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Strange Behavior of Hello World

Dear forum community,

I have been trying to run the basic Hello World example as described on the page: http://websharper.com/docs/running-snippets

The source code compiles error-free on my platform MonoDevelop 5.9.5 on Centos 7. The HelloWorld page runs without errors reported by MonoDevelop and it is accessible by the browser on 127.0.0.1:8080. However, the result is just a blank page with the title "HelloWorld".

Here is my source code of Client.fs from the tutorial:

namespace HelloWorld

open WebSharper open WebSharper.JavaScript open WebSharper.Html open WebSharper.Html.Client

<JavaScript> module HelloWorld =

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let Main () =
    let welcome = P [Text "Welcome"]
    Div [
        welcome
        Button [Text "ClickMe!"]
        |>! OnClick (fun e args ->
            welcome.Text <- "Bonjour Monsigneur!")
    ]

let _ = Main () |> fun res -> res.AppendTo "entrypoint"

The index.html file is given below - each element should start with "\<", but since I do not know what is the proper way to display HTML verbatim on this forum, it is removed.

!DOCTYPE html> html lang="en"> head> title>HelloWorld</title> meta charset="utf-8" /> meta name="viewport" content="width=device-width, initial-scale=1.0" /> link rel="stylesheet" type="text/css" href="Content/HelloWorld.css" /> script type="text/javascript" src="Content/HelloWorld.head.js"></script> /head> body> div id="entrypoint" /> script type="text/javascript" src="Content/HelloWorld.min.js"></script> /body> /html>"

The browser output from 127.0.0.1:8080 and index.html are identical. Apparently, nothing from the Client.fs source code is appended to the div element in the web page. What could be the cause of this? I have installed the websharper package by using nuget. There is one clue in monodevelop, however; it reports: "Assembly not found for framework Mono/.NET 4.0" under FSharp.Core in the References section of the HelloWorld project tree. As I am new to this framework, I am somewhat puzzled by this message, since I have the FSharp compiler and interpreter packages installed.

Thank you in advance!

.

Apparently the problem is in the libraries. Websharper requires an MS Core Net library. However, the latest library cannot be obtained by the installed nuget version. I am somewhat at a loss which packages need to be installed in what order to be able to work with F# and .NET for Websharper:
monodevelop, mono, nuget, fsharp, websharper ?

There seem to exist packages with slightly different version numbers from different repositories that apparently should all do the same job, but do not quite match up together.

What needs to installed from repositories or from source and what can be obtained from nuget? I find the nuget's interface and help messages quite rudimentary.

There also seems to be an option to enable different run time environments in monodevelop. A similar option used to exist in eclipse allowing the choice between different Java Development Kit providers, i.e. core libraries. Are there alternatives to the default NET core library in monodevelop?

By on 9/13/2015 11:43 AM ()

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