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Passing non-duocode objects to duocode objects

Let's take the same example from my first post:


using System;
namespace Company.Product.Presentation.Model
    public class UserInterface
        protected readonly IApplicationService _applicationService;
        public UserInterface( IApplicationService appService) 
            _applicationService= appService;
        public virtual void Execute()

It is ok now if I also have an implementation od IApplicationService in c# and transpiled with DuoCode.

But if I make an implementation of IApplicationService in typescript/js and pass that object to the  UserInterface constructor it Will not work when the code in the Execute function tries to call the ExecuteSpecial.

Because it is transpiled into:




Of course the typescript object does not have that long name in its implementation,


class AppSvc implements IApplicationService{

 How will we resolve such problems?  

You can and should add field in AppSvc like this:


class AppSvc implements IApplicationService{
  ExecuteSpecial() { ("Test"); }
  $Product$Presentation$IApplicationService$ExecuteSpecial: Function = this.ExecuteSpecial;


Also stay tuned to our next version release, we are going to support TypeScript and .d.ts files, which will very help in your case !!

Ok, thanks. I'm looking forward for the ts/d.ts features. The upper solution is not yet a solution, it couples ts/js code with generated code "internals"!

Thanks again.

Hi, have another question similar to this one. How can I implement a C# defined interface(transpiled) in ts/js that allows me to set a delegate(callback) to be called from the transpiled code?

Lets have this in c#:


    public interface IConnection
        void Send(string message);
        OnReceivedDelegate OnReceived{get;set;}

    public delegate void OnReceivedDelegate(object data);

 and now I have a ts/js implementation of this interface like this:


export class RgsConnection implements IConnection {
        srConnection: SignalR;
        constructor() {
        public Start(url:string, callback: () => void)
        IConnection$Send: Function = this.Send;
        IConnection$get_OnReceived: ?;
        IConnection$set_OnReceived: ?;

        public Send(message: string) {

        public OnReceived: (data: any) => void;
        private received(data: any): SignalR {
            if (this.OnReceived !== undefined) {
            return this.srConnection;


Now if I create this rgsConnection ts/js object in javascript code and I pass it to a transpiled js code I don't know how to implement IConnection$set_OnReceived since it provides a $d.delegate() from the c# transpiled code.? I hope it's clear enough? In summary I want to pass a c# delegate to a js object that implements c# interface.

This works(in typescript):


        IConnection$get_OnReceived: Function = () => { return this.OnReceived; };
        IConnection$set_OnReceived: Function = (value) => {
            this.OnReceived = value; return value;

        get OnReceived(): (data: any) => void {
            return this._OnReceived;

        set OnReceived(callback:(data:any)=>void) {
            this._OnReceived = callback;
        private _OnReceived: (data: any) => void;

        private received(data: any) {
            if (this._OnReceived !== undefined) {


Please try our latest DuoCode v1.0 with TypeScript support, and even hybrid C# + TypeScript projects.

Download it from:

More info:

Regarding your question:

In summary I want to pass a c# delegate to a js object that implements c# interface?

DuoCode will auto generate IConection and OnReceivedDelegate interfaces in .d.ts file, you must implement it in TS, similar to what you did with RgsConnection.

Passing C# delegate (which is actually a JS function + typeinfo + additional Delegate methods) is straightforward.

I hope this is clear and helpful.

Note: currently TS generation of delegates doesn't contain method parameters in .d.ts, we already fixed this in the coming version, but u still can call it from TS since it's a Function.

In other words, currently DuoCode generates:

export interface OnReceivedDelegate extends System.MulticastDelegate { }

instead of, more strongly typed:

export interface OnReceivedDelegate extends System.MulticastDelegate { (data: any): void }

I've tried the generated d.ts and now my example code is no longer ts compilable with usage:


    var rgsConnection: IConnection;
    rgsConnection = new RgsConnection();

 I get:

Type rgsConnection is not assignable to IConnection because of types of property IConnection$Send are incompatible. Type "Function" is not assignable to type "(message:string)=>void".

I can fix that by changing the rgsConnection to:

IConnection$Send: (message:string)=>void = this.Send;

I then get same issue for the getOnReceived: Type "Function" is not assignable to type "()=>OnReceivedDelegate". The following code won't compile: 

        IConnection$get_OnReceived: () => OnReceivedDelegate =
        () => { return this.OnReceived; };

 Any hint how can I pass a function as an OnReceivedDelegate and vice versa in this sample?


In order to create C# like delegate in TS, you should use $d.delegate() with target object binded and cast it to <OnReceivedDelegate>.

like this:


  var onReceiveDlg = <OnReceivedDelegate>$d.delegate(myHandler, target_obj);


Note, in DuoCode v1.1 (released by this month) we improved TS defintion of $d.delegate<TDelegate>(...) method, like this:


var delegate: { <TDelegate>(method: Function, target?: any): TDelegate; };


Hope this helps and feel free to ask more.

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