Fable decorators for Flask

Flask.fs

module Flask =
    type App() = class end

    [<AbstractClass>]
    type RouteAttribute(route: string) =
        inherit JS.DecoratorAttribute()
        abstract App: App
        override this.Decorate(fn) =
            let app = this.App // Access the app
            // Do some initialization
            fn // Return the function

// User code

let app = Flask.App() // Initialize the app

// User overrides the attribute to give it access to the app
type RouteAttribute(route: string) =
    inherit Flask.RouteAttribute(route)
    override _.App = app

// Declare the routes
[<Route("/foo")>]
let foo() = ()