- From: James M Snell <jasnell@gmail.com>
- Date: Tue, 19 Jun 2012 07:58:23 -0700
- To: Dan Brickley <danbri@danbri.org>
- Cc: public-vocabs@w3.org, "Martin Hepp (UniBW)" <martin.hepp@ebusiness-unibw.org>, Peter Mika <pmika@yahoo-inc.com>, Ramanathan Guha <guha@google.com>, Jeni Tennison <jeni@jenitennison.com>
I know there has been quite a bit of discussion around this already, and I cannot really speak for the microdata use cases, but I do work with the activity streams format [1] and we've had a number of recent discussions around the use of schema.org properties within a JSON Activity Stream... AS has it's own basic type model (and "objectType" property whose value is either a simple label representing known types or an absolute IRI to identify types from other vocabularies. Having a "type" property in the schema.org vocabulary would help us tremendously in bridging the AS model into the schema.org realm. I'd certainly be in favor of introducing it. ("additionalType" works too). [1] http://activitystrea.ms - James Snell On Fri, Jun 15, 2012 at 11:26 AM, Dan Brickley <danbri@danbri.org> wrote: > HTML5 Microdata, as defined in > http://www.whatwg.org/specs/web-apps/current-work/multipage/microdata.html#encoding-microdata > > ... has only limited support for describing multiple types that > something belongs to. In particular it requires they are described > using a single schema. > > > For Good Relations integration (and other scenarios) people have asked > for a way of listing more types within schema.org markup. > > * One model is to use RDFa 1.1 (Lite), where this is quite natural. > * Another is to add (as a workaround) a new property, e.g. called > 'type' or 'additionalType', to schema.org's vocab (Martin requests > this in http://www.w3.org/wiki/WebSchemas/GoodRelations ) > * A 3rd is to stretch > http://www.whatwg.org/specs/web-apps/current-work/multipage/microdata.html#items > to allow different namespaces to be used. > > The note at http://www.w3.org/TR/html-data-guide/#multiple-types-microdata > discusses just this issue. > > I'm sending this as followup from discussion amongst schema.org > partners, who welcome community advise on this point. Should we add a > 'type' property to schema.org, try to change or stretch microdata > syntax, ... or encourage people who want multiple diverse types to use > RDFa Lite instead? > > Dan > > > > Copied below is the current Microdata / HTML5 spec text, > > "The item types of an item are the tokens obtained by splitting the > element's itemtype attribute's value on spaces. If the itemtype > attribute is missing or parsing it in this way finds no tokens, the > item is said to have no item types. > > The item types must all be types defined in applicable specifications > and must all be defined to use the same vocabulary. > > Except if otherwise specified by that specification, the URLs given as > the item types should not be automatically dereferenced. > > A specification could define that its item type can be derefenced to > provide the user with help information, for example. In fact, > vocabulary authors are encouraged to provide useful information at the > given URL. > > Item types are opaque identifiers, and user agents must not > dereference unknown item types, or otherwise deconstruct them, in > order to determine how to process items that use them. > > The itemtype attribute must not be specified on elements that do not > have an itemscope attribute specified." >
Received on Tuesday, 19 June 2012 14:59:13 UTC