fix(typeahead): revert filter functionality

Revert filter functionality to allow developers implement their own

Close valor-software#5624

demo/src/app/components/+typeahead/demos/async/async.html

@@ -4,5 +4,6 @@
        [typeahead]="dataSource"
        [typeaheadAsync]="true"
        typeaheadOptionField="name"
+       (typeaheadLoading)="changeTypeaheadLoading($event)"
        placeholder="Locations loaded via observable"
        class="form-control">

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

@@ -1,6 +1,7 @@
 import { Component } from '@angular/core';
 
-import { Observable, of } from 'rxjs';
+import { Observable, of, Subscriber } from 'rxjs';
+import { mergeMap } from 'rxjs/operators';
 
 interface DataSourceType {
   id: number;
@@ -15,6 +16,7 @@ interface DataSourceType {
 export class DemoTypeaheadAsyncComponent {
   asyncSelected: string;
   dataSource: Observable<DataSourceType[]>;
+  typeaheadLoading: boolean;
   statesComplex: DataSourceType[] = [
     { id: 1, name: 'Alabama', region: 'South' },
     { id: 2, name: 'Alaska', region: 'West' },
@@ -69,6 +71,26 @@ export class DemoTypeaheadAsyncComponent {
   ];
 
   constructor() {
-    this.dataSource = of(this.statesComplex);
+    this.dataSource = new Observable((observer: Subscriber<string>) => {
+      // Runs on every search
+      observer.next(this.asyncSelected);
+    })
+      .pipe(
+        mergeMap((token: string) => this.getStatesAsObservable(token))
+      );
+  }
+
+  getStatesAsObservable(token: string): Observable<DataSourceType[]> {
+    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;
   }
 }

src/typeahead/typeahead.directive.ts

@@ -22,7 +22,7 @@ import { TypeaheadContainerComponent } from './typeahead-container.component';
 import { TypeaheadMatch } from './typeahead-match.class';
 import { TypeaheadConfig } from './typeahead.config';
 import { getValueFromObject, latinize, tokenize } from './typeahead-utils';
-import { debounceTime, filter, map, mergeMap, switchMap, toArray } from 'rxjs/operators';
+import { debounceTime, filter, mergeMap, switchMap, toArray } from 'rxjs/operators';
 
 @Directive({selector: '[typeahead]', exportAs: 'bs-typeahead'})
 export class TypeaheadDirective implements OnInit, OnDestroy {
@@ -394,18 +394,7 @@ export class TypeaheadDirective implements OnInit, OnDestroy {
       this.keyUpEventEmitter
         .pipe(
           debounceTime(this.typeaheadWaitMs),
-          switchMap((value: string) => {
-            return this.typeahead
-              .pipe(
-                // tslint:disable-next-line:no-any
-                map((typeahead: any[]) => {
-                  const normalizedQuery = this.normalizeQuery(value);
-
-                  return typeahead.filter((option: any) =>
-                    option && this.testMatch(this.normalizeOption(option), normalizedQuery));
-                })
-              );
-          })
+          switchMap(() => this.typeahead)
         )
         .subscribe((matches: TypeaheadMatch[]) => {
           this.finalizeAsyncCall(matches);