How to authenticate in Google Fusion Tables with Oauth2 in Dart? - oauth-2.0

Question

I'm trying to get data from a fusion table. I write, as it is written in the example
import "package:google_fusiontables_v1_api/fusiontables_v1_api_browser.dart";
import "package:google_oauth2_client/google_oauth2_browser.dart";
class CFusionTable
{
static const _tableName = '*mytablename*';
static const _clientID = "*myclientid*";
GoogleOAuth2 _gauth;
CFusionTable()
{
_gauth = new GoogleOAuth2(_clientID, [Fusiontables.FUSIONTABLES_SCOPE]);
var fusiontables = new Fusiontables(_gauth);
fusiontables.query.sql('select ID, Name, Latitude, Longitude, Country, Territory, City, Photo, ROWID from '+_tableName,
hdrs: false)
.then(_loadData);
}
void _loadData(data)
{
print (data.toString());
}
}
But the authentication does not work:
Failed to load resource: the server responded with a status of 403
(Forbidden)
As">https://www.googleapis.com/fusiontables/v1/query?hdrs=false&sql=select%20ID%2C%20Name%2C%20Latitude%2C%20Longitude%2C%20Country%2C%20Territory%2C%20City%2C%20Photo%2C%20ROWID%20from%201bSQ16GyMgRuleMBdn1aF4Xfu0E3HRv_As
Uncaught Error: APIRequestException: 403 Daily Limit for
Unauthenticated Use Exceeded. Continued use requires signup.
Exception: APIRequestException: 403 Daily Limit for Unauthenticated
Use Exceeded. Continued use requires signup. undefined
(undefined:0:0)
Tell me please, what am I doing wrong?

Answer 1

You need to authenticate first before you can execute methods on the fusion tables. In the example code below, call the login method to invoke the authentication and the fusion tables when authentication was successful.
import "package:google_fusiontables_v1_api/fusiontables_v1_api_browser.dart";
import "package:google_oauth2_client/google_oauth2_browser.dart";
class CFusionTable
{
static const _tableName = '*mytablename*';
static const _clientID = "*myclientid*";
GoogleOAuth2 _gauth;
CFusionTable() {
_gauth = new GoogleOAuth2(_clientID, [Fusiontables.FUSIONTABLES_SCOPE]);
}
void login() {
_gauth.login().then(_gauth_tokenLoadedHandler);
}
void _gauth_tokenLoadedHandler(Token token) {
var fusiontables = new Fusiontables(_gauth);
fusiontables.query.sql('select ID, Name, Latitude, Longitude, Country, Territory, City, Photo, ROWID from '+_tableName,hdrs: false)
.then(_loadData);
}
void _loadData(data) {
print (data.toString());
}
}

Answer 2

Another thing to check when you see 403 is your Client ID. Many of the Google APIs have rate limits, and for unregistered apps the rate limit is essentially zero. So when you see 403 it’s often the case that (a) you didn’t register the app or (b) you registered the app but put the wrong Client ID value in your code or (c) you did all those but registered your app for the wrong scopes... you see the pattern.