I am struggling with this error for days. Here are the steps that I followed to obtain the token.
- login in client side using facebook sdk
- pass the short lived token to server
- get long lived token
here is the error
{"error":{"message":"Cannot specify an empty identifier","type":"OAuthException","code":2500,"fbtrace_id":"BIEldWBZras"}}
Should Client authenticate directly? It looks like the oauth authentication is not established because of error code 2500. I also don't understand this sentence from the error "Cannot specify an empty identifier" here is the code so far:
func handleExtendFacebookToken(w http.ResponseWriter, r *http.Request) {
w.Header().Add("Access-Control-Allow-Origin", "*")
shortLivedToken := r.FormValue("token")
tokenExpiration := time.Now().Local()
resp, err := http.Get("https://graph.facebook.com/oauth/access_token?client_id=" + oauthConf.ClientID + "&client_secret=" + oauthConf.ClientSecret + "&grant_type=fb_exchange_token&fb_exchange_token=" +
url.QueryEscape(shortLivedToken))
if err != nil {
fmt.Printf("Get: %s
", err)
return
}
defer resp.Body.Close()
response, err := ioutil.ReadAll(resp.Body)
if err != nil {
return
}
var token FacebookToken;
//fmt.Print("response ",string(response))
err = json.Unmarshal(response, &token)
if err != nil {
log.Fatal("error" + err.Error())
return
}
//fmt.Println("duration ", token.AccessToken)
tokenExpiration = tokenExpiration.Add(time.Duration(token.Expiry) * time.Second)
fmt.Println(tokenExpiration)
/*resp, err = http.Get("https://graph.facebook.com/me?id&access_token=" +
url.QueryEscape(token.AccessToken))
if err != nil {
fmt.Printf("Get: %s
", err)
return
}
defer resp.Body.Close()
response, err = ioutil.ReadAll(resp.Body)
if err != nil {
fmt.Printf("ReadAll: %s
", err)
return
}
//fmt.Println(string(response))
token.userId = string(response)*/
token.Expire_Date = tokenExpiration
token.AccessToken = strings.TrimSpace(token.AccessToken)
res, err := oauthConf.Client(oauth2.NoContext, token.convertFacebookToken()).Get("https://graph.facebook.com/me?id")
if err != nil {
fmt.Printf("ReadAll: %s
", err)
return
}
defer res.Body.Close()
response, err = ioutil.ReadAll(res.Body)
if err != nil {
fmt.Printf("ReadAll: %s
", err)
return
}
fmt.Println(string (response))
token.saveTokenToDB()
}