Consider:
<form action="?login" method="post"> <button>Login with Google</button> </form>
I usually see the action refer to a PHP or HTML file, but the "?login" stumps me.
Background information:
This is buried within the example-google.php file from lightopenid framework. I've been staring at the OpenID code to use Google as a third-party OpenID provider for user login on my web site and the sample code all works.
I am trying to get a clearer picture of what the framework is doing when the user presses the login button. I know that we must be sending a bunch of arguments to Google on this button action, but the ?login doesn’t seem to point anywhere.
A question mark denotes the query string.
It will post to the current URL with a query string parameter of login. I am not sure how you are processing the request after you click submit (post the form), but usually it would have a value assigned to it as in login=value.