[wp-hackers] WordPress, web standards, and (X)HTML

[Robin Adrianse]

It doesn't help that IE (I think it's IE6 and maybe IE7) chokes on
application/xhtml+xml headers...

On 11/30/06, Benjamin Hawkes-Lewis <bhawkeslewis at googlemail.com> wrote:
>
> It's been suggested that we move this discussion
> [ http://trac.wordpress.org/ticket/3406 ] from Trac to this mailing
> list.
>
> WordPress bills itself on its homepage as producing standard markup.
>
> By default, WordPress produces a variation on XHTML 1.0 markup which is
> always served as text/html. There appears to be no effective enforcement
> of conformance to protect against user "stupidity" or misbehaving
> plugins. As a result, /in practice/, many (if not most) WordPress blogs
> include non-conformant, even non-validating, pages.
>
> XHTML 1.0 should be served as application/xhtml+xml to supporting user
> agents. Serving XHTML 1.0 as text/html was envisaged by the XHTML 1.0
> specification writers as a compatibility hack for legacy browsers, not
> as the main MIME type for XHTML 1.0 content.
>
> There is no specification for how user agents should parse or render
> XHTML 1.0 served as text/html, except that they should try and mimic
> rival user agents' error recovery:
>
> http://www.w3.org/TR/xhtml1/#guidelines
>
> http://www.apps.ietf.org/rfc/rfc2854.html#page-3
>
> Most user agents hand such XHTML over to the same tag soup parsers that
> parse any other HTML. These parsers are only capable of rendering XHTML
> 1.0 acceptably because of their historical failure to conform to the
> HTML 4.01 specification in the first place. Worse, certain JavaScript
> and CSS techniques that work with documents served as text/html will not
> work when the same documents are served as application/xhtml+xml. For
> this and other reasons, many consider serving XHTML 1.0 as text/html at
> all to be bad practice:
>
> http://www.hixie.ch/advocacy/xhtml
>
> http://www.webdevout.net/articles/beware_of_xhtml.php
>
> I like XHTML. But I believe that best practice is to either:
>
> 1) Serve XHTML 1.1 or modular XHTML to user agents that can handle
> application/xhtml+xml correctly and HTML 4.01 Strict to user agents that
> cannot.
>
> OR
>
> 2) More simply, serve HTML 4.01 Strict to everyone.
>
> I can understand why WordPress developers should be loathe to break
> existing templates. Rather than breaking existing templates, I suggest
> that a standards-compliance mode be implemented where either 1) or 2)
> takes place.
>
> At the /very least/, WordPress should serve XHTML 1.x as
> application/xhtml+xml to supporting user agents and reserve text/html
> for non-supporting user agents.
>
> Such a change will be crucial if WordPress wishes to eventually migrate
> to Web Applications 1.0 or XHTML 2.0.
>
> If this forces WordPress to double-check markup for well-formedness,
> validity, and conformance, so much the better. People put a lot of
> effort into writing their blogs. They deserve markup that user agents
> can read correctly if they follow the specifications; markup that will
> still be parsable in a hundred years time when Internet Explorer and
> Firefox will be long forgotten.
>
> P.S. XHTML 1.1 should NEVER be served as text/html. To do so with the
> WordPress blog itself [ http://wordpress.org/development/ ] radically
> undermines WordPress's claim to be the choice for those who want
> standard markup. (Yes, it validates. The W3C Validator pretends all
> XHTML documents were received with the proper application/xhtml+xml MIME
> type.)
>
> --
> Benjamin Hawkes-Lewis
>
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