Angular2 Class Decorator Pattern

ng2.class.decorator.pattern.ts

export function MyDecorator(target: any) {
    // save a reference to the original constructor
    var original = target;

    // a utility function to generate instances of a class
    function construct(constructor, args) {
        let c: any = () => {
            return constructor.apply(this, args);
        };
        c.prototype = constructor.prototype;
        return new c();
    }

    var f: any = (...args) => {
        // the new constructor behavior
        // change how you construct before constructing here...
        let newInstance = construct(original, args);
        // do something with the instance here...
        return newInstance;
    };

    // copy prototype so intanceof operator still works
    f.prototype = original.prototype;

    // return new constructor (will override original)
    return f;
};