Giraffe: Question: configuration settings

[nojaf]

How would one get a configuration setting, say a connectionstring inside a HttpContextHandler?
Is it possible to get the IConfiguration from HttpContext.RequestServices? I'm less familiar with this.

[slang25]

You could do something like this:

let someHander () =
    fun (ctx : HttpHandlerContext) ->
        async {
            let dbConfig = ctx.Services.GetService<IOptions<MyDbConfig>>()
            let dbConnectionString = dbConfig.ConnectionString
            // your code here
            return! ctx
        }

You can read about configuration and IOptions with DI here, which will explain how you get IOptions<MyDbConfig> registered.

You could use the HttpContext.RequestService but Giraffe already has an IServiceProvider on the HttpHandlerContext, I'd be interested to know who we couldn't just recommend the usage of HttpContext.RequestService. @dustinmoris ?

[dustinmoris]

Using the IServiceProvider from the HttpContext would make sense, was it always there? If yes then I must have missed it o.0

[nojaf]

Could the ILogger not be fetched from the HttpContext.RequestService as well?
Would it not make sense to transition from the HttpHandlerContext to the HttpContext?
If there a function getLogger, that might suffice as well

let getLogger (ctx: HttpContext) =
    ctx.RequestService<ILogger>()

let myHandler() =
    fun (ctx: HttpContext) ->
        async {
              let logger = getLogger ctx
             // do loggin
            return! ctx
        }

[slang25]

It would be a big change, but given this is pre 1.0 that makes a lot of sense. @dustinmoris ?

[dustinmoris]

Now that you say that it is actually such an obvious change :). I am working on it (This is why I am hesitant to declare this library 1.0 too early, thanks!).

[dustinmoris]

What's your opinion on helper method vs. extension method:

type HttpContext with
    member this.GetService<'T>() =
        this.RequestServices.GetService(typeof<'T>) :?> 'T

    member this.GetLogger<'T>() =
        this.GetService<ILogger<'T>>()

[nojaf]

Hmm, interesting. Extensions might be a better fit here.

[dustinmoris]

Ok cool, I had the same feeling, but wanted to get at least a second opinion.

[dustinmoris]

Done: https://github.com/dustinmoris/Giraffe/releases/tag/v0.1.0-alpha017

Thanks as always!