RDF/XML Syntax Specification (Revised)
RDF/XML Syntax Specification (Revised)
W3C Recommendation 10 February 2004
Document Status Update, 1 December 2023
The
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this version of RDF
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Editor:
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(University of Bristol)
Series editor:
Brian McBride
(Hewlett Packard Labs)
Please refer to the
errata
for this document, which may include some normative corrections.
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Abstract
The Resource Description Framework
RDF
) is a
general-purpose language for representing information in the Web.
This document defines an
XML
syntax for RDF called RDF/XML in terms of
Namespaces in XML
the
XML Information Set
and
XML Base
The
formal grammar
for the syntax
is annotated with actions generating triples of the
RDF graph
as defined in
RDF Concepts and Abstract Syntax
The triples are written using the
N-Triples
RDF graph serializing format which enables more precise recording of
the mapping in a machine processable form. The mappings are
recorded as tests cases, gathered and published in
RDF Test Cases
Status of this Document
This document has been reviewed by W3C Members and other interested
parties, and it has been endorsed by the Director as a
W3C
Recommendation
. W3C's role in making the Recommendation is to
draw attention to the specification and to promote its widespread
deployment. This enhances the functionality and interoperability of
the Web.
This is one document in a
set
of six
Primer
Concepts
Syntax
Semantics
Vocabulary
and
Test
Cases
) intended to jointly replace the original Resource
Description Framework specifications,
RDF Model and Syntax (1999
Recommendation)
and
RDF Schema
(2000 Candidate Recommendation)
. It has been developed by the
RDF Core Working Group
as part of the
W3C Semantic Web
Activity
Activity
Statement
Group
Charter
) for publication on 10 February 2004.
Changes to this document since the
Proposed Recommendation Working Draft
are detailed in
the
change log
The public is invited to send comments to
www-rdf-comments@w3.org
archive
and to participate in general discussion of related technology on
www-rdf-interest@w3.org
archive
).
A list of
implementations
is available.
The W3C maintains a list of
any patent disclosures related to this work
This section describes the status of this document at the time of its
publication. Other documents may supersede this document. A list of current W3C
publications and the latest revision of this technical report can be found in
the
W3C technical reports index
at
Table of Contents
Introduction
An XML Syntax for RDF
2.1
Introduction
2.2
Node Elements and Property Elements
2.3
Multiple Property Elements
2.4
Empty Property Elements
2.5
Property Attributes
2.6
Completing the Document: Document Element and XML Declaration
2.7
Languages:
xml:lang
2.8
XML Literals:
rdf:parseType="Literal"
2.9
Typed Literals:
rdf:datatype
2.10
Identifying Blank Nodes:
rdf:nodeID
2.11
Omitting Blank Nodes:
rdf:parseType="Resource"
2.12
Omitting Nodes: Property Attributes on an empty Property Element
2.13
Typed Node Elements
2.14
Abbreviating URI References:
rdf:ID
and
xml:base
2.15
Container Membership Property Elements:
rdf:li
and
rdf:_
2.16
Collections:
rdf:parseType="Collection"
2.17
Reifying Statements:
rdf:ID
Terminology
RDF MIME Type, File Extension and Macintosh File Type
Global Issues
5.1
The RDF Namespace and Vocabulary
5.2
Identifiers
5.3
Resolving URIs
5.4
Constraints
5.5
Conformance
Syntax Data Model
6.1
Events
6.2
Information Set Mapping
6.3
Grammar Notation
RDF/XML Grammar
7.1
Grammar Summary
7.2
Grammar Productions
7.3
Reification Rules
7.4
List Expansion Rules
Serializing an RDF Graph to RDF/XML
Using RDF/XML with HTML and XHTML
10
Using RDF/XML with SVG
11
Acknowledgments
12
References
Appendices
Syntax Schemas
(Informative)
A.1
RELAX NG Compact Syntax Schema
(Informative)
Revisions since Working Draft 10 October 2003
(Informative)
1 Introduction
This document defines the
XML
[XML]
syntax for RDF graphs
which was originally defined in the
RDF Model & Syntax
[RDF-MS]
W3C
Recommendation. Subsequent implementations of this syntax and
comparison of the resulting RDF graphs have shown that there was
ambiguity — implementations generated different graphs and certain
syntax forms were not widely implemented.
This document revises the
original RDF/XML grammar
in terms of
XML Information Set
[INFOSET]
information items which moves
away from the rather low-level details of XML, such as particular
forms of empty elements. This allows the grammar to be more
precisely recorded and the mapping from the XML syntax to the RDF
Graph more clearly shown. The mapping to the RDF graph is done by
emitting statements in the form defined in the
N-Triples
section of
RDF Test Cases
[RDF-TESTS]
which creates an RDF graph, that has semantics defined by
RDF Semantics
[RDF-SEMANTICS]
The complete specification of RDF consists of a number of documents:
RDF Primer
[RDF-PRIMER]
RDF Concepts and Abstract Syntax
[RDF-CONCEPTS]
RDF Semantics
[RDF-SEMANTICS]
RDF/XML Syntax (this document)
RDF Vocabulary Description Language 1.0: RDF Schema
[RDF-VOCABULARY]
RDF Test Cases
[RDF-TESTS]
For a longer introduction to the RDF/XML syntax with a historical
perspective, see
RDF: Understanding the Striped RDF/XML Syntax
[STRIPEDRDF]
2 An XML Syntax for RDF
This section introduces the RDF/XML syntax, describes how it
encodes RDF graphs and explains this with examples. If there is any
conflict between this informal description and the formal description
of the syntax and grammar in sections
6 Syntax Data Model
and
7 RDF/XML Grammar
, the
latter two sections take precedence.
2.1 Introduction
The
RDF Concepts and Abstract Syntax
[RDF-CONCEPTS]
defines the
RDF Graph data model
(Section 3.1)
and the
RDF Graph abstract syntax
(Section 6).
Along with the
RDF Semantics
[RDF-SEMANTICS]
this provides an abstract syntax with a formal semantics for it.
The RDF graph has
nodes
and labeled directed
arcs
that link pairs of nodes and this is represented as a set of
RDF triples
where each triple contains a
subject node
predicate
and
object node
Nodes are
RDF URI references
RDF literals
or are
blank nodes
Blank nodes may be given
a document-local, non-
RDF URI references
identifier called a
blank node identifier
Predicates are
RDF URI references
and can be interpreted as either a relationship between the two
nodes or as defining an attribute value (object node) for some
subject node.
In order to encode the graph in XML, the nodes and predicates have to be
represented in XML terms — element names, attribute names, element contents
and attribute values.
RDF/XML uses XML
QNames
as defined in
Namespaces in XML
[XML-NS]
to represent
RDF URI references
All QNames have a
namespace name
which is a URI reference
and a short
local name
In addition, QNames can either have a short
prefix
or be declared with the default namespace declaration and have none (but
still have a namespace name)
The
RDF URI reference
represented by a QName is determined by appending the
local name
part of the QName after the
namespace name
(URI reference) part of the QName.
This is used to shorten the
RDF URI references
of all predicates and some nodes.
RDF URI references
identifying
subject and object nodes can also be stored as XML attribute values.
RDF literals
which can only be object nodes,
become either XML element text content or XML attribute values.
A graph can be considered a collection of paths of the form node,
predicate arc, node, predicate arc, node, predicate arc, ... node
which cover the entire graph. In RDF/XML these turn into sequences of
elements inside elements which alternate between elements for nodes
and predicate arcs. This has been called a series of node/arc
stripes. The node at the start of the sequence turns into the
outermost element, the next predicate arc turns into a child element,
and so on. The stripes generally start at the top of an RDF/XML
document and always begin with nodes.
Several RDF/XML examples are given in the following sections
building up to complete RDF/XML documents.
Example 7
is the first complete RDF/XML document.
2.2 Node Elements and Property Elements
Figure 1: Graph for RDF/XML Example
SVG version
An RDF graph is given in
Figure 1
where the nodes are represented as ovals and contain their
RDF URI references
where they have them, all the predicate arcs are labeled with
RDF URI references
and
plain literal
nodes have been written in rectangles.
If we follow one node, predicate arc ... , node path through the
graph shown in
Figure 2
Figure 2: One Path Through the Graph
SVG version
The left hand side of the
Figure 2
graph corresponds to the node/predicate arc stripes:
Node with
RDF URI reference
Predicate Arc labeled with
RDF URI reference
Node with no
RDF URI reference
Predicate Arc labeled with
RDF URI reference
Node with
RDF URI reference
In RDF/XML, the sequence of 5 nodes and predicate arcs on
the left hand side of
Figure 2
corresponds to
the usage of five XML elements of two types, for the graph nodes and
predicate arcs. These are conventionally called
node elements
and
property elements
respectively. In the striping shown in
Example 1
rdf:Description
is the
node element (used three times for the three nodes) and
ex:editor
and
ex:homePage
are the two
property elements.
Example 1: Striped RDF/XML (
nodes
and
predicate arcs
The
Figure 2
graph consists of some nodes
that are
RDF URI references
(and others that are not) and this can be added
to the RDF/XML using the
rdf:about
attribute on node
elements to give the result in
Example 2
Example 2: Node Elements with RDF URI references added
Adding the other two paths through the
Figure 1
graph to the RDF/XML in
Example 2
gives the result in
Example 3
(this example fails to show that the blank node is
shared between the two paths, see
2.10
):
Example 3: Complete description of all graph paths
2.3 Multiple Property Elements
There are several abbreviations that can be used to make common
uses easier to write down. In particular, it is common that a
subject node in the RDF graph has multiple outgoing predicate arcs. RDF/XML
provides an abbreviation for the corresponding syntax when a node
element about a resource has multiple property elements. This can be
abbreviated by using multiple child property elements inside the node
element describing the subject node.
Taking
Example 3
, there are
two node elements that can take multiple property elements.
The subject node with URI reference
has property elements
ex:editor
and
ex:title
and the node element for the blank node can take
ex:homePage
and
ex:fullName
. This abbreviation
gives the result shown in
Example 4
(this example does show that there is a single blank node):
Example 4: Using multiple property elements on a node element
2.4 Empty Property Elements
When a predicate arc in an RDF graph points to an object node which has no
further predicate arcs, which appears in RDF/XML as an empty node element
(or
this form can be shortened. This is done by using the
RDF URI reference
of the object node as the value of an XML attribute
rdf:resource
on the containing property element and making the property element empty.
