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Error in DR doc appendix - another LC comment (was Re: Multiple display text/icons (treat as LC comment))

From: Phil Archer <parcher@fosi.org>
Date: Wed, 03 Sep 2008 20:09:10 +0100
Message-ID: <48BEE0D6.90308@fosi.org>
To: public-powderwg@w3.org

Just working on building a POWDER Processor and I notice, following on 
fro this conversation, that there's an error in the summary table in the 
DR doc [1] - it says that there must be exactly 1 descriptor set (unless 
there's a tagset). No, no no... you can have any number of descriptor sets.

[1]

Phil Archer wrote:
> 
> 
> 
> David Rooks wrote:
>> Ah, good point Phil. I'd forgotten about multiple descriptor sets. These
>> certainly address the point I raised.
>>
>> So, going back the the original problem. Should we enforce a maximum of 1
>> displaytext / displayicon per descriptor set?
> 
> It's tempting, and we could do it, but since you can have multiple 
> descriptor sets, one display text per descriptor set does not ensure one 
> display text per DR. Therefore, I'm not sure we need to bother (in 
> general, the fewer restrictions, the better). Even if we do restrict the 
> cardinality, we should still, I think, add a line to the effect that 
> where a DR contains more than one descriptor set, it SHOULD only contain 
> one displaytext and displayicon element.
> 
> P
> 
>>
>> On Wed, Sep 3, 2008 at 11:40 AM, Phil Archer <parcher@fosi.org> wrote:
>>
>>> Hmmm... this started out as a quick e-mail but I seem to have written 
>>> more
>>> than I expected and ended up at a conclusion I wasn't expecting...
>>>
>>> I agree that option 2 looks attractive. To repeat the second example of
>>> option 2:
>>>
>>> <descriptorset>
>>>   <ex:wcag>AA</ex:wcag>
>>>   <ex:mok>true</ex:mok>
>>>   <displaytext icon="http://authority.example.org/wcag.png
>>>                      http://authority.example.org/mok.png">
>>>     Everything on example.com is wcag aa and mok compliant
>>>   </displaytext>
>>> </descriptorset>
>>>
>>> So the rules here would be:
>>>
>>> - <displaytext> can appear any number of times as a child
>>>  of descriptorset.
>>>
>>>  - The icon attribute takes a white space separated list
>>>   of images that may be displayed (whether and how this
>>>   is done is application-specific).
>>>
>>> Which is all well and good... until you generate the POWDER-S from this:
>>>
>>> Option 2 as POWDER-S
>>> ====================
>>>
>>> <owl:Class rdf:nodeID="descriptorset_1">
>>>  <owl:intersectionOf rdf:parseType="Collection">
>>>    <owl:Restriction>
>>>      <owl:onProperty rdf:resource="&ex;#wcag" />
>>>      <owl:hasValue>aa</owl:hasValue>
>>>    </owl:Restriction>
>>>    <owl:Restriction>
>>>      <owl:onProperty rdf:resource="&ex;#mok" />
>>>      <owl:hasValue>true</owl:hasValue>
>>>    </owl:Restriction>
>>>  </owl:intersectionOf>
>>>  <dcterms:description>Everything on example.com is wcag aa
>>>     and mok compliant</dcterms:description>
>>>  <foaf:depiction
>>>     rdf:resource="http://authority.example.org/wcag.png" />
>>>  <foaf:depiction
>>>     rdf:resource="http://authority.example.org/mok.png" />
>>> </owl:Class>
>>>
>>> Notice that we've lost the close association between the icons and the
>>> text, so I guess we'd want to add a layer of complexity (remember 
>>> this is
>>> RDF, not XML, you need resource->property->resource, not 
>>> property->property
>>> etc):
>>>
>>> More complex POWDER-S
>>> =====================
>>>
>>> <wdrs:mayDisplay>
>>>  <wdrs:Display>
>>>    <dcterms:description>Everything on example.com is wcag aa
>>>      and mok compliant</dcterms:description>
>>>    <foaf:depiction
>>>      rdf:resource="http://authority.example.org/wcag.png" />
>>>    <foaf:depiction
>>>      rdf:resource="http://authority.example.org/mok.png" />
>>>  </wdrs:Display>
>>> </wdr:mayDisplay>
>>>
>>> I don't think that the semantics are right here. We have a class, 
>>> that is,
>>> a type of thing, and *that type of thing* has a property of maydispay 
>>> that
