20260 2012-12-06 06:22:25 +0000 [Shadow]: ShadowRoot should have olderShadowRoot attribute to get older shadow tree. 2013-10-24 11:07:27 +0000 1 1 1 Unclassified WebAppsWG HISTORICAL - Component Model unspecified PC All RESOLVED FIXED P2 normal --- 22715 1 morrita hayato dominicc hayato sgrekhov sorvell public-webapps-bugzilla oldest_to_newest 79527 0 morrita 2012-12-06 06:22:25 +0000 It could be named olderShadowRoot but |shadowRoot| aligns ShadowAware interface and better for iterating over for() loop. 79581 1 dglazkov 2012-12-06 21:21:59 +0000 I am not sure about this. We expose the composed shadow tree with .shadowRoot and .olderShadowRoot. This would expose the tree stack, and I don't know if that's good. 79598 2 morrita 2012-12-07 01:38:17 +0000 > I am not sure about this. We expose the composed shadow tree with > .shadowRoot and .olderShadowRoot. This would expose the tree stack, and I > don't know if that's good. Then we can hide older shadow root by putting younger one over it without any <shadow> element. If we prefer encapsulation by default, this would be way to. If we switch to all-visible-by-default principle, we should have this. I'm not sure which is better either. If it is intentional not to have this, that's totally fine for me. 83853 3 sorvell 2013-03-01 00:17:14 +0000 Currently olderShadowRoot is defined only as a property of a <shadow> element. Given a shadowRoot, to find olderShadowRoot, one must find the <shadow> element inside it and then interrogate that object for the olderShadowRoot. This is inconvenient and it would be simpler if olderShadowRoot were simply a property of a shadowRoot node. 83887 4 dominicc 2013-03-01 21:51:15 +0000 *** Bug 21166 has been marked as a duplicate of this bug. *** 83888 5 dominicc 2013-03-01 21:53:50 +0000 Defining olderShadowRoot on HTMLShadowElement is inconvenient for code that wants to walk the list of ShadowRoots. It is necessary to write something like: function forEachShadowRoot(host, f) { for (var s = host.shadowRoot; s; s = olderShadowRootOf(s)) { f(s); } } function olderShadowRootOf(s) { var shadowElements = s.querySelectorAll('shadow'); for (var i = 0; i < shadowElements.length; i++) { var shadowElement = shadowElements[i]; if (shadowElement.olderShadowRoot) { return shadowElement.olderShadowRoot; } } // There were no shadow elements, or they were all inert shadowElement = document.createElement('shadow'); s.appendChild(shadowElement); var result = shadowElement.olderShadowRoot; shadowElement.remove(); return result; } This seems excessively complicated for this use case; it would be better if olderShadowRoot was defined on ShadowRoot, then one could simply write the loop in a straightforward way: function forEachShadowRoot(host, f) { for (var s = host.shadowRoot; s; s = s.olderShadowRoot) { f(s); } } (In reply to comment #0) > It could be named olderShadowRoot but |shadowRoot| aligns ShadowAware > interface and better for iterating over for() loop. I agree that this simplifies loops. However it could be confusing if in future ShadowRoot could have a ShadowRoot, or if ShadowRoot became an element. So I think the name olderShadowRoot is better. 89297 6 dominicc 2013-06-14 05:39:28 +0000 Since anyone who could have an objection has had a reeeeeeeasonable time to respond, I am implementing this in Blink now (behind a flag.) 90880 7 dglazkov 2013-07-17 20:22:53 +0000 *** Bug 20355 has been marked as a duplicate of this bug. *** 95294 8 hayato 2013-10-24 11:07:27 +0000 The spec was updated: https://dvcs.w3.org/hg/webcomponents/rev/867a6026f003