diff --git a/src/app/app.module.ts b/src/app/app.module.ts
index 75f12fb..f4a576a 100644
--- a/src/app/app.module.ts
+++ b/src/app/app.module.ts
@@ -6,24 +6,22 @@ import { UserListComponent } from './user-list/user-list.component';
 
 import { ErrorMetadataService } from './services/error-metadata.service';
 import { HighlightTextPipe } from './pipes/highlight-text.pipe';
-import { HTTP_INTERCEPTORS, HttpClientModule } from '@angular/common/http';
-import { UserListInterceptorService } from './mocks/user-list-interceptor.service';
+import { FilterLocationidPipe } from './pipes/filter-locationid.pipe';
 
 @NgModule({
-    declarations: [
-        AppComponent,
-        UserListComponent,
-        HighlightTextPipe
-    ],
-    imports: [
-        BrowserModule,
-        AppRoutingModule,
-        HttpClientModule
-    ],
-    providers: [
-    // { provide: ErrorHandler, useClass: ErrorMetadataService },
-        { provide: HTTP_INTERCEPTORS, useClass: UserListInterceptorService, multi: true }
-    ],
-    bootstrap: [AppComponent]
+  declarations: [
+    AppComponent,
+    UserListComponent,
+    HighlightTextPipe,
+    FilterLocationidPipe
+  ],
+  imports: [
+    BrowserModule,
+    AppRoutingModule
+  ],
+  providers: [
+    { provide: ErrorHandler, useClass: ErrorMetadataService }
+  ],
+  bootstrap: [AppComponent]
 })
 export class AppModule { }
diff --git a/src/app/mocks/user-list-interceptor.service.spec.ts b/src/app/mocks/user-list-interceptor.service.spec.ts
index 1668494..dccec07 100644
--- a/src/app/mocks/user-list-interceptor.service.spec.ts
+++ b/src/app/mocks/user-list-interceptor.service.spec.ts
@@ -1,16 +1,16 @@
-import { TestBed } from '@angular/core/testing';
-
-import { UserListInterceptorService } from './user-list-interceptor.service';
-
-describe('UserListInterceptorService', () => {
-    let service: UserListInterceptorService;
-
-    beforeEach(() => {
-        TestBed.configureTestingModule({});
-        service = TestBed.inject(UserListInterceptorService);
-    });
-
-    it('should be created', () => {
-        expect(service).toBeTruthy();
-    });
-});
+import { TestBed } from '@angular/core/testing';
+
+import { UserListInterceptorService } from './user-list-interceptor.service';
+
+describe('UserListInterceptorService', () => {
+  let service: UserListInterceptorService;
+
+  beforeEach(() => {
+    TestBed.configureTestingModule({});
+    service = TestBed.inject(UserListInterceptorService);
+  });
+
+  it('should be created', () => {
+    expect(service).toBeTruthy();
+  });
+});
diff --git a/src/app/mocks/user-list-interceptor.service.ts b/src/app/mocks/user-list-interceptor.service.ts
index 71e9900..e1a315d 100644
--- a/src/app/mocks/user-list-interceptor.service.ts
+++ b/src/app/mocks/user-list-interceptor.service.ts
@@ -1,41 +1,50 @@
-import { HttpEvent, HttpHandler, HttpInterceptor, HttpRequest, HttpResponse } from '@angular/common/http';
-import { Injectable } from '@angular/core';
-import { Observable } from 'rxjs';
-
-@Injectable({
-    providedIn: 'root'
-})
-export class UserListInterceptorService implements HttpInterceptor {
-  private readonly API_URL = '/mock/api/filter';
-  private readonly STORAGE_KEY = 'MOCK_API_FILTER';
-
-  intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<string>> {
-
-      if (request.url === this.API_URL && request.method === 'GET') {
-          return this.getFilter();
-      }
-
-      if (request.url === this.API_URL && request.method === 'PUT') {
