Summary: The HTML Standard has for the longest time defined a feature whereby you could exclusively use the h1 and sectioning elements, and user agents would take care of adjusting the heading level according to the nesting depth. Due to the complexity it never got adopted. There’s an alternative proposal that amounts to counting sectioning element ancestors for h1 elements only (and h2-h6 if their parent is hgroup), which is much more doable performance-wise. That proposal might see some further refinements for behavior around hgroup, based on discussion in the issue linked below. (https://annevankesteren.nl/2019/10/heading-levels goes into the high-level idea a bit more.)
The idea is to ship this by default on Nightly and maybe Dev, but not ride the trains (until the standard is more fully agreed and there's an intent to ship). Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=998590. Standard: https://github.com/whatwg/html/pull/3499 coupled with https://github.com/whatwg/html/issues/5002. Platform coverage: All. Preference: accessibility.heading-element-level-changes.enabled. DevTools bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1588784. Other browsers: Have expressed mild interest to get to it eventually, us having some code hopefully gets them more fully on board. web-platform-tests: Unclear how to test heading levels, but once there's a corresponding CSS pseudo-class to expose them there will be. Secure contexts: No, bifurcating an existing HTML feature like that doesn’t seem like a good idea. Is this feature enabled by default in sandboxed iframes? Yes. _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
