Question: How to get data on postback about giraffe

[dustinmoris]

Hey, I will get back to you with an example over the weekend and include it into the current sample app! That is a good question, thanks for asking!

[nojaf]

Modelbinding appears to be to tightly coupled to Mvc, aspnet/Mvc#6109.
Parsing the raw request to string (json) and converting the json to the model seems like an option.

Question is do we want other ways of extracting the model from the request? Would it make sense to have our own modelbinding?

[nojaf]

I'm able to get the json from the request

let readAllBytes (s : Stream) = 
    let ms = new MemoryStream()
    s.CopyTo(ms)
    ms.ToArray()

// ...

        POST >=> 
            choose [
                route "/contact" >=> (fun (ctx: HttpHandlerContext) -> 
                    async {
                        let model = 
                            ctx.HttpContext.Request.Body
                            |> readAllBytes
                            |> Encoding.UTF8.GetString
                            |> JsonConvert.DeserializeObject
                        
                        sprintf "Received model %s" (model.ToString())
                        |> Console.WriteLine

                        let json = JsonConvert.SerializeObject(model)
                        return! ctx |> (sprintf "Received %s" json |> text)
                    }                    
                )
            ]

Might be a good idea to provide some things out of the box for this.

[dustinmoris]

Agreed. It would be nice if there would be a function similar like let model = bindModel<Person> ctx.

I would expect that this function would also inspect the requests' Content-Type and at least support the deserialization of a JSON, XML or URL encoded object by default with a facility for users to extend if they have some custom binding requriements.

[nojaf]

Perhaps the return type of bindModel should be Result<'TOk, 'TError>.
See https://gist.github.com/nojaf/cf176f304a7843bbf15e6a3b3d9dc9f2

[dustinmoris]

Just published Giraffe.ModelBinding this morning.

Have a look if the updated documentation makes sense and if you can think of any improvements?

I think an additional bindQueryString function would be useful which can bind a model from query string parameters, but I didn't have time to add this one as well now.

[nojaf]

Great work, simple and clean. This is a good starting point and I would create separate issues for missing functionality. F.ex. complex type properties with the form data or a combination of form data and querystring, etc.