The Mandatory 'grant_type' permission is missing when calling post request from Angular

Question

I am getting this error when I am calling the api via Angular. However, when I call it via Postman, I am getting the desired response. I dont know what am I doing wrong. Below is the code that I have used:

generateToken() {
    let serverUIUri: string;
    const sessionState = sessionStorage.getItem('state');
    if (sessionState === undefined || sessionState !== this.state) {
        this.router.navigate(['/account/login']);
    } else {
        this.userService.tokenGeneration("SSO", 'authorization_code', 'http://localhost:4200', this.code).subscribe((response: any) => {
            sessionStorage.setItem('demo_cookiee', response.accessToken);
            
            this.router.navigate(['/']);

        }, error => {
            this.continueToAppSelection();
            //this.router.navigate(['/account/login']);
        });
    }
}

tokenGeneration(clientId: any, authorizationCode: any, redirectUri: any, code: any): Observable<any> {
    const options = {
        headers: new HttpHeaders()
            .append('Content-Type', 'application/x-www-form-urlencoded'),
        withCredentials: true,
        origin: 'http://localhost:4200/',
        referer: 'http://localhost:4200/'
    };

    const body = {
        grant_type: authorizationCode,
        redirect_uri: redirectUri,
        client_id: clientId,
        code: code
    }
    return this.demohttp.postData(this.url + 'connect/token', options, body);
}

postData(url: string, headers: any, body: any): Observable<any> {
    return this.http.post(url, body, headers);
}

I am passing the same parameters that are in Body and Header to postman as well. There it is successfully getting a response. However, through code it gives the below error:

Object {error: "invalid_request", error_description: "The mandatory 'grant_type' parameter is missing."}

I am passing the grant_type as 'authorization_code', it still gives the error though. Any idea what am I doing wrong?

Answer 1

I rectified the issue, the body object was created correctly due to which I was getting the error The mandatory 'grant_type' parameter is missing.. However after fixing the body object, it worked perfectly fine.

tokenGeneration(clientId: any, authorizationCode: any, redirectUri: any, code: any): Observable<any> {
    const options = {
        headers: new HttpHeaders()
            .append('Content-Type', 'application/x-www-form-urlencoded'),
        withCredentials: true
    };

    const body = 'grant_type=' + authorizationCode + '&redirect_uri=' + redirectUri + '&client_id=' + clientId + '&code=' + code;

    return this.demoHttp.postDataWithOptions(this.ssoUrl + 'connect/token',options, body);
}