Protect Content with WebSharper.Warp

ProtectedContent.fsx

#I "../packages/Owin.1.0/lib/net40"
#I "../packages/Microsoft.Owin.3.0.1/lib/net45"
#I "../packages/Microsoft.Owin.Host.HttpListener.3.0.1/lib/net45"
#I "../packages/Microsoft.Owin.Hosting.3.0.1/lib/net45"
#I "../packages/Microsoft.Owin.FileSystems.3.0.1/lib/net45"
#I "../packages/Microsoft.Owin.StaticFiles.3.0.1/lib/net45"
#I "../packages/WebSharper.3.2.8.170/lib/net40"
#I "../packages/WebSharper.Compiler.3.2.4.170/lib/net40"
#I "../packages/WebSharper.Owin.3.2.6.83/lib/net45"
#load "../packages/WebSharper.Warp.3.2.10.13/tools/reference.fsx"

open WebSharper
open WebSharper.Sitelets
open WebSharper.Html.Server

type Endpoints =
    | [<EndPoint "GET /">] Home
    | [<EndPoint "GET /login">] Login
    | [<EndPoint "GET /locked">] Locked

let Protect content verify redirectAction =
    Content.CustomContentAsync <| fun ctx ->
        async {
            let! user = ctx.UserSession.GetLoggedInUser ()
            if verify user then
                return! Content.ToResponseAsync content ctx
            else
                return! Content.ToResponseAsync (Content.RedirectTemporary redirectAction) ctx
        }

let MySite =
    Warp.CreateApplication (fun ctx endpoint ->
        let (=>) label endpoint = A [HRef (ctx.Link endpoint)] -< [Text label]
        match endpoint with
        | Endpoints.Home ->
            Warp.Page(
                Body =
                    [
                        H1 [Text "Hello world!"]
                        "Login" => Endpoints.Login
                        "Protected" => Endpoints.Locked
                    ]
            )
        | Endpoints.Locked ->
            Protect
            <| Warp.Page(
                    Body =
                        [
                            P [Text "This the protected page"]
                        ]
                )
            <| Option.isSome // only allow logged in users
            <| Home
        | Endpoints.Login ->
            Protect
            <| Content.CustomContentAsync (fun ctx ->
                // Some random login logic
                async {
                    do! ctx.UserSession.LoginUser <| System.Guid.NewGuid().ToString()
                    return! Content.ToResponseAsync (Content.RedirectTemporary Endpoints.Home) ctx
                })
            <| Option.isNone // redirect user back to the homepage if they are already logged in
            <| Endpoints.Home

            
    )

[<EntryPoint>]
do Warp.RunAndWaitForInput(MySite) |> ignore