Firefox for Web DevelopersHTML might be getting a new type of tag, which… hasn't happened this millennium. Here's the new syntax, and how it works.
And here's the explainer on HTML patching https://github.com/WICG/declarative-partial-updates/blob/main/patching-explainer.md
John Ulrik@firefoxwebdevs Please don’t borrow XML processing instruction syntax only halfway. Either use PI syntax exactly, or invent a clearly different one.
@ujay68 what's missing from the current handling? The ProcessingInstruction 'class' should get new capabilities as a result of this, such as proper attributes.
vrugtehagel@firefoxwebdevs @ujay68 I think they meant being able to omit the question mark in "?>". Personally, I don't mind it, because HTML is not XML; for example, the slash in "<br/>" is also optional. The "<?" syntax seems to be chosen partly because it is backwards compatible, for which the closing "?" doesn't matter, since bogus comments end at the nearest ">". Either way, the closing question mark is allowed, so write it if you'd like! Jake even uses "?>" throughout the rest of the video ;)
@vrugtehagel @firefoxwebdevs Yes, this is what I meant. I’ve checked the HTML specification and the <? syntax is there, defined as “bogus comment” (!) up to the next closing >. This is already different from XML, sadly.
@ujay68 @vrugtehagel right, but the goal is not to have all HTML and XML syntax be treated as the same, it's to have some subset that works the same in both.