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Mark blank node property labels as obsolete #90

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Nov 1, 2018
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Mark blank node property labels as obsolete #90

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1472e27
Mark blank node property labels and generalized RDF datasets as obsol…
gkellogg Oct 31, 2018
5055bfa
Fix minor HTML syntax error.
gkellogg Nov 1, 2018
6e7c654
"generalized rdf datasets" => "generalized RDF Datasets"
gkellogg Nov 1, 2018
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4 changes: 3 additions & 1 deletion common/terms.html
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Expand Up @@ -109,7 +109,9 @@
Every <a>edge</a> has a direction associated with it
and is labeled with an <a>IRI</a> or a <a>blank node identifier</a>.
Within the JSON-LD syntax these edge labels are called <a>properties</a>.
Whenever possible, an <a>edge</a> should be labeled with an <a>IRI</a>.</dd>
Whenever possible, an <a>edge</a> should be labeled with an <a>IRI</a>.
<div class="issue atrisk">The use of <a>blank node identifiers</a> to label properties is obsolete,
and may be removed in a future version of JSON-LD.</div></dd>
<dt><dfn>expanded term definition</dfn></dt><dd>
An expanded term definition is a <a>term definition</a>
where the value is a <a>dictionary</a>
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48 changes: 20 additions & 28 deletions index.html
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Expand Up @@ -4956,7 +4956,6 @@ <h3>Using the Document Base as the Default Vocabulary</h3>
href="#type-coercion">type coercion</a> of the <code>knows</code> property
is not required, as the value is not a string.</p>


<p>While it is considered a best practice to identify nodes in a graph,
at times this is impractical. In the data model, nodes without an explicit
identifier are called <a>blank nodes</a>, which can be represented in a
Expand Down Expand Up @@ -8381,10 +8380,11 @@ <h1>Data Model</h1>

<ul>
<li>A <a>JSON-LD document</a> serializes a
<a>generalized RDF Dataset</a>
<a>RDF Dataset</a>
[[RDF11-CONCEPTS]], which is a collection of <a>graphs</a>
that comprises exactly one <a>default graph</a>
and zero or more <a>named graphs</a>.</li>
and zero or more <a>named graphs</a>.
</li>
<li>The <a>default graph</a> does not have a name and MAY be empty.</li>
<li>Each <a>named graph</a> is a pair consisting of an <a>IRI</a> or
<a>blank node identifier</a> (the
Expand All @@ -8396,7 +8396,10 @@ <h1>Data Model</h1>
<li>Every <a>edge</a> has a direction associated with it and is labeled with
an <a>IRI</a> or a <a>blank node identifier</a>. Within the JSON-LD syntax
these edge labels are called <a>properties</a>.
Whenever practical, an <a>edge</a> SHOULD be labeled with an <a>IRI</a>.</li>
Whenever practical, an <a>edge</a> SHOULD be labeled with an <a>IRI</a>.
<div class="issue atrisk">The use of <a>blank node identifiers</a> to label properties is obsolete,
and may be removed in a future version of JSON-LD.</div>
</li>
<li>Every <a>node</a>
is an <a>IRI</a>, a <a>blank node</a>, a <a>JSON-LD value</a>,
or a <a>list</a>.</li>
Expand Down Expand Up @@ -8426,7 +8429,7 @@ <h1>Data Model</h1>
<a>graph</a> SHOULD return a Linked Data document describing
the resource denoted by that <a>IRI</a> when being dereferenced.</li>
<li>A <a>blank node</a> is a <a>node</a> which is neither an <a>IRI</a>,
nor a <a>JSON-LD value</a>, nor a <a>list</a>. A blank node MAY be identified
nor a <a>JSON-LD value</a>, nor a <a>list</a>. A blank node is identified
using a <a>blank node identifier</a>.</li>
<li>A <a>blank node identifier</a>
is a string that can be used as an identifier for a <a>blank node</a> within
Expand Down Expand Up @@ -9183,33 +9186,20 @@ <h2>Relationship to RDF</h2>
between JSON's native data types and RDF's counterparts to allow round-tripping.</li>
</ul>

