POST表格Angular2

Question

I'm trying to execute a login form with Angular2 with NodeJS API as a backend server.

I cant't post any request to the API. Here it's my front code example:

private authenticate_url = "Server_URL:PORT/authenticate";
login(username: string, password: string): Observable<User> {
    let headers = new Headers({ 'Content-Type': 'application/json' });
    let options = new RequestOptions({ headers: headers });
    console.log("Username : "+username+" Password : "+password);
    return this.http.post(this.authenticate_url, { username, password }, options)
                .map(this.extractData)
                .catch(this.handleError)
}

Either when I'm checking network activity, no POST request was executed.

Answer 1

You need to use .subscribe() method of RxJS in order to actually execute the query, so you need to write it like this:

return this.http.post(this.authenticate_url, { username, password }, options)
                .map(this.extractData)
                .catch(this.handleError)
                .subscribe((queryResult) => {console.log(queryResult)})

Or you can do it outside your function like:

login("baksdasd", "asfasfasdf").subscribe((queryResult) => {console.log(queryResult)})

You also need to import the operators that you use:

import 'rxjs/add/operator/map';
import 'rxjs/add/operator/catch';

Here you have a detailed tutorial to solve any other problem that you may have: https://scotch.io/tutorials/angular-2-http-requests-with-observables