FSharpPlus.AspNetCore

F#+ bindings for asp.net core. This is intended to enable development of web api:s leveraging F#+ and asp.net core.

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Builds

MacOS/Linux	Windows

Nuget

Stable	Prerelease

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Building

Make sure the following requirements are installed in your system:

• dotnet SDK 2.0 or higher
• Mono if you're on Linux or macOS.

PM> dotnet build

Getting Started

PM> mkdir MySite
PM> dotnet new console -lang f# -o MySite
PM> dotnet add ./MySite package FSharpPlus.AspNetCore
PM> dotnet add ./MySite package FSharpPlus.AspNetCore.Suave

You can then add your code in the style of Suave

// Learn more about F# at http://fsharp.org

open System

open FSharpPlus

open FSharpPlus.AspNetCore
open FSharpPlus.AspNetCore.Suave
open HttpAdapter
open Successful
open RequestErrors
open Filters
open Writers

open Microsoft.AspNetCore
open Microsoft.AspNetCore.Hosting
open Microsoft.AspNetCore.Builder

open Newtonsoft.Json

module Json=
  let inline OK v=
    OK (JsonConvert.SerializeObject v)
    >=> setContentType "application/json; charset=utf-8"
  let inline CREATED v=
    CREATED (JsonConvert.SerializeObject v)
    >=> setContentType "application/json; charset=utf-8"

type Todo = { id:int; text:string }
type IDb =
  abstract member AddTodo: string -> Async<Todo>
  abstract member GetTodo: int ->Async<Todo option>

let myWebPart(db:IDb) =
  let register =
      POST >=> hasFormContentType >=> fun ctx -> monad {
      match ctx.request |> Request.Form.tryGet "text" with
      | Some text ->
        let! todo = lift (db.AddTodo (string text))
        return! Json.CREATED todo ctx
      | None ->
        return! BAD_REQUEST "Could not find form text" ctx
    }
  let getTodo id=
      GET >=> fun ctx -> monad {
        match! lift (db.GetTodo id) with
        | Some todo ->     
          return! Json.CREATED todo ctx
        | None ->
          return! NOT_FOUND "Could not find todo" ctx
    }
  WebPart.choose [ 
                  path "/" >=> (OK "/")
                  path "/todo" >=> register
                  pathScan "/todo/%d" getTodo
                  ]


type CmdArgs =
  { Json : string option }
[<EntryPoint>]
let main argv =
  let buildWebHost args =
    WebHost.CreateDefaultBuilder(args)
      .Configure(fun (app: IApplicationBuilder)->
        let db = { new IDb with
                   member this.AddTodo(text)=failwith "not implemented" 
                   member this.GetTodo(id)=failwith "not implemented" 
                 }
        let webPart = myWebPart db
        app
            |> appMap "/v1/" (Suave.appRun webPart)
            |> ignore
      ).Build()
  buildWebHost(argv).Run()
  0

Alternatives

If you are looking for a composable library for web then Suave and Giraffe are the ones mostly used. Giraffe should have better performance than this library. Suave has been around the longest (it inspired Giraffe). For a simple web framework you have also Frank.