[x3d-public] custom elements in HTML5

Wed Aug 14 14:50:32 PDT 2019

Thanks for this excellent analysis Andreas.

On 8/1/2019 12:59 PM, Andreas Plesch wrote:
> As I had mentioned  at Web3D 2019, the use of dashes is a name space mechanism in HTML5,. Let me follow up with background and references:
> 
> A) What is HTML5 ?
> 
> I believe the W3C and WHATWG spec. divergence was resolved:
> 
> WHATWG:
> https://html.spec.whatwg.org/multipage/introduction.html#is-this-html5?
> 
> W3C:
> latest recommendation:
> https://www.w3.org/TR/2017/REC-html52-20171214/
> latest working draft:
> https://www.w3.org/TR/2018/WD-html53-20181018/

Indeed there is a long and colorful history of interactions between WHATWG and W3C.  Of interest:

	W3C
	https://www.w3.org
	https://en.wikipedia.org/wiki/WHATWG

	WHATWG
	https://whatwg.org
	https://en.wikipedia.org/wiki/World_Wide_Web_Consortium

	W3C and the WHATWG signed an agreement to collaborate on a single version of HTML and DOM
	https://www.w3.org/blog/news/archives/7753

	W3C and WHATWG to work together to advance the open Web
	28 May 2019 by Jeff Jaffe, W3C CEO
	https://www.w3.org/blog/2019/05/w3c-and-whatwg-to-work-together-to-advance-the-open-web-platform

	Memorandum of Understanding Between W3C and WHATWG
	https://www.w3.org/2019/04/WHATWG-W3C-MOU.html

Web3D Consortium is a liaison member of W3C.

	https://www.w3.org/Consortium/Member/Testimonial/#t393
	"The Web3D Consortium, like W3C, supports open standardization. Web3D's open standards for real-time 3D communication include X3D, a powerful and extensible XML-based ISO standard for 3D visual effects, behavioral modeling, interaction and interoperability. Web3D membership includes companies, institutions, working groups and individuals.
W3C Member since 1 April 1999."

Of note is that Web3D can only align X3Dv4 with approved international standards.  I think this means the standards you indicated (HTML5.2 and potentially 5.3) as we proceed with X3Dv4.

	X3D Version 4 Strategy
	https://www.web3d.org/X3D4

> B) Why custom elements ?
> 
> Custom elements are the recommended, standardized method to extend HTML5 to other domains. However, both x3dom and x-cite use other mechanisms. Currently, x3dom uses Unknown Elements and x-cite uses DOM provided XML parsing.
> 
> Unless W3C/WHATWG adopts X3D as native elements (such as SVG) which is unlikely in the near to medium term, the custom element specification would be the best fit to strongly couple X3D to HTML.

Agreed here.  Good topic for discussion on a future X3D teleconference when convenient to you.

Recommended course of action:
- Work with HTML5 custom elements.
- Look at how SVG is supported.
- Once stable and specified, consider proposal for X3D as native elements to W3C.

> C) Dashes in custom element names
> 
> A valid custom element must contain a dash ("-") character. See the production here:
> 
> WHATWG:
> https://html.spec.whatwg.org/multipage/custom-elements.html#valid-custom-element-name
> 
> W3C:
> https://www.w3.org/TR/2018/WD-html53-20181018/semantics-scripting.html#valid-custom-element-name
> https://www.w3.org/TR/2017/REC-html52-20171214/dom.html#elements links to
> https://www.w3.org/TR/custom-elements/#valid-custom-element-name
> which points back to HTML5.3 draft
> 
> The suggestion would be to add a "x3d-" prefix to all X3D nodes and keywords. "x-" is already used by multiple custom element collections.

Sounds like a do-able plan.

Interestingly this is almost identically similar to practice in python, which also has pythonic form of "prefix.element" for common use to avoid class collisions - for example x3d.X3D, x3d.head, x3d.Scene, x3d.Group, etc.

	X3D Resources, Examples: Scene Archives for X3D
	https://www.web3d.org/x3d/content/examples/X3dResources.html#Examples

	HelloWorld.py
	https://www.web3d.org/x3d/content/examples/HelloWorld.py

The time is approaching when we should compare these:
- X3DOM form,
- X_ITE form,
- Custom HTML5 including "custom"-prefixed X3D elements, and
- any other alternatives.

Added as Mantis issue 1260.

	Use of custom elements (x3d- prefix) for X3Dv4 in HTML5
	https://www.web3d.org/member-only/mantis/view.php?id=1260

all the best, Don
-- 
Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman