[feature/oauth] Add method to return necessary data for auth_link

PHPBB3-11673

phpBB/includes/ucp/ucp_auth_link.php

@@ -21,7 +21,16 @@ class ucp_auth_link
 
 	public function main($id, $mode)
 	{
-		global $template, $phpbb_container;
+		global $config, $request, $template, $phpbb_container;
+
+		$auth_provider = $phpbb_container->get('auth.provider.' . $config['auth_method']);
+
+		// confirm that the auth provider supports this page
+		$provider_data = $auth_provider->get_auth_link_data();
+		if ($provider_data === null)
+		{
+			// does not support this page, throw error?
+		}
 
 		$error = array();
 		$s_hidden_fields = array();

phpBB/phpbb/auth/provider/base.php

@@ -62,6 +62,14 @@ abstract class phpbb_auth_provider_base implements phpbb_auth_provider_interface
 		return;
 	}
 
+	/**
+	* {@inheritdoc}
+	*/
+	public function get_auth_link_data()
+	{
+		return;
+	}
+
 	/**
 	* {@inheritdoc}
 	*/