In this example, the property element
ex:homePage
contains an empty node element with the
RDF URI reference
. This can be replaced with
the empty property element form giving the result shown in
Example 5
Example 5: Empty property elements
2.5 Property Attributes
When a property element's content is string literal,
it may be possible to use it as an XML attribute on the
containing node element.
This can be done for multiple properties on the same node element
only if the property element name is not repeated
(required by XML — attribute names are unique on an XML element)
and any in-scope
xml:lang
on the
property element's string literal (if any) are the same (see
Section 2.7
This abbreviation is known as a
Property Attribute
and can be applied to any node element.
This abbreviation can also be used when the property element is
rdf:type
and it has an
rdf:resource
attribute
the value of which is interpreted as a
RDF URI reference
object node.
In
Example 5
:,
there are two property elements with string literal content,
the
dc:title
and
ex:fullName
property elements. These can be replaced with property attributes
giving the result shown in
Example 6
Example 6: Replacing property elements with string literal content into property attributes
2.6 Completing the Document: Document Element and XML Declaration
To create a complete RDF/XML document, the serialization of the
graph into XML is usually contained inside an
rdf:RDF
XML element which becomes the top-level XML document element.
Conventionally the
rdf:RDF
element is also used to
declare the XML namespaces that are used, although that is not
required. When there is only one top-level node element inside
rdf:RDF
, the
rdf:RDF
can be omitted
although any XML namespaces must still be declared.
The XML specification also permits an XML declaration at
the top of the document with the XML version and possibly the XML
content encoding. This is optional but recommended.
Completing the RDF/XML could be done for any of the correct
complete graph examples from
Example 4
onwards but taking the smallest
Example 6
and adding the final components,
gives a complete RDF/XML representation of the original
Figure 1
graph
in
Example 7
Example 7: Complete RDF/XML description of Figure 1 graph
example07.rdf
output
example07.nt
xmlns:ex="http://example.org/stuff/1.0/">
It is possible to omit
rdf:RDF
in
Example 7
above since there is only one
rdf:Description
inside
rdf:RDF
but this
is not shown here.
2.7 Languages:
xml:lang
RDF/XML permits the use of the
xml:lang
attribute as defined by
2.12 Language Identification
of
XML 1.0
[XML]
to allow the identification of content language.
The
xml:lang
attribute can be used on any node element or property element
to indicate that the included content is in the given language.
Typed literals
which includes
XML literals
are not affected by this attribute.
The most specific in-scope language present
(if any) is applied to property element string literal content or
property attribute values. The
xml:lang=""
form
indicates the absence of a language identifier.
Some examples of marking content languages for RDF properties are shown in
Example 8
Example 8: Complete example of
xml:lang
example08.rdf
output
example08.nt
2.8 XML Literals:
rdf:parseType="Literal"
RDF allows
XML literals
[RDF-CONCEPTS]
Section 5,
XML Content within an RDF graph
to be given as the object node of a predicate.
These are written in RDF/XML as content of a property element (not
a property attribute) and indicated using the
rdf:parseType="Literal"
attribute on the containing
property element.
An example of writing an XML literal is given in
Example 9
where
there is a single RDF triple with the subject node
RDF URI reference
, the predicate
RDF URI reference
(from
ex:prop
) and the object node with XML literal
content beginning
a:Box
Example 9: Complete example of
rdf:parseType="Literal"
example09.rdf
output
example09.nt
2.9 Typed Literals:
rdf:datatype
RDF allows
typed literals
to be given as the object node of a predicate. Typed literals consist of a literal
string and a datatype
RDF URI reference
. These are written in RDF/XML using
the same syntax for literal string nodes in the property element form
(not property attribute) but with an additional
rdf:datatype="
datatypeURI
attribute on the property element. Any
RDF URI reference
can be used in the attribute.
An example of an RDF
typed literal
is given in
Example 10
where
there is a single RDF triple with the subject node
RDF URI reference
, the predicate
RDF URI reference
(from
ex:size
) and the object node with the
typed literal
("123",
to be interpreted as an
W3C XML Schema
[XML-SCHEMA2]
datatype int.
Example 10: Complete example of
rdf:datatype
example10.rdf
output
example10.nt
2.10 Identifying Blank Nodes:
rdf:nodeID
Blank nodes
in the RDF graph are distinct but have no
RDF URI reference
identifier.
It is sometimes required that the same graph
blank node
is referred to in the
RDF/XML in multiple places, such as at the subject and object
of several RDF triples. In this case, a
blank node identifier
can be given to the
blank node
for identifying it
in the document. Blank node identifiers in RDF/XML are scoped to the
containing XML Information Set
document information item
blank node identifier
is used
on a node element to replace
rdf:about="
RDF URI reference
or on a property element to replace
rdf:resource="
RDF URI reference
with
rdf:nodeID="
blank node identifier
in both cases.
Taking
Example 7
and explicitly giving
blank node identifier
of
abc
to the blank node in it
gives the result shown in
Example 11
The second
rdf:Description
property element is
about the blank node.
Example 11: Complete RDF/XML description of graph using
rdf:nodeID
identifying the blank node
example11.rdf
output
example11.nt
xmlns:ex="http://example.org/stuff/1.0/">
2.11 Omitting Blank Nodes:
rdf:parseType="Resource"
Blank nodes
(not
RDF URI reference
nodes) in RDF graphs can be written
in a form that allows the
pair to be omitted.
The omission is done by putting an
rdf:parseType="Resource"
attribute on the containing property element
that turns the property element into a property-and-node element,
which can itself have both property elements and property attributes.
Property attributes and the
rdf:nodeID
attribute
are not permitted on property-and-node elements.
Taking the earlier
Example 7
the contents of the
ex:editor
property element
could be alternatively done in this fashion to give
the form shown in
Example 12
Example 12: Complete example using
rdf:parseType="Resource"
example12.rdf
output
example12.nt
xmlns:ex="http://example.org/stuff/1.0/">
2.12 Omitting Nodes: Property Attributes on an empty Property Element
If all of the property elements on a blank node element have
string literal values with the same in-scope
xml:lang
value (if present) and each of these property elements appears at
most once and there is at most one
rdf:type
property
element with a
RDF URI reference
object node, these can be abbreviated by
moving them to be property attributes on the containing property
element which is made an empty element.
Taking the earlier
Example 5
the
ex:editor
property element contains a
blank node element with two property elements
ex:fullname
and
ex:homePage
ex:homePage
is not suitable here since it
does not have a string literal value, so it is being
ignored
for the purposes of this example.
The abbreviated form removes the
ex:fullName
property element
and adds a new property attribute
ex:fullName
with the
string literal value of the deleted property element
to the
ex:editor
property element.
The blank node element becomes implicit in the now empty
ex:editor
property element. The result is shown in
Example 13
Example 13: Complete example of property attributes on an empty property element
example13.rdf
output
example13.nt
xmlns:ex="http://example.org/stuff/1.0/">
2.13 Typed Node Elements
It is common for RDF graphs to have
rdf:type
predicates
from subject nodes. These are conventionally called
typed
nodes
in the graph, or
typed node elements
in the
RDF/XML. RDF/XML allows this triple to be expressed more concisely.
by replacing the
rdf:Description
node element name with
the namespaced-element corresponding to the
RDF URI reference
of the value of
the type relationship. There may, of course, be multiple
rdf:type
predicates but only one can be used in this way, the others must remain as
property elements or property attributes.
The typed node elements are commonly used in RDF/XML with the built-in
classes in the
RDF vocabulary
rdf:Seq
rdf:Bag
rdf:Alt
rdf:Statement
rdf:Property
and
rdf:List
For example, the RDF/XML in
Example 14
could be written as shown in
Example 15
Example 14: Complete example with
rdf:type
example14.rdf
output
example14.nt
xmlns:ex="http://example.org/stuff/1.0/">
Example 15: Complete example using a typed node element to replace an
rdf:type
example15.rdf
output
example15.nt
xmlns:ex="http://example.org/stuff/1.0/">
2.14 Abbreviating URIs:
rdf:ID
and
xml:base
RDF/XML allows further abbreviating
RDF URI references
in XML attributes in two
ways. The XML Infoset provides a base URI attribute
xml:base
that sets the base URI for resolving relative
RDF URI references
, otherwise the base URI is that of the document. The base URI applies to
all RDF/XML attributes that deal with
RDF URI references
which are
rdf:about
rdf:resource
rdf:ID
and
rdf:datatype
The
rdf:ID
attribute on a node element (not property
element, that has another meaning) can be used instead of
rdf:about
and gives a relative
RDF URI reference
equivalent to
concatenated with the
rdf:ID
attribute value. So for
example if
rdf:ID="name"
, that would be equivalent
to
rdf:about="#name"
rdf:ID
provides an additional
check since the same
name
can only appear once in the
scope of an
xml:base
value (or document, if none is given),
so is useful for defining a set of distinct,
related terms relative to the same
RDF URI reference
Both forms require a base URI to be known, either from an in-scope
xml:base
or from the URI of the RDF/XML document.
Example 16
shows abbreviating the node
RDF URI reference
of
using an
xml:base
of
and
an
rdf:ID
on the
rdf:Description
node element.
The object node of the
ex:prop
predicate is an
absolute
RDF URI reference
resolved from the
rdf:resource
XML attribute value
using the in-scope base URI to give the
RDF URI reference
Example 16: Complete example using
rdf:ID
and
xml:base
for shortening URIs
example16.rdf
output
example16.nt
xml:base="http://example.org/here/">
2.15 Container Membership Property Elements:
rdf:li
and
rdf:_
RDF has a set of container membership properties
and corresponding property elements that are mostly used with
instances of the
rdf:Seq
rdf:Bag
and
rdf:Alt
classes which may be written as typed node elements. The list properties are
rdf:_1
rdf:_2
etc. and can be written
as property elements or property attributes as shown in
Example 17
. There is an
rdf:li
special property element that is equivalent to
rdf:_1
rdf:_2
in order,
explained in detail in
section 7.4
The mapping to the container membership properties is
always done in the order that the
rdf:li
special
property elements appear in XML — the document order is significant.
The equivalent RDF/XML to
Example 17
written
in this form is shown in
Example 18
Example 17: Complex example using RDF list properties
example17.rdf
output
example17.nt
Example 18: Complete example using
rdf:li
property element for list properties
example18.rdf
output
example18.nt
2.16 Collections:
rdf:parseType="Collection"
RDF/XML allows an
rdf:parseType="Collection"
attribute on a property element to let it contain multiple node
elements. These contained node elements give the set of subject
nodes of the collection. This syntax form corresponds to a set of
triples connecting the collection of subject nodes, the exact triples
generated are described in detail in
Section 7.2.19 Production parseTypeCollectionPropertyElt
The collection construction is always done in the order that the node
elements appear in the XML document. Whether the order of the
collection of nodes is significant is an application issue and not
defined here.
