Extending Element in MooTools gives error "Uncaught TypeError: Cannot call method 'set' of null"

Question

I have this very simple MooTools script:

var MyElement = new Class({
    Extends: Element
});

which gives the error: Uncaught TypeError: Cannot call method 'set' of null

I'm using MooTools 1.4.5, full without compatability.

If I change the class it extends to any other class, it works fine.

What's going on here? Is this a bug?

EDIT:

Same thing happens with Implements: Element!

Answer 1

As pointed out on this page:

element is not extendable as its not a real class.

This is because it is mostly an interface wrapper ('proxy') around your browser's native internal classes wrapping 'real' elements. There is a 'workaround' for this though with the toElement function. If you implement it on an object or class, passing the class to the $ function will automatically invoke it, as such making your class behave completely like an Element, and allowing you to use aggregation instead of (faulty!) inheritance to wrap browser elements.

Example of toElement.