-          return this.setFilter(request.body);
-      }
-
-      return next.handle(request);
-  }
-
-  private getFilter(): Observable<HttpResponse<string>> {
-      return new Observable(observer => {
-          observer.next(new HttpResponse<string>({
-              status: 200,
-              body: window.localStorage.getItem(this.STORAGE_KEY)
-          }));
-
-          observer.complete();
-      });
-  }
-
-  private setFilter(filter: string): Observable<HttpResponse<string>> {
-      window.localStorage.setItem(this.STORAGE_KEY, filter);
-      return this.getFilter();
-  }
-
-}
+import {
+  HttpEvent,
+  HttpHandler,
+  HttpInterceptor,
+  HttpRequest,
+  HttpResponse,
+} from '@angular/common/http';
+import { Injectable } from '@angular/core';
+import { Observable } from 'rxjs';
+
+@Injectable({
+  providedIn: 'root',
+})
+export class UserListInterceptorService implements HttpInterceptor {
+  private readonly API_URL = '/mock/api/filter';
+  private readonly STORAGE_KEY = 'MOCK_API_FILTER';
+
+  intercept(
+    request: HttpRequest<any>,
+    next: HttpHandler,
+  ): Observable<HttpEvent<string>> {
+    if (request.url === this.API_URL && request.method === 'GET') {
+      return this.getFilter();
+    }
+
+    if (request.url === this.API_URL && request.method === 'PUT') {
+      return this.setFilter(request.body);
+    }
+
+    return next.handle(request);
+  }
+
+  private getFilter(): Observable<HttpResponse<string>> {
+    return new Observable((observer) => {
+      observer.next(
+        new HttpResponse<string>({
+          status: 200,
+          body: window.localStorage.getItem(this.STORAGE_KEY),
+        }),
+      );
+
+      observer.complete();
+    });
+  }
+
+  private setFilter(filter: string): Observable<HttpResponse<string>> {
+    window.localStorage.setItem(this.STORAGE_KEY, filter);
+    return this.getFilter();
+  }
+}
diff --git a/src/app/pipes/filter-locationid.pipe.spec.ts b/src/app/pipes/filter-locationid.pipe.spec.ts
new file mode 100644
index 0000000..aa72284
--- /dev/null
+++ b/src/app/pipes/filter-locationid.pipe.spec.ts
@@ -0,0 +1,8 @@
+import { FilterLocationidPipe } from './filter-locationid.pipe';
+
+describe('FilterLocationidPipe', () => {
+  it('create an instance', () => {
+    const pipe = new FilterLocationidPipe();
+    expect(pipe).toBeTruthy();
+  });
+});
diff --git a/src/app/pipes/filter-locationid.pipe.ts b/src/app/pipes/filter-locationid.pipe.ts
new file mode 100644
index 0000000..7342748
--- /dev/null
+++ b/src/app/pipes/filter-locationid.pipe.ts
@@ -0,0 +1,15 @@
+import { Pipe, PipeTransform } from '@angular/core';
+import { User } from '../user/user';
+
+@Pipe({
+  name: 'filterLocationid',
+})
+export class FilterLocationidPipe implements PipeTransform {
+  transform(users: User[] | null, ...ids: number[]): User[] | null {
+    if (users === null || ids.length === 0) {
+      return users;
+    }
+
+    return users.filter((user) => ids.some((id) => user.locationId === id));
+  }
+}
diff --git a/src/app/pipes/highlight-text.pipe.ts b/src/app/pipes/highlight-text.pipe.ts
index 8ce4cff..1f3cd6e 100644
--- a/src/app/pipes/highlight-text.pipe.ts
+++ b/src/app/pipes/highlight-text.pipe.ts
@@ -1,20 +1,17 @@
 import { Pipe, PipeTransform } from '@angular/core';
 
 @Pipe({
-    name: 'highlightText'
+  name: 'highlightText',
 })
 export class HighlightTextPipe implements PipeTransform {
+  transform(value: string, filter: string): string {
+    if (filter.length === 0) return value;
 
