About this project

Tiny JsInterop is a small library which helps with C# <-> JavaScript interoperability in unity engine (Tiny/DOTS runtime and WebGL builds). Idea is simple. Add one attribute and let the system do the job.

Example

Consider simple task of calling window.prompt from C#. With this library, all you have to do is to declare one external method:

        [JsFunction("window.prompt")]
        public static extern string Prompt(string message, string defaultValue);

That's all! :) Now you can use this function wherever you want (except from job system... yet).

What about Js -> C# calls?

        [JsCallback("window.unityCallback.CallbackTest")]
        public static string CallbackTest(string messageToUnity)
        {
            ConsoleLog(messageToUnity);
            return "returned from C#!";
        }

Once you set JsCallback attribute, a method will be available from JS. But how does these attrubites work?

How does it work

All the magic comes from ILPostProcessor. It's a new and undocumented feature introduced in newer versons of Unity. ILPostProcessor allows us to inject additional IL code after assembly compilation. This library implements its own ILPostProcessor. It looks for JsCallback and JsFunction attributes, and injects additional code for initialization and parameters/return serialization.

Installation

There are two ways to install this repository:

1. Clone both repositories into your "Packages" folder:

• com.tinyutils.msgpack
• com.tinyutils.jsinterop

2. Open package manager, click "+" button, and select "Add package from git URL...". Then paste HTTPS clone URLs:

• https://github.com/supron54321/com.tinyutils.msgpack.git
• https://github.com/supron54321/com.tinyutils.jsinterop.git

This method sometimes does not work, so if you have any problems, try restart unity and try again or use first method.

Supported types

Unity DllImport() by default supports only primitive types, strings and arrays of primitives. This library can transfer all serializable complex types except arrays and built-in containers (System.Collections.*). Support for containers is being implemented and will be released soon.

Exceptions support

JsCallback supports exceptions transfer between C# and JS. JsFunction support will be added in the future. Exceptions do not work in Tiny/DOTS, but they do work in old WebGL build.

Known issues

• Void return type is not implemented for JsCallback
• JsCallback does not work in Development mode (NativeList bug)
• Arrays and other containers are not supported yet

Roadmap

• Containers support
• Reference type support (transfer reference instead of serialized copy)
• Delegates transfer support