attachShadow vs createShadowRoot

Question

I read in mozilla doc, Element.createShadowRoot() is deprecated:

This method has been deprecated in favor of attachShadow.

But in my canary: chrome 49.0.2599.0

thats work:

 var shadow = document.getElementById("node-sh").createShadowRoot();  

And thats not work

 var shadow = document.getElementById("node-sh").attachShadow({mode: 'closed'});

Anyone know what's right?

Answer 1

createShadowRoot() is the old way of attaching a shadow-root to host element. It was proposed in initial spec, which has then been deprecated in favor of attachShadow. Spec also has been updated.

But, new API hasn't been standardized and none of the browsers currently support it. So I would suggest to stick to createShadowRootfor now. Once you start getting browser warnings for deprecation, that would be the time to move to attachShadow.