Example 19
shows a collection of three
nodes elements at the end of the
ex:hasFruit
property element using this form.
Example 19: Complete example of a RDF collection of nodes using
rdf:parseType="Collection"
example19.rdf
output
example19.nt
2.17 Reifying Statements:
rdf:ID
The
rdf:ID
attribute can be used on a property
element to reify the triple that it generates (See
section 7.3 Reification Rules
for the
full details).
The identifier for the triple should be constructed as a
RDF URI reference
made from the relative URI reference
concatenated with the
rdf:ID
attribute
value, resolved against the in-scope base URI. So for example if
rdf:ID="triple"
, that would be equivalent to the
RDF URI reference
formed from relative URI reference
#triple
against the base URI.
Each (
rdf:ID
attribute value, base URI)
pair has to be unique in an RDF/XML document,
see
constraint-id
Example 20
shows a
rdf:ID
being used to reify a triple made from the
ex:prop
property element giving the reified triple the
RDF URI reference
Example 20: Complete example of
rdf:ID
reifying a property element
example20.rdf
output
example20.nt
xml:base="http://example.org/triples/">
3 Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in
this document are to be interpreted as described in
RFC 2119
[KEYWORDS]
All use of string without further qualification refers to
a Unicode
[UNICODE]
character string;
a sequence of characters represented by a code point in Unicode.
(Such as defined in
[CHARMOD]
in section
3.4 Strings
).
4 RDF MIME Type, File Extension and Macintosh File Type
The Internet media type / MIME type for RDF/XML is
application/rdf+xml
" —
see
RFC 3023
[RFC-3023]
section 8.18.
Registration Note (Informative):
For the state of the MIME type registration, consult
IANA MIME Media Types
[IANA-MEDIA-TYPES]
It is recommended that RDF/XML files have the extension
".rdf"
(all lowercase) on all platforms.
It is recommended that RDF/XML files stored on Macintosh HFS file
systems be given a file type of
"rdf "
(all lowercase, with a space character as the fourth letter).
5 Global Issues
5.1 The RDF Namespace and Vocabulary
Note (Informative):
The names
aboutEach
and
aboutEachPrefix
were removed
from the language and the RDF vocabulary by the RDF Core Working Group.
See the resolution of issues
rdfms-abouteach
and
rdfms-abouteachprefix
for further information.
Note (Informative):
The names
List
first
rest
and
nil
were added for issue
rdfms-seq-representation
The names
XMLLiteral
and
datatype
were added
to support RDF datatyping.
The name
nodeID
was added
for issue
rdfms-syntax-incomplete
See the
RDF Core Issues List
for further information.
The
RDF namespace URI reference
(or namespace name) is
and is typically used in XML with the prefix
rdf
although other prefix strings may be used.
The
RDF Vocabulary
is identified by this namespace name and consists of the following names only:
Syntax names — not concepts
RDF Description ID about parseType resource li nodeID datatype
Class names
Seq Bag Alt Statement Property XMLLiteral List
Property names
subject predicate object type value first rest _
where
is a decimal integer greater than zero with no leading zeros.
Resource names
nil
Any other names are not defined and SHOULD generate a warning when
encountered, but should otherwise behave normally.
Within RDF/XML documents it is not permitted to use XML namespaces
whose namespace name is the
RDF namespace URI reference
concatenated with additional characters.
Throughout this document the terminology
rdf:
name
will be used to indicate
name
is from the RDF vocabulary
and it has a
RDF URI reference
of the concatenation of the
RDF namespace URI reference
and
name
For example,
rdf:type
has the
RDF URI reference
5.2 Identifiers
The
RDF Graph
RDF Concepts and Abstract Syntax
Section 3)
defines three types of nodes and one type of predicate:
RDF URI reference
nodes and predicates
RDF URI references
RDF Concepts and Abstract Syntax
Section 3.1)
can be either:
given as XML attribute values interpreted as relative
URI references that are resolved against the in-scope base URI
as described in
section 5.3
to give absolute
RDF URI references
transformed from XML namespace-qualified element and attribute names
(QNames)
transformed from
rdf:ID
attribute values.
Within RDF/XML, XML QNames are transformed into
RDF URI references
by appending the XML local name to the namespace name (URI reference).
For example, if the XML namespace prefix
foo
has
namespace name (URI reference)
then the QName
foo:bar
would correspond to the RDF URI reference
. Note that this
restricts which
RDF URI references
can be made and the same URI can be given in multiple ways.
The
rdf:ID
values
are transformed into
RDF URI references
by appending the attribute value to the result of appending
"#" to the in-scope base URI which is defined in
Section 5.3 Resolving URIs
Literal nodes (always object nodes)
RDF literals
RDF Concepts and Abstract Syntax
6.5) are either
plain literals
(ibid),
or
typed literals
(ibid).
The latter includes
XML literals
(ibid section 5,
XML Content within an RDF graph
).
Blank Node Identifiers
Blank nodes
have distinct identity in the RDF graph.
When the graph is written in a syntax such as RDF/XML, these
blank nodes may need graph-local identifiers and a syntax
in order to preserve this distinction. These local identifiers are called
blank node identifiers
and are used in RDF/XML as values of the
rdf:nodeID
attribute
with the syntax given in
Production nodeIdAttr
Blank node identifiers in RDF/XML are scoped to the XML Information Set
document information item
If no blank node identifier is given explicitly as an
rdf:nodeID
attribute value then one will need to be
generated (using generated-blank-node-id, see section
6.3.3
).
Such generated blank node
identifiers must not clash with any blank node identifiers derived
from
rdf:nodeID
attribute values. This can be
implemented by any method that preserves the distinct identity of all
the blank nodes in the graph, that is, the same blank node identifier
is not given for different blank nodes. One possible method would be
to add a constant prefix to all the
rdf:nodeID
attribute
values and ensure no generated blank node identifiers ever used that
prefix. Another would be to map all
rdf:nodeID
attribute
values to new generated blank node identifiers and perform that mapping
on all such values in the RDF/XML document.
5.3 Resolving URIs
RDF/XML supports
XML Base
[XML-BASE]
which defines a
base-uri
accessor for each
root event
and
element event
Relative URI references are resolved into
RDF URI references
according to the algorithm specified in
XML Base
[XML-BASE]
(and RFC 2396).
These specifications do not specify an algorithm for resolving a
fragment identifier alone, such as
#foo
, or the empty
string
""
into an
RDF URI reference
. In RDF/XML, a fragment identifier
is transformed into a
RDF URI reference
by appending the fragment identifier to the in-scope base URI. The
empty string is transformed
into an
RDF URI reference
by substituting the in-scope base URI.
Test:
Indicated by
test001.rdf
and
test001.nt
Test:
Indicated by
test004.rdf
and
test004.nt
Test:
Indicated by
test008.rdf
and
test008.nt
Test:
Indicated by
test013.rdf
and
test013.nt
Test:
Indicated by
test016.rdf
and
test016.nt
An empty same document reference ""
resolves against the URI part of the base URI; any fragment part
is ignored. See
Uniform Resource Identifiers (URI)
[URIS]
section 4.2
Test:
Indicated by
test013.rdf
and
test013.nt
Implementation Note (Informative):
When using a hierarchical base
URI that has no path component (/), it must be added before using as a
base URI for resolving.
Test:
Indicated by
test011.rdf
and
test011.nt
5.4 Constraints
constraint-id
Each application of production
idAttr
matches an attribute. The pair formed by the
string-value
accessor of the matched attribute and the
base-uri
accessor of the matched attribute is unique within a single RDF/XML
document.
The syntax of the names must match the
rdf-id production
Test:
Indicated by
test014.rdf
and
test014.nt
5.5 Conformance
Definition:
An
RDF Document
is a serialization of an
RDF Graph
into a concrete syntax.
Definition:
An
RDF/XML Document
is an
RDF Document
written in the
recommended XML transfer syntax for RDF as defined in this document.
Conformance:
An
RDF/XML Document
is a
conforming RDF/XML document
if it adheres to the specification defined in this document.
6 Syntax Data Model
This document specifies the syntax of RDF/XML as a grammar on an
alphabet of symbols. The symbols are called
events
in the
style of the
[XPATH]
Information Set Mapping
A sequence of events is normally derived from an XML document, in
which case they are in document order as defined below in
Section 6.2 Information Set Mapping
The sequence these events form are intended to be similar to the sequence
of events produced by the
[SAX2]
XML API from
the same XML document. Sequences of events may be checked against
the grammar to determine whether they are or are not syntactically
well-formed RDF/XML.
The grammar productions may include actions which fire when the
production is recognized. Taken together these actions define a
transformation from any syntactically well-formed RDF/XML sequence of
events into an RDF graph represented in the
N-Triples
language.
The model given here illustrates one way to create a representation of
an
RDF Graph
from an RDF/XML document. It does not mandate any implementation
method — any other method that results in a representation of the same
RDF Graph
may be used.
In particular:
This specification permits any
representation
of an RDF graph (see
[RDF-CONCEPTS]
);
in particular, it does not require the use of
N-Triples
This specification does not require the use of
[XPATH]
or
[SAX2]
This specification places no constraints on the order in which
software transforming RDF/XML into a representation of a graph,
constructs the representation of the graph.
Software transforming RDF/XML into a representation of a graph
MAY eliminate duplicate predicate arcs.
The syntax does not support non-well-formed XML documents, nor
documents that otherwise do not have an XML Information Set; for
example, that do not conform to
Namespaces in XML
[XML-NS]
The Infoset requires support for
XML Base
[XML-BASE]
RDF/XML uses the information item property [base URI], discussed in
section 5.3
This specification requires an
XML Information Set
[INFOSET]
which supports at least the following information items and
properties for RDF/XML:
document information item
[document element], [children], [base URI]
element information item
[local name], [namespace name], [children], [attributes], [parent], [base URI]
attribute information item
[local name], [namespace name], [normalized value]
character information item
[character code]
There is no mapping of the following items to data model events:
processing instruction information item
unexpanded entity reference information item
comment information item
document type declaration information item
unparsed entity information item
notation information item
namespace information item
Other information items and properties have no mapping to
syntax data model events.
