On Tue, Jan 6, 2015 at 7:54 PM, Dimitri Glazkov <dglaz...@google.com> wrote: > Right, that's why to create a valid custom element that subclasses > HTMLInputElement, you should use type extensions. With type extensions, the > HTMLInputElement is what's instantiated.
But without using type extensions this will work (provided we sort out the other bits): class X extends HTMLInputElement { ... } document.registerElement("x-input", X) var xinput = new X It seems sad to require type extensions (and therefore requiring a more complicated version of document.registerElement) for translating this into markup. Having actual subclassing in JavaScript, but not for elements unless you use some sort of hack seems sad. -- https://annevankesteren.nl/