[tenaciousDaniel]

Yep, to some degree. Though what I would love in an xml-based UI description language is the ability to opt into default system behaviors, while maintaining the ability to use whatever semantic naming convention that fits my application.

I wrote this code in another comment, but imagine if you could hook functionality to an element via defined attributes. With custom elements, you have to add the functionality via a script, and they aren't system functions (from what I can remember, I may be wrong).

  <LabelList list>
    <LabelItem label listItem>
    </LabelItem>
  </LabelList>

In the above code:

- the LabelList element hooks into the systems "list" behavior

- the LabelItem element hooks into the systems "label" behavior

- the LabelItem element hooks into the systems "listItem" behavior

[warp]

Maybe the is="" attribute gets you partway there?

    <ul is="label-list">
        <li is="list-item">foo</li>
    </ul>

EDIT: google's documentation: https://developers.google.com/web/fundamentals/web-component...