>>> has a Resource that itself has properties of a description and a 
>>> depiction
>>> (perhaps more than one).
>>>
>>> This differs from the present spec which says that *that type of 
>>> thing* has
>>> a description (text) and a depiction (image). I think we'd need to 
>>> create
>>> some new terms in our own namespace
>>>
>>> More complex POWDER-S (variant)
>>> ==============================
>>>
>>> <wdrs:mayDisplay>
>>>  <wdrs:Info>
>>>    <wdrs:text>Everything on example.com is wcag aa
>>>      and mok compliant</wdrs:text>
>>>    <wdrs:logo
>>>      rdf:resource="http://authority.example.org/wcag.png" />
>>>    <wdrs:logo
>>>      rdf:resource="http://authority.example.org/mok.png" />
>>>  </wdrs:Info>
>>> </wdr:mayDisplay>
>>>
>>> But even this doesn't feel right. It says that an instance of this class
>>> has the property of being able to display the text and logos - that's 
>>> not
>>> the same as instances of this class being described by the text and the
>>> depiction. The new proposal makes it more appropriate for the resource
>>> itself to display the text and logo, whereas the current specs make it
>>> equally appropriate for the user agent to display them (which is what we
>>> actually have in mind).
>>>
>>> So, whilst I fully appreciate what Dave is trying to do - be able to
>>> combine the two separate statements that a Web site is both mobileOK and
>>> WCAG AA, I think the better way to do it would be to have a single image
>>> that showed both logos.
>>>
>>> Single logo, current spec
>>> =========================
>>>
>>> <descriptorset>
>>>  <ex:wcag>AA</ex:wcag>
>>>  <ex:mok>true</ex:mok>
>>>  <displaytext>
>>>     Everything on example.com is wcag aa and mok compliant
>>>  </displaytext>
>>>  <displayicon src="http://authority.example.org/wcag_and_mok.png">
>>> </descriptorset>
>>>
>>> The current lack of clarity on whether display text and icons can appear
>>> more than once means that, as things stand, this is also perfectly 
>>> valid:
>>>
>>> Multiple logos, current spec
>>> ============================
>>>
>>> <descriptorset>
>>>  <ex:wcag>AA</ex:wcag>
>>>  <ex:mok>true</ex:mok>
>>>  <displaytext>
>>>     Everything on example.com is wcag aa and mok compliant
>>>  </displaytext>
>>>  <displayicon src="http://authority.example.org/mok.png">
>>>  <displayicon src="http://authority.example.org/wcag.png">
>>> </descriptorset>
>>>
>>> If you *really* want to keep things separate, the current spec allows 
>>> a DR
>>> to have more than one descriptor set. User agents concerned with 
>>> resources
>>> that are mobileOK may or may not be concerned with WCAG and vice versa
>>>
>>> Multiple descriptor sets (current spec)
>>> ======================================
>>>
>>> <dr>
>>>  <iriset>
>>>    <includehosts>example.com</includehosts>
>>>  </iriset>
>>>
>>>  <descriptorset>
>>>    <ex:wcag>AA</ex:wcag>
>>>    <displaytext>
>>>       Everything on example.com is wcag AA compliant
>>>    </displaytext>
>>>    <displayicon src="http://authority.example.org/wcag.png">
>>>  </descriptorset>
>>>
>>>  <descriptorset>
>>>    <ex:mok>true</ex:mok>
>>>    <displaytext>
>>>       Everything on example.com is mobileOK compliant
>>>    </displaytext>
>>>    <displayicon src="http://authority.example.org/mok.png">
>>>  </descriptorset>
>>> </dr>
>>>
>>> This means that it would be ineffective to state that a display text 
>>> and or
>>> icon element can only have a cardinality of 0 or 1.
>>>
>>> So working through all this, my personal view is that the current 
>>> spec is
>>> right but that we should highlight that it is possible that more than 
>>> one
>>> line of text and icon may be available and that user agents should be 
>>> aware
>>> of this. Moreover, DR authors SHOULD only offer a single displaytext 
>>> and/or
>>> displayicon per DR.
>>>
>>> Phil.
>>>
>>>
>>>
>>> David Rooks wrote:
>>>
>>>> Cheers Andrea,
>>>>
>>>> I like option 2 the best.
>>>>
>>>> Dave.
>>>>
>>>> On Tue, Sep 2, 2008 at 9:57 PM, Andrea Perego
>>>> <andrea.perego@uninsubria.it>wrote:
