CODEWITHSUNDEEP
typescript
xamiro
xamiro

Reputation: 1401

Method decorator which modifies class ?

Might it be possible to develop a method decorator, ie: "@rpcMethod" which modifies a class's prototype ?

At the end I want: 

@rpcMethod
get(){
   ....
}

and at run-time: 

instance.getRpcMethods(); //returns ['get']

I tried all sort of things inside the decorator (ie:modify target.prototype) but it all failed.

thanks!

Upvotes: 0

Views: 91

Answers (1)

Alex
Alex

Reputation: 14523

Sorry for late reply, try this:

var rpcMethod = (target: Object, propName: string, propertyDescriptor: TypedPropertyDescriptor<() => any>) => {
    var desc = Object.getOwnPropertyDescriptor(target, "getRpcMethods");
    if (desc.configurable)
    {
        Object.defineProperty(target, "getRpcMethods", { value: function() { return this["rpcMethods"]; }, configurable: false });
        Object.defineProperty(target, "rpcMethods", { value: [] });
    }

    target["rpcMethods"].push(propName);
};


class MyClass
{
    public getRpcMethods():string[] {
        throw new Error("Should be implemented by decorator");
    }

    @rpcMethod
    public get() {
        return "x";
    }

    @rpcMethod
    public post() {
        return "y";
    }
}

var myInstance = new MyClass();

myInstance.getRpcMethods();

Upvotes: 1

Related Questions