f# - 观察模式下的 Suave(开发期间)

Question

我正在处理 Suave 1.0 + Angular 2.0 sample app在监视模式下启动Suave服务器非常有趣，因此服务器监视根文件夹和子文件夹中的文件(js，css，html)并自动发送refresh当任何文件发生更改时，我的应用程序对所有打开的浏览器选项卡的命令。
lite-server来自 Angular 2 5min Quckstark可以做到这一点，而且非常方便。

我认为大部分 watch 都可以在latest Steffen Forkmann's post中找到。但是不是很干净怎么发refresh到打开的浏览器选项卡。

请提供类似实现的完整代码 Suave .

Answer 1

Suave的代码服务器应该与此类似

#r "packages/Suave/lib/net40/suave.dll"
#r "packages/FAKE/tools/FakeLib.dll"

open Fake
open Suave
open Suave.Operators
open Suave.Sockets.Control
open Suave.WebSocket
open Suave.Utils
open Suave.Files
open Suave.RequestErrors
open Suave.Filters
open System
open System.Net


let port =
    let rec findPort port =
        let portIsTaken =
            System.Net.NetworkInformation.IPGlobalProperties.GetIPGlobalProperties().GetActiveTcpListeners()
            |> Seq.exists (fun x -> x.Port = int(port))
        if portIsTaken then findPort (port + 1us) else port
    findPort 8083us

let logger = Logging.Loggers.ConsoleWindowLogger Logging.LogLevel.Verbose

let refreshEvent = new Event<_>()

let handleWatcherEvents (events:FileChange seq) =
    for e in events do
        let fi = fileInfo e.FullPath
        traceImportant <| sprintf "%s was changed." fi.Name
    refreshEvent.Trigger()

let socketHandler (webSocket : WebSocket) =
  fun cx -> socket {
    while true do
      let! refreshed =
        Control.Async.AwaitEvent(refreshEvent.Publish)
        |> Suave.Sockets.SocketOp.ofAsync
      do! webSocket.send Text (ASCII.bytes "refreshed") true
  }

let cfg =
  { defaultConfig with
      homeFolder = Some (__SOURCE_DIRECTORY__)
      bindings =
        [ HttpBinding.mk HTTP IPAddress.Loopback port ]
      listenTimeout = TimeSpan.FromMilliseconds 3000. }

let app : WebPart =
  choose [
    Filters.log logger logFormat >=> never
    Filters.path "/websocket" >=> handShake socketHandler
    Filters.GET >=> Filters.path "/" >=> file "index.html"
    Writers.setHeader "Cache-Control" "no-cache, no-store, must-revalidate"
      >=> Writers.setHeader "Pragma" "no-cache"
      >=> Writers.setHeader "Expires" "0"
      >=> browseHome
    NOT_FOUND "Found no handlers."
  ]


let watcher =
    !! ("app/*.js")
      ++ ("*.html")
    |> WatchChanges handleWatcherEvents

try
    System.Diagnostics.Process.Start(sprintf "http://localhost:%d/index.html" port) |> ignore
    startWebServer cfg app
finally
    watcher.Dispose()

所以我们设置观察者来处理 js 中的变化(由 TypeScript 生成)和 html文件并发送 refresh命令到客户端，但同时我们需要将以下代码添加到 head index.html的部分处理 refresh在客户端

<!-- 3. Listen on refresh events from the server -->
<script language="javascript" type="text/javascript">
    function init()
    {
        websocket = new WebSocket("ws://"+window.location.host+"/websocket");
        websocket.onmessage = function(evt) { location.reload(); };
    }
    window.addEventListener("load", init, false);
</script>

您可以找到完整的演示应用程序 here