We are happy to announce the release of Bolero version 0.4. Bolero is a library that enables writing full-stack applications in F#, whose client side runs in WebAssembly using Blazor.

Install the latest project template with:

dotnet new -i Bolero.Templates

Remote authentication

Version 0.4 brings user authentication to remote functions. Authentication is done through standard ASP.NET Core APIs, with a few F#-friendly methods on HttpContext for convenience.

/// A simple service that performs signin / signout.
type MyRemoteService =
    {
        signIn : string -> Async<unit>
        signOut : unit -> Async<unit>
    }

let myRemoteService =
    {
        signIn = Remote.withContext <| fun http username -> async {
            return! http.AsyncSignIn(username)
        }
        signOut = Remote.withContext <| fun http () -> async {
            return! http.AsyncSignOut()
        }
    }

Learn more about authentication in the documentation.

Remote authorization

You can also mark a remote function as requiring authentication with Remote.authorize, and provide additional authorization policies with Remote.authorizeWith.

type MyPrivateService =
    {
        getSecretData : unit -> Async<string>
    }
    
let myPrivateService =
    {
        getSecretData = Remote.authorize <| fun http () -> async {
            return "Secret user data!"
        }
    }

On the client side, authorization failure can be easily detected by the Elmish update function.

type Message =
    | GetSecretData
    | GotSecretData of RemoteResponse<string>
    | Error of exn
    
let update service message model =
    match message with
    | GetSecretData ->
        // Call the remote service
        model, Cmd.ofRemote service.getSecretData () GotSecretData Error
    | GotSecretData (Success data) ->
        // The call was successful
        { model with secretData = data }, Cmd.none
    | GotSecretData Unauthorized ->
        // The user wasn't logged in
        { model with showLoginPopup = true }, Cmd.none
    | Error exn ->
        // Another error happened (eg. the server was unavailable)
        { model with latestError = Some exn }, Cmd.none

Full changelog

Breaking changes

• NuGet package reorganization: the package Bolero.HotReload.Server is renamed to Bolero.Server and now contains all server-side facilities. It is necessary to reference it in the server-side project to use remoting.

• #22 Move the server-side and client-side AddRemoting extension methods to namespaces Bolero.Remoting.Server and Bolero.Remoting.Client, respectively.

Features

• #24 Add remoting authentication.

  • Add F#-friendly extension methods on HttpContext for authentication:

    member AsyncSignIn : name: string
                       * ?persistsFor: TimeSpan
                       * ?claims: seq<Claim>
                       * ?properties: AuthenticationProperties
                       * ?authenticationType: string
                      -> Async<unit>
    
    member AsyncSignOut : ?properties: AuthenticationProperties
                       -> Async<unit>
    
    member TryUsername : unit -> option<string>
    
    member TryIdentity : unit -> option<Identity>
    

  • Add module Bolero.Remoting.Server.Remote with remote function wrappers to get access to the HttpContext and mark a function as requiring authorization:

    module Remote =
        val withContext : (HttpContext -> 'req -> Async<'resp>)
                       -> ('req -> Async<'resp>)
    
        val authorize : (HttpContext -> 'req -> Async<'resp>)
                     -> ('req -> Async<'resp>)
    
        val authorizeWith : seq<IAuthorizeData>
                         -> (HttpContext -> 'req -> Async<'resp>)
                         -> ('req -> Async<'resp>)
    

• #28 Templating: Holes that fill an HTML attribute's value (eg: some-attr="${SomeHole}") now have type obj rather than string. This is useful in particular to fill attributes such as disabled with a boolean.

Bug fixes

• #29 Templating: fix exception when using the bound value of a number input as a text hole.

Happy coding!