Google Play Game Services Sign-In - Code

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Prerequisites

Before Google Sign-In will work properly, the Unity project must be configured to support GPGS as a third-party authentication provider. Make sure that GPGS is working correctly and the user can login to GPGS in-game before using it as third-party provider.

• Prerequisites
• Configure Unity Project

The Beamable SDK contains a wrapper for GPGS behavior on Android (iOS is not supported). The provided class is called SignInWithGPG, which can be initialized after following steps from Google documentation. It does contain two Actions that developer can subscribe to: OnLoginResult and OnRequestServerSideAccessResult. In order to perform login as third party to Beamable both of them must return succesfully- first returns info about local login, second one about getting server side access token that is required for Beamable backend.

SignInWithGPG _gpg;

/// <summary>
/// Starts Google Login process, then calls `HandleLoginResult` and/or `HandleRequestServerSideAccessResult` with a results.
/// </summary>
public void StartLogin()
{
	_gpg = new SignInWithGPG();
	_gpg.OnLoginResult += HandleLoginResult;
	_gpg.OnRequestServerSideAccessResult += HandleRequestServerSideAccessResult;
	_gpg.Login();
}

After the Login process is started, the callback functions (HandleLoginResult and HandleRequestServerSideAccessResult) will be invoked with a results:

/// <summary>
/// Callback to be invoked with information about if local login did succeed.
/// </summary>
/// <param name="success">returns bool value that informs about local login success</param>
private void HandleLoginResult(bool success)
{
	if(!success)
	{
                //Login failed or was cancelled
	}
}

private void HandleRequestServerSideAccessResult(bool success, string token)
{
	if(!success)
	{
                // Cannot get server token from GPGS, please check if your configuration is correct.
	}
	else
	{
		//Login successful, see additional functions below
	}
}

Handle Various Flow Scenarios

Now that we have the Google credential (token), we need to account for 3 different scenarios:

• New Player
• Returning Player already linked to Google
• Returning Player linking their account with Google

We can account for this by determining if we need to:

Switch Player - Player wants to switch credentials to a new Player
Create New Player - Player wants to Create a new Player account
Attach To Current Player - Player wants to Attach this 3rd Party Login to an already authenticated Player.

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Beamable SDK Initialization

The following assumes that you have initialized the Beamable SDK and it is stored in _beamContext variable.

_beamContext = BeamContext.Default; await _beamContext.OnReady;

The following code will establish conditions for various flow scenarios.

//Specify the third party auth provider
var thirdParty = AuthThirdParty.GoogleGamesServices;
//Get information about the user's third party credential
var available = await _beamContext.Api.AuthService.IsThirdPartyAvailable(thirdParty, token);
var userHasCredentials = _beamContext.Api.User.HasThirdPartyAssociation(thirdParty);

//Should we switch to a user that's not currently logged in?
var shouldSwitchUsers = !available;
//Should we create a brand new user with these credentials?
var shouldCreateUser = available && userHasCredentials;
//Should we attach the credentials to an existing user?
var shouldAttachToCurrentUser = available && !userHasCredentials;

Switch Users

In this example, the AuthService is used to authenticate a user with a third-party auth provider.

if(shouldSwitchUsers)
{
	  await _beamContext.Api.AuthService.LoginThirdParty(thirdParty, token, false);
}

Create New User

If we want to create a new user then apply the third party credentials, we can use the following calls from AuthService.

if(shouldCreateUser)
{
	  var tokenResponse = await _beamContext.AuthService.CreateUser();
	  _beamContext.ApplyToken(tokenResponse);
    var user = await _beamContext.Api.AuthService.RegisterThirdPartyCredentials(thirdParty, token);
    _beamContext.Api.UpdateUserData(user);
}

Link To Existing User

If the user already exists and is now trying to link their Google credentials to it, the flow is very similar to new user creation.

if(shouldAttachToCurrentUser)
{
 	  var user = await _beamContext.Api.AuthService.RegisterThirdPartyCredentials(thirdParty, token);
    _beamContext.Api.UpdateUserData(user);
}

Remarks

A complete example demonstrating the functionality for GPGS Sign-in can be found in GoogleGameServicesBehavior.cs, which is utilized by the Account Management Flow prefab packaged with Beamable.