- From: Belov, Charles <Charles.Belov@sfmta.com>
- Date: Tue, 8 Nov 2011 00:33:49 +0000
- To: "'Jukka K. Korpela'" <jukka.k.korpela@kolumbus.fi>
- Cc: <public-html-comments@w3.org>
Jukka K. Korpela wrote on Monday, November 07, 2011 1:32 PM > > 11/7/2011 10:12 PM, Belov, Charles wrote: > > >> So if any search engine tried anything with <time>, it was a wasted > >> effort, it seems. > > > > If nothing else, it would eliminate the issue that has kept me from > > using > > the time microformat as well as any other microformat that requires > > the time microformat. > > I'm not sure whether "it" was meant to refer to the last note in my text > that you quoted, the <time> element, but I suppose it did. [cbelov] It did. > If I understand you correctly, you are referring to the possibility of > writing a time in a globalized standard format in an attribute, while > keeping the text content localized (i.e., in some human language). [cbelov] Yes. > That's an important point, and probably it is behind the ideas for the > general-purpose <data> element, too. The need for such a distinction is > not limited to times. For example, in metadata for content that deals with > weights and measures or sums of money, it is surely desirable to include > the meta using standardized units and expressions (say, "USD > 42.50") while letting authors write them as localized (say, "42,50 $"). > > > Specifically, the current recommendation is to use the title attribute > > of > > the abbreviation tag, but the date-time format is not human-friendly. > > And it's rather odd to use <abbr> for something that isn't abbreviation at > all. [cbelov] Indeed it is, in my opinion. > It is also odd to use the title attribute for machine-readable > metadata, as you say. > > There are two issues here: elements and attributes. > > I don't think we need any new elements for this, but we need a new > attribute, or attributes. New attributes provide better compatibility with > old browsers. If you use, say, the <span> element, you can style it at > will and you can process it in client-side scripting, without needing to > worry about lack of support in browsers. If a new attribute is added, the > element keeps working, and while the attribute as such does not "do" > anything in old browsers - it just needs to be recognized by new software > that will use it. > > Introducing a new attribute to existing elements, instead of a new element, > has the additional advantage that existing documents very often already > have _some_ markup for the data in question. For example, the time, or > weight, or whatever might appear as the content of a table cell, i.e. a > <td> element. It might also be wrapped inside a <span> (or > <div>) for styling or scripting, or inside <em> for emphasis. Then we just > need to add an attribute to the existing tag. This may sound trivial, but > such simplicity matters in the adoption of new features. > > > From > > http://microformats.org/wiki/value-class-pattern#Date_and_time_values > - - > > <span class="dtstart"> > > <abbr class="value" title="2008-06-24">this Tuesday</abbr> > > at <span class="value">18:30</span> > > </span> > > That's rather artificial, and in addition to the semantic question "is > this really an abbreviation", it causes special default rendering on many > browsers. The <span> element would be more adequate than the <abbr> > element. > > Instead of using the title attribute for something that is incompatible > with its defined meaning and existing usage, a new attribute is needed. > > The simplest approach would be to add two attributes that apply to all > elements: one specifying the type of data, and another specifying the > value in a standardized format. I'm sure good names can be invented, even > though the name "type" is effectively reserved (it exists in a different > meaning and is disturbingly polymorphic). As working names, I'll use "dt" > (short for datatype) and "d" (for data). For example: > > <span class="value" dt="date" d="2008-06-24">this Tuesday</span> at <span > class="value" dt="time" d="18:30">6:30 PM</span> [cbelov] I'm not invested in time being a tag. Your attribute recommendation would seem to work for screen-reading software, which I would expect to ignore the tags. > This would make <time> redundant and would make it possible to distinguish > dates from times (of day) and from combined date and time. > > As far as I can see, this would be compatible with any microlevel metadata > approach and would not interfere with them, though they _could_ be > enhanced to pay attention to the new attributes in addition to their own > conventions. > > > The 2008-06-24 date format is not friendly to humans. > > To some humans it is. It is widely used in Japan, Poland, and Sweden and > largely recognized in a few other countries. But this just means that in > addition to being machine-readable standardized format, it is _also_ > suitable localization in _some_ locales. [cbelov] Interesting; thank you. > > > The 18:30 part is not friendly in the United States. > > To some people it might be, but the general point of course is that even > time denotations may need to be localized, whereas for metadata, a > standard format is needed. > > > Availability of a time tag would alleviate this issue. > > I don't think a <time> tag has much to do with the solutions. You really > want the datetime attribute from it. But I have outlined a more general > approach here, and approach that is suitable for a much wider range of use. > > (If times are so special, we might specify that when d="..." attribute is > specified without a dt="..." attribute, dt="datetime" is implied, meaning > that the data value is a date, a time, or a combined date and time > denotation in ISO 8601 format.) [cbelov] I would not raise an objection to that. > > Presumably a time tag would have an optional format attribute that > > would > > eliminate ambiguity between m/d/yy and d/m/yy. > > The ambiguity can be resolved in metadata by using ISO 8601. In document > content, it's a different issue and a matter of conventions used in text > rather than markup. Markup is not crucial here. What matters is that > people understand expressions correctly, and for this, authors should use > notations that are unambiguous to their audience. > [cbelov] Understood. Hope this helps, Charles Belov SFMTA Webmaster
Received on Tuesday, 8 November 2011 00:36:04 UTC