I just want to make sure that code inside map
function should be called only on success but not on failure.
delete(department: Department): Observable<Department[]> {
return this.post('/delete', body).map(response => {
let index: number = this.departments.indexOf(department);
if (index > -1) {
this.departments.splice(index, 1);
}
return this.departments;
});
}
I don't know whether the code inside map
executes only on success or not. And also, I have to return an Observable
so , I can't apply subscribe
function here.
Observable#map
operator will be executed on success response only (eg status 200). Observable#catch
operator is intended to catch failures.
Also, Observable#catch
operator will catch javascript errors thrown while mapping success response as well. Example:
fetchDashboardData(): Observable<Dashboard> {
return this._http.get(reqUrl, reqOptions)
.map((response: Response) => new Dashboard(response.json().items[0].dashboard))
.catch((error: any) => {
if (error instanceof Error) {
// js error, e.g. response.json().items was an empty array
console.log(error); // => “Cannot read property 'dashboard' of undefined...
return Observable.throw('Incomplete response data!');
} else {
return Observable.throw('Server error!');
}
});
}
Subscribe block:
this.dashboardService.fetchDashboardData().subscribe(
(dashboard: Dashboard) => {
this.dashboard = dashboard;
console.log('Success fetching dashboard data!', dashboard);
},
(errMssg: string) => {
console.error(errMssg); // => 'Incomplete response data!'
// or 'Server error!'
},
() => {
// finally block!
}
);
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.