title: Facebook login for wordpress without a plugin
body: <p>I'm providing a custom login page for the website visitors and would like to include the Login with Facebook button such that the application checks if the user email is registered, and if so it will log the user in.</p>
  
  <p>using wp_signon I can log a user in by providing the email and password, but in that case I don't have a password for the user, so is there a way I can provide a Facebook login button without using plugins?</p>