We invite users to visit our app via a link in an email. To make things even less complicated we'd like to prefill the username when users click on the link. Is this possible using the Login Form? I don't see any customizable attributes in the Login Form and simply putting the widget in a 'Login' dataview doesn't do the trick.
You can provide users a link with GUID or random number that is handled by a deeplink. The user is automatically logged in. For security reasons:
Use link only once
Use link within reasonable time.