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JohnMasen / ChakraCore.NET

A dotnet hosting library for chakra (javascript) engine
MIT License
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ChakraCore.NET

A dotnet hosting library for chakracore (javascript) engine to provide scripting capability to dotnet applications.

Build Status

Due to the workload of my daily job and baby sitting my 2yr old son, I have to hold the update of this library for several month. during this period, bug fix and feature update will be on hold. I may add some samples if I have enough bandwith. the planned continute date will be about 2018/12/1.

Thanks for your support.

Before you start

Please use the chakracore.net.hosting to load javascript class to your host environment instead of using the chakracore runtime/context directly. I'll update the samples section later to reflect this suggestion.

After several projects of using this library, I found the better solution is use the javascript class instead of run the whole script

There's a RunScript project in the source folder demostrates the usage of chakracore.net.hosting namespace, the samples repository (https://github.com/JohnMasen/Chakracore.NET-Samples) also provides a good start.

Allow user to

There're 2 major ways to use this library.

As the feature implementation is almost done, I'll focus on documents and demos from now.

Debugging: The debug extension is available at VSCode marketplace, you can find a simple how-to at https://github.com/JohnMasen/ChakraCore.NET/issues/12 . image

Platform

This library is build with NetStandard 1.4 and Chakracore 1.7.3

Support following platform:

As DotnetCore and Chakracore 1.7.3 supports cross platform, idealy you can use this library at any OS which supported by these 2 libraries. This library is created and tested on windows 10 platform. If you're using it on other platform than Windows 10, feel free to send me a feed back.

nuget:

https://www.nuget.org/packages/ChakraCore.NET/

Key features

Easy project ES6 module class to C# proxy class

Import/Export C# functions to/from javascript

Read/Write javascript values

Call javascript function from dotnet, support callback to dotnet

Expose dotnet function to javascript, support callback to javascript

Flexible value converter system

Support ArrayBuffer,TypedArray,DataView

Support Task <-> Promise convert

Support "require" feature (not enalbed by default)

Support ES6 Modules

Support VSCode debug

Samples

You can find the samples at https://github.com/JohnMasen/Chakracore.NET-Samples

Documents and samples are still under development, there's another sample project "RunScript" in the main repository "Tools" folder. It is strongly suggest use the Chakracore.Net.Hosting to host your script(which is the Samples project using). The following code shows some features of the engine. some of the code will be updated to use Hosting namespace in the future.

Setup runtime and context, then run a script (will be replaced with Hosting namespace)

    ChakraRuntime runtime=ChakraRuntime.Create();
    ChakraContext context=runtime.CreateContext(true);
    context.RunScript("var a=1;");

write 1 to variable a

    context.GlobalObject.WriteProperty<int>("a", 1); //js: var a=1;

read variable a

    int value=context.GlobalObject.ReadProperty<T>("a"); //js: return a;

call js function

    context.RunScript("function add(v){return v+1}");  //run the script to create function add
    var b=context.GlobalObject.CallFunction<int, int>("add", 1); //js: return add([value]);

expose function 

    public int Add(int value)
    {
        return value + 1;
    }
    context.GlobalObject.Binding.SetFunction<int,int>("add", Add); //js: function add(v){[native code]}

call js function with callback

    public void echo(string s)
    {
        Debug.WriteLine(s);
    }
    context.RunScript("function test(callback){callback('hello world')})");  //init js function
    context.ServiceNode.GetService<IJSValueConverterService>().RegisterMethodConverter<string>();  //regiser callback method type
    context.GlobalObject.CallMethod<Action<string>>("test", echo);   //js: test([native function]);

map a dotnet object instance to js

    public class DebugEcho
    {
        public void Echo(String s)
        {
            Debug.WriteLine(s);
        }
    }

    context.ServiceNode.GetService<IJSValueConverterService>().RegisterProxyConverter<DebugEcho>( //register the object converter
        (binding, instance, serviceNode) =>
        {
            binding.SetMethod<string>("echo",instance.Echo); //js: [object].echo=function(s){[native code]}
        });
    DebugEcho obj = new DebugEcho();
    context.GlobalObject.WriteProperty<DebugEcho>("debugEcho", obj); //js: var debugEcho=[native object]

using "require" (obsolete, please use ES6 import/export instead)

c#  
    JSRequireLoader.EnableRequire(context,"Script\\Require"); //enable require, set root folder to "Script\Require"
    runScript("RequestTest"); 

RequestTest.js

    var p = require("TestLib");
    var output = p.t1("abc");

TestLib.js

    function t1(source) {
        return source + source;
    }
    exports.t1 = t1;

ES6 module (project exported class as global object) (will be replaced with Hosting namespace)

        protected JSValue projectModuleClass(string moduleName,string className)
        {
            //setup local moudle callback, assume every script is embedded in resource without ".js" extension
            return context.ProjectModuleClass("__value", moduleName, className, (name) => Properties.Resources.ResourceManager.GetString(name));
        }

        public void ImportExport()
        {
            var value = projectModuleClass("BasicExport", "TestClass"); //load BasicImport.js module file, create an instance of exported class "TestClass" and map it to global scope . return the exported value
            var result = value.CallFunction<int, int>("Test1", 1);//call the function on exported class
            Assert.AreEqual(2, result);
        }

BasicExport.js
        export 
    class TestClass {
        Test1(v) {
            return v + v;
    }
}