Renamed groups to roles in the frontend

Working:
 Account
 Cost Centre
 Employee
 Product Group
 Product
 Role
 User
 Client

overlord/src/app/role/role.service.ts

@@ -0,0 +1,64 @@
+import {Injectable} from '@angular/core';
+import {HttpClient, HttpHeaders, HttpParams} from '@angular/common/http';
+import {ErrorLoggerService} from '../core/error-logger.service';
+import {catchError} from 'rxjs/operators';
+import {Observable} from 'rxjs/internal/Observable';
+import {Role} from './role';
+
+const httpOptions = {
+  headers: new HttpHeaders({'Content-Type': 'application/json'})
+};
+const url = '/api/roles';
+const serviceName = 'RoleService';
+
+@Injectable({
+  providedIn: 'root'
+})
+export class RoleService {
+  constructor(private http: HttpClient, private log: ErrorLoggerService) {
+  }
+
+  get(id: string): Observable<Role> {
+    const getUrl: string = (id === null) ? `${url}` : `${url}/${id}`;
+    return <Observable<Role>>this.http.get<Role>(getUrl)
+      .pipe(
+        catchError(this.log.handleError(serviceName, `get id=${id}`))
+      );
+  }
+
+  list(): Observable<Role[]> {
+    return <Observable<Role[]>>this.http.get<Role[]>(`${url}/list`)
+      .pipe(
+        catchError(this.log.handleError(serviceName, 'list'))
+      );
+  }
+
+  save(role: Role): Observable<Role> {
+    return <Observable<Role>>this.http.post<Role>(`${url}`, role, httpOptions)
+      .pipe(
+        catchError(this.log.handleError(serviceName, 'save'))
+      );
+  }
+
+  update(role: Role): Observable<Role> {
+    return <Observable<Role>>this.http.put<Role>(`${url}/${role.id}`, role, httpOptions)
+      .pipe(
+        catchError(this.log.handleError(serviceName, 'update'))
+      );
+  }
+
+  saveOrUpdate(role: Role): Observable<Role> {
+    if (!role.id) {
+      return this.save(role);
+    } else {
+      return this.update(role);
+    }
+  }
+
+  delete(id: string): Observable<Role> {
+    return <Observable<Role>>this.http.delete<Role>(`${url}/${id}`, httpOptions)
+      .pipe(
+        catchError(this.log.handleError(serviceName, 'delete'))
+      );
+  }
+}