How to set Facebook login permissions when using a custom login button in Android

Question

I am following this guide to set up social login via Facebook in my Android app: https://developers.facebook.com/docs/facebook-login/android/permissions

With Facebook's LoginButton setting the callback to handle user authentication result is easy:

facebookCallbackManager = CallbackManager.Factory.create();
final LoginButton facebookLoginButton = findViewById(R.id.facebook);
facebookLoginButton.setReadPermissions(Collections.singletonList(EMAIL));
LoginManager.getInstance().registerCallback(facebookCallbackManager,
        new FacebookCallback<LoginResult>() {
            @Override
            public void onSuccess(LoginResult loginResult) {
                final String accessToken = loginResult.getAccessToken().getToken();
                ...
            }

            @Override
            public void onCancel() {
            }

            @Override
            public void onError(FacebookException exception) {
            }
        });

But when I swap LoginButton with other Android button, I can no longer user the setReadPermissions function.

My question is: How do I request user's email permission from Facebook when using a custom login button?

Answer 1

Add onClickListener on your custom button and call logInWithReadPermissions method on LoginManager inside onClick. This method accepts a list of permissions to request from the user.

Complete example:

facebookCallbackManager = CallbackManager.Factory.create();
final MyFacebookButton facebookLoginButton = findViewById(R.id.facebook);
LoginManager.getInstance().registerCallback(facebookCallbackManager,
        new FacebookCallback<LoginResult>() {
            @Override
            public void onSuccess(LoginResult loginResult) {
                ...
            }

            @Override
            public void onCancel() {
            }

            @Override
            public void onError(FacebookException exception) {
            }
        });
facebookLoginButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        LoginManager
                .getInstance()
                .logInWithReadPermissions(
                        LoginActivity.this,
                        Collections.singletonList(EMAIL)
                );
    }
});