Element information items with reserved XML Names
(See
Name
in
XML 1.0
are not mapped to data model element events. These are all those
with property [prefix] beginning with
xml
(case
independent comparison) and all those with [prefix] property
having no value and which have [local name] beginning with
xml
(case independent comparison).
All information items contained inside XML elements matching the
parseTypeLiteralPropertyElt
production form
XML literals
and do not follow this mapping. See
parseTypeLiteralPropertyElt
for further information.
This section is intended to satisfy the requirements for
Conformance
in the
[INFOSET]
specification.
It specifies the information items and properties that are needed
to implement this specification.
6.1 Events
There are nine types of event defined in the following subsections.
Most events are constructed from an Infoset information item (except
for
URI reference
blank node
plain literal
and
typed literal
). The effect
of an event constructor is to create a new event with a unique identity,
distinct from all other events. Events have accessor operations on them
and most have the
string-value
accessor that may be a static value
or computed.
6.1.1 Root Event
Constructed from a
document information item
and takes the following accessors and values.
document-element
Set to the value of document information item property [document-element].
children
Set to the value of document information item property [children].
base-uri
Set to the value of document information item property [base URI].
language
Set to the empty string.
6.1.2 Element Event
Constructed from an
element information item
and takes the following accessors and values:
local-name
Set to the value of element information item property [local name].
namespace-name
Set to the value of element information item property [namespace name].
children
Set to the value of element information item property [children].
base-uri
Set to the value of element information item property [base URI].
attributes
Made from the value of element information item property [attributes] which is a set of attribute information items.
If this set contains an attribute information item
xml:lang
[namespace name] property with the value
"http://www.w3.org/XML/1998/namespace" and
[local name] property value "lang")
it is removed from the set of attribute information items and the
language
accessor is set to the
[normalized-value] property of the attribute information item.
All remaining reserved XML Names
(See
Name
in
XML 1.0
are now removed from the set. These are, all
attribute information items in the set with property [prefix]
beginning with
xml
(case independent
comparison) and all attribute information items with [prefix]
property having no value and which have [local name] beginning with
xml
(case independent comparison) are removed.
Note that the [base URI] accessor is computed by XML Base before any
xml:base
attribute information item is deleted.
The remaining set of attribute information items are then used
to construct a new set of
Attribute Events
which is assigned as the value of this accessor.
URI
Set to the string value of the concatenation of the
value of the namespace-name accessor and the value of the
local-name accessor.
URI-string-value
The value is the concatenation of the following in this order "<",
the escaped value of the
URI
accessor and ">".
The escaping of the
URI
accessor uses the N-Triples escapes for
URI references as described in 3.3 URI References.
li-counter
Set to the integer value 1.
language
Set from the
attributes
as described above.
If no value is given from the attributes, the value is set to the value of
the language accessor on the parent event (either a
Root Event
or an
Element Event
), which may be the empty string.
subject
Has no initial value. Takes a value that is an
Identifier
event.
This accessor is used on elements that deal with one node in the RDF graph,
this generally being the subject of a statement.
6.1.3 End Element Event
Has no accessors. Marks the end of the containing element in
the sequence.
6.1.4 Attribute Event
Constructed from an
attribute information item
and takes the following accessors and values:
local-name
Set to the value of attribute information item property [local name].
namespace-name
Set to the value of attribute information item property [namespace name].
string-value
Set to the value of the attribute information item property [normalized value] as specified by
[XML]
(if an attribute whose normalized
value is a zero-length string, then the string-value is also
a zero-length string).
URI
If
namespace-name
is present,
set to a string value of the concatenation of the value of the
namespace-name
accessor
and the value of the
local-name
accessor.
Otherwise if
local-name
is
ID
about
resource
parseType
or
type
, set to a string value of the
concatenation of the
RDF namespace URI reference
and the value of the
local-name
accessor. Other non-namespaced
local-name
accessor values are forbidden.
The support for a limited set of non-namespaced names is
REQUIRED and intended to allow RDF/XML documents specified in
[RDF-MS]
to remain valid; new documents
SHOULD NOT use these unqualified attributes and applications MAY
choose to warn when the unqualified form is seen in a document.
The construction of
RDF URI references
from XML attributes can generate the same
RDF URI references
from different XML attributes. This can cause ambiguity in the
grammar when matching attribute events (such as when
rdf:about
and
about
XML attributes are
both present). Documents that have this are illegal.
URI-string-value
The value is the concatenation of the following in this order "<",
the escaped value of the
URI
accessor and ">".
The escaping of the
URI
accessor uses the N-Triples escapes for
URI references as described in 3.3 URI References.
6.1.5 Text Event
Constructed from a sequence of one or more consecutive
character information items
Has the single accessor:
string-value
Set to the value of the string made from concatenating the
character code
] property of each of the character information items.
6.1.6 URI Reference Event
An event for a
RDF URI references
which has the following accessors:
identifier
Takes a string value used as an
RDF URI reference
string-value
The value is the concatenation of "<", the escaped value of the
identifier
accessor and ">"
The escaping of the
identifier
accessor value
uses the
N-Triples
escapes for URI references as described in
3.3 URI References
These events are constructed by giving a value for the
identifier
accessor.
For further information on identifiers in the RDF graph, see
section 5.2
6.1.7 Blank Node Identifier Event
An event for a
blank node identifier
which has the following accessors:
identifier
Takes a string value.
string-value
The value is a function of the value of the
identifier
accessor.
The value begins with "_:" and the entire value MUST match the
N-Triples
nodeID
production.
The function MUST preserve distinct blank node identity as discussed in in section
5.2 Identifiers
These events are constructed by giving a value for the
identifier
accessor.
For further information on identifiers in the RDF graph, see
section 5.2
6.1.8 Plain Literal Event
An event for a
plain literal
which can have the following accessors:
literal-value
Takes a string value.
literal-language
Takes a string value used as a
language tag
in an RDF plain literal.
string-value
The value is calculated from the other accessors as follows.
If
literal-language
is the empty string
then the value is the concatenation of """ (1 double quote),
the escaped value of the
literal-value
accessor
and """ (1 double quote).
Otherwise the value is the concatenation of """ (1 double quote),
the escaped value of the
literal-value
accessor
""@" (1 double quote and a '@'),
and the value of the
literal-language
accessor.
The escaping of the
literal-value
accessor value uses the
N-Triples
escapes for strings as described in
3.2 Strings
for escaping certain characters such as ".
These events are constructed by giving values for the
literal-value
and
literal-language
accessors.
Interoperability Note (Informative):
Literals beginning with a Unicode combining character are
allowed however they may cause interoperability problems.
See
[CHARMOD]
for further information.
6.1.9 Typed Literal Event
An event for a
typed literal
which can have the following accessors:
literal-value
Takes a string value.
literal-datatype
Takes a string value used as an
RDF URI reference
string-value
The value is the concatenation of the following in this order
""" (1 double quote),
the escaped value of the
literal-value
accessor,
""" (1 double quote), "^^<",
the escaped value of the
literal-datatype
accessor
and ">".
The escaping of the
literal-value
accessor value
uses the
N-Triples
escapes for strings as described in
3.2 Strings
for escaping certain characters such as ".
The escaping of the
literal-datatype
accessor value
must use the
N-Triples
escapes for URI references as described in
3.3 URI References
These events are constructed by giving values for the
literal-value
and
literal-datatype
accessors.
Interoperability Note (Informative):
Literals beginning with a Unicode combining character are
allowed however they may cause interoperability problems.
See
[CHARMOD]
for further information.
Implementation Note (Informative):
In
XML Schema (part 1)
[XML-SCHEMA1]
white space normalization
occurs during validation according to the value of the whiteSpace
facet. The syntax mapping used in this document occurs after this,
so the whiteSpace facet formally has no further effect.
6.2 Information Set Mapping
To transform the Infoset into the sequence of events
in
document order
, each
information item is transformed as described above to generate a
tree of events with accessors and values. Each element event is
then replaced as described below to turn the tree of events
into a sequence in document order.
The original
element event
The value of the
children
accessor recursively transformed, a possibly empty ordered list of events.
An
end element event
6.3 Grammar Notation
The following notation is used to describe matching the sequence
of data model events as given in
Section 6
and the actions to perform for the matches.
The RDF/XML grammar is defined in terms of mapping from these matched
data model events to triples, using notation of the form:
number
event-type
event-content
action
...
N-Triples
where the
event-content
is an expression matching
event-types
(as defined in
Section 6.1
),
using notation given in the following sections.
The number is used for reference purposes.
The grammar
action
may include generating
new triples to the graph, written in
N-Triples
format.
The following sections describe the general notation used and that
for event matching and actions.
6.3.1 Grammar General Notation
Grammar General Notation.
Notation
Meaning
event
accessor
The value of an event accessor.
rdf:
A URI as defined in
section 5.1
"ABC"
A string of characters A, B, C in order.
6.3.2 Grammar Event Matching Notation
Grammar Event Matching Notation.
Notation
Meaning
A == B
Event accessor A matches expression B.
A != B
A is not equal to B.
A | B | ...
The A, B, ... terms are alternatives.
A - B
The terms in A excluding all the terms in B.
anyURI
Any URI.
anyString
Any string.
list(item1, item2, ...); list()
An ordered list of events. An empty list.
set(item1, item2, ...); set()
An unordered set of events. An empty set.
Zero or more of preceding term.
Zero or one of preceding term.
One or more of preceding term.
root(acc1 == value1,
acc2 == value2, ...)
Match a
Root Event
with accessors.
start-element(acc1 == value1,
acc2 == value2, ...)
children
end-element()
Match a sequence of
Element Event
with accessors,
a possibly empty list of events as element content and an
End Element Event
attribute(acc1 == value1,
acc2 == value2, ...)
Match an
Attribute Event
with accessors.
text()
Match a
Text Event
6.3.3 Grammar Action Notation
Grammar Action Notation.
Notation
Meaning
A := B
Assigns A the value B.
concat(A, B, ..)
A string created by concatenating the terms in order.
resolve(
A string created by interpreting string
as a relative URI reference to the
base-uri
accessor of
as defined in
Section 5.3 Resolving URIs
The resulting string represents an
RDF URI reference
generated-blank-node-id()
A string value for a new distinct generated
blank node identifier
as defined in
section 5.2 Identifiers
event
accessor
:=
value
Sets an event accessor to the given value.
uri(identifier := value)
Create a new
URI Reference Event
bnodeid(identifier := value)
Create a new
Blank Node Identifier Event
. See also section
5.2 Identifiers
literal(literal-value := string,
literal-language := language, ...)