-    transform(value: string, filter: string): string {
-        if (filter.length === 0) {
-            return value;
-        }
+    const search = new RegExp(filter, 'ig'); //i => ignore case, g => global
+    return value.replace(search, (match) => {
+      return `<span class="highlight-text">${match}</span>`;
+    });
+  }
+}
 
-        const search = new RegExp(filter, 'ig');
-
-        return value.replace(search, (match) => {
-            return `<span class="highlight-text">${match}</span>`;
-        });
-    }
-
-} 
+//cross site scripting, angular security
diff --git a/src/app/user-list/user-list.component.html b/src/app/user-list/user-list.component.html
index c3f1dda..8e93473 100644
--- a/src/app/user-list/user-list.component.html
+++ b/src/app/user-list/user-list.component.html
@@ -1,11 +1,27 @@
 <div class="input-group">
-  <input type="text" class="form-control" placeholder="Find Users by Name" #filter (keyup)="update(filter.value)">
+  <input
+    type="text"
+    class="form-control"
+    placeholder="Find Users by Name"
+    #filter
+    (keyup)="update(filter.value)"
+  />
 
   <span class="input-group-btn">
-    <button class="btn btn-default" type="button" (click)="update(''); filter.value = ''">Clear</button>
+    <button
+      class="btn btn-default"
+      type="button"
+      (click)="update(''); filter.value = ''"
+    >
+      Clear
+    </button>
   </span>
 </div>
 
 <ul class="user-list">
-  <li *ngFor="let user of (users | async)" class="user-list-item" [innerHtml]="user.name | highlightText : filter.value"></li>
+  <li
+    *ngFor="let user of users | filterLocationid: 3 : 4 : 5"
+    class="user-list-item"
+    [innerHtml]="user.name | highlightText: filter.value"
+  ></li>
 </ul>
diff --git a/src/app/user-list/user-list.component.ts b/src/app/user-list/user-list.component.ts
index b0f9f0c..e260917 100644
--- a/src/app/user-list/user-list.component.ts
+++ b/src/app/user-list/user-list.component.ts
@@ -1,34 +1,33 @@
 import { Component, OnInit } from '@angular/core';
 import { User } from '../user/user';
 import { UserListService } from './user-list.service';
+import { WebStorageService } from '../services/web-storage.service';
 
 import { WebStorageService } from '../services/web-storage.service';
 
 @Component({
-    selector: 'app-user-list',
-    templateUrl: './user-list.component.html',
-    styleUrls: ['./user-list.component.css']
+  selector: 'app-user-list',
+  templateUrl: './user-list.component.html',
+  styleUrls: ['./user-list.component.css'],
 })
 export class UserListComponent implements OnInit {
   public users: Promise<User[]> | null = null;
 
   constructor(
     private userListService: UserListService,
-    private webStorageService: WebStorageService
-  ) { }
+    private webStorage: WebStorageService,
+  ) {}
 
   public async ngOnInit(): Promise<void> {
-      this.webStorageService.getRemote().subscribe(filtered => {
-          this.users = (filtered === null) ? this.userListService.getAll() : this.userListService.filter(filtered);
-      }, error => {
-          console.error('ngOnInit Error', error);
-      });
+    const filtered = this.webStorage.get('USERS');
+    this.users =
+      filtered === null
+        ? await this.userListService.getAll()
+        : JSON.parse(filtered);
   }
 
   public async update(text: string): Promise<void> {
-      this.webStorageService.setRemote(text).subscribe(filtered => {
-          this.users = (filtered === null) ? this.userListService.getAll() : this.userListService.filter(filtered);
-      });
+    this.users = await this.userListService.filter(text);
+    this.webStorage.set('USERS', JSON.stringify(this.users));
   }
-
 }
diff --git a/src/styles.css b/src/styles.css
index 36858da..7768bd5 100644
--- a/src/styles.css
+++ b/src/styles.css
@@ -14,4 +14,4 @@ body {
 
 .highlight-text {
   background: yellow;
-}
\ No newline at end of file
+}