I have a android app that requires permission from the user to access its google spreadsheets (the scope is google spreadsheet API).
At the first time the app is launched its all good, I can acces the spreadsheets just fine. I am saving the email address the user chooses to the Shared Preferences.
What I want is that in the next time that the user launches the app (after the first time), the app will only get the token (because I already have the email address of the user) without the user having to go through the account picker again.
I imagine this has been done before, because the user should only choose his account once. none the less, I couldn't figure what is the best practice for it.
He is the Google OAuth 2.0 class
straight from here http://developer.android.com/google/auth/http-auth.html
public class GoogleAccountActivity extends Activity {
static final int REQUEST_CODE_PICK_ACCOUNT = 1000;
static final int REQUEST_CODE_RECOVER_FROM_PLAY_SERVICES_ERROR = 1001;
static final int REQUEST_CODE_RECOVER_FROM_AUTH_ERROR = 1002;
String mEmail;
private static final String SCOPE =
"oauth2:https://spreadsheets.google.com/feeds/";
private Intent homeIntent;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
homeIntent=new Intent(this, HomeActivity.class);
// next activity tto launch
pickUserAccount();
}
private void getUsername() {
if (mEmail == null) {
pickUserAccount();
} else {
if (isDeviceOnline()) {
new GetUsernameTask(this, mEmail, SCOPE).execute();
} else {
Toast.makeText(this, R.string.not_online, Toast.LENGTH_LONG).show();
}
}
}
public boolean isDeviceOnline() {
ConnectivityManager connMgr = (ConnectivityManager)
getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
if (networkInfo != null && networkInfo.isConnected()) {
return true;
} else {
return false;
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_CODE_PICK_ACCOUNT) {
// Receiving a result from the AccountPicker
if (resultCode == RESULT_OK) {
mEmail = data.getStringExtra(AccountManager.KEY_ACCOUNT_NAME);
// With the account name acquired, go get the auth token
getUsername();
} else if (resultCode == RESULT_CANCELED) {
// The account picker dialog closed without selecting an account.
// Notify users that they must pick an account to proceed.
Toast.makeText(this, R.string.pick_account, Toast.LENGTH_SHORT).show();
}
} else if ((requestCode == REQUEST_CODE_RECOVER_FROM_AUTH_ERROR ||
requestCode == REQUEST_CODE_RECOVER_FROM_PLAY_SERVICES_ERROR)
&& resultCode == RESULT_OK) {
// Receiving a result that follows a GoogleAuthException, try auth again
getUsername();
}
}
private void pickUserAccount() {
String[] accountTypes = new String[]{"com.google"};
Intent intent = AccountPicker.newChooseAccountIntent(null, null,
accountTypes, false, null, null, null, null);
startActivityForResult(intent, REQUEST_CODE_PICK_ACCOUNT);
}
public void handleException(final Exception e) {
// Because this call comes from the AsyncTask, we must ensure that the following
// code instead executes on the UI thread.
runOnUiThread(new Runnable() {
@Override
public void run() {
if (e instanceof GooglePlayServicesAvailabilityException) {
// The Google Play services APK is old, disabled, or not present.
// Show a dialog created by Google Play services that allows
// the user to update the APK
int statusCode = ((GooglePlayServicesAvailabilityException)e)
.getConnectionStatusCode();
Dialog dialog = GooglePlayServicesUtil.getErrorDialog(statusCode,
GoogleAccountActivity.this,
REQUEST_CODE_RECOVER_FROM_PLAY_SERVICES_ERROR);
dialog.show();
} else if (e instanceof UserRecoverableAuthException) {
// Unable to authenticate, such as when the user has not yet granted
// the app access to the account, but the user can fix this.
// Forward the user to an activity in Google Play services.
Intent intent = ((UserRecoverableAuthException)e).getIntent();
startActivityForResult(intent,
REQUEST_CODE_RECOVER_FROM_PLAY_SERVICES_ERROR);
}
}
});
}
public class GetUsernameTask extends AsyncTask<Void, Void, String>{
Activity mActivity;
String mScope;
String mEmail;
GetUsernameTask(Activity activity, String name, String scope) {
this.mActivity = activity;
this.mScope = scope;
this.mEmail = name;
}
/**
* Executes the asynchronous job. This runs when you call execute()
* on the AsyncTask instance.
*/
@Override
protected String doInBackground(Void... params) {
try {
String token = fetchToken();
if (token != null) {
homeIntent.putExtra("userToken", token);
startActivity(homeIntent); // starting the Home Activity
}
} catch (IOException e) {
// The fetchToken() method handles Google-specific exceptions,
// so this indicates something went wrong at a higher level.
// TIP: Check for network connectivity before starting the AsyncTask.
}
return null;
}
/**
* Gets an authentication token from Google and handles any
* GoogleAuthException that may occur.
*/
protected String fetchToken() throws IOException {
try {
return GoogleAuthUtil.getToken(mActivity, mEmail, mScope);
} catch (UserRecoverableAuthException userRecoverableException) {
// GooglePlayServices.apk is either old, disabled, or not present
// so we need to show the user some UI in the activity to recover.
handleException(userRecoverableException);
} catch (GoogleAuthException fatalException) {
// Some other type of unrecoverable exception has occurred.
// Report and log the error as appropriate for your app.
}
return null;
}
}
}
It works fine for the first launch, but I am not sure what to do in the next time.
To sum up:
I want to understand if I need to get a token every time I launch the app??
and if so, How do I do only the fetching of the token (and handling exceptions) without the account picking and the other stuff required in the first launch.
Do I need to work with a refresh token? because I read about it but didn't see any example for it in the do.
any help would be appreciated.
Thanks, Ofek
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