helpers\BaseUrl normalizeRoute()

Normalizes route and makes it suitable for UrlManager. Absolute routes are staying as is while relative routes are converted to absolute ones.

A relative route is a route without a leading slash, such as "view", "post/view".

• If the route is an empty string, the current route will be used;
• If the route contains no slashes at all, it is considered to be an action ID of the current controller and will be prepended with yii\web\Controller::$uniqueId;
• If the route has no leading slash, it is considered to be a route relative to the current module and will be prepended with the module's uniqueId.

Starting from version 2.0.2, a route can also be specified as an alias. In this case, the alias will be converted into the actual route first before conducting the above transformation steps.