Create a new
Plain Literal Event
typed-literal(literal-value := string, ...)
Create a new
Typed Literal Event
7 RDF/XML Grammar
7.1 Grammar summary
7.2.2
coreSyntaxTerms
rdf:RDF
rdf:ID
rdf:about
rdf:parseType
rdf:resource
rdf:nodeID
rdf:datatype
7.2.3
syntaxTerms
coreSyntaxTerms
rdf:Description
rdf:li
7.2.4
oldTerms
rdf:aboutEach
rdf:aboutEachPrefix
rdf:bagID
7.2.5
nodeElementURIs
anyURI
- (
coreSyntaxTerms
rdf:li
oldTerms
7.2.6
propertyElementURIs
anyURI
- (
coreSyntaxTerms
rdf:Description
oldTerms
7.2.7
propertyAttributeURIs
anyURI
- (
coreSyntaxTerms
rdf:Description
rdf:li
oldTerms
7.2.8
doc
root(
document-element
==
RDF
children
== list(
RDF
))
7.2.9
RDF
start-element(
URI
==
rdf:RDF
attributes
== set())
nodeElementList
end-element()
7.2.10
nodeElementList
ws
* (
nodeElement
ws
* )*
7.2.11
nodeElement
start-element(
URI
==
nodeElementURIs
attributes
== set((
idAttr
nodeIdAttr
aboutAttr
)?,
propertyAttr
*))
propertyEltList
end-element()
7.2.12
ws
text event
matching white space
defined by
[XML]
definition
White Space
Rule [3]
in section
Common Syntactic Constructs
7.2.13
propertyEltList
ws
* (
propertyElt
ws
* ) *
7.2.14
propertyElt
resourcePropertyElt
literalPropertyElt
parseTypeLiteralPropertyElt
parseTypeResourcePropertyElt
parseTypeCollectionPropertyElt
parseTypeOtherPropertyElt
emptyPropertyElt
7.2.15
resourcePropertyElt
start-element(
URI
==
propertyElementURIs
),
attributes
== set(
idAttr
?))
ws
nodeElement
ws
end-element()
7.2.16
literalPropertyElt
start-element(
URI
==
propertyElementURIs
),
attributes
== set(
idAttr
?,
datatypeAttr
?))
text()
end-element()
7.2.17
parseTypeLiteralPropertyElt
start-element(
URI
==
propertyElementURIs
),
attributes
== set(
idAttr
?,
parseLiteral
))
literal
end-element()
7.2.18
parseTypeResourcePropertyElt
start-element(
URI
==
propertyElementURIs
),
attributes
== set(
idAttr
?,
parseResource
))
propertyEltList
end-element()
7.2.19
parseTypeCollectionPropertyElt
start-element(
URI
==
propertyElementURIs
),
attributes
== set(
idAttr
?,
parseCollection
))
nodeElementList
end-element()
7.2.20
parseTypeOtherPropertyElt
start-element(
URI
==
propertyElementURIs
),
attributes
== set(
idAttr
?,
parseOther
))
propertyEltList
end-element()
7.2.21
emptyPropertyElt
start-element(
URI
==
propertyElementURIs
),
attributes
== set(
idAttr
?, (
resourceAttr
nodeIdAttr
)?,
propertyAttr
*))
end-element()
7.2.22
idAttr
attribute(
URI
==
rdf:ID
string-value
==
rdf-id
7.2.23
nodeIdAttr
attribute(
URI
==
rdf:nodeID
string-value
==
rdf-id
7.2.24
aboutAttr
attribute(
URI
==
rdf:about
string-value
==
URI-reference
7.2.25
propertyAttr
attribute(
URI
==
propertyAttributeURIs
string-value
==
anyString
7.2.26
resourceAttr
attribute(
URI
==
rdf:resource
string-value
==
URI-reference
7.2.27
datatypeAttr
attribute(
URI
==
rdf:datatype
string-value
==
URI-reference
7.2.28
parseLiteral
attribute(
URI
==
rdf:parseType
string-value
== "Literal")
7.2.29
parseResource
attribute(
URI
==
rdf:parseType
string-value
== "Resource")
7.2.30
parseCollection
attribute(
URI
==
rdf:parseType
string-value
== "Collection")
7.2.31
parseOther
attribute(
URI
==
rdf:parseType
string-value
==
anyString
- ("Resource" | "Literal" | "Collection") )
7.2.32
URI-reference
An
RDF URI reference
7.2.33
literal
Any XML element content that is allowed according to
[XML]
definition
Content of Elements
Rule [43]
content
in section
3.1 Start-Tags, End-Tags, and Empty-Element Tags
7.2.34
rdf-id
An attribute
string-value
matching any legal
[XML-NS]
token
NCName
7.2 Grammar Productions
7.2.1 Grammar start
If the RDF/XML is a standalone XML document
(identified by presentation as an
application/rdf+xml
RDF MIME type
object,
or by some other means) then the grammar may start with
production
doc
or
production
nodeElement
If the content is known to be RDF/XML by context, such as when
RDF/XML is embedded inside other XML content, then the grammar
can either start
at
Element Event
RDF
(only when an element is legal at that point in the XML)
or at production
nodeElementList
(only when element content is legal, since this is a list of elements).
For such embedded RDF/XML, the
base-uri
value on the outermost element must be initialized from the containing
XML since no
Root Event
will be available.
Note that if such embedding occurs, the grammar may be entered
several times but no state is expected to be preserved.
7.2.2 Production coreSyntaxTerms
rdf:RDF
rdf:ID
rdf:about
rdf:parseType
rdf:resource
rdf:nodeID
rdf:datatype
A subset of the syntax terms from the RDF vocabulary in
section 5.1
which are used in RDF/XML.
7.2.3 Production syntaxTerms
coreSyntaxTerms
rdf:Description
rdf:li
All the syntax terms from the RDF vocabulary in
section 5.1
which are used in RDF/XML.
7.2.4 Production oldTerms
rdf:aboutEach
rdf:aboutEachPrefix
rdf:bagID
These are the names from the
RDF vocabulary
that have been withdrawn from the language. See the resolutions of
Issue
rdfms-aboutEach-on-object
Issue
rdfms-abouteachprefix
and
Last Call Issue
timbl-01
for further information.
Error Test:
Indicated by
error001.rdf
and
error002.rdf
7.2.5 Production nodeElementURIs
anyURI
- (
coreSyntaxTerms
rdf:li
oldTerms
The
RDF URI references
that are allowed on node elements.
7.2.6 Production propertyElementURIs
anyURI
- (
coreSyntaxTerms
rdf:Description
oldTerms
The URIs that are allowed on property elements.
7.2.7 Production propertyAttributeURIs
anyURI
- (
coreSyntaxTerms
rdf:Description
rdf:li
oldTerms
The
RDF URI references
that are allowed on property attributes.
7.2.8 Production doc
root(
document-element
==
RDF
children
== list(
RDF
))
7.2.9 Production RDF
start-element(
URI
==
rdf:RDF
attributes
== set())
nodeElementList
end-element()
7.2.10 Production nodeElementList
ws
* (
nodeElement
ws
* )*
7.2.11 Production nodeElement
start-element(
URI
==
nodeElementURIs
attributes
== set((
idAttr
nodeIdAttr
aboutAttr
)?,
propertyAttr
*))
propertyEltList
end-element()
For node element
, the processing of some of the attributes
has to be done before other work such as dealing with children events
or other attributes. These can be processed in any order:
If there is an attribute
with
URI
==
rdf:ID
, then
subject
:= uri(
identifier
:= resolve(
, concat("#",
string-value
))).
If there is an attribute
with
URI
==
rdf:nodeID
, then
subject
:= bnodeid(
identifier
:=
string-value
).
If there is an attribute
with
URI
==
rdf:about
then
subject
:= uri(
identifier
:= resolve(
string-value
)).
If
subject
is empty,
then
subject
:= bnodeid(
identifier
:= generated-blank-node-id()).
The following can then be performed in any order:
If
URI
!=
rdf:Description
then the following statement is added to the graph:
subject
string-value
URI-string-value
If there is an attribute
in
propertyAttr
with
URI
==
rdf:type
then
:=uri(identifier:=resolve(
string-value
))
and the following tiple is added to the graph:
subject
string-value
string-value
For each attribute
matching
propertyAttr
(and not
rdf:type
),
the Unicode string
string-value
SHOULD be in Normal Form C
[NFC]
:= literal(
literal-value
:=
string-value
literal-language
:=
language
and the following statement is added to the graph:
subject
string-value
URI-string-value
string-value
Handle the
propertyEltList
children events
in document order.
7.2.12 Production ws
text event
matching white space
defined by
[XML]
definition
White Space
Rule [3]
in section
Common Syntactic Constructs
7.2.13 Production propertyEltList
ws
* (
propertyElt
ws
* ) *
7.2.14 Production propertyElt
resourcePropertyElt
literalPropertyElt
parseTypeLiteralPropertyElt
parseTypeResourcePropertyElt
parseTypeCollectionPropertyElt
parseTypeOtherPropertyElt
emptyPropertyElt
If element
has
URI
rdf:li
then apply the list expansion rules on element
.parent in
section 7.4
to give a new URI
and
URI
:=
The action of this production must be done before the
actions of any sub-matches (
resourcePropertyElt
...
emptyPropertyElt
).
Alternatively the result must be equivalent to as if it this action
was performed first, such as performing as the first
action of all of the sub-matches.
