Angular 5 Http Request calls the Rest API's twice

Question

Can anybody help to find out what i'm doing wrong here. For every rest calls application calls the Rest APIs twice.

But first request doesn't contains request payload and No response, but both requests give same response status code.

Here is my code.

login(username: string, password: string) {
    const body = { userName: username, password: password };
    this. httpClient.post<User>(this.url, body, { headers: this.header })
    .subscribe( data => {
      return data;
 });

The browser does that (search for CORS), that's not related to Angular in any way. — Günter Zöchbauer, Dec 27 '17 at 06:32
@GünterZöchbauer Thanks for the comment But I've added CORS config in the HttpHeaders and server is also configured to handle CORS requests. — Gavishiddappa Gadagi, Dec 27 '17 at 06:35
The `OPTIONS` request is to check if the server is OK with the CORS (preflight request) request, the 2nd request is the actual request. — Günter Zöchbauer, Dec 27 '17 at 06:35
I think it is related to the preflight request send by the browsers to the server to check everything is okay or not — Rahul Singh, Dec 27 '17 at 06:36
@GünterZöchbauer Then how I can handle this in my app please provide any suggestions that will be helpful. — Gavishiddappa Gadagi, Dec 27 '17 at 06:39
@GavishiddappaGadagi checkout [this question](https://stackoverflow.com/questions/29954037/why-is-an-options-request-sent-and-can-i-disable-it) — Dhyey, Dec 27 '17 at 06:42

score 3 · Accepted Answer · answered Dec 27 '17 at 07:11

HTTP Preflight Request

This a normal behavior. When you attempt to send data to a server using HTTP methods, the browser sends a preflight request, to ensure that the requested resource and other properties are available and allowed on the backend.

Then if the server accepts the request options, the main request is sent. which is why you are seeing two requests.

So your case is pretty normal and expected.

Angular 5 Http Request calls the Rest API's twice

1 Answers1

HTTP Preflight Request