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Re: Multiple display text/icons (treat as LC comment)

From: Phil Archer <parcher@fosi.org>
Date: Wed, 03 Sep 2008 11:40:29 +0100
Message-ID: <48BE699D.6030609@fosi.org>
To: public-powderwg@w3.org

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 10:41:04 GMT

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