Embedding JavaScript in a C# application (Part I)

Embedding JavaScript in a C# application or service

Why would you want to do that?

• Configuration (my post about that with IronPython)
• JSON over XML to implement configuration file.
• Configuration file implemented with a dynamic language can execute code.
• Configuration file can contain object instances.
• Plug-in architecture
• Plug-ins can be updated with notepad on the fly or not
• Script-able applications

Implementation

For now I am using the JavaScript run-time Noesis JavaScript.NET which use Google V8 v 2.2.
I wrote a library which I may name DynamicJavaScript.Net, which allow to access the JavaScript objects and arrays using the dynamic feature of C# 4 (see my post here).

A simple configuration file in JavaScript

function User(userName, firstName, lastName) { 

    this.UserName  = userName;
    this.LastName  = lastName;
    this.FirstName = firstName;
}
var Configuration = {

    Server  : 'TOTO',
    Database: 'Rene',
    Debug   : true,
    Users   : [
        { 
            UserName : 'bpascal', 
            FirstName: 'blaise', 
            LastName : 'pascal' 
        },
        new User('cmontesquieu', 'charles', 'montesquieu')
    ]
}

The C# source code to load the configuration

dynamic csContext = new DynamicJavascriptContext(
                              new JavascriptContext()
                        );

csContext.Run(System.IO.File.ReadAllText("configuration.js"));

var server  = csContext.Configuration.Server;
var databse = csContext.Configuration.Database;
var debug   = csContext.Configuration.Debug;

for(var i=0; i<csContext.Configuration.Users.Length; i++) {

    var userName  = csContext.Configuration.Users[i].UserName;
}