length of html attribute

[Oliver Block]

Hi,

I did not find any length limit for attributes. Is there any? Maybe
"inherited" by SGML?

Best Regards,

Oliver

[Benjamin Niemann]

Oliver Block wrote:

I did not find any length limit for attributes. Is there any? Maybe
"inherited" by SGML?

The SGML declaration (http://www.w3.org/TR/html40/sgml/sgmldecl.html)
declares a maximum length of 65536 characters, which is the largest value
that SGML allows and which comes closest to the 'intended limit' of 'no
limit'.
If you write a HTML parser, do not implement size limitations. If you are
authoring HTML code, you'll win a prize, if you manage to exceed the 64k
limit with meaningful data...

--
Benjamin Niemann
Email: pink at odahoda dot de
WWW: http://pink.odahoda.de/

[Andy Dingley]

Benjamin Niemann wrote:

If you write a HTML parser, do not implement size limitations. If you are
authoring HTML code, you'll win a prize, if you manage to exceed the 64k
limit with meaningful data...

Been there, done that.

For metadata embedding, it's (reasonably) common practice to embed
annotations and descriptions as attributes that are lifted from a
Dublin Core (or similar) "pseudo-namespace". These aren't part of valid
HTML, but XML namespacing isn't really available to the web yet and
it's long-established web practice that extra attributes are silently
and safely ignored by user-agents that don't understand them.

Once you're adding annotation or metadata, it's not hard to start
breaking 64k length limits, if you're unaware of the issue.

[Toby Inkster]

Benjamin Niemann wrote:

If you write a HTML parser, do not implement size limitations. If you are
authoring HTML code, you'll win a prize, if you manage to exceed the 64k
limit with meaningful data...

Writing a CMS, it's often the case that you'll have fairly big chunks of
data in the value attributes for hidden INPUT elements.

--
Toby A Inkster BSc (Hons) ARCS
Contact Me ~ http://tobyinkster.co.uk/contact