WebSharper 4.2.9 released

By Loïc Denuzière on Tuesday, April 17, 2018 — 1 comment

This is a minor release for WebSharper and WebSharper.UI.

Install templates for .NET Core SDK: dotnet new -i WebSharper.Templates::

Download templates for Visual Studio 2017:

WebSharper Core


  • #921 Now JSON deserialization can handle the System.Object type, implemented as follows:
    • deserializing on the client side just returns the parsed value (ie. one of: null, a boolean, a string, a number, an array or a plain object).
    • deserializing on the server side produces a boxed value:
      • null, boolean, string return a value of the corresponding type.
      • number: returns a float (System.Double)
      • array: returns a recursively parsed obj[]
      • object: returns a recursively parsed Dictionary<string, obj>
    • serializing from System.Object is not supported. This is to avoid accidentally upcasting the argument of Json.Serialize to System.Object when a type annotation is missing.


  • #935 Seq.chunkBySize and other similar functions does not fail erroneously on some inputs.
  • #934 If for a website project, there is no "outputdir" in ws.config or WebSharperOutputDir in project properties or a web.config file in the project folder, an explicit error is given that the unpack output directory cannot be determined.

WebSharper UI


  • Add Router.InstallInto and Router.InstallHashInto, which are similar to Router.Install and Router.InstallHash respectively except that they take a Var<'EndPoint> as argument rather than creating and returning one.


  • #164 Remove click event handler on Doc.Checkbox, only keeping change, to avoid setting the Var twice.
  • #166 Add proxy for quotation-based .OnXyz(...) event handlers.
  • #167 Fix initial value of Var.Make whenever an initial value is available from the View.
  • #168 Add View.TryGet : View<'T> -> option<'T> which returns the current value of a View if available, or None if not (eg if a View.MapAsync hasn't returned yet).

Happy coding!