- From: Michael A Squillace <masquill@us.ibm.com>
- Date: Thu, 18 Jun 2009 09:22:48 -0500
- To: public-wai-ert@w3.org
- Message-ID: <OFF3475524.39585914-ON852575D9.004ED33B-862575D9.004F00E8@us.ibm.com>
Group:
It would be personally easier for me both in terms of reading the document
and of uploading it to CVS if we attached html/xhtml documents rather than
inline in the notes. Johannes - do you mind doing this for this and the
Content doc?
Thanks,
--> Mike Squillace
IBM Human Ability and Accessibility Center
W:512.286.8694
M:512.970.0066
External: http://www.ibm.com/able
Internal: http://w3.ibm.com/able
Johannes Koch
<johannes.koch@fi
t.fraunhofer.de> To
Sent by: ERT WG <public-wai-ert@w3.org>
public-wai-ert-re cc
quest@w3.org
Subject
[HTTP-in-RDF] new editor's fraft
06/18/2009 09:06
AM
Hi group,
please find attached a new editor's draft of HTTP-in-RDF.
BTW, I found out that there's an RDF schema at
<http://www.w3.org/2006/http.rdfs> and at
<http://www.w3.org/2008/http.rdfs>. The namespace we use is
"http://www.w3.org/2006/http#".
--
Johannes Koch
Fraunhofer Institute for Applied Information Technology FIT
Web Compliance Center
Schloss Birlinghoven, D-53757 Sankt Augustin, Germany
Phone: +49-2241-142628 Fax: +49-2241-142065
[attachment "http.rdf" deleted by Michael A Squillace/Austin/IBM] W3C
HTTP Vocabulary in RDF
Editor's Working Draft 18 June 2009
This version:
http://www.w3.org/WAI/ER/HTTP/WD-HTTP-in-RDF-20090618
Latest published version:
http://www.w3.org/TR/HTTP-in-RDF/
Latest internal version:
http://www.w3.org/WAI/ER/HTTP-in-RDF/
Previous published version:
http://www.w3.org/TR/2008/WD-HTTP-in-RDF-20080908/
Previous internal version:
http://www.w3.org/WAI/ER/HTTP/WD-HTTP-in-RDF-20090514
Editors:
Johannes Koch, Fraunhofer-Gesellschaft (Fraunhofer Institute for
Applied Information Technology FIT)
Carlos A Velasco, Fraunhofer-Gesellschaft (Fraunhofer Institute for
Applied Information Technology FIT)
The terms defined by this document are also provided in RDF Schema format.
Copyright © 2008 W3C® (MIT, ERCIM, Keio), All Rights Reserved. W3C
liability, trademark and document use rules apply.
Abstract
The identification of resources on the Web by a Uniform Resource Identifier
(URI) alone may not be sufficient, as other factors such as HTTP content
negotiation might come into play. This issue is particularly significant
for quality assurance testing, conformance claims, and reporting languages
like the W3C Evaluation And Report Language (EARL). This document provides
a representation of the HTTP vocabulary in the Resource Description
Framework (RDF), to allow quality assurance tools to record the HTTP
headers that have been exchanged between a client and a server. The RDF
terms defined by this document represent the core HTTP specification
defined by RFC 2616, as well as additional HTTP headers registered by the
Internet Assigned Numbers Authority (IANA). These terms can also be used to
record HTTPS exchanges.
Status of this document
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 http://www.w3.org/TR/.
This Working Draft of the HTTP Vocabulary in RDF document was published on
8 September 2008 by the Evaluation and Repair Tools Working Group (ERT WG).
It is an update of the previous HTTP Vocabulary in RDF Working Draft of 23
March 2007, and addresses the comments received since (see history of
document changes). This document is part of the W3C Evaluation And Report
Language (EARL). It is expected to be the last working draft before
publication as a W3C Working Group Note.
[Editor's note: change text appropriately]
The RDF terms defined by this document can be used to extend the Evaluation
And Report Language (EARL) 1.0 Schema, but can also be used separately to
record an HTTP exchange between a client and a server for any purpose. The
Working Group encourages feedback about the approach, as well as about the
completeness and maturity of this document by developers and researchers
who have interest in a representation of the HTTP vocabulary in RDF format.
Feedback from the W3C Quality Assurance Interest Group, the W3C Semantic
Web Interest Group, and the Protocol for Web Description Resources Working
Group is particularly welcome. Please send comments on this document by @@@
CHANGE @@@29 September 2008 to the public mailing list of the working group
public-wai-ert@w3.org. The archives of the working group mailing list are
publicly available.
[Editor's note: change date for comments]
Publication as a Working Draft does not imply endorsement by the W3C
Membership. This is a draft document and may be updated, replaced or
obsoleted by other documents at any time. It is inappropriate to cite this
document as other than work in progress.
