Check if user used Facebook login on KLEO Wordpress theme

check-fb-login.php

<?php

/**
 * Check if user used Facebook login
 *
 * @param int $user_id The user ID to check.
 * @return bool
 */
function sq_is_facebook_user( $user_id = null ) {
	if ( ! is_user_logged_in() ) {
		return false;
	}
	if ( ! $user_id ) {
		$current_user = wp_get_current_user();
		if ( isset( $current_user->ID ) ) {
			$user_id = $current_user->ID;
		} else {
			return false;
		}
	}
	if ( get_user_meta( $user_id, '_fbid', true ) !== false ) {
		return true;
	}

	return false;
}