Sign In With Google - Trigger sign in programatically instead of button

Question

I'm trying to migrate to the new Sign In With Google and I'm missing one crucial functionality I was using previously.

Basicly my application is working with locally created application users. At one point in the application, the user is prompted to login with Google Account to confirm that he's the correct user that will do some Google API action. I was able to achieve that with following code from the soon deprecated Google Sign-In library:

const auth = gapi.auth2.getAuthInstance();

if (!auth.isSignedIn.get())
    await auth.signIn({
        prompt: "select_account",
        login_hint: employeeEmail
    });
...

And it worked just fine. Now all the above methods are being deprecated and there are no direct replacements, or at least I don't understand how to achieve the same result. I am able to confirm the user identity by checking the id token received by using:

google.accounts.id.initialize({/*options*/);
...
google.accounts.id.prompt();

But if there's no google session active for the user, nothing happens. The only way to actually trigger the Sign In is to click the Google Sign In Button, rendered using:

google.accounts.id.renderButton(htmlElement, {/*options*/});

After the button is clicked, the sign in popup is shown and everything is fine, the callback of the initialize configuration is called and the flow is resumed.

The problem is, how do I trigger the Sign In popup programatically? All of the above starts with a specific button click on my website.

Answer 1

FYI

I actually managed to reproduce almost the same behavior with the new API. It might not be the most elegant way of doing this, but I replaced the signIn method from my post above with google.accounts.oauth2.initTokenClient. Even though it should be used to only receive the tokens, it will also create a valid Google session that then can be detected by using silent auth (prompt: "none");