- From: Jarno van Driel <jarnovandriel@gmail.com>
- Date: Tue, 5 Aug 2014 22:52:30 +0200
- To: Dan Brickley <danbri@google.com>
- Cc: Dan Scott <dan@coffeecode.net>, Jocelyn Fournier <jocelyn.fournier@gmail.com>, W3C Web Schemas Task Force <public-vocabs@w3.org>
- Message-ID: <CADK2AU0yhGbkhRc8fHP+ggfkmsshAt70oZvjJTwcBRKm8=45mQ@mail.gmail.com>
To revive the subject of this thread I have made some markup examples (microdata). The first example illustrates what could happen if we add a new property like 'mainEntity' as opposed to expanding the range of 'mainContentOfPage' to Thing: https://www.w3.org/wiki/WebSchemas/ChainingLayoutElements#A_CollectionPage_which_has_an_ItemList_as_it.27s_mainEntity_.28down_the_DOM.2C_normal_relation.29_2 While the next two examples illustrate, that if the markup is less elaborate, explaining the difference when to use mainContentOfPage or mainEntity start to become difficult: https://www.w3.org/wiki/WebSchemas/ChainingLayoutElements#A_CollectionPage_which_has_an_ItemList_as_it.27s_mainContentOfPage_.28down_the_DOM.2C_normal_relation.29 https://www.w3.org/wiki/WebSchemas/ChainingLayoutElements#A_CollectionPage_which_has_an_ItemList_as_it.27s_mainEntity_.28down_the_DOM.2C_normal_relation.29 Yet if we expand the range of 'mainContentOfPage' to Thing we could get something like this: https://www.w3.org/wiki/WebSchemas/ChainingLayoutElements#CollectionPage.2C_ItemList.2C_Product Looking at this I think I'd prefer to expand the range of 'mainContentOfPage' to Thing as opposed to adding 'mainEntity'. Solely because a lot less markup is needed. Any thoughts? 2014-06-02 21:20 GMT+02:00 Jarno van Driel <jarnovandriel@gmail.com>: > Besides the naming of the property I was wondering what to do when the > main entity isn't a single thing but a collection of things. For example a > category page (CollectionPage) of an eCommerce site which shows a > collection of products? > > In this case there is no main entity unless it's the predicate for a > Collection entity. (Maybe something as described in the Collection proposal > - http://www.w3.org/wiki/WebSchemas/Collection). > > When I combine the 2 I can imagine marking up something like this: > > <body vocab="http://schema.org/" typeof="CollectionPage"> > <header property="hasPart" typeof="WPHeader">...</header> > > <main property="mainEntity" typeof="Collection"> > <ul> > <li property="hasPart" typeof="Product">...</li> > <li property="hasPart" typeof="Product">...</li> > ... > </ul> > </main> > > <aside property="hasPart" typeof="WPSideBar">...</aside> > </body> > > Or would it be OK to add a property like @mainEntity first and work on the > collection issue separately? > > *Jarno van Driel* > Technical & Semantic SEO Consultant > 8 Digits - Digital Marketing Technologies > > > 2014-05-21 22:59 GMT+02:00 Jarno van Driel <jarnovandriel@gmail.com>: > > What I think we want is a property that performs the same role as FOAF's >>> 'primaryTopic': it should point to at most one entity/thing. Given >>> currently popular terminology we might call it 'mainEntity' as a >>> strawman. >> >> >> Couldn't changing the expected value of @mainContantOfPage to Thing work >> for this? >> >> Doing so would actually help a lot of websites. I've lost count how >> many times I've encountered: >> <div itemprop="mainContentOfPage" itemscope itemtype=" >> http://schema.org/Product"> (or Article or Blog). >> >> And by expanding the domain of @mainContentOfPage all those websites >> would automagically have valid markup. >> >> >> 2014-05-21 21:22 GMT+02:00 Dan Brickley <danbri@google.com>: >> >> On 21 May 2014 19:21, Dan Scott <dan@coffeecode.net> wrote: >>> > On Wed, May 21, 2014 at 02:04:20PM +0200, Jarno van Driel wrote: >>> >> >>> >> I was wondering, can an entity also have multiple @about properties? >>> >>> That's the right question to be asking. And I didn't ask it hard >>> enough yesterday (probably because I wouldn't have liked the answer). >>> >>> The wording http://schema.org/about has currently, "The subject matter >>> of the content." is awkward. The word "the" suggests a single thing is >>> the subject matter, but it is vague enough that you could have several >>> entities via repeated properties together capturing "the subject >>> matter". >>> >>> What I think we want is a property that performs the same role as >>> FOAF's 'primaryTopic': it should point to at most one entity/thing. >>> Given currently popular terminology we might call it 'mainEntity' as a >>> strawman. >>> >>> I was hoping we could get away with refining the interpretation of >>> 'about', but I'm coming around to the view that it has been used in >>> too many diverse ways over the last 3 years for that to work. >>> >>> >> I ask because when chaining multiple entities to a WebPageElement, to >>> me >>> >> it >>> >> seems the following is the logical thing to do: >>> >> >>> >> <body itemscope itemtype="http://schema.org/WebPage"> >>> >> ... >>> >> <div itemprop="hasPart" itemscope >>> >> itemtype="http://schema.org/WPSideBar"> >>> >> <div itemprop="about" itemscope >>> >> itemtype="http://schema.org/ContactPoint">...</div> >>> >> <div itemprop="about" itemscope >>> >> itemtype="http://schema.org/ItemList">...</div> >>> >> </div> >>> >> ... >>> >> </body> >>> >> >>> >> Or would @hasPart or @mentions be prefered over @about? >>> >>> I don't think they're great examples of about-ness, except >>> ContactPoint, if the page is indeed about contact info. The >>> stereotypical use for 'about' is a specific person-place-or-thing that >>> the content is 'about'. Sidebars and lists are structural mechanisms; >>> it would be more typical to see Product, Book, Person, Place etc used. >>> However your main point, that 'about' could credibly be repeated given >>> its definition, is quite reasonable. >>> >>> > >>> > I'm not going to offer any advice about whether "hasPart" or "mentions" >>> > might be preferred here, but you can certainly have multiple "about" >>> > properties for a single entity. >>> >>> Yeah. It is tempting to defend a strict reading of the word 'the' and >>> claim it shouldn't _really_ be repeated; but I don't think that's >>> credible. >>> >>> > See the example for http://schema.org/MedicalScholarlyArticle - >>> "about" >>> > is used twice, because the article is about a type of drug and >>> > about a type of medical condition. >>> >>> quite :) >>> >>> >>> > The cardinality of schema.org properties appears to be a FAQ dating >>> back >>> > to at least 2011 (http://www.w3.org/2011/webschema/track/issues/5); we >>> > should probably add an explicit statement to >>> > http://schema.org/docs/gs.html or http://schema.org/docs/faq.html (or >>> > both) saying that you can, in general, repeat properties in schema.org >>> > entities as necessary. >>> >>> There are a few (e.g. birthDate, deathDate, most boolean-valued >>> properties) that have at most one sensible value. However even those >>> might have several reasonable encodings. And there are some, e.g. >>> iataCode hopefully, for which there should be at most one entity that >>> has any given value for that property. However we've not attempted >>> cataloguing these cases, partly through a concern to avoid making >>> unrealistically brittle and rigid rules that will be ignored... >>> >>> cheers, >>> >>> Dan >>> >> >> >
Received on Tuesday, 5 August 2014 20:52:58 UTC