fix(typeahead): fix focus after leaving control (#4622)

demo/src/app/components/+typeahead/demos/cancel-on-focus-lost/cancel-on-focus-lost.html

@@ -0,0 +1,11 @@
+<pre class="card card-block card-header">Model: {{asyncSelected | json}}</pre>
+
+<input [(ngModel)]="asyncSelected"
+       [typeahead]="dataSource"
+       (typeaheadLoading)="changeTypeaheadLoading($event)"
+       (typeaheadOnSelect)="typeaheadOnSelect($event)"
+       [typeaheadOptionsLimit]="7"
+       typeaheadOptionField="name"
+       placeholder="Locations loaded with timeout"
+       class="form-control">
+<div *ngIf="typeaheadLoading">Loading</div>

demo/src/app/components/+typeahead/demos/cancel-on-focus-lost/cancel-on-focus-lost.ts

@@ -0,0 +1,102 @@
+import { Component } from '@angular/core';
+import { Observable, of } from 'rxjs';
+import { TypeaheadMatch } from 'ngx-bootstrap/typeahead';
+import { mergeMap, delay } from 'rxjs/operators';
+import { TypeaheadConfig } from 'ngx-bootstrap/typeahead';
+
+export function getTypeaheadConfig(): TypeaheadConfig {
+  return Object.assign(new TypeaheadConfig(), { cancelRequestOnFocusLost: true });
+}
+
+@Component({
+  selector: 'demo-typeahead-cancel-on-focus-lost',
+  templateUrl: './cancel-on-focus-lost.html',
+  providers: [{ provide: TypeaheadConfig, useFactory: getTypeaheadConfig }]
+})
+export class DemoTypeaheadCancelRequestOnFocusLostComponent {
+  asyncSelected: string;
+  typeaheadLoading: boolean;
+  typeaheadNoResults: boolean;
+  dataSource: Observable<any>;
+  statesComplex: any[] = [
+    { id: 1, name: 'Alabama', region: 'South' },
+    { id: 2, name: 'Alaska', region: 'West' },
+    { id: 3, name: 'Arizona', region: 'West' },
+    { id: 4, name: 'Arkansas', region: 'South' },
+    { id: 5, name: 'California', region: 'West' },
+    { id: 6, name: 'Colorado', region: 'West' },
+    { id: 7, name: 'Connecticut', region: 'Northeast' },
+    { id: 8, name: 'Delaware', region: 'South' },
+    { id: 9, name: 'Florida', region: 'South' },
+    { id: 10, name: 'Georgia', region: 'South' },
+    { id: 11, name: 'Hawaii', region: 'West' },
+    { id: 12, name: 'Idaho', region: 'West' },
+    { id: 13, name: 'Illinois', region: 'Midwest' },
+    { id: 14, name: 'Indiana', region: 'Midwest' },
+    { id: 15, name: 'Iowa', region: 'Midwest' },
+    { id: 16, name: 'Kansas', region: 'Midwest' },
+    { id: 17, name: 'Kentucky', region: 'South' },
+    { id: 18, name: 'Louisiana', region: 'South' },
+    { id: 19, name: 'Maine', region: 'Northeast' },
+    { id: 21, name: 'Maryland', region: 'South' },
+    { id: 22, name: 'Massachusetts', region: 'Northeast' },
+    { id: 23, name: 'Michigan', region: 'Midwest' },
+    { id: 24, name: 'Minnesota', region: 'Midwest' },
+    { id: 25, name: 'Mississippi', region: 'South' },
+    { id: 26, name: 'Missouri', region: 'Midwest' },
+    { id: 27, name: 'Montana', region: 'West' },
+    { id: 28, name: 'Nebraska', region: 'Midwest' },
+    { id: 29, name: 'Nevada', region: 'West' },
+    { id: 30, name: 'New Hampshire', region: 'Northeast' },
+    { id: 31, name: 'New Jersey', region: 'Northeast' },
+    { id: 32, name: 'New Mexico', region: 'West' },
+    { id: 33, name: 'New York', region: 'Northeast' },
+    { id: 34, name: 'North Dakota', region: 'Midwest' },
+    { id: 35, name: 'North Carolina', region: 'South' },
+    { id: 36, name: 'Ohio', region: 'Midwest' },
+    { id: 37, name: 'Oklahoma', region: 'South' },
+    { id: 38, name: 'Oregon', region: 'West' },
+    { id: 39, name: 'Pennsylvania', region: 'Northeast' },
+    { id: 40, name: 'Rhode Island', region: 'Northeast' },
+    { id: 41, name: 'South Carolina', region: 'South' },
+    { id: 42, name: 'South Dakota', region: 'Midwest' },
+    { id: 43, name: 'Tennessee', region: 'South' },
+    { id: 44, name: 'Texas', region: 'South' },
+    { id: 45, name: 'Utah', region: 'West' },
+    { id: 46, name: 'Vermont', region: 'Northeast' },
+    { id: 47, name: 'Virginia', region: 'South' },
+    { id: 48, name: 'Washington', region: 'South' },
+    { id: 49, name: 'West Virginia', region: 'South' },
+    { id: 50, name: 'Wisconsin', region: 'Midwest' },
+    { id: 51, name: 'Wyoming', region: 'West' }
+  ];
+
+  constructor() {
+    this.dataSource = Observable.create((observer: any) => {
+      // Runs on every search
+      observer.next(this.asyncSelected);
+    })
+      .pipe(
+        mergeMap((token: string) => this.getStatesAsObservable(token)),
+        delay(1000)
+      );
+  }
+
+  getStatesAsObservable(token: string): Observable<any> {
+    const query = new RegExp(token, 'i');
+
+    return of(
+      this.statesComplex.filter((state: any) => {
+        return query.test(state.name);
+      })
+    );
+  }
+
+  changeTypeaheadLoading(e: boolean): void {
+    this.typeaheadLoading = e;
+  }
+
+  typeaheadOnSelect(e: TypeaheadMatch): void {
+    console.log('Selected value: ', e.value);
+  }
+}

