Initial commit for the Angular part. We are nowhere yet.

bookie/src/app/core/error-logger.service.ts

@@ -0,0 +1,36 @@
+import {Injectable} from '@angular/core';
+import {Observable} from 'rxjs/internal/Observable';
+import {throwError} from 'rxjs';
+
+@Injectable({
+  providedIn: 'root'
+})
+export class ErrorLoggerService {
+  constructor() {
+  }
+
+  /**
+   * Handle Http operation that failed.
+   * Let the app continue.
+   * @param operation - name of the operation that failed
+   * @param result - optional value to return as the observable result
+   */
+  public handleError<T>(serviceName = 'error-logger', operation = 'operation', result?: T) {
+    return (error: any): Observable<T> => {
+
+      // TODO: send the error to remote logging infrastructure
+      console.error(error); // log to console instead
+
+      // TODO: better job of transforming error for user consumption
+      this.log(serviceName, `${operation} failed: ${error.message}`);
+
+      // // Let the app keep running by returning an empty result.
+      // return of(result as T);
+      return throwError(error);
+    };
+  }
+
+  public log(serviceName = 'error-logger', message: string) {
+    console.log(serviceName + 'Service: ' + message);
+  }
+}