Value Class Pattern Issues
This page documents issues with the Value Class Pattern specification before 2016-06-20.
Please add new issues to GitHub issues, prefixed with "vcp:"
See change control for how to move new issues forward.
These issues are awaiting resolution and reflection in the specification, but may not be blockers on the implementation of the specification.
- There seem to be some properties within which value excerpting is NOT allowed (or should not be allowed!) e.g. "type" in hCard. TobyInk 07:38, 22 May 2008 (PDT)
- You mean
typeas a sub-property of
tel? That's one of the identified Machine Data in Microformats items that needs a means of including the publisher's choice text along with the microformat specified one. Not to conflate two separate issues, but just noting that separation of
type valueneeds to be handled somewhere, and value-excerption-pattern could be considered as part of the solution. BenWard 07:54, 22 May 2008 (PDT)
- Some fields make sense to exclude this, as it seems unintuitive, and can be used to avoid many of nested-microformat problems that may avoid a messier mfo pattern. E.g.
entry-contentin hAtom 0.1, both could very feasibly have nested formats or any kind, but doesn't strike me as useful to segregate into "value" at all. BenWard 10:41, 6 Jun 2008 (PDT)
- Total other alternative, make value-excerption opt-in. Would need a bit of effort to go through all the specs and clarify, but actually might make more sense. It's a useful pattern for some properties (especially those with data patterns). BenWard 10:41, 6 Jun 2008 (PDT)
- Setting the rules over depth-of-parsing (see below) to children-only would obviate the remaining need for this issue.
- You mean
White-space behavior when concatenating value nodes
- We specify that no characters get inserted between concatenated occurrences of ‘value’. Need to audit all properties to ensure that this behavior would be correct in all cases.
- Possibly specify that individual properties can override this behavior, specifying a separator character.
- Possibly specify that this should be a provision of parsing implementations, so as to maintain flexibility for future publishing.
Depth of Parsing
Currently any descendent is parsed, which causes issues if a microformat field using the value-excerption-pattern is nested within another.
<div class="hentry vevent"> <h1 class="entry-title summary">Party on Sunday!</h1> <div class="updated published">Tuesday <span class="value">2008-06-17</span></div> <p class="entry-content description">We're having a party on <span class="dtstart">Sunday, at 7pm! <span class="value">2008-06-22T19:00:00+0100</span></span>. Please bring your friends!</p> </div>
In this example, hAtom and hCalendar are interleaved. The DTSTART property of the event is contained within the entry-content of the hAtom entry, using the value-excerption-pattern to include the machine-data datetime. However, with full descendent parsing, the hAtom model will come out as the following:
ENTRY ENTRY-TITLE=Party on Sunday! UPDATED= 2008-06-17 PUBLISHED=2008-06-17 ENTRY-CONTENT=2008-06-22T19:00:00+0100
- e.g. an hCalendar 1.0
veventnested inside hAtom 0.1
entry-contentmust not result in
- e.g. hCalendar 1.0 defines
organizer, which may be an hCard 1.0, which may have a
telproperty containing a sub-property
value. Under these parsing rules, the entire
organizerfield would be parsed as the telephone number.
- Cognition copes with this OK -- the organizer is parsed as a full contact with an hCard - not just a number. TobyInk 07:38, 22 May 2008 (PDT)
- Specify the
mfo(‘microformat object’) class be used when nesting microformats, as a processing instruction to parsers not to parse unrelated nested items
- Specify that
valuemust only be read from children, not from all descendants. Restrictive, unlikely to work for existing hCard TEL usage.
- Specify the above (
parse children, not all descendants), but allow individual properties (such as
telto override and parse all descendants. This would result in a parse-depth flag on all fields, and many getting overridden for all descendants, but again, seems to be a well structured solution. Property name dictionaries in parsers would have to include the depth flag with the property.
- This may break existing published microformats. TobyInk 07:25, 22 Jun 2008 (PDT)
title from Empty
Moved to: value excerption pattern brainstorming
Parsing the value-excerption-pattern in combination with the ABBR-pattern
- How does
<span class="country-name"><abbr class="value" title="Great">G</abbr> <span class="value">Britain</span></span>parse?
- The main issue with this example is the lack of any explicit whitespace between the values. Under present parsing rules, this will parse as "GreatBritain". TobyInk 15:20, 6 Jul 2008 (PDT)
These issues are closed, and either dismissed with reason, or the specification has been updated in resolution.
<span class="value">Foo <span class="value">Bar</span></span> parse as
foo bar or
value elements be allowed to be nested within
Resolution: Disallowed. Deemed complex to parse, and unnecessary when publishing.