On Sat, 25 Jul 2009 12:08:23 +0200, Eduard Pascual <herenva...@gmail.com>
wrote:
On Fri, Jul 24, 2009 at 9:52 PM, Keryx Web<webmas...@keryx.se> wrote:
On 2009-07-23 20:32, Eduard Pascual wrote:
While I don't consider a hard requirement would be appropriate, there
is an audience sector this discussion seems to be ignoring: Authoring
Tools' developers. IMO, it would be highly desirable to have some
guidelines for these tools to determine when they*should* quote
attribute values.
There is one further rub. Code that initially has been made by authoring
tools have a tendency to wind up in some front end developers lap, to be
amended and/or fixed manually at a later stage. That is even more a
reason
for a strong recommendation about quotes.
Furthermore, I doubt that most people on this list did read my blog
post I
included as an URL when starting this discussion.[1]
I can't speak for others, but I did read your post. And still I am
convinced that a hard requirement to quote all values is not the best
solution. There are some values that MUST be quoted, some that SHOULD
be quoted, and even some that SHOULD NOT be quoted. Those that must be
quoted are already covered by the spec, and validators will yield the
relevant error message when encountering such values unquoted. For
those values that *should* be quoted (those that improve in
readability when quoted, or those that could lead to errors when they
are later changed if unquoted), a warning from the validator should be
enough. Finally, there are some values that are better unquoted, such
as those attributes that can only take a number (there is no risk of
errors, and the quotes would normally hurt readability more than they
help it).
Actually boolean attributes are allowed to take the empty string as value,
and it's not allowed to leave the empty string unquoted. However, boolean
attributes aren't subject to the template/backend mismatch because you
have to omit the attribute altogether for the false value, so the backend
developer has to be responsible for writing out the whole attribute.
Therefore, it should be safe to leave boolean attributes unquoted.
It should be safe to leave any attribute in the minimized form, because it
also isn't subject to the template/backend mismatch.
Non-boolean attributes that are safe to leave unquoted:
<link hreflang>
<meta http-equiv>
<meta charset>
<script charset>
<article pubdate>
<ol start>
<li value>
<a hreflang>
<time datetime>
<progress value max>
<meter value min low high max optimum>
<bdo dir>
<ins datetime>
<del datetime>
<img width height>
<iframe width height>
<embed width height>
<object width height>
<video width height>
<canvas width height>
<area shape hreflang>
<colgroup span>
<col span>
<td colspan rowspan>
<th colspan rowspan scope>
<form autocomplete enctype method>
<input autocomplete formenctype formmethod height max maxlength min size
step type width>
<button formenctype formmethod>
<select size>
<textarea cols maxlength rows wrap>
<keygen keytype>
<command type>
<bb type>
Global non-boolean attributes that are safe to leave unquoted:
dir
tabindex
All other attributes can take one of the special characters [\s"'<>] in
the value, or the empty string as the value.
--
Simon Pieters
Opera Software
