W3C home > Mailing lists > Public > public-html@w3.org > March 2010

Re: Possible Conservative Proposal : no prefixes, but allow xmlns on a root element

From: Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>
Date: Mon, 22 Mar 2010 21:11:25 +0100
To: "Ennals, Robert" <robert.ennals@intel.com>
Cc: "public-html@w3.org WG" <public-html@w3.org>, "Carr, Wayne" <wayne.carr@intel.com>
Message-ID: <20100322211125804793.56e56b9b@xn--mlform-iua.no>
Ennals, Robert, Mon, 22 Mar 2010 18:22:32 +0000:

> [...] you must introduce your extension in the same 
> manner that SVG and MathML have been integrated into HTML5. That is:
> 
> * Define a root element (like math or svg) that content for 
>   your new extension can be included under.
> * If the extension is not yet part of HTML, the root element 
>   MUST contain an xmlns.
> * Such a root element MUST NOT be an existing HTML5 tag
> * If the extension is part of HTML, then the parser will 
>   infer the xmlns based on the name if no xmlns is currently present

> * Compatible with XML namespaces
> * No ugly prefixes
> * When a feature becomes standard, it does not get stuck with 
>   a hard-to-remove prefix
> * When a feature is not standard, an author can see they are 
>   using an extension by the requirement to use xmlns.

I think it should be permitted to declare prefixed namespaces for 
content inside the <script> element. E.g. I find this example at 
AmpleSDK.com: [1]

  <script type="application/ample+xml"
    xmlns="http://www.w3.org/1999/xhtml"
    xmlns:d="http://www.amplesdk.com/ns/data"
    xmlns:a="http://www.amplesdk.com/ns/aml">

On another page at AmpleSDK.com I see this, outside <script> - why 
ought it to be invalid? Or I am wrong that it would be invalid 
according to this proposal? Example code: [2]

  <svg:svg height="600px" width="600px" viewBox="0 0 600 600" 
           xmlns:svg="http://www.w3.org/2000/svg">

I also think it should be possible to declare prefixes for attributes 
inside HTML5 elements. Outside, <script>, to avoid that they are used 
on element level, one could require that the prefix starts with a "_" 
underscore.

Your proposal doesn't solve the RDFa use case.

> What do people think?
> 
> As with my last proposal, if it looks like this will get support then 
> I'll write it up. If it looks like there are serious problems then I 
> won't.

Much good. It looks to solve much of the element extensibility use 
case. But little w.r.t. attributes.

[1] http://www.amplesdk.com/examples/aml/databinding/

[2] http://www.amplesdk.com/examples/svg/tiger/

-- 
leif halvard silli
Received on Monday, 22 March 2010 20:12:23 UTC

This archive was generated by hypermail 2.3.1 : Thursday, 29 October 2015 10:15:59 UTC