271645 2024-03-25 07:25:47 -0700 Declarative shadow DOM does not work for XHTML 2024-04-03 06:57:39 -0700 1 1 1 Unclassified WebKit DOM Other Unspecified Unspecified RESOLVED INVALID InRadar P2 Normal --- 148695 1 mail webkit-unassigned cdumez rniwa webkit-bug-importer oldest_to_newest 2023647 0 mail 2024-03-25 07:25:47 -0700 Browser: Epiphany 45.3 on Arch Linux. The Declarative shadow DOM function does not work for XHTML documents (though it does for plain HTML ones). # Steps to reproduce: Paste the following XHTML snippet into the address bar: data:application/xhtml+xml,<div xmlns="http://www.w3.org/1999/xhtml"><template shadowrootmode="open">OpenDeclarativeShadowDOMsupported</template></div> # Actual results: An empty page is shown (and the developer tool DOM tree shows the <template> element is not removed, the template contents aren't moved into the parent and no shadow DOM is created. # Expected results: I would have expected the same (working) behaviour we see for equivalent HTML documents (see snippet below): data:text/html,<div><templateshadowrootmode="open">OpenDeclarativeShadowDOMsupported</template></div> This shows "OpenDeclarativeShadowDOMsupported" when opened in a browser. # Other browsers The same bug also appears to effect: * Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=1887436 * Chromium: https://issues.chromium.org/issues/330967152 2025086 1 webkit-bug-importer 2024-04-01 07:26:14 -0700 <rdar://problem/125716107> 2025671 2 gsnedders 2024-04-03 06:57:39 -0700 As per the Chromium bug, this is intended behaviour: specific shadow DOM treatment requires changes to the parser, and the XML parser doesn't do this. The discussion on the Chromium bug has ended up with https://github.com/whatwg/html/issues/10237 against the HTML spec, and it probably makes sense to keep the discussion there.