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Could you tell me how to translate this into TypeScript? using SharpKit.JavaScript;

namespace MyNamespace
{
    [JsType(JsMode.Prototype)]
    public class JsEventArgs
    {
    }

    public delegate void JsEventHandler<in T>(object sender, T args) where T : JsEventArgs;
    public delegate void JsEventHandler(object sender, JsEventArgs args);
}

And usage in the other class:

public event JsEventHandler<LayerVisivilityEventArgs> Changed;

I tried that:

module JsEvent {

    export class JsEventArgs {
    }

    public JsEventHandler: (sender: Object, args: any) => void;
    public JsEventHandler: (sender: Object, args: JsEventArgs) => void;
}

Could you tell me how to translate this into TypeScript? using SharpKit.JavaScript;

namespace MyNamespace
{
    [JsType(JsMode.Prototype)]
    public class JsEventArgs
    {
    }

    public delegate void JsEventHandler<in T>(object sender, T args) where T : JsEventArgs;
    public delegate void JsEventHandler(object sender, JsEventArgs args);
}

And usage in the other class:

public event JsEventHandler<LayerVisivilityEventArgs> Changed;

I tried that:

module JsEvent {

    export class JsEventArgs {
    }

    public JsEventHandler: (sender: Object, args: any) => void;
    public JsEventHandler: (sender: Object, args: JsEventArgs) => void;
}

• c#
• javascript
• typescript

Share Improve this question Follow edited Nov 30, 2012 at 14:03 Picrofo Software 5,57133 gold badges2525 silver badges3737 bronze badges asked Nov 30, 2012 at 14:01 NickonNickon 10.2k1313 gold badges6767 silver badges127127 bronze badges 10

• 1 I'm confused as to what you are trying to do. What does SharpKit have to do with TypeScript? – Jude Fisher Commented Nov 30, 2012 at 14:05
• I'm translating a C# app onto TypeScript. I want to create an event that will work as the one from C# code. – Nickon Commented Nov 30, 2012 at 14:06
• And what's wrong with the TypeScript you've tried above? – Jude Fisher Commented Nov 30, 2012 at 14:07
• 1 It's not because they are public - it's because you can't add properties to a module. – Jude Fisher Commented Nov 30, 2012 at 14:40
• 1 The question is not clear at all. That JsEventHandler and JsEventArgs and JsMode — how would anybody guess their purpose? You need to define clearly what are you trying to achieve rather than giving your raw source code out without any explanation. – Oleg Mihailik Commented Nov 30, 2012 at 16:09

 |  Show 5 more ments

3 Answers 3

Sorted by: Reset to default 7

I wrote a little class which behaves like the .NET Delegate class (which is implicitly created for an event in .NET)

export interface IDelegate {
    (sender: any, ...parameters: any[]): void;
}

export class DelegateBuilder {
    private callees: IDelegate[];

    constructor() {
        this.callees = [];
    }

    invoke(sender: any, ...parameters: any[]) {
        for (var i = 0; i < this.callees.length; i++) {
            var callee = this.callees[i];
            if (caller)
                callee(sender, parameters);
        }
    }

    contains(callee: IDelegate) : bool {
        if (!callee)
            return false;

        return this.callees.indexOf(callee) >= 0;
    }

    add(callee: IDelegate): DelegateBuilder {
        if (!callee)
            return this;

        if (!this.contains(callee))
            this.callees.push(callee);

        return this;
    }

    remove(callee: IDelegate): DelegateBuilder {
        if (!callee)
            return this;

        var index = this.callees.indexOf(callee);
        if (index >= 0)
            this.callees.splice(index, 1);

        return this;
    }

    toDelegate() : IDelegate {
        return (sender: any, ...parameters: any[]) => this.invoke(sender, parameters);
    }
}

I think you need to stop thinking in C#, and begin thinking in TypeScript.

This code:

module JsEvent {

    export class JsEventArgs {
    }

    public JsEventHandler: (sender: Object, args: any) => void;
    public JsEventHandler: (sender: Object, args: JsEventArgs) => void;
}

... tries to add two properties to a module, but properties are only permitted on a class (or interface).

TypeScript doesn't really use delegates - you can wire up an event (for example, in JQuery), like this:

$('selector').click((e:JQueryEventObject) => {
     // Do something here.
});

... or, avoiding JQuery:

var div: HTMLDivElement = new HTMLDivElement();
div.onclick = (e: MouseEvent) => {
    // Do something here.
};

... or, without an anonymous function:

div.onclick = doSomething;
function doSomething(e:MouseEvent):void{
    // Do something here.
}

I think the closest pattern you'll get to a delegate is something like this (cribbed from http://forum.unity3d./threads/9679-Javascript-Delegates!):

module JSEvents {
    class JSEventClass {

        public delegate:(e:string) => any;

        constructor() => {
            this.delegate = this.doSomething;
            this.delegate("Hello, Delegate World");
        }

        public doSomething(e: string): any {
            console.log("Doing Something: " + e);
        }
    }
}

... but in a TypeScript / JavaScript world, I don't see what this pattern achieves over just calling doSomething() directly.

I think this is a close translation of the code in question. However, this doesn't address event handling, which is already covered by another answer.

module MyNamespace
{
    export class JsEventArgs
    {
    }

    export interface JsEventHandler<T extends JsEventArgs> {
        (sender: any, args: T): void;
    }

    export interface JsEventHandler {
        (sender: any, args: JsEventArgs): void;
    }
}

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