Re: Metadata question

Hi John,

Welcome to EPUB land (smille).

The "refines" attribute is used to define subexpressions [1]. Subexpressions provide additional information on an existing metadata expression. But a refining property is typically limited to a specific set of properties it can extend. The specific rules are defined for each metadata property.

For "identifier-type" [2], the definition says it can only extends either "identifier" or "source" (from DCMES). In other words, you cannot associate an identifier type to, say, an author name —or in your case, a subject.

For subjects, you can use the "authority" and "term" properties to provided additional information as subexpressions. See the examples in the section about dc:subject [3]

To summarize:
>  • Can Dublin Core and Onix metadata live together in harmony in the opf file?

Yes.

>  • Am I correct in my assumption that the actual error is the "cross-linking" of the two schemes?

No, the error is using a property to refine another property that it is not allowed to refine.

>   • ...and would the remediation path be to remove the refines="#subject01" entry from the second declaration?

Yes, and you can use "authority" and "term" to refine a "dc:subject"


>  • Or am I completely missing the boat and looking in the wrong place? Is this correct in principle, but incorrect in implementation?

I hope I helped clarify things a bit!

Best,
Romain.


[1] https://www.w3.org/publishing/epub32/epub-packages.html#subexpression
[2] https://www.w3.org/publishing/epub32/epub-packages.html#sec-identifier-type 
[3] https://www.w3.org/publishing/epub32/epub-packages.html#sec-opf-dcsubject


> On 23 Jun 2021, at 23:48, John Foliot <john@foliot.ca> wrote:
> 
> Hello All,
> 
> As a long time accessibility specialist who's been involved in W3C work for more than 15 years, I am now getting involved with accessibility in ePub (thanks to a new contradict), and while accessibility principles are old-hat to me, some of the peculiarities of epub packaging are still kind of new to me.
> 
> While I hope to get more involved overall with epub+accessibility, at this time I wonder if I may pose a question to the assembled experts on this list? Specifically:
> 
> Currently epubcheck is telling me that there is an error with some of the metadata in a specific opf file, but epubcheck doesn't tell me with enough detail what the actual error is, only where to find it (sigh). This is the problematic error message and metadata:
> 
> "Error while parsing file: Property "identifier-type" must refine an "identifier" or "source" property"
> 
> <dc:subject xmlns:html="http://www.w3.org/1999/xhtml" id="subject01">Marketing</dc:subject>
> <meta xmlns:html="http://www.w3.org/1999/xhtml" refines="#subject01" property="identifier-type" scheme="onix:codelist26">10</meta>
> 
> My *assumption* at this time is that the issue here is that this code is attempting to refine the dc:subject with an onix 'term', but... (?) 
> 
> Questions: 
>  • Can Dublin Core and Onix metadata live together in harmony in the opf file?
>  • Am I correct in my assumption that the actual error is the "cross-linking" of the two schemes?
>   • ...and would the remediation path be to remove the refines="#subject01" entry from the second declaration?
>  • Or am I completely missing the boat and looking in the wrong place? Is this correct in principle, but incorrect in implementation?
> Any light anyone can shed on this would be appreciated - references would be an absolute bonus - but today I'd be happy to just understand what to do to fix this.
> 
> Thanks in advance!
> 
> JF
> -- 
> John Foliot | Senior Industry Specialist, Digital Accessibility
> 
> "I made this so long because I did not have time to make it shorter." - Pascal
> 
> "links go places, buttons do things"

Received on Thursday, 24 June 2021 07:01:10 UTC