Amplify with Cognito for Login

How To:

In the project’s directory in your CLI (that is already provisioned with aws) run the following line:

amplify add auth

Then follow the below fill-in for the default setup:

? Do you want to use the default authentication and security configuration?
    `Default configuration`
? How do you want users to be able to sign in?
    `Username`
? Do you want to configure advanced settings?
    `No, I am done.`

Then finish with amplify push

The project’s build.gradle file will now need to include the following within its dependencies:

  implementation 'com.amplifyframework:aws-auth-cognito:1.4.1'

and then include the following lines of code alongside the other Amplify plugins within your project’s code (likely in the MainActivity):

Amplify.addPlugin(new AWSCognitoAuthPlugin());

To see if it’s live and working include this code (below the Amplify.addPlugin… snippet you added from above):

Amplify.Auth.fetchAuthSession(
        result -> Log.i("AmplifyQuickstart", result.toString()),
        error -> Log.e("AmplifyQuickstart", error.toString())
);

And this will set you up with the necessary bits to allow users to authenticate with a username and password.

How to Allow Usernames and Passwords

Amplify.Auth.signUp(
        "username",
        "Password123",
        AuthSignUpOptions.builder().userAttribute(AuthUserAttributeKey.email(), "my@email.com").build(),
        result -> Log.i("AuthQuickStart", "Result: " + result.toString()),
        error -> Log.e("AuthQuickStart", "Sign up failed", error)
);

That above is the default manner to create a defaultuser. It then recommends (or requires? I’m currently uncertain) an email confirmation. The below code is only the starting point as it looks very barebones, not even a real visual. Or perhaps that is all done w/in the email sent.

Amplify.Auth.confirmSignUp(
    "username",
    "the code you received via email",
    result -> Log.i("AuthQuickstart", result.isSignUpComplete() ? "Confirm signUp succeeded" : "Confirm sign up not complete"),
    error -> Log.e("AuthQuickstart", error.toString())
);

At which point the console should alert you: Confirm signUp succeeded

Now with a user within and confirmed, you can allow/enable user sign in, with the following code:

Amplify.Auth.signIn(
    "username",
    "password",
    result -> Log.i("AuthQuickstart", result.isSignInComplete() ? "Sign in succeeded" : "Sign in not complete"),
    error -> Log.e("AuthQuickstart", error.toString())
);

And if it works, console shall say: Sign in succeeded

Note: if you want to add MFA (multi-factor authentification) there is much more to be done, but it is possible. And in this day and age, it is a good option to allow.

Note 2: the documentation emphasizes that the phone number be formatted as: +15551234567

Lastly - and this might only pertain to MFA being enabled, but likely in either case - the final step is:

Amplify.Auth.confirmSignIn(
    "confirmation code received via SMS",
    result -> Log.i("AuthQuickstart", result.toString()),
    error -> Log.e("AuthQuickstart", error.toString())
);

and you now have a logged in user. Or, at least the background work. I get the feeling it’s up to the user to actually visually enable the auth(entification) capabilities. Likely using Handler (for the threads that amplify create/utilize).

### Note: all code is originally from Amazon documentation here.