7.2.15 Production resourcePropertyElt
start-element(
URI
==
propertyElementURIs
),
attributes
== set(
idAttr
?))
ws
nodeElement
ws
end-element()
For element
, and the single contained nodeElement
, first
must be processed using production
nodeElement
Then the following statement is added to the graph:
.parent.
subject
string-value
URI-string-value
subject
string-value
If the
rdf:ID
attribute
is given, the above
statement is reified with
:= uri(
identifier
:= resolve(
, concat("#",
string-value
)))
using the reification rules in
section 7.3
and
subject
:=
7.2.16 Production literalPropertyElt
start-element(
URI
==
propertyElementURIs
),
attributes
== set(
idAttr
?,
datatypeAttr
?))
text()
end-element()
Note that the empty literal case is defined in production
emptyPropertyElt
For element
, and the text event
The Unicode string
string-value
SHOULD be in Normal Form C
[NFC]
If the
rdf:datatype
attribute
is given
then
:= typed-literal(
literal-value
:=
string-value
literal-datatype
:=
string-value
otherwise
:= literal(
literal-value
:=
string-value
literal-language
:=
language
and the following statement is added to the graph:
.parent.
subject
string-value
URI-string-value
string-value
If the
rdf:ID
attribute
is given, the above
statement is reified with
:= uri(
identifier
:= resolve(
, concat("#",
string-value
)))
using the reification rules in
section 7.3
and
subject
:=
7.2.17 Production parseTypeLiteralPropertyElt
start-element(
URI
==
propertyElementURIs
),
attributes
== set(
idAttr
?,
parseLiteral
))
literal
end-element()
For element
and the literal
that is the
rdf:parseType="Literal"
content.
is not transformed by the syntax data model mapping into events
(as noted in
6 Syntax Data Model
but remains an XML Infoset of XML Information items.
is transformed into the lexical form of an
XML literal
in the RDF graph
(a Unicode string)
by the following algorithm. This does not mandate any implementation
method — any other method that gives the same result may be used.
Use
to construct an XPath
[XPATH]
node-set
(a
document subset
Apply
Exclusive XML Canonicalization
XML-XC14N
])
with comments and with empty
InclusiveNamespaces PrefixList
to this node-set to give a sequence of octets
This sequence of octets
can be considered to be
a UTF-8 encoding of some Unicode string
(sequence
of Unicode characters)
The Unicode string
is used as the lexical form of
This Unicode string
SHOULD be in NFC Normal Form C
[NFC]
Then
:= typed-literal(
literal-value
:=
literal-datatype
:=
and the following statement is added to the graph:
.parent.
subject
string-value
URI-string-value
string-value
Test:
Empty literal case indicated by
test009.rdf
and
test009.nt
If the
rdf:ID
attribute
is given, the above
statement is reified with
:= uri(
identifier
:= resolve(
, concat("#",
string-value
)))
using the reification rules in
section 7.3
and
subject
:=
7.2.18 Production parseTypeResourcePropertyElt
start-element(
URI
==
propertyElementURIs
),
attributes
== set(
idAttr
?,
parseResource
))
propertyEltList
end-element()
For element
with possibly empty element content
:= bnodeid(
identifier
:= generated-blank-node-id()).
Add the following statement to the graph:
.parent.
subject
string-value
URI-string-value
string-value
Test:
Indicated by
test004.rdf
and
test004.nt
If the
rdf:ID
attribute
is given, the
statement above is reified with
:= uri(
identifier
:= resolve(
, concat("#",
string-value
)))
using the reification rules in
section 7.3
and
subject
:=
If the element content
is not empty, then use event
to create a new sequence of events as follows:
start-element(
URI
:=
rdf:Description
subject
:=
attributes
:= set())
end-element()
Then
process the resulting sequence using production
nodeElement
7.2.19 Production parseTypeCollectionPropertyElt
start-element(
URI
==
propertyElementURIs
),
attributes
== set(
idAttr
?,
parseCollection
))
nodeElementList
end-element()
For element event
with possibly empty
nodeElementList
. Set
:=list().
For each element event
in
:= bnodeid(
identifier
:= generated-blank-node-id()) and append
to
to give a sequence of events.
If
is not empty,
is the first event identifier in
and the following statement is added to the graph:
.parent.
subject
string-value
URI-string-value
string-value
otherwise the following statement is added to the graph:
.parent.
subject
string-value
URI-string-value
If the
rdf:ID
attribute
is given,
either of the the above statements is reified with
:= uri(
identifier
:= resolve(
, concat("#",
string-value
)))
using the reification rules in
section 7.3
If
is empty, no further work is performed.
For each event
in
and the
corresponding element event
in
, the following
statement is added to the graph:
string-value
string-value
For each consecutive and overlapping pair of events
) in
, the following statement is
added to the graph:
string-value
string-value
If
is not empty,
is the last event identifier
in
, the following statement is added to the graph:
string-value
7.2.20 Production parseTypeOtherPropertyElt
start-element(
URI
==
propertyElementURIs
),
attributes
== set(
idAttr
?,
parseOther
))
propertyEltList
end-element()
All
rdf:parseType
attribute values other than the strings
"Resource", "Literal" or "Collection" are treated as if the value was
"Literal". This production matches and acts as if production
parseTypeLiteralPropertyElt
was matched.
No extra triples are generated for other
rdf:parseType
values.
7.2.21 Production emptyPropertyElt
start-element(
URI
==
propertyElementURIs
),
attributes
== set(
idAttr
?, (
resourceAttr
nodeIdAttr
)?,
propertyAttr
*))
end-element()
If there are no attributes
or
only the
optional
rdf:ID
attribute
then
:= literal(
literal-value
:="",
literal-language
:=
language
and the following statement is added to the graph:
.parent.
subject
string-value
URI-string-value
string-value
and then if
is given, the above statement is reified with
uri(
identifier
:= resolve(
, concat("#",
string-value
)))
using the reification rules in
section 7.3
Test:
Indicated by
test002.rdf
and
test002.nt
Test:
Indicated by
test005.rdf
and
test005.nt
Otherwise
If
rdf:resource
attribute
is present, then
:= uri(
identifier
:= resolve(
string-value
))
If
rdf:nodeID
attribute
is present, then
:= bnodeid(
identifier
:=
string-value
If neither,
:= bnodeid(
identifier
:= generated-blank-node-id())
The following are done in any order:
For all
propertyAttr
attributes
(in any order)
If
URI
==
rdf:type
then
:=uri(identifier:=resolve(
string-value
))
and the following triple is added to the graph:
string-value
string-value
Otherwise Unicode string
string-value
SHOULD be in Normal Form C
[NFC]
:= literal(
literal-value
:=
string-value
literal-language
:=
language
and the following statement is added to the graph:
string-value
URI-string-value
string-value
Test:
Indicated by
test013.rdf
and
test013.nt
Test:
Indicated by
test014.rdf
and
test014.nt
Add the following statement to the graph:
.parent.
subject
string-value
URI-string-value
string-value
and then if
rdf:ID
attribute
is given, the above statement is
reified with
uri(
identifier
:= resolve(
, concat("#",
string-value
)))
using the reification rules in
section 7.3
7.2.22 Production idAttr
attribute(
URI
==
rdf:ID
string-value
==
rdf-id
Constraint:
constraint-id
applies to the values of
rdf:ID
attributes
7.2.23 Production nodeIdAttr
attribute(
URI
==
rdf:nodeID
string-value
==
rdf-id
7.2.24 Production aboutAttr
attribute(
URI
==
rdf:about
string-value
==
URI-reference
7.2.25 Production propertyAttr
attribute(
URI
==
propertyAttributeURIs
string-value
==
anyString
7.2.26 Production resourceAttr
attribute(
URI
==
rdf:resource
string-value
==
URI-reference
7.2.27 Production datatypeAttr
attribute(
URI
==
rdf:datatype
string-value
==
URI-reference
7.2.28 Production parseLiteral
attribute(
URI
==
rdf:parseType
string-value
== "Literal")
7.2.29 Production parseResource
attribute(
URI
==
rdf:parseType
string-value
== "Resource")
7.2.30 Production parseCollection
attribute(
URI
==
rdf:parseType
string-value
== "Collection")
7.2.31 Production parseOther
attribute(
URI
==
rdf:parseType
string-value
==
anyString
- ("Resource" | "Literal" | "Collection") )
7.2.32 Production URI-reference
An
RDF URI reference
7.2.33 Production literal
Any XML element content that is allowed according to
[XML]
definition
Content of Elements
Rule [43]
content
in section
3.1 Start-Tags, End-Tags, and Empty-Element Tags
The string-value for the resulting event is discussed in
section 7.2.17
7.2.34 Production rdf-id
An attribute
string-value
matching any legal
[XML-NS]
token
NCName
7.3 Reification Rules
For the given URI reference event
and
the statement with terms
and
corresponding to the N-Triples:
add the following statements to the graph:
string-value
string-value
string-value
string-value
7.4 List Expansion Rules
For the given element
, create a new
RDF URI reference
:=
concat("http://www.w3.org/1999/02/22-rdf-syntax-ns#_",
li-counter
),
increment the
li-counter
property by 1 and return
8 Serializing an RDF Graph to RDF/XML
There are some
RDF Graphs
as defined in
RDF Concepts and Abstract Syntax
that cannot be serialized in RDF/XML. These are those that:
Use property names that cannot be turned into XML namespace-qualified names.
An XML namespace-qualified name
QName
has restrictions on the legal characters such that not all property URIs
can be expressed as these names.
It is recommended that implementors of RDF serializers, in order to
break a URI into a namespace name and a local name, split it after
the last XML non-
NCName
character, ensuring that the first character of the name is a
Letter
or '_'.
If the URI ends in a
non-
NCName
character then throw a "this graph cannot be serialized in RDF/XML"
exception or error.
Use inappropriate reserved names as properties
For example, a property with the same URI as any of the
syntaxTerms
production.
Implementation Note (Informative):
When an RDF graph is serialized to RDF/XML and has an XML Schema
Datatype (XSD), it SHOULD be written in a form that does not require
whitespace processing. XSD support is NOT required by RDF or RDF/XML
so this is optional.
9 Using RDF/XML with HTML and XHTML
If RDF/XML is embedded inside HTML or XHTML this can
add many new elements and attributes, many of which will not be
in the appropriate DTD. This embedding causes validation against the DTD to fail.
The obvious solution of changing or extending the DTD is not practical
for most uses. This problem has been analyzed extensively by Sean B. Palmer in
RDF in HTML: Approaches
[RDF-IN-XHTML]
and it concludes that there is no single embedding
method that satisfies all applications and remains simple.
The recommended approach is to not embed RDF/XML in HTML/XHTML but
rather to use
element in the
element of the HTML/HTML to point at a separate RDF/XML document.
This approach has been used for several years by the
Dublin Core Metadata Initiative (DCMI)
on its Web site.
To use this technique, the
element
href
should point at the URI of the RDF/XML content
and the
type
attribute should be used with the value of
"application/rdf+xml"
, the proposed MIME type for
RDF/XML, see
Section 4
The value of the
rel
attribute may also be set to
indicate the relationship; this is an application dependent value.
The DCMI has used and recommended
rel="meta"
when linking
in
RFC 2731 — Encoding Dublin Core Metadata in HTML
[RFC-2731]
however
rel="alternate"
may also be appropriate.