demo/src/app/components/+typeahead/demos/index.ts

@@ -7,6 +7,8 @@ import { DemoTypeaheadContainerComponent } from './container/container';
 import { DemoTypeaheadDelayComponent } from './delay/delay';
 import { DemoTypeaheadDropupComponent } from './dropup/dropup';
 import { DemoTypeaheadFieldComponent } from './field/field';
+import { DemoTypeaheadCancelRequestOnFocusLostComponent } from './cancel-on-focus-lost/cancel-on-focus-lost';
+import { DemoTypeaheadReactiveFormComponent } from './reactive-form/reactive-form';
 import { DemoTypeaheadFirstItemActiveComponent } from './first-item-active/first-item-active';
 import { DemoTypeaheadFormComponent } from './form/form';
 import { DemoTypeaheadGroupingComponent } from './grouping/grouping';
@@ -17,7 +19,6 @@ import { DemoTypeaheadNoResultComponent } from './no-result/no-result';
 import { DemoTypeaheadOnBlurComponent } from './on-blur/on-blur';
 import { DemoTypeaheadOnSelectComponent } from './on-select/on-select';
 import { DemoTypeaheadPhraseDelimitersComponent } from './phrase-delimiters/phrase-delimiters';
-import { DemoTypeaheadReactiveFormComponent } from './reactive-form/reactive-form';
 import { DemoTypeaheadScrollableComponent } from './scrollable/scrollable';
 import { DemotypeaheadSelectFirstItemComponent } from './selected-first-item/selected-first-item';
 import { DemoTypeaheadShowOnBlurComponent } from './show-on-blur/show-on-blur';
@@ -33,6 +34,9 @@ export const DEMO_COMPONENTS = [
   DemoTypeaheadDelayComponent,
   DemoTypeaheadDropupComponent,
   DemoTypeaheadFieldComponent,
+  DemoTypeaheadAsyncComponent,
+  DemoTypeaheadCancelRequestOnFocusLostComponent,
+  DemoTypeaheadReactiveFormComponent,
   DemoTypeaheadFirstItemActiveComponent,
   DemoTypeaheadFormComponent,
   DemoTypeaheadGroupingComponent,

