f# - Suave中带有可选参数的路线

Question

我有一个带有hello world终结点的Web服务，如下所示:

let app =
  choose [ 
      GET >=> 
        choose [ 
          path "/hello" >=> OK "Hello World!"
          pathScan "/hello/%s" (fun name -> OK (sprintf "Hello World from %s" name)) ]
      NOT_FOUND "Not found" ]

[<EntryPoint>]
let main argv = 
  startWebServer defaultConfig app
  0

现在，我想添加一个额外的端点，它可以处理这样的路由: http://localhost:8083/hello/{name}?lang={lang}
此路由应适用于以下URL:

http://localhost:8083/hello/FooBar在这种情况下，应设置lang
的默认值是“en-GB”

http://localhost:8083/hello/FooBar?lang=en-GB

http://localhost:8083/hello/FooBar?lang=de-DE

但它不适合

http://localhost:8083/hello/FooBar/en-GB

只能在查询参数字符串中而不是在路径中允许使用可选参数。

知道如何使用Suave做到这一点吗？

Answer 1

为了处理查询参数，我可能只使用request函数，该函数为您提供了有关原始HTTP请求的所有信息。您可以使用它来检查查询参数:

let handleHello name = request (fun r ->
  let lang = 
    match r.queryParam "lang" with
    | Choice1Of2 lang -> lang
    | _ -> "en-GB"
  OK (sprintf "Hello from %s in language %s" name lang)) 

let app =
  choose [ 
      GET >=> 
        choose [ 
          path "/hello" >=> OK "Hello World!"
          pathScan "/hello/%s" handleHello ]
      NOT_FOUND "Not found" ]