInput cancellable

Author: Lipata

CHANGELOG.md

@@ -7,6 +7,7 @@ All notable changes for each version of this project will be documented in this
 ### General
 - `igxCombo`
     - **Behavioral Change** - Change default positioning strategy from `ConnectedPositioningStrategy` to `AutoPositionStrategy`. The [`Auto`](https://www.infragistics.com/products/ignite-ui-angular/angular/components/overlay_position.html#auto) strategy will initially try to show the element like the Connected strategy does. If the element goes out of the viewport Auto will flip the starting point and the direction, i.e. if the direction is 'bottom', it will switch it to 'top' and so on. If after flipping direction the content goes out of the view, auto strategy will revert to initial start point and direction and will push the content into the view. Note after pushing the content it may hide the combo's input.
+    - Make `onSearchInput` event cancellable. The event args type has been changed to `IComboSearchInputEventArgs`, which have the following properties: `searchText` - holds the text typed into the search input, `owner` - holds a reference to the combo component and `cancel` - indicates whether the event should be canceled.
 - `IgxOverlay`
     - Added new property `closeOnEscape` in `OverlaySettings` that controls whether the overlay should close on escape keypress. By default `closeOnEsc` is set to `false`.
     - **Behavioral Change** - `modal` overlays shown directly through the Overlay Service no longer close on Escape by default. That behavior can now be specified using the `closeOnEscape` property.

projects/igniteui-angular/src/lib/combo/combo.component.spec.ts

@@ -18,6 +18,7 @@ import { configureTestSuite } from '../test-utils/configure-suite';
 import { DisplayDensity } from '../core/density';
 import { AbsoluteScrollStrategy, ConnectedPositioningStrategy } from '../services/public_api';
 import { IgxSelectionAPIService } from '../core/selection';
+import { CancelableEventArgs } from '../core/utils';
 
 const CSS_CLASS_COMBO = 'igx-combo';
 const CSS_CLASS_COMBO_DROPDOWN = 'igx-combo__drop-down';
@@ -530,21 +531,42 @@ describe('igxCombo', () => {
             expect(matchSpy).toHaveBeenCalledTimes(1);
             expect(combo.onSearchInput.emit).toHaveBeenCalledTimes(0);
 
+            const args = {
+                searchText: 'Fake',
+                owner: combo,
+                cancel: false
+            };
             combo.handleInputChange('Fake');
             expect(matchSpy).toHaveBeenCalledTimes(2);
             expect(combo.onSearchInput.emit).toHaveBeenCalledTimes(1);
-            expect(combo.onSearchInput.emit).toHaveBeenCalledWith('Fake');
+            expect(combo.onSearchInput.emit).toHaveBeenCalledWith(args);
 
+            args.searchText = '';
             combo.handleInputChange('');
             expect(matchSpy).toHaveBeenCalledTimes(3);
             expect(combo.onSearchInput.emit).toHaveBeenCalledTimes(2);
-            expect(combo.onSearchInput.emit).toHaveBeenCalledWith('');
+            expect(combo.onSearchInput.emit).toHaveBeenCalledWith(args);
 
             combo.filterable = false;
             combo.handleInputChange();
             expect(matchSpy).toHaveBeenCalledTimes(4);
             expect(combo.onSearchInput.emit).toHaveBeenCalledTimes(2);
         });
+        it('should be able to cancel onSearchInput', () => {
+            combo = new IgxComboComponent({ nativeElement: null }, mockCdr, mockSelection as any, mockComboService, null, mockInjector);
+            combo.ngOnInit();
+            combo.data = data;
+            combo.filterable = true;
+            combo.onSearchInput.subscribe((e) => {
+                e.cancel = true;
+            });
+            const matchSpy = spyOn<any>(combo, 'checkMatch').and.callThrough();
+            spyOn(combo.onSearchInput, 'emit').and.callThrough();
+
+            combo.handleInputChange('Item1');
+            expect(combo.onSearchInput.emit).toHaveBeenCalledTimes(1);
+            expect(matchSpy).toHaveBeenCalledTimes(0);
+        });
     });
     describe('Initialization and rendering tests: ', () => {
         configureTestSuite();

projects/igniteui-angular/src/lib/combo/combo.component.ts

@@ -96,6 +96,12 @@ export interface IComboSelectionChangeEventArgs extends CancelableEventArgs, IBa
     event?: Event;
 }
 
+/** Event emitted when the igx-combo's search input changes */
+export interface IComboSearchInputEventArgs extends CancelableEventArgs, IBaseEventArgs {
+    /** The text that has been typed into the search input */
+    searchText: string;
+}
+
 export interface IComboItemAdditionEvent extends IBaseEventArgs {
     oldCollection: any[];
     addedItem: any;
@@ -483,7 +489,7 @@ export class IgxComboComponent extends DisplayDensityBase implements IgxComboBas
      * ```
      */
     @Output()
-    public onSearchInput = new EventEmitter();
+    public onSearchInput = new EventEmitter<IComboSearchInputEventArgs>();
 
     /**
      * Emitted when new chunk of data is loaded from the virtualization
@@ -981,7 +987,16 @@ export class IgxComboComponent extends DisplayDensityBase implements IgxComboBas
      */
     public handleInputChange(event?: string) {
         if (event !== undefined) {
-            this.onSearchInput.emit(event);
+            const args: IComboSearchInputEventArgs = {
+                searchText: event,
+                owner: this,
+                cancel: false
+            };
+            this.onSearchInput.emit(args);
+            if (args.cancel) {
+                this.searchValue = null;
+                return;
+            }
         }
         this.checkMatch();
     }
@@ -1436,8 +1451,8 @@ export class IgxComboComponent extends DisplayDensityBase implements IgxComboBas
     /** Returns a string that should be populated in the combo's text box */
     private concatDisplayText(selection: any[]): string {
         const value = this.displayKey !== null && this.displayKey !== undefined ?
-        this.convertKeysToItems(selection).map(entry => entry[this.displayKey]).join(', ') :
-        selection.join(', ');
+            this.convertKeysToItems(selection).map(entry => entry[this.displayKey]).join(', ') :
+            selection.join(', ');
         return value;
     }