<p class="issue atrisk">The use of <a>blank node identifiers</a> to label properties is obsolete,
and may be removed in a future version of JSON-LD, as is the support for <a>generalized RDF Datasets</a>.</p>

<p>Summarized, these differences mean that JSON-LD is capable of serializing any RDF
<a>graph</a> or <a>dataset</a> and most, but not all, JSON-LD documents can be directly
interpreted as RDF as described in RDF 1.1 Concepts [[RDF11-CONCEPTS]].</p>

<p>For authors and developers working with <a>blank nodes</a>
as <a>properties</a> when deserializing to RDF,
three potential approaches are suggested:</p>

<p>Authors are strongly encouraged to avoid labeling properties using <a>blank node identifiers</a>,
instead, consider one of the following mechanisms:</p>
<ul>
<li>If the author is not yet ready to commit to a stable IRI, the
property should be mapped to a <a>relative IRI</a>, or an IRI that is documented as unstable.</li>
<li>If the developer wishes to use <a>blank nodes</a>
as <a>properties</a> and also wishes to interpret the
data as a
<a>generalized RDF Dataset</a>,
there is an option, <a data-cite="JSON-LD11-API#dom-jsonldoptions-producegeneralizedrdf"><em>produce generalized RDF</em></a>, in the
<a data-cite="JSON-LD11-API#deserialize-json-ld-to-rdf-algorithm">Deserialize JSON-LD to RDF algorithm</a> [[JSON-LD11-API]] to do so. Note that a
<a>generalized RDF Dataset</a>
is an extension of RDF; it does not conform to the RDF standard.</li>
<li>If the author or developer wishes to use <a>blank nodes</a>
as <a>properties</a> and wishes to interpret the data
as a standard (non-generalized)
<a>RDF Dataset</a>,
it is possible to losslessly interpret JSON-LD as RDF by transforming
<a>blank nodes</a> used as
<a>properties</a> to <a>IRIs</a>,
by minting new "Skolem IRIs" as per
<li>a <a>relative IRI</a>, either relative to the document or the vocabulary
(see <a href="#using-the-document-base-as-the-default-vocabulary" class="sectionRef"></a> for a discussion on using the document base as the <a>vocabulary mapping</a>).</li>
<li>a URN such as <code>urn:example:1</code>, see [[?URN]], or</li>
<li>a "Skolem IRI" as per
<a data-cite="RDF11-CONCEPTS#section-skolemization">Replacing Blank Nodes with IRIs</a>
of [[RDF11-CONCEPTS]].</li>
</ul>
Expand All @@ -9219,7 +9209,7 @@ <h2>Relationship to RDF</h2>
specification [[JSON-LD11-API]].</p>

<p>Even though JSON-LD serializes
<a>generalized RDF Datasets</a>, it can
<a>RDF Datasets</a>, it can
also be used as a <dfn data-cite="RDF11-CONCEPTS#dfn-rdf-source">RDF graph source</dfn>.
In that case, a consumer MUST only use the <a>default graph</a> and ignore all <a>named graphs</a>.
This allows servers to expose data in languages such as Turtle and JSON-LD
Expand Down Expand Up @@ -9895,6 +9885,8 @@ <h2>Changes since JSON-LD Community Group Final Report</h2>
to ensure that <code>@type</code> members are always represented as an array. This
also allows a term to be defined for <code>@type</code>, where the value MUST be a <a>dictionary</a>
with <code>@container</code> set to <code>@set</code>.</li>
<li>The use of <a>blank node identifiers</a> to label properties is obsolete,
and may be removed in a future version of JSON-LD, as is the support for <a>generalized RDF Datasets</a>.</li>
</ul>
</section>

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