6: Get Data from a Server

[examples/angular-tour-of-heroes] / src / app / hero.service.ts

diff --git a/src/app/hero.service.ts b/src/app/hero.service.ts
index f8374b1..b794b8a 100644 (file)
--- a/src/app/hero.service.ts
+++ b/src/app/hero.service.ts
@@ -12,7 +12,10 @@ import { catchError, tap } from 'rxjs/operators';
 })
 export class HeroService {
 
-  private heroesUrl = 'api/heroes';  // URL to web api
+  heroesUrl = 'api/heroes';  // URL to web api
+  httpOptions = {
+    headers: new HttpHeaders({ 'Content-Type': 'application/json' })
+  };
 
   constructor(
     private http: HttpClient,
@@ -28,14 +31,44 @@ export class HeroService {
       );
   }
 
+  /** POST: add a new hero to the server */
+  addHero(hero: Hero): Observable<Hero> {
+    return this.http.post<Hero>(this.heroesUrl, hero, this.httpOptions).pipe(
+      tap((newHero: Hero) => this.log(`added hero w/ id=${newHero.id}`)),
+      catchError(this.handleError<Hero>('addHero'))
+    );
+  }
+
+  /** GET hero by id. Will 404 if id not found */
   getHero(id: number): Observable<Hero> {
     this.log(`requested hero id=${id}`);
-    const found: Hero | undefined = HEROES.find(hero => hero.id === id);
-    if (found === undefined) {
-      return EMPTY;
-    } else {
-      return of(found);
+    const url = `${this.heroesUrl}/${id}`;
+    return this.http.get<Hero>(url).pipe(
+      tap(_ => this.log(`fetched hero id=${id}`)),
+      catchError(this.handleError<Hero>(`getHero id=${id}`))
+    );
+  }
+
+  /** PUT: update the hero on the server */
+  updateHero(hero: Hero): Observable<any> {
+    return this.http.put(this.heroesUrl, hero, this.httpOptions).pipe(
+      tap(_ => this.log(`updated hero id=${hero.id}`)),
+      catchError(this.handleError<any>('updateHero'))
+    );
+  }
+
+  /* GET heroes whose name contains search term */
+  searchHeroes(term: string): Observable<Hero[]> {
+    if (!term.trim()) {
+      // if not search term, return empty hero array.
+      return of([]);
     }
+    return this.http.get<Hero[]>(`${this.heroesUrl}/?name=${term}`).pipe(
+      tap(x => x.length ?
+        this.log(`found heroes matching "${term}"`) :
+        this.log(`no heroes matching "${term}"`)),
+      catchError(this.handleError<Hero[]>('searchHeroes', []))
+    );
   }
 
   /**
@@ -54,7 +87,11 @@ export class HeroService {
       this.log(`${operation} failed: ${error.message}`);
 
       // Let the app keep running by returning an empty result.
-      return of(result as T);
+      if (result === undefined) {
+        return EMPTY as Observable<T>;
+      } else {
+        return of(result as T);
+      }
     };
   }