demo/src/app/components/+typeahead/typeahead-section.list.ts

@@ -3,13 +3,15 @@ import { ContentSection } from '../../docs/models/content-section.model';
 import { DemoTopSectionComponent } from '../../docs/demo-section-components/demo-top-section';
 import { DemoTypeaheadAdaptivePositionComponent } from './demos/adaptive-position/adaptive-position';
 import { DemoTypeaheadAnimatedComponent } from './demos/animated/animated';
-import { DemoTypeaheadAsyncComponent } from './demos/async/async';
 import { DemoTypeaheadBasicComponent } from './demos/basic/basic';
+import { DemoTypeaheadCancelRequestOnFocusLostComponent } from './demos/cancel-on-focus-lost/cancel-on-focus-lost';
 import { DemoTypeaheadConfigComponent } from './demos/config/config';
 import { DemoTypeaheadContainerComponent } from './demos/container/container';
 import { DemoTypeaheadDelayComponent } from './demos/delay/delay';
 import { DemoTypeaheadDropupComponent } from './demos/dropup/dropup';
 import { DemoTypeaheadFieldComponent } from './demos/field/field';
+import { DemoTypeaheadAsyncComponent } from './demos/async/async';
+import { DemoTypeaheadReactiveFormComponent } from './demos/reactive-form/reactive-form';
 import { DemoTypeaheadFormComponent } from './demos/form/form';
 import { DemoTypeaheadGroupingComponent } from './demos/grouping/grouping';
 import { DemoTypeaheadItemTemplateComponent } from './demos/item-template/item-template';
@@ -19,7 +21,6 @@ import { DemoTypeaheadNoResultComponent } from './demos/no-result/no-result';
 import { DemoTypeaheadOnBlurComponent } from './demos/on-blur/on-blur';
 import { DemoTypeaheadOnSelectComponent } from './demos/on-select/on-select';
 import { DemoTypeaheadPhraseDelimitersComponent } from './demos/phrase-delimiters/phrase-delimiters';
-import { DemoTypeaheadReactiveFormComponent } from './demos/reactive-form/reactive-form';
 import { DemoTypeaheadScrollableComponent } from './demos/scrollable/scrollable';
 import { DemotypeaheadSelectFirstItemComponent } from './demos/selected-first-item/selected-first-item';
 import { DemoTypeaheadShowOnBlurComponent } from './demos/show-on-blur/show-on-blur';
@@ -89,6 +90,14 @@ export const demoComponentContent: ContentSection[] = [
         html: require('!!raw-loader!./demos/async/async.html'),
         outlet: DemoTypeaheadAsyncComponent
       },
+      {
+        title: 'Cancel on focus lost',
+        anchor: 'cancel-on-focus-lost',
+        description: `<p>Set config property <code>cancelRequestOnFocusLost</code> to <code>true</code> if you want to cancel async request on focus lost event</p>`,
+        component: require('!!raw-loader!./demos/cancel-on-focus-lost/cancel-on-focus-lost.ts'),
+        html: require('!!raw-loader!./demos/cancel-on-focus-lost/cancel-on-focus-lost.html'),
+        outlet: DemoTypeaheadCancelRequestOnFocusLostComponent
+      },
       {
         title: 'With delay',
         anchor: 'delay',
@@ -233,7 +242,7 @@ export const demoComponentContent: ContentSection[] = [
         title: 'Show results on blur',
         anchor: 'show-on-blur',
         description: `
-          <p>Use input property <code>typeaheadHideResultsOnBlur</code> or config property <code>hideResultsOnBlur</code> 
+          <p>Use input property <code>typeaheadHideResultsOnBlur</code> or config property <code>hideResultsOnBlur</code>
           to prevent hiding typeahead's results until a user doesn't choose an item</p>
         `,
         component: require('!!raw-loader!./demos/show-on-blur/show-on-blur.ts'),

