MSIE JavaScript Engine for .NET

This project is a .NET wrapper for working with the Internet Explorer's JavaScript engines (JsRT version of Chakra, ActiveScript version of Chakra and Classic JavaScript Engine). Project was based on the code of SassAndCoffee.JavaScript and Chakra Sample Hosts.

MSIE JavaScript Engine requires a installation of Internet Explorer on the machine and can work in 4 modes, that are defined in the MsieJavaScriptEngine.JsEngineMode enumeration:

• Auto. Automatically selects the most modern JavaScript engine from available on the machine.
• Classic. Classic MSIE JavaScript engine (supports ECMAScript 3 with possibility of using the ECMAScript 5 Polyfill and the JSON2 library). Requires Internet Explorer 6 or higher on the machine.
• ChakraActiveScript. ActiveScript version of Chakra JavaScript engine (supports ECMAScript 3 with possibility of using the ECMAScript 5 Polyfill and the JSON2 library). Requires Internet Explorer 9 or higher on the machine.
• ChakraJsRt. JsRT version of Chakra JavaScript engine (supports ECMAScript 5). Requires Internet Explorer 11 or higher on the machine. Detailed information about JsRT you can read in the Paul Vick's blog.

The supported .NET types are as follows:

• MsieJavaScriptEngine.Undefined
• System.Boolean
• System.Int32
• System.Double
• System.String

Installation

This library can be installed through NuGet - http://nuget.org/packages/MsieJavaScriptEngine.

Usage

Consider a simple example of usage of the MSIE JavaScript Engine:

namespace MsieJavaScriptEngine.Example.Console
{
using System;
using MsieJavaScriptEngine;
using MsieJavaScriptEngine.Helpers;
class Program
{
static void Main(string[] args)
{
try
{
using (var jsEngine = new MsieJsEngine(engineMode: JsEngineMode.Auto, useEcmaScript5Polyfill: false, useJson2Library: false))
{
const string expression = "7 * 8 - 20";
var result = jsEngine.Evaluate<int>(expression);
Console.WriteLine("{0} = {1}", expression, result);
}
}
catch (JsEngineLoadException e)
{
Console.WriteLine("During loading of JavaScript engine an error occurred.");
Console.WriteLine();
Console.WriteLine(JsErrorHelpers.Format(e));
}
catch (JsRuntimeException e)
{
Console.WriteLine("During execution of JavaScript code an error occurred.");
Console.WriteLine();
Console.WriteLine(JsErrorHelpers.Format(e));
}
Console.ReadLine();
}
}
}

First we create an instance of the MsieJsEngine class and pass the following parameters to the constructor:

1. engineMode - JavaScript engine mode;
2. useEcmaScript5Polyfill - flag for whether to use the ECMAScript 5 Polyfill;
3. useJson2Library - flag for whether to use the JSON2 library.

The values of constructor parameters in the above code correspond to the default values.

Then we evaluate a JavaScript expression by using of the Evaluate method and output its result to the console.

In addition, we provide handling of the following exception types: JsEngineLoadException and JsRuntimeException.

Release History

See the changelog.

License

Microsoft Public License (Ms-PL)

Credits

• SassAndCoffee.JavaScript - License: Microsoft Public License (Ms-PL) Part of the code of this library served as the basis for the ActiveScript version of Chakra and Classic JavaScript Engine.
• Chakra Sample Hosts - License: Apache License 2.0 (Apache) C# example from this project served as the basis for the JsRT version of Chakra.
• ECMAScript 5 Polyfill and MDN JavaScript Polyfills - Adds support for many of the new functions in ECMAScript 5 to downlevel browsers.
• Cross-Browser Split - Adds ECMAScript compliant and uniform cross-browser split method.
• JSON2 library - Adds support of the JSON object from ECMAScript 5 to downlevel browsers.
• Microsoft Ajax Minifier - License: Apache License 2.0 (Apache) JS-files, that used MSIE JS Engine, minificated by using AjaxMinifier.exe.

Who's Using MSIE JavaScript Engine

If you use the MSIE JavaScript Engine in some project, please send me a message so I can include it in this list:

• Chevron by Simon Cropp
• JavaScript Engine Switcher by Andrey Taritsyn
• SquishIt by Justin Etheredge and Alex Cuse
• Strike by Simon Cropp