Updated and released 2nd HTML+RDFa draft.

msporny · msporny · commit 78fce537c8b9 · 2009-09-06T22:35:54.000-04:00
diff --git a/docs/microsections-process.svg b/docs/microsections-process.svg
diff --git a/headers/header-w3c-rdfa b/headers/header-w3c-rdfa
@@ -3,7 +3,7 @@
 <!-- when publishing, change bits marked ZZZ -->
 <html lang="en-US-x-Hixie">
  <head>
-  <title>HTML5+RDFa</title>
+  <title>HTML+RDFa</title>
   <style type="text/css">
  pre { margin-left: 2em; white-space: pre-wrap; }
    h2 { margin: 3em 0 1em 0; }
@@ -202,11 +202,11 @@
          src="http://www.w3.org/Icons/w3c_home"
          width="72"></a>
    </p>
-   <h1>HTML5+RDFa</h1>
+   <h1>HTML+RDFa</h1>
    <h2 class="no-num no-toc" id="a-mechanism-for-embedding-rdf-in-html">
     A mechanism for embedding RDF in HTML
    </h2>
-   <h2 class="no-num no-toc" id="editor-s-draft-date-30-August-2009">Editor's Draft 30 August 2009</h2>
+   <h2 class="no-num no-toc" id="editor-s-draft-date-05-September-2009">Editor's Draft 05 September 2009</h2>
     <!--:ZZZ-->
    <dl>
     <!-- ZZZ: update the month/day (twice), (un)comment out
@@ -233,7 +233,7 @@
      Steven Pemberton (Chair, XHTML2, CWI)
     </dd>
     <dd>
-     <a href="mailto:msporny@digitalbazaar.com">Manu Sporny</a>, (Editor, HTML5+RDFa, Digital Bazaar, Inc.)
+     <a href="mailto:msporny@digitalbazaar.com">Manu Sporny</a>, (Editor, HTML+RDFa, Digital Bazaar, Inc.)
     </dd>
    </dl>
    <p class="copyright">
@@ -259,8 +259,8 @@
    This specification defines rules and guidelines for adapting the 
    RDF in XHTML: Syntax and Processing (RDFa) specification for use in the 
    HTML5 and XHTML5 members of the HTML family. The rules defined in this 
-   document not only apply to HTML5 documents, but also to HTML4 documents 
-   interpreted through the HTML5 parsing rules.
+   document not only apply to HTML5 documents in non-XML and XML mode, but 
+   also to HTML4 documents interpreted through the HTML5 parsing rules.
   </p>
   <h2 class="no-num no-toc"
       id="status-of-this-document">
@@ -318,8 +318,9 @@
   </p>
   <!-- UNDER NO CIRCUMSTANCES IS THE FOLLOWING PARAGRAPH TO BE REMOVED OR EDITED WITHOUT TALKING TO IAN FIRST --><!-- UNDER NO CIRCUMSTANCES IS THE PRECEDING PARAGRAPH TO BE REMOVED OR EDITED WITHOUT TALKING TO IAN FIRST --><!-- context and rationale (required) -->
   <p>
-   This specification is intended to be included in the HTML5 specification
-   as a section of the overall specification.
+   This specification is an extension to the HTML5 language. All
+   normative content in the HTML5 specification, unless overridden by this
+   specification, is intended to be the basis for this specification.
   </p>
   <!-- UNDER NO CIRCUMSTANCES IS THE FOLLOWING PARAGRAPH TO BE REMOVED OR EDITED WITHOUT TALKING TO IAN FIRST --><!-- required patent boilerplate -->
   <p>
diff --git a/microsections/rdfa/rdfa-conformance-requirements b/microsections/rdfa/rdfa-conformance-requirements
@@ -13,6 +13,7 @@
   <h3>
    Document Conformance
   </h3>
+  
   <p>
    In order for a document to claim that it is a conforming HTML+RDFa document,
    it must provide the facilities described as mandatory in this section.
@@ -22,15 +23,14 @@
 
