Attribute Macro screen 

#[screen]

Defines a screen. The first argument is its params; a screen without params takes none or _: ().

#[screen(route = "/products", permission = "stock.product.read")]
pub fn product_list() -> Screen { ... }

cache = N (seconds, public screens only) lets browsers and shared caches keep the page of a request without a session. no_prefetch keeps the browser from loading the screen ahead of a click (see App::prefetch).