Re: [Bug 8611] Consider adding a full schema to H:TML

On Tue, Jan 5, 2010 at 9:08 PM, Joe D Williams <> 
>> I don't see how to define a boolean attribute (absence or presence
?> effectively gives boolean value) in XML schema.

"Thomas Broyer" <> replied
> As an optional attribute whose value can only be the empty string or 
> the same as the attribute's name?

Ok, so that is a rule for XHTML but does not describe or explain the 
text/html usage where the atttribute may appear in html as a string 
not followed by = but having the special rule that says if only the 
attribute name string is present and followed by separator then that 
is ok and the default value is the empty string which means a default 
functionality that you can go read in the spec what it does. In this 
case it is the =value part of the attribute that is optional in the 
user code (or is the name= part optional?) .

I still don't see how to identify this special case of an attribute 
which has an optional name= or =value part can be identified in 
text/html using xml schema. I really don't think this a weakness in 
the xml schema, or shows a shortcoming. But this might show a gap 
between html in text/html and html in application/xhtml+xml where of 
course the complete HTML5 vocabulary and structure is completely 
defined and ennumerated using xml schema. It seems like we all agree 
that xml stuff requires the construction of name=value even though the 
case where quotes that are not required are optional is also being 
exploited as a simpification in the text/html that may fail for +xml.

Maybe more like: changed but not tested or examined much
<xs:attribute name="autobuffer">
      <xs:restriction base="xs:string">
         <whiteSpace value="collapse" />
         <xs:enumeration value="" />
         <xs:enumeration value="autobuffer" />

> But there are things that are waaaay more difficult to implement in 
> XML Schema (and I believe some are just impossible to represent in 
> XML Schema)

I think everyone should bring these forward immediately because 
whatever it finally is really also has to work with only some minimum 
amount of hand waving in xml ... I guess. Anyway I would like to see 
the list of html5 that is not already defined or definable by xml 
schema as already used in xhtml and svg and x3d and mathml and 
elsewhere html5 might appear.

Thank You and Best Regards,

Thomas Broyer

Received on Wednesday, 6 January 2010 04:01:18 UTC