Angular2 HTTP POST发生错误SyntaxError：JSON输入的意外结束

Question

I have error meantime angular2 post rest data to NodeJS backend.

I see POST is done, server is LOG correct data, but error is showing up on browser.

An error occurred: SyntaxError: JSON.parse: unexpected end of data at line 1 column 1 of the JSON data

My NG2 call and service:

onSubmit(form:FormGroup) {
        let userform: FormGroup = form.value;
        console.log("userform: ", userform);

        if (form.valid) {
            console.log(form.value);
            this.appService.signIn(userform)  
                .subscribe(form => console.log('subscribe: ', form))
        } else {
            console.log("Form is not VALID!"); 
        }
    }

SERVICE:

signIn(dataUser: Object): Observable<User> {
   dataUser = JSON.stringify(dataUser);
   debugger;

    let headers = new Headers({
        'Content-Type': 'application/json',
        'Access-Control-Allow-Origin': 'http://127.0.0.1:3005'
    });
    let options = new RequestOptions({ headers: headers });

    console.log("data: ", dataUser, "\nHeaders: ", headers);

    return this.http
        .post( this.signInUrl, dataUser, options)
        .map( (res:Response) => res.json().data || {  } as User )
        .catch(this.handleError);

}

and nodeJS:

app.post('/login', function (req, res) {
    console.log("Recived login request!");
    console.log("Request: ", req.body);
    res.header({
        'Content-Type': 'application/json',
        'Access-Control-Allow-Origin': '*',
        'Access-Control-Allow-Methods': 'GET,PUT,POST,DELETE',
        'Accept': 'q=0.8;application/json;q=0.9'
    })
    res.end();
});

In post we have: "{"username":"username","password":"password"}".

What I'am making wrong? Please for help or solution.

Answer 1

Awwwww. That was my bad, Take care of your NodeJS Server response. After get POST, should be sended any res.json({status: "OK"}) or sommething similar, to get response. This error was not because of Angular2, but because of NodeJS. Browser get empty response from nodeJS, or it was not JSON format.