demo/src/ng-api-doc.ts

@@ -3780,6 +3780,12 @@ export const ngdoc: any = {
         "type": "boolean",
         "description": "<p>used to hide results on blur</p>\n"
       },
+      {
+        "name": "cancelRequestOnFocusLost",
+        "defaultValue": "false",
+        "type": "boolean",
+        "description": "<p>if true, typeahead will cancel async request after focus was lost</p>\n"
+      },
       {
         "name": "isAnimated",
         "defaultValue": "false",
@@ -3920,7 +3926,7 @@ export const ngdoc: any = {
         "name": "typeaheadSingleWords",
         "defaultValue": "true",
         "type": "boolean",
-        "description": "<p>Can be use to search words by inserting a single white space between each characters\nfor example &#39;C a l i f o r n i a&#39; will match &#39;California&#39;.</p>\n"
+        "description": "<p>can be use to search words by inserting a single white space between each characters\nfor example &#39;C a l i f o r n i a&#39; will match &#39;California&#39;.</p>\n"
       },
       {
         "name": "typeaheadWaitMs",
@@ -3932,7 +3938,7 @@ export const ngdoc: any = {
         "defaultValue": " ",
         "type": "string",
         "description": "<p>should be used only in case typeaheadSingleWords attribute is true.\nSets the word delimiter to break words. Defaults to space.</p>\n"
-      }
+      },
     ],
     "outputs": [
       {

src/typeahead/typeahead.config.ts

@@ -9,6 +9,8 @@ export class TypeaheadConfig {
   isAnimated = false;
   /** used to hide results on blur */
   hideResultsOnBlur = true;
+  /** if true, typeahead will cancel async request on blur */
+  cancelRequestOnFocusLost = false;
   /** used to choose the first item in typeahead container */
   selectFirstItem = true;
   /** used to active/inactive the first item in typeahead container */

src/typeahead/typeahead.directive.ts

@@ -137,6 +137,8 @@ export class TypeaheadDirective implements OnInit, OnDestroy {
   _container: TypeaheadContainerComponent;
   isActiveItemChanged = false;
   isTypeaheadOptionsListActive = false;
+  isFocused = false;
+  cancelRequestOnFocusLost = false;
 
   // tslint:disable-next-line:no-any
   protected keyUpEventEmitter: EventEmitter<any> = new EventEmitter();
@@ -168,6 +170,7 @@ export class TypeaheadDirective implements OnInit, OnDestroy {
     Object.assign(this,
       {
         typeaheadHideResultsOnBlur: config.hideResultsOnBlur,
+        typeaheadCancelRequestOnFocusLost: config.cancelRequestOnFocusLost,
         typeaheadSelectFirstItem: config.selectFirstItem,
         typeaheadIsFirstItemActive: config.isFirstItemActive,
         typeaheadMinLength: config.minLength,
@@ -269,6 +272,7 @@ export class TypeaheadDirective implements OnInit, OnDestroy {
   @HostListener('click')
   @HostListener('focus')
   onFocus(): void {
+    this.isFocused = true;
     if (this.typeaheadMinLength === 0) {
       this.typeaheadLoading.emit(true);
       this.keyUpEventEmitter.emit(this.element.nativeElement.value || '');
@@ -277,6 +281,7 @@ export class TypeaheadDirective implements OnInit, OnDestroy {
 
   @HostListener('blur')
   onBlur(): void {
+    this.isFocused = false;
     if (this._container && !this._container.isFocused) {
       this.typeaheadOnBlur.emit(this._container.active);
     }
@@ -492,6 +497,10 @@ export class TypeaheadDirective implements OnInit, OnDestroy {
       return;
     }
 
+    if (!this.isFocused && this.cancelRequestOnFocusLost) {
+      return;
+    }
+
     if (this._container) {
       // fix: remove usage of ngControl internals
       const _controlValue = (this.typeaheadLatinize