Angular2 Firebase : Response for preflight has invalid HTTP status code 405

Question

I am new to Angular2. While trying to get the values from Firebase API , I am getting below Error:

OPTIONS https://udemy-ng-http.firebaseio.com/data 405 (Method Not Allowed)

Failed to load https://udemy-ng-http.firebaseio.com/data: Response for preflight has 

invalid HTTP status code 405

But I am able to post the data to Firebase API Endpoint.

I also tried other solutions provided on this community but it did not help. Below is my code.

Code:

 getServer(){
    let headers = new Headers();
    headers.append('Access-Control-Allow-Headers', 'Content-Type');
    headers.append('Access-Control-Allow-Origin', '*');
    headers.append('Content-Type', 'application/json') ;
    headers.append('charset','UTF-8');
    headers.append('Accept','application/json');
    let options = new RequestOptions({ headers: headers });

    return this.http.get('https://udemy-ng-http.firebaseio.com/data',options)
        .map(
            (response: Response) => {
                const data = response.json();
                for (const server of data) {
                  server.name = 'FETCHED_' + server.name;
                }
                return data;
            }
        )
        .catch(
            (error: Response) => {
              return Observable.throw('Something went wrong');
            }
        );
}

Answer 1

Try removing headers.append('Access-Control-Allow-Origin', '*');

There are two sample functions provided by the Firebase team that demonstrate the use of CORS:

• Time server with date formatting
• HTTPS endpoint requiring Authentication

The second sample uses a different way of working with cors than you're currently using.

Also, consider importing like this, as shown in the samples:

const cors = require('cors')({origin: true});