I'm trying to learn about Facebook login. I'm able to successfully login in my app using Facebook sdk. But while fetching the email id of the user sometimes I get null value when user have hidden their email in Facebook website settings.In that case I am asking user to enter their Facebook email id.After that I want to check if the email id is register to Facebook or not. Is there any way to check if the entered email is registered with Facebook?
public class LoginActivity extends AppCompatActivity implements LoaderCallbacks<Cursor> {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
facebookOncreateCalling();
ImageView facebookLogin = (ImageView) findViewById(R.id.facebook_login_imageView2);
facebookLogin.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
try {
LoginManager.getInstance().logOut();
} catch (Exception e) {
e.printStackTrace();
}
LoginManager.getInstance().logInWithReadPermissions(LoginActivity.this, Arrays.asList("public_profile", "user_friends", "email" /*, "user_mobile_phone", "email", "user_birthday"*/));
}
});
}
public void hideSoftKeyboard(EditText inputtext) {
InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(inputtext.getWindowToken(), 0);
}
CallbackManager callbackManager;
AccessTokenTracker accessTokenTracker;
AccessToken accessToken;
private void facebookOncreateCalling() {
try {
PackageInfo info = getPackageManager().getPackageInfo(
getApplicationContext().getPackageName(),
PackageManager.GET_SIGNATURES);
for (Signature signature : info.signatures) {
MessageDigest md = MessageDigest.getInstance("SHA");
md.update(signature.toByteArray());
Log.d("Facebook KeyHash:", "KeyHash:-> " + Base64.encodeToString(md.digest(), Base64.DEFAULT));
}
} catch (PackageManager.NameNotFoundException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
FacebookSdk.sdkInitialize(getApplicationContext());
AppEventsLogger.activateApp(this);
callbackManager = CallbackManager.Factory.create();
LoginManager.getInstance().registerCallback(callbackManager,
new FacebookCallback<LoginResult>() {
@Override
public void onSuccess(LoginResult loginResult) {
callGraphApi(loginResult);
}
@Override
public void onCancel() {
Log.e("====Login Activity===","Cancel");
}
@Override
public void onError(FacebookException exception) {
Log.e("====Login Activity===","Error"+exception);
}
});
accessTokenTracker = new AccessTokenTracker() {
@Override
protected void onCurrentAccessTokenChanged(
AccessToken oldAccessToken,
AccessToken currentAccessToken) {
accessToken = currentAccessToken;
}
};
accessToken = AccessToken.getCurrentAccessToken();
}
private void callGraphApi(LoginResult loginResult) {
GraphRequest request = GraphRequest.newMeRequest(
loginResult.getAccessToken(),
new GraphRequest.GraphJSONObjectCallback() {
@Override
public void onCompleted(
JSONObject object,
GraphResponse response) {
try {
Log.e("LoginActivity", "GraphRequest:" + object);
String fbUserId = object.optString("id");
String firstNameString = object.optString("first_name");
String lastNameString = object.optString("last_name");
String email = object.optString("email");
String name = object.optString("name");
String url = AppDataUtill.APP_BASE_URL + "facebookSignup";
HashMap<String, String> map = new HashMap<String, String>();
map.put("fname",firstNameString);
map.put("lname",lastNameString);
map.put("email",email);
map.put("fb_user_id", fbUserId);
callFbSignupApi(url, map, 1, fbUserId);
} catch (Exception e) {
e.printStackTrace();
}
}
});
Bundle parameters = new Bundle();
parameters.putString("fields", "id,name,first_name,last_name,link,birthday,gender,email");
request.setParameters(parameters);
request.executeAsync();
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
callbackManager.onActivityResult(requestCode, resultCode, data);
}
private void validation(){
AlertDialog.Builder alert = new AlertDialog.Builder(getApplicationContext());
alert.setMessage("Enter Your Email");
final EditText input = new EditText(getApplicationContext());
alert.setView(input);
alert.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
String srt = input.getEditableText().toString();
if (srt.matches("")) {
Toast.makeText(getApplicationContext(), "Enter Your Email", Toast.LENGTH_LONG).show();
return;
}
}
});
alert.setNegativeButton("CANCEL", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
dialog.cancel();
}
});
AlertDialog alertDialog = alert.create();
alertDialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
alertDialog.show();
}
}