See
HTML 4.01 link types
XHTML Modularization — LinkTypes
and
XHTML 2.0 — LinkTypes
for further information on the values that may be appropriate
for the different versions of HTML.
Example 21
shows using this method with
the
link
tag inside an XHTML document to link to an
external RDF/XML document.
Example 21: Using
link
in XHTML with an external RDF/XML document
example21.html
linking to
example21.rdfMy document
10 Using RDF/XML with SVG (Informative)
There is a standardized approach for associating RDF compatible
metadata with SVG — the metadata element which was explicitly
designed for this purpose as defined in
Section 21 Metadata
of the
Scalable Vector Graphics (SVG) 1.0 Specification
[SVG]
and
Section 21 Metadata
of the
Scalable Vector Graphics (SVG) 1.1 Specification
[SVG11]
This document contains two example graphs in SVG with such
embedded RDF/XML inside the metadata element:
figure 1
and
figure 2
11 Acknowledgments (Informative)
The following people provided valuable contributions to the document:
Dan Brickley, W3C/ILRT
Jeremy Carroll, HP Labs, Bristol
Graham Klyne, Nine by Nine
Bijan Parsia, MIND Lab at University of Maryland at College Park
This document is a product of extended deliberations by the RDF
Core working group, whose members have included: Art Barstow (W3C)
Dave Beckett (ILRT), Dan Brickley (W3C/ILRT), Dan Connolly (W3C),
Jeremy Carroll (Hewlett Packard), Ron Daniel (Interwoven Inc), Bill
dehOra (InterX), Jos De Roo (AGFA), Jan Grant (ILRT), Graham Klyne
(Clearswift and Nine by Nine), Frank Manola (MITRE Corporation),
Brian McBride (Hewlett Packard), Eric Miller (W3C), Stephen
Petschulat (IBM), Patrick Stickler (Nokia), Aaron Swartz (HWG), Mike
Dean (BBN Technologies / Verizon), R. V. Guha (Alpiri Inc), Pat Hayes
(IHMC), Sergey Melnik (Stanford University), Martyn Horner (Profium
Ltd).
This specification also draws upon an earlier RDF Model and Syntax
document edited by Ora Lassilla and Ralph Swick, and RDF Schema
edited by Dan Brickley and R. V. Guha. RDF and RDF Schema Working
group members who contributed to this earlier work are:
Nick Arnett (Verity), Tim Berners-Lee (W3C), Tim Bray (Textuality),
Dan Brickley (ILRT / University of Bristol), Walter Chang (Adobe),
Sailesh Chutani (Oracle), Dan Connolly (W3C), Ron Daniel
(DATAFUSION), Charles Frankston (Microsoft), Patrick Gannon
(CommerceNet), RV Guha (Epinions, previously of Netscape
Communications), Tom Hill (Apple Computer), Arthur van Hoff
(Marimba), Renato Iannella (DSTC), Sandeep Jain (Oracle), Kevin
Jones, (InterMind), Emiko Kezuka (Digital Vision Laboratories), Joe
Lapp (webMethods Inc.), Ora Lassila (Nokia Research Center), Andrew
Layman (Microsoft), Ralph LeVan (OCLC), John McCarthy (Lawrence
Berkeley National Laboratory), Chris McConnell (Microsoft), Murray
Maloney (Grif), Michael Mealling (Network Solutions), Norbert Mikula
(DataChannel), Eric Miller (OCLC), Jim Miller (W3C, emeritus), Frank
Olken (Lawrence Berkeley National Laboratory), Jean Paoli
(Microsoft), Sri Raghavan (Digital/Compaq), Lisa Rein (webMethods
Inc.), Paul Resnick (University of Michigan), Bill Roberts
(KnowledgeCite), Tsuyoshi Sakata (Digital Vision Laboratories), Bob
Schloss (IBM), Leon Shklar (Pencom Web Works), David Singer (IBM),
Wei (William) Song (SISU), Neel Sundaresan (IBM), Ralph Swick (W3C),
Naohiko Uramoto (IBM), Charles Wicksteed (Reuters Ltd.), Misha Wolf
(Reuters Ltd.), Lauren Wood (SoftQuad).
12 References
Normative References
[RDF-MS]
Resource Description Framework (RDF) Model and Syntax Specification
, O. Lassila and R. Swick, Editors. World Wide Web Consortium. 22 February 1999. This version is http://www.w3.org/TR/1999/REC-rdf-syntax-19990222. The
latest version of RDF M&S
is available at http://www.w3.org/TR/REC-rdf-syntax.
[XML]
Extensible Markup Language (XML) 1.0, Second Edition
, T. Bray, J. Paoli, C.M. Sperberg-McQueen and E. Maler, Editors. World Wide Web Consortium. 6 October 2000. This version is http://www.w3.org/TR/2000/REC-xml-20001006.
latest version of XML
is available at http://www.w3.org/TR/REC-xml.
[XML-NS]
Namespaces in XML
, T. Bray, D. Hollander and A. Layman, Editors. World Wide Web Consortium. 14 January 1999. This version is http://www.w3.org/TR/1999/REC-xml-names-19990114. The
latest version of Namespaces in XML
is available at http://www.w3.org/TR/REC-xml-names.
[INFOSET]
XML Information Set
, J. Cowan and R. Tobin, Editors. World Wide Web Consortium. 24 October 2001. This version is http://www.w3.org/TR/2001/REC-xml-infoset-20011024. The
latest version of XML Information set
is available at http://www.w3.org/TR/xml-infoset.
[URIS]
RFC 2396 — Uniform Resource Identifiers (URI): Generic Syntax
, T. Berners-Lee, R. Fielding and L. Masinter, IETF, August 1998. This document is http://www.isi.edu/in-notes/rfc2396.txt.
[RDF-CONCEPTS]
Resource
Description Framework (RDF): Concepts and Abstract
Syntax
, Klyne G., Carroll J. (Editors), W3C Recommendation, 10 February 2004.
This version
is http://www.w3.org/TR/2004/REC-rdf-primer-20040210/. The
latest version
is http://www.w3.org/TR/rdf-concepts/.
[RDF-TESTS]
RDF
Test Cases
, Grant J., Beckett D. (Editors), W3C
Recommendation, 10 February 2004.
This version
is http://www.w3.org/TR/2004/REC-rdf-testcases-20040210/. The
latest
version
is http://www.w3.org/TR/rdf-testcases/.
[KEYWORDS]
RFC 2119 — Key words for use in RFCs to Indicate Requirement Levels
, S. Bradner, IETF. March 1997. This document is http://www.ietf.org/rfc/rfc2119.txt.
[RFC-3023]
RFC 3023 — XML Media Types
, M. Murata, S. St.Laurent, D.Kohn, IETF. January 2001. This document is http://www.ietf.org/rfc/rfc3023.txt.
[IANA-MEDIA-TYPES]
MIME Media Types
, The Internet Assigned Numbers Authority (IANA). This document is http://www.iana.org/assignments/media-types/ . The
registration for
application/rdf+xml
is archived at http://www.w3.org/2001/sw/RDFCore/mediatype-registration .
[XML-BASE]
XML Base
, J. Marsh, Editor, W3C Recommendation. World Wide Web Consortium, 27 June 2001. This version of XML Base is http://www.w3.org/TR/2001/REC-xmlbase-20010627. The
latest version of XML Base
is at http://www.w3.org/TR/xmlbase.
[XML-XC14N]
Exclusive XML Canonicalization Version 1.0
, J. Boyer, D.E. Eastlake 3rd, J. Reagle, Authors/Editors. W3C Recommendation. World Wide Web Consortium, 18 July 2002. This version of Exclusive XML Canonicalization is http://www.w3.org/TR/2002/REC-xml-exc-c14n-20020718. The
latest version of Canonical XML
is at http://www.w3.org/TR/xml-exc-c14n.
[UNICODE]
The Unicode Standard, Version 3
, The Unicode
Consortium, Addison-Wesley, 2000. ISBN 0-201-61633-5, as updated
from time to time by the publication of new versions. (See
for the latest version and additional information on versions of
the standard and of the Unicode Character Database).
[NFC]
Unicode
Normalization Forms,
Unicode Standard Annex #15, Mark
Davis, Martin Dürst. (See
for the latest version).
Informational References
[CHARMOD]
Character Model for the World Wide Web 1.0
, M. Dürst, F. Yergeau, R. Ishida, M. Wolf, A. Freytag, T Texin, Editors, World Wide Web Consortium Working Draft, work in progress, 20 February 2002. This version of the Character Model is http://www.w3.org/TR/2002/WD-charmod-20020220. The
latest version of the Character Model
is at http://www.w3.org/TR/charmod.
[RDF-SEMANTICS]
RDF
Semantics
, Hayes P. (Editor), W3C Recommendation,
10 February 2004.
This
version
is
latest version
is http://www.w3.org/TR/rdf-mt/.
[RDF-PRIMER]
RDF
Primer
, F. Manola, E. Miller, Editors, W3C Recommendation, 10 February 2004.
This
version
is
latest version
is at
[RDF-VOCABULARY]
RDF
Vocabulary Description Language 1.0: RDF Schema
, Brickley
D., Guha R.V. (Editors), W3C Recommendation, 10 February 2004.
This
version
is
latest version
is
[STRIPEDRDF]
RDF: Understanding the Striped RDF/XML Syntax
, D. Brickley, W3C, 2001. This
document is http://www.w3.org/2001/10/stripes/.
[SVG]
Scalable Vector Graphics (SVG) 1.0 Specification
, J. Ferraiolo (editor), 4 September 2001, W3C Recommendation. This version of SVG is http://www.w3.org/TR/2001/REC-SVG-20010904. The
latest version of SVG
is at http://www.w3.org/TR/SVG.
[SVG11]
Scalable Vector Graphics (SVG) 1.1 Specification
, J. Ferraiolo, J. FUJISAWA, D. Jackson (editors), 14 January 2003, W3C Recommendation. This version of SVG is http://www.w3.org/TR/2003/REC-SVG11-20030114/. The
latest version of SVG
is at http://www.w3.org/TR/SVG11.
[XPATH]
XML Path Language (XPath) Version 1.0
, J. Clark and S. DeRose, Editors. World Wide Web Consortium, 16 November 1999. This version of XPath is http://www.w3.org/TR/1999/REC-xpath-19991116. The
latest version of XPath
is at http://www.w3.org/TR/xpath.
[SAX2]
SAX Simple API for XML, version 2
, D. Megginson, SourceForge, 5 May 2000. This document is http://sax.sourceforge.net/.
