src/Helpers/Request/UrlHelper.php
public function previous($name = null)
    {
        if ($name === null) {
            return $this->app->user->getReturnUrl();
        }

        return $this->app->session->get($name);
    }
public function previous($name = null)
    {
        if ($name === null) {
            return $this->app->user->getReturnUrl();
        }

        return $this->app->session->get($name);
    }
Returns the URL previously [[remember()|remembered]].

@param string $name the named associated with the URL that was remembered previously.
If not set, [[\Reaction\Web\User::getReturnUrl()]] will be used to obtain remembered URL.
@return string|null the URL previously remembered. Null is returned if no URL was remembered with the given name
and `$name` is not specified.
@see remember()
@see \Reaction\Web\User::getReturnUrl()
@see \Reaction\Helpers\Url::previous()