service_url

Returns the URL of the variant on the service. This URL is intended to be short-lived for security and not used directly with users. Instead, the service_url should only be exposed as a redirect from a stable, possibly authenticated URL. Hiding the service_url behind a redirect also gives you the power to change services without updating all URLs. And it allows permanent URLs that redirect to the service_url to be cached in the view.

Use url_for(variant) (or the implied form, like +link_to variant+ or +redirect_to variant+) to get the stable URL for a variant that points to the ActiveStorage::RepresentationsController, which in turn will use this service_call method for its redirection.