[UNPARSING]
Unparsing RDF/XML
, J. J. Carroll, HP Labs Technical Report, HPL-2001-294, 2001.
This document is available at http://www.hpl.hp.com/techreports/2001/HPL-2001-294.html.
[RELAXNG]
RELAX NG Specification
, James Clark and MURATA Makoto, Editors, OASIS Committee Specification, 3 December 2001. This version of RELAX NG is http://www.oasis-open.org/committees/relax-ng/spec-20011203.html. The
latest version of the RELAX NG Specification
is at http://www.oasis-open.org/committees/relax-ng/spec.html.
[RELAXNG-COMPACT]
RELAX NG Compact Syntax
, James Clark, Editor. OASIS Committee Specification, 21 November 2002. This document is http://www.oasis-open.org/committees/relax-ng/compact-20021121.html.
[RDF-IN-XHTML]
RDF in HTML: Approaches
, Sean B. Palmer, 2002
[RFC-2731]
RFC 2731 — Encoding Dublin Core Metadata in HTML
, John Kunze, DCMI, December 1999.
[XML-SCHEMA1]
XML Schema Part 1: Structures
, H.S. Thompson, D. Beech, M. Maloney, N. Mendelsohn, Editors, World Wide Web Consortium Recommendation, 2 May 2001. This version of XML Schema Part 1: Structures is http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/. The
latest version of XML Schema Part 1: Structures
is at http://www.w3.org/TR/xmlschema-1.
[XML-SCHEMA2]
XML Schema Part 2: Datatypes
, P.V. Biron, A. Malhotra, Editors, World Wide Web Consortium Recommendation, 2 May 2001. This version of XML Schema Part 2: Datatypes is http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/. The
latest version of XML Schema Part 2: Datatypes
is at http://www.w3.org/TR/xmlschema-2.
A Syntax Schemas (Informative)
This appendix contains XML schemas for validating RDF/XML forms.
These are example schemas for information only and are not part of
this specification.
A.1
RELAX NG Compact Schema (Informative)
This is an example schema in RELAX NG Compact (for ease of reading)
for RDF/XML. Applications can also use the
RELAX NG XML version
These formats are described in
RELAX NG
[RELAXNG]
and
RELAX NG
Compact
[RELAXNG-COMPACT]
).
Note:
The RNGC schema has been updated to attempt to match the grammar but
this has not been checked or used to validate RDF/XML.
RELAX NG Compact Schema for RDF/XML
# RELAX NG Compact Schema for RDF/XML Syntax
# This schema is for information only and NON-NORMATIVE
# It is based on one originally written by James Clark in
# http://lists.w3.org/Archives/Public/www-rdf-comments/2001JulSep/0248.html
# and updated with later changes.
namespace local = ""
namespace rdf = "http://www.w3.org/1999/02/22-rdf-syntax-ns#"
datatypes xsd = "http://www.w3.org/2001/XMLSchema-datatypes"
start = doc
# I cannot seem to do this in RNGC so they are expanded in-line
# coreSyntaxTerms = rdf:RDF | rdf:ID | rdf:about | rdf:parseType | rdf:resource | rdf:nodeID | rdf:datatype
# syntaxTerms = coreSyntaxTerms | rdf:Description | rdf:li
# oldTerms = rdf:aboutEach | rdf:aboutEachPrefix | rdf:bagID
# nodeElementURIs = * - ( coreSyntaxTerms | rdf:li | oldTerms )
# propertyElementURIs = * - ( coreSyntaxTerms | rdf:Description | oldTerms )
# propertyAttributeURIs = * - ( coreSyntaxTerms | rdf:Description | rdf:li | oldTerms )
# Also needed to allow rdf:li on all property element productions
# since we can't capture the rdf:li rewriting to rdf_
# Need to add these explicitly
xmllang = attribute xml:lang { text }
xmlbase = attribute xml:base { text }
# and to forbid every other xml:* attribute, element
doc =
RDF | nodeElement
RDF =
element rdf:RDF {
xmllang?, xmlbase?, nodeElementList
nodeElementList =
nodeElement*
# Should be something like:
# ws* , ( nodeElement , ws* )*
# but RELAXNG does this by default, ignoring whitespace separating tags.
nodeElement =
element * - ( local:* | rdf:RDF | rdf:ID | rdf:about | rdf:parseType |
rdf:resource | rdf:nodeID | rdf:datatype | rdf:li |
rdf:aboutEach | rdf:aboutEachPrefix | rdf:bagID ) {
(idAttr | nodeIdAttr | aboutAttr )?, xmllang?, xmlbase?, propertyAttr*, propertyEltList
# It is not possible to say "and not things
# beginning with _ in the rdf: namespace" in RELAX NG.
ws =
" "
# Not used in this RELAX NG schema; but should be any legal XML
# whitespace defined by http://www.w3.org/TR/2000/REC-xml-20001006#NT-S
propertyEltList =
propertyElt*
# Should be something like:
# ws* , ( propertyElt , ws* )*
# but RELAXNG does this by default, ignoring whitespace separating tags.
propertyElt =
resourcePropertyElt |
literalPropertyElt |
parseTypeLiteralPropertyElt |
parseTypeResourcePropertyElt |
parseTypeCollectionPropertyElt |
parseTypeOtherPropertyElt |
emptyPropertyElt
resourcePropertyElt =
element * - ( local:* | rdf:RDF | rdf:ID | rdf:about | rdf:parseType |
rdf:resource | rdf:nodeID | rdf:datatype |
rdf:Description | rdf:aboutEach | rdf:aboutEachPrefix | rdf:bagID |
xml:* ) {
idAttr?, xmllang?, xmlbase?, nodeElement
literalPropertyElt =
element * - ( local:* | rdf:RDF | rdf:ID | rdf:about | rdf:parseType |
rdf:resource | rdf:nodeID | rdf:datatype |
rdf:Description | rdf:aboutEach | rdf:aboutEachPrefix | rdf:bagID |
xml:* ) {
(idAttr | datatypeAttr )?, xmllang?, xmlbase?, text
parseTypeLiteralPropertyElt =
element * - ( local:* | rdf:RDF | rdf:ID | rdf:about | rdf:parseType |
rdf:resource | rdf:nodeID | rdf:datatype |
rdf:Description | rdf:aboutEach | rdf:aboutEachPrefix | rdf:bagID |
xml:* ) {
idAttr?, parseLiteral, xmllang?, xmlbase?, literal
parseTypeResourcePropertyElt =
element * - ( local:* | rdf:RDF | rdf:ID | rdf:about | rdf:parseType |
rdf:resource | rdf:nodeID | rdf:datatype |
rdf:Description | rdf:aboutEach | rdf:aboutEachPrefix | rdf:bagID |
xml:* ) {
idAttr?, parseResource, xmllang?, xmlbase?, propertyEltList
parseTypeCollectionPropertyElt =
element * - ( local:* | rdf:RDF | rdf:ID | rdf:about | rdf:parseType |
rdf:resource | rdf:nodeID | rdf:datatype |
rdf:Description | rdf:aboutEach | rdf:aboutEachPrefix | rdf:bagID |
xml:* ) {
idAttr?, xmllang?, xmlbase?, parseCollection, nodeElementList
parseTypeOtherPropertyElt =
element * - ( local:* | rdf:RDF | rdf:ID | rdf:about | rdf:parseType |
rdf:resource | rdf:nodeID | rdf:datatype |
rdf:Description | rdf:aboutEach | rdf:aboutEachPrefix | rdf:bagID |
xml:* ) {
idAttr?, xmllang?, xmlbase?, parseOther, any
emptyPropertyElt =
element * - ( local:* | rdf:RDF | rdf:ID | rdf:about | rdf:parseType |
rdf:resource | rdf:nodeID | rdf:datatype |
rdf:Description | rdf:aboutEach | rdf:aboutEachPrefix | rdf:bagID |
xml:* ) {
idAttr?, (resourceAttr | nodeIdAttr)?, xmllang?, xmlbase?, propertyAttr*
idAttr =
attribute rdf:ID {
IDsymbol
nodeIdAttr =
attribute rdf:nodeID {
IDsymbol
aboutAttr =
attribute rdf:about {
URI-reference
propertyAttr =
attribute * - ( local:* | rdf:RDF | rdf:ID | rdf:about | rdf:parseType |
rdf:resource | rdf:nodeID | rdf:datatype | rdf:li |
rdf:Description | rdf:aboutEach |
rdf:aboutEachPrefix | rdf:bagID |
xml:* ) {
string
resourceAttr =
attribute rdf:resource {
URI-reference
datatypeAttr =
attribute rdf:datatype {
URI-reference
parseLiteral =
attribute rdf:parseType {
"Literal"
parseResource =
attribute rdf:parseType {
"Resource"
parseCollection =
attribute rdf:parseType {
"Collection"
parseOther =
attribute rdf:parseType {
text
URI-reference =
string
literal =
any
IDsymbol =
xsd:NMTOKEN
any =
mixed { element * { attribute * { text }*, any }* }
B Revisions since Draft 10 October 2003 (Informative)
Changes since
10 October 2003
second last call working draft
These are are divided into non-editorial and editorial. The
non-editorial changes also list consquential editorial changes.
Editorial changes are those which do not result in any change in the
meaning of an RDF document or the behaviour of an RDF
application.
Appendix B.1: Non-Editorial Revisions
None
Appendix B.2: Editorial Revisions
German Translation
Fix the German in
Example 8
in section
2.7
after the
comment by Benjamin Nowack
No property attributes on rdf:parseType="Resource"
2.5
Update to reflect the syntax definition that property attributes cannot
be used with
rdf:parseType="Resource"
as pointed out by
comment by Sabadello 2003-10-30
URI Encoding
6.1.6
6.1.8
6.1.9
after
proposal by Jeremy Carroll
6.1.2
6.1.4
Added element/attribute URI-string-value accessors
7.2.11
7.2.21
Added use of new uri event for the
rdf:type
cases
7.2.11
(
7.2.15
(
7.2.16
(
7.2.17
(
7.2.18
(
7.2.19
(
7.2.21
(
changed from X.URI to X.URI-string-value (anywhere "<"..">" appeared
in the grammar action without a hardcoded URI reference)
7.2.32
Replace action wording with "An RDF URI reference"
All changed as outlined in
proposal 2003-10-06
after
comment by Patel-Schneider 2003-10-29
Appendix B.3: Issues requiring no document revisions
None