>>>>
>>>>  Hi, David.
>>>>>  [snip]
>>>>>
>>>>>> Following on from this example - it seems reasonable to me that if 
>>>>>> more
>>>>>> than 1 icon is acceptable then more than 1 displaytext is also
>>>>>> acceptable.
>>>>>> i.e. you should be able to have a displaytext for each icon you 
>>>>>> want to
>>>>>> display. However, i can only see this working if we can associate
>>>>>> displaytext with displayicons. This would be particularly useful in a
>>>>>> powder
>>>>>> application as it would allow the app to display a list of icons with
>>>>>> some
>>>>>> text beside each.
>>>>>>
>>>>>> e.g.
>>>>>> MOK.png - everything on example.com <http://example.com/> is MOK
>>>>>> compliant
>>>>>> WCAG.png - everything on example.com <http://example.com/> is WCAG AA
>>>>>> compliant
>>>>>> ICRA.png - everything on example.com <http://example.com/> has
>>>>>> nakedness
>>>>>>
>>>>>>  Good point. In such a case, we might use one of the following 
>>>>>> options:
>>>>>
>>>>> (1) <text> and <icon> as child elements of <display>
>>>>>
>>>>> Different text for each icon:
>>>>>
>>>>> <descriptorset>
>>>>>  <ex:wcag>AA</ex:wcag>
>>>>>  <ex:mok>true</ex:mok>
>>>>>  <display>
>>>>>    <text>Everything on example.com is wcag aa compliant</text>
>>>>>    <icon src="http://authority.example.org/wcag.png" />
>>>>>  <display>
>>>>>  <display>
>>>>>    <text>Everything on example.com is mok compliant</text>
>>>>>    <icon src="http://authority.example.org/mok.png" />
>>>>>  <display>
>>>>> </descriptorset>
>>>>>
>>>>> Same text for all icons:
>>>>>
>>>>> <descriptorset>
>>>>>  <ex:wcag>AA</ex:wcag>
>>>>>  <ex:mok>true</ex:mok>
>>>>>  <display>
>>>>>    <text>Everything on example.com is wcag aa and mok compliant</text>
>>>>>    <icon src="http://authority.example.org/wcag.png" />
>>>>>    <icon src="http://authority.example.org/mok.png" />
>>>>>  <display>
>>>>> </descriptorset>
>>>>>
>>>>> or
>>>>>
>>>>> <descriptorset>
>>>>>  <ex:wcag>AA</ex:wcag>
>>>>>  <ex:mok>true</ex:mok>
>>>>>  <display>
>>>>>    <text>Everything on example.com is wcag aa and mok compliant</text>
>>>>>    <icon src="http://authority.example.org/wcag.png
>>>>> http://authority.example.org/mok.png" />
>>>>>  <display>
>>>>> </descriptorset>
>>>>>
>>>>>
>>>>> (2) <displaytext> along with an @icon attribute:
>>>>>
>>>>> Different text for each icon:
>>>>>
>>>>> <descriptorset>
>>>>>  <ex:wcag>AA</ex:wcag>
>>>>>  <ex:mok>true</ex:mok>
>>>>>  <displaytext 
>>>>> icon="http://authority.example.org/wcag.png">Everything on
>>>>> example.com is wcag aa compliant</displaytext>
>>>>>  <displaytext 
>>>>> icon="http://authority.example.org/mok.png">Everything on
>>>>> example.com is mok compliant</displaytext>
>>>>> </descriptorset>
>>>>>
>>>>> Same text for all icons:
>>>>>
>>>>> <descriptorset>
>>>>>  <ex:wcag>AA</ex:wcag>
>>>>>  <ex:mok>true</ex:mok>
>>>>>  <displaytext icon="http://authority.example.org/wcag.png
>>>>> http://authority.example.org/mok.png">Everything on example.com is 
>>>>> wcag
>>>>> aa
>>>>> and mok compliant</displaytext>
>>>>> </descriptorset>
>>>>>
>>>>>
>>>>> (3) <displayicon> along with its @src attribute and text:
>>>>>
>>>>> Different text for each icon:
>>>>>
>>>>> <descriptorset>
>>>>>  <ex:wcag>AA</ex:wcag>
>>>>>  <ex:mok>true</ex:mok>
>>>>>  <displayicon 
>>>>> src="http://authority.example.org/wcag.png">Everything on
>>>>> example.com is wcag aa compliant</displayicon>
>>>>>  <displayicon src="http://authority.example.org/mok.png">Everything on
>>>>> example.com is mok compliant</displayicon>
>>>>> </descriptorset>
>>>>>
>>>>> Same text for all icons:
>>>>>
>>>>> <descriptorset>
>>>>>  <ex:wcag>AA</ex:wcag>
>>>>>  <ex:mok>true</ex:mok>
>>>>>  <displayicon src="http://authority.example.org/wcag.png
>>>>> http://authority.example.org/mok.png">Everything on example.com is 
>>>>> wcag
>>>>> aa
>>>>> and mok compliant</displayicon>
>>>>> </descriptorset>
>>>>>
>>>>>
>>>>> Andrea
Received on Wednesday, 3 September 2008 19:09:43 GMT

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