   <ol>
    <li>
-    There should be a DOCTYPE declaration specified prior to the root element
-    in the document that follows the conventions outlined in the 
-    <span>The DOCTYPE</span> section in the HTML5 specification 
-    [<a href="http://www.w3.org/TR/html5">HTML5</a>].
+    All document conformance requirements stated as mandatory in the HTML5 
+    specification must be met.
    </li>
    <li>
-    The root element of the document must follow the conventions outlined
-    in <span>The root element</span> section in the HTML5 specification 
-    [<a href="http://www.w3.org/TR/html5">HTML5</a>].
+    There should be a <code>version</code> attribute on the <code>html</code>
+    element. The value of the <code>version</code> attribute should be
+    "HTML+RDFa 1.0" if the document is a non-XML mode document, or 
+    "XHTML+RDFa 1.0" if the document is a XML mode document.
    </li>
    <li>
     There may be a <code>link</code> element contained in the 
@@ -56,7 +56,8 @@
    <li>
     Implement all of the features specified in the XHTML+RDFa specification, 
     excluding those features which are specifically overridden by 
-    this specification.
+    this specification as detailed in the 
+    <a href="#modifications-to-xhtml-rdfa">Modifications to XHTML+RDFa</a>.
    </li>
    </ul>
   </p>
diff --git a/microsections/rdfa/rdfa-modifications-to-html5 b/microsections/rdfa/rdfa-modifications-to-html5
@@ -1,5 +1,5 @@
   <h2>
-   Modifications to HTML5
+   Extensions to the HTML5 Syntax
   </h2>
   <p>
    <em>This section is normative.</em>
@@ -10,14 +10,70 @@
     necessary modifications to the base HTML5 specification.
   </p>
 
-  <h3>Preservation of the <code>profile</code> keyword in <code>rel</code> attributes</h3>
+  <h3>The <code>profile</code> attribute and link type</h3>
   <p>
-    In order to provide a language version signalling mechanism, the 
-    <code>profile</code> keyword is provided for use in <code>rel</code>
-    attributes embedded in <code>link</code> elements. 
+    For content conforming to this specification, <code>profile</code> 
+    is an obsolete but conforming attribute name when used in the 
+    <code>head</code> element and when its value is set to the 
+    XHTML Vocabulary URI: "http://www.w3.org/1999/xhtml/vocab". 
+    The <code>profile</code> link type replaces
+    the <code>profile</code> attribute. The <code>profile</code> link type
+    should be used in the <code>rel</code> attribute in a <code>link</code> 
+    element contained in the <code>head</code> element of a conforming 
+    document. When the <code>profile</code> link type is specified, its
+    value must be the XHTML Vocabulary URI: 
+    "http://www.w3.org/1999/xhtml/vocab". For example:
+  </p>
+<pre>
+  &lt;head&gt;
+    &lt;link rel="profile" href="http://www.w3.org/1999/xhtml/vocab" /&gt;
+  &lt;/head&gt;
+</pre>
+  <p>
+    This particular attribute and link type is used to provide a language 
+    version signalling mechanism to the RDFa Processor. In future versions
+    of RDFa, the value of the profile may trigger different processing
+    rules in RDFa Processors.
+  </p>
+  <p>
+    Authors should use the <code>profile</code> link type instead of the
+    <code>profile</code> attribute when authoring new HTML documents.
+  </p>
+
+  <p>
+   The table entry below extends the list of link types as specified in 
+   <a href="http://www.w3.org/TR/html5/Overview.html#linkTypes">Link types section</a> 
+   of the HTML5 specification:
+   <table>
+    <thead>
+     <tr>
+      <th rowspan="2">Link type</th>
+      <th colspan="2">Effect on...</th>
+      <th rowspan="2">Brief description</th>
+     </tr>
+     <tr>
+      <th><code>link</code></th>
+      <th><code>a</code> and <code>area</code></th>
+     </tr>
+    </thead>
+    <tbody>
+
+     <tr>
+      <td><code title="rel-profile">profile</code></td>
+      <td><span title="hyperlink link">Hyperlink</span></td>
+      <td><em>not allowed</em></td>
+      <td>
+        In the future, this may trigger different RDFa Processor behavior
+        based on the value of the <code>href</code> attribute.
+      </td>
+     </tr>
+
+    </tbody
+    </thead>
+   </table>
   </p>
 
-  <h3>Preservation and Validation of <code>xmlns:</code></h3>
+  <h3>Attributes That Start With <code>xmlns:</code></h3>
 
   <p>
     Since RDFa uses <code>xmlns:</code> to specify CURIE prefixes, it is
diff --git a/microsections/rdfa/rdfa-modifications-to-xhtml-rdfa b/microsections/rdfa/rdfa-modifications-to-xhtml-rdfa
@@ -12,43 +12,115 @@
    attributes and processing rules defined in XHTML+RDFa in order to
    support extracting RDF from HTML documents.
   </p>
+  <p>
+   The requirements and rules, as specified in XHTML+RDFa and further 
+   modified in this document, apply to all HTML5 documents. The RDFa Processor 
+   operating on HTML and XHTML documents, specifically the resulting DOMs, 
+   must apply the same processing rules for both types of serializations an 
+   DOMs.
+  </p>
 
