Support initiating patterns on `rdfa:copy` when attribute is `rel`

[csarven]

This part of the code supports RDFa property copying when property="rdfa:copy" on the link element:

rdfa-streaming-parser.js/lib/RdfaParser.ts

Lines 187 to 199 in cea018b

	// Instantiate patterns on rdfa:copy
	if (attributes.property === 'rdfa:copy') {
	const copyTargetPatternId: string = attributes.resource || attributes.href || attributes.src;
	if (this.rdfaPatterns[copyTargetPatternId]) {
	this.emitPatternCopy(parentTag, this.rdfaPatterns[copyTargetPatternId], copyTargetPatternId);
	} else {
	if (!this.pendingRdfaPatternCopies[copyTargetPatternId]) {
	this.pendingRdfaPatternCopies[copyTargetPatternId] = [];
	}
	this.pendingRdfaPatternCopies[copyTargetPatternId].push(parentTag);
	}
	return;
	}

rdfa-streaming-parser.js/lib/RdfaParser.ts

Lines 743 to 751 in cea018b

	// Emit all unreferenced copy links
	for (const patternId in this.pendingRdfaPatternCopies) {
	for (const parentTag of this.pendingRdfaPatternCopies[patternId]) {
	this.activeTagStack.push(parentTag);
	this.onTagOpen('link', { property: 'rdfa:copy', href: patternId });
	this.onTagClose();
	this.activeTagStack.pop();
	}
	}

The RDFa in HTML specification does not limit property copying ( https://www.w3.org/TR/rdfa-in-html/#implementing-property-copying ) to a particular element (HTML/SVG tag) or the property attribute, and so rel="rdfa:copy" on any element should also be possible.

(A simple usage is human-visible <a href="#foo" rel="rdfa:copy">foo</a> -- yes, it is possible to achieve the equivalent with <a href="" property="" but that's beside the point.)

I've also tested with http://rdf.greggkellogg.net/distiller and https://librdf.org/raptor/ , and they seem to give the expected result.

[rubensworks]

Aha, that looks like an oversight indeed!
Unfortunate that we don't have spec tests yet for that case.

[csarven]

Thanks for ack!

Is no tests a blocker for this issue from getting resolved?

I was using markup along the lines (below) at https://dokie.li/docs but the parser was having problems with it so I pulled it out until it gets fixed. It was breaking other functionality on the page that relied on the parser. (The code below is using base for your convenience to copy/paste into http://rdf.greggkellogg.net/distiller

<base href="https://dokie.li/docs" />

<p about="#illustrations-patrick-hochstenbach"
   id="illustrations-patrick-hochstenbach"
   typeof="rdfa:Pattern">Illustrations by 
     <a href="https://patrickhochstenbach.net/"
        rel="schema:creator"
        resource="https://patrickhochstenbach.net/profile/card#me"
        typeof="schema:Person">Patrick Hochstenbach</a>,
     <a href="https://creativecommons.org/licenses/by/4.0/"
        rel="schema:license">Creative Commons Attribution 4.0 Unported</a>.</p>

<figcaption about="media/images/dokieli-illustration-publishing.jpg">
  <a href="#illustrations-patrick-hochstenbach"
     rel="rdfa:copy">CC-BY</a>
</figcaption>

Expected output:

<https://patrickhochstenbach.net/profile/card#me>
  <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://schema.org/Person> .
<https://dokie.li/media/images/dokieli-illustration-publishing.jpg>
  <http://schema.org/creator> <https://patrickhochstenbach.net/profile/card#me> .
  <http://schema.org/license> <https://creativecommons.org/licenses/by/4.0/> .