   <h3>Specifying the language for a literal</h3>
   <p>
-   The <code>lang</code> attribute must be supported in the same manner 
-   as the <code>xml:lang</code> attribute is in the XHTML+RDFa specification.
-   The precedence rules for selecting which value overrides the other is
-   outlined in the section titled "The lang and xml:lang attributes" in
-   the HTML5 specification.
+   The <code>lang</code> attribute must be processed in the same manner 
+   as the <code>xml:lang</code> attribute is in the XHTML+RDFa specification,
+   <a href="http://www.w3.org/TR/rdfa-syntax/#sec_5.5.">Section 5.5</a>, 
+   step #3.
+  </p>
+   The rules for determining the language of a node are specified in the
+   section titled 
+   <a href="http://www.w3.org/TR/html5/Overview.html#the-lang-and-xml:lang-attributes">The lang and xml:lang attributes</a> in the HTML5 specification.
   </p>
   <p>
-   If an author is unsure of the final encapsulating DOCTYPE for their
-   markup, such as HTML5 vs. XHTML5, it is suggested that the author specify
-   both <code>lang</code> and <code>xml:lang</code> where the value in
-   both attributes is exactly the same.
+   If an author is editing an HTML fragment and is unsure of the final 
+   encapsulating MIME type for their markup, it is suggested that the 
+   author specify both <code>lang</code> and <code>xml:lang</code> where the 
+   value in both attributes is exactly the same.
   </p>
 
   <h3>Invalid XMLLiteral values</h3>
   <p>
    When generating literals of type XMLLiteral, the processor must ensure that
-   the output XMLLiteral is 
-   <a href="http://www.w3.org/TR/xml/#dt-wellformed">well-formed XML</a>. 
-   If the input is not well-formed XML</a>, the processor must transform
-   the input text in a way that generates well-formed XML. An RDFa Processor
-   that is transforming not well-formed XML to well-formed XML must use the
-   algorithm for serializing a DOM subtree into XHTML5 as specified in the
-   HTML5 specification.
+   the output XMLLiteral is a namespace well-formed XML fragment. A namespace 
+   well-formed XML fragment has the following properties:
+   <ul>
+    <li>
+     The XML fragment, when placed inside of a single root element, must
+     validate as well-formed XML. The normative language that describes a
+     well-formed XML document is specified in 
+     <a href="http://www.w3.org/TR/REC-xml/#sec-well-formed">Section 2.1 "Well-Formed XML Documents"</a> 
+     of the XML specification.
+    </li>
+    <li>
+     A case-insensitive match for the currently active <code>xmlns</code> 
+     attribute as well as all currently active attributes starting with
+     <code>xmlns:</code> must be preserved in the generated XMLLiteral. 
+     This preservation must be accomplished by placing all active namespaces 
+     in each top-level element in the generated XMLLiteral, taking care to
+     not over-write pre-existing namespace values.
+    </li>
+   </ul>
+   If the input is not a namespace well-formed XML fragment, the processor 
+   must transform the input text in a way that ensures the well-formedness
+   rules described in this section. If a sequence of characters cannot be 
+   transformed into a namespace well-formed XML fragment, the triple 
+   containing the XMLLiteral must not be generated.
   </p>
   <p>
-   Transformation to well-formed XML is required because an application
-   that consumes XMLLiteral data expects that data to be well-formed.
+   An RDFa Processor that transforms the XML fragment must use the 
+   <a href="http://www.w3.org/TR/html5/Overview.html#coercing-an-html-dom-into-an-infoset">Coercing an HTML DOM into an Infoset</a> 
+   rules, as specified in the HTML5 specification, prior to generating the 
+   triple containing the XMLLiteral. The serialization algorithm that must
+   be used for generating the XMLLiteral is normatively defined in the
+   <a href="http://www.w3.org/TR/html5/Overview.html#serializing-xhtml-fragments">Serializing XHTML Fragments</a>
+   section of the HTML5 specification.
+  </p>
+  <p>
+   Transformation to a namespace well-formed XML fragment is required 
+   because an application that consumes XMLLiteral data expects that 
+   data to be a namespace well-formed XML fragment.
   </p>
   <p>
    The transformation requirement does not apply to input data that are
    text-only, such as literals that contain a <code>datatype</code> attribute
    with an empty value (<code>""</code>), or input data that that contain
    only text nodes.
   </p>
+  <p>
+   An example transformation demonstrating the preservation of namespace values is provided below. The &rarr; symbol is used to denote that the line is a continuation of the previous line and is included purely for the purposes of readability:
+
+   <pre>
+&lt;p xmlns:ex="http://example.org/vocab#" 	
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"&gt;
+ Two rectangles (the example markup for them are stored in a triple):
+ &lt;svg xmlns="http://www.w3.org/2000/svg" property="ex:markup" datatype="rdf:XMLLiteral"&gt;
+&rarr; &lt;rect width="300" height="100" 
+&rarr; style="fill:rgb(0,0,255);stroke-width:1; stroke:rgb(0,0,0)"/&gt;
+&rarr; &lt;rect width="50" height="50" 
+&rarr; style="fill:rgb(255,0,0);stroke-width:2; 
+&rarr; stroke:rgb(0,0,0)"/&gt;&lt;/svg&gt;
+&lt;/p&gt;
+   </pre>
+
+   The markup above should produce the following triple:
+
+   <pre>
+&lt;&gt; 
+   &lt;http://example.org/vocab#markup&gt;
+      "&lt;rect xmlns=\"http://www.w3.org/2000/svg\" xmlns:ex=\"http://example.org/vocab#\" 
+&rarr; xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\" width=\"300\" 
+&rarr; height=\"100\" style=\"fill:rgb(0,0,255);stroke-width:1; stroke:rgb(0,0,0)\"/&gt;
+&rarr; &lt;rect xmlns=\"http://www.w3.org/2000/svg\" xmlns:ex=\"http://example.org/vocab#\" 
+&rarr; xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\" width=\"50\" 
+&rarr; height=\"50\" style=\"fill:rgb(255,0,0);stroke-width:2; 
+&rarr; stroke:rgb(0,0,0)\"/&gt;"^^http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral
+   </pre>
+
+   Note the preservation of the namespaces by injecting a new 
+   <code>xmlns</code> attribute, as well as the attributes starting 
+   with the character sequence <code>xmlns:</code>, into each <code>rect</code>
+   element.
+  </p>
 
   <h3>The <code>xmlns:</code> attribute</h3>
   <p>
diff --git a/microsections/rdfa/rdfa-parsing-model b/microsections/rdfa/rdfa-parsing-model
@@ -1,6 +1,9 @@
   <h2>
    Parsing Model
   </h2>
+  <p>
+   <em>This section is normative.</em>
+  </p>
   <p>
    Section 5 of the
    [<a href="http://www.w3.org/TR/rdfa-syntax/">XHTML+RDFa</a>] specification
@@ -9,22 +12,32 @@
    model suited for the RDFa processing rules is intentionally not defined
    in the XHTML+RDFa specification. The method of transformation was intended
    to be defined in the implementation language, in this case, this section of
-   the HTML5 specification.
+   the HTML+RDFa specification.
+  </p>
+  <p>
+   The HTML5 and XHTML5 DOMs are each a super-set of the tree-based model
+   on which the RDFa processing rules operate. Therefore, a mapping mechanism 
+   to translate from a DOM to a tree-model is not necessary.
+   The HTML5 and XHTML5 DOM, or equivalent data structure, should be used 
+   as input to the RDFa processing rules. The normative language for
+   construction of the HTML5 DOM and XHTML5 DOM is contained in the HTML5
+   specification.
   </p>
+  <h3>Modifying the Input Document</h3>
   <p>
-   In the context of the HTML5 specification, the parsing rules for an input 
-   document in HTML4 and HTML5 are clearly defined. The processing model 
-   defined in Section 5 of the XHTML+RDFa specification should be executed 
-   on the HTML5 DOM. While the HTML5 DOM is not currently stable, any 
-   mechanism that generates a valid HTML5 DOM, such as the html5lib library,
-   may provide a mechanism that is guaranteed to eventually provide a 
-   stable, tree-based model for the RDFa processing rules.
+   <em>This section is informative.</em>
   </p>
   <p>
    RDFa's tree-based processing rules enable an input document to be 
    automatically corrected, cleaned-up, re-arranged, or modified in any
    way that is approved by the host language. For example, element nesting 
    issues in HTML documents may be corrected before the input document is 
-   serialized into the tree-based model on which the RDFa processing rules 
-   will operate.
+   translated into the DOM, a valid tree-based model, on which the 
+   RDFa processing rules will operate.
+  </p>
+  <p>
+   Any mechanism that generates a data structure equivalent to the HTML5 or 
+   XHTML5 DOM, such as the html5lib library, may be used as the mechanism to
+   construct the tree-based model provided as input to the RDFa processing 
+   rules.
   </p>