This document was produced by a group operating under the 5 February 2004
W3C Patent Policy. The group does not expect this document to become a W3C
Recommendation. W3C maintains a public list of any patent disclosures made
in connection with the deliverables of the group; that page also includes
instructions for disclosing a patent. An individual who has actual
knowledge of a patent which the individual believes contains Essential
Claim(s) must disclose the information in accordance with section 6 of the
W3C Patent Policy.
Table of Contents
1. Introduction
1.1 Namespaces
1.2 Use Cases
1.3 Limitations
2. Classes
2.1 Connection Class
2.2 Message Class
2.2.1 Request Class
2.2.2 Response Class
2.3 MessageHeader Class
2.4 HeaderElement Class
2.5 Parameter Class
2.6 Method Class
2.7 StatusCode Class
2.8 HeaderName Class
3. Properties
3.1 body Property
3.2 connectionAuthority Property
3.3 elementName Property
3.4 elementValue Property
3.5 fieldName Property
3.6 fieldValue Property
3.7 headers Property
3.8 headerElements Property
3.9 hdrName Property
3.10 httpVersion Property
3.11 mthd Property
3.12 methodName Property
3.13 params Property
3.14 paramName Property
3.15 paramValue Property
3.16 reasonPhrase Property
3.17 requests Property
3.18 requestURI Property
3.18.1 absoluteURI Property
3.18.2 abs_path Property
3.18.3 authority Property
3.19 resp Property
3.20 sc Property
3.21 statusCodeNumber Property
4. Conformance
4.1 Conforming HTTP-in-RDF graphs
4.2 Conforming Producers
4.3 Conforming Consumers
Appendices
A. A practical Example
B. Terms
C. References
D. Document Changes
1 Introduction
This document defines a representation of the Hypertext Transfer Protocol
(HTTP) using the Resource Description Framework (RDF). It defines a
collection of RDF classes and properties that represent the HTTP vocabulary
as defined by the HTTP specification. These RDF terms can be used to record
HTTP or secure HTTP request and response messages in RDF format, such as by
automated Web accessibility evaluation tools that want to describe Web
resources, including the various headers exchanged between the client and
server during content negotiation. More usage examples for these terms are
described in section 1.2 Use Cases.
This document is not intended to be a clarification or extension of the
different concepts of the HTTP specification. The HTTP specification is
defined by a series of Request for Comments (RFC) publications and other
documentation, including RFC 2616 and RFC 4229. These are listed in
Appendix C: References.
Additionally this document assumes the following background knowledge:
Basic knowledge of the Extensible Markup Language (XML) [XML] and its
associated technologies.
Basic knowledge about the Semantic Web and RDF. For references,
consult [RDF], [RDF-PRIMER] and [RDFS].
By default, the vocabulary introduced by this document uses names starting
with upper-case letters for classes and names starting with lower-case
letters for properties. The keywords must, required, recommended, should,
may, and optional are used in accordance with [RFC2119].
1.1 Namespaces
The RDF representation of the HTTP vocabulary defined by this document uses
the namespace http://www.w3.org/2006/http#. The prefix http is used
throughout this document to denote this namespace. Table 1 presents the
namespaces used by this document. The prefix notation presents the typical
conventions used in the Web and in this document to denote a given
namespace, and can be freely modified. Table 2 presents additional RDF data
used by this document.
|-----------------+
|Table 1: |
|namespaces used |
|by this document.|
| |
|-----------------+------------------------------------------------------
|Namespace prefix | Namespace URI | Description |
|-----------------+----------------------------+-------------------------|
|http |http://www.w3.org/2006/http#|Namespace for the core |
| | |terms of HTTP vocabulary |
| | |in RDF. |
|-----------------+----------------------------+-------------------------|
|cnt |http://www.w3.org/2008/conte|Namespace for |
| |nt# |Representing Content in |
| | |RDF [Content-in-RDF]. |
|-----------------+----------------------------+-------------------------|
|dct |http://purl.org/dc/terms/ |Namespace for the Dublin |
| | |Core Metadata Terms. |
|-----------------+----------------------------+-------------------------|
|rdf |http://www.w3.org/1999/02/22|Namespace for RDF [RDF]. |
| |-rdf-syntax-ns# | |
|-----------------+----------------------------+-------------------------|
|---------------------------+
|Table 2: RDF data used by |
|this document. |
|---------------------------+---------------------------------------------
| URI | Description |
|---------------------------+---------------------------------------------|
|http://www.w3.org/2008/http|HTTP headers as registered by the IANA (see [|
|-headers |RFC4229], [Permanent Headers], and [ |
| |Provisional Headers]). |
|---------------------------+---------------------------------------------|
|http://www.w3.org/2008/http|HTTP methods for requests. |
|-methods | |
|---------------------------+---------------------------------------------|
|http://www.w3.org/2008/http|HTTP status codes for responses. |
|-statusCodes | |
|---------------------------+---------------------------------------------|
1.2 Use Cases
The following (non-exhaustive) list of use cases aims to highlight some of
the different usages of the terms provided by this document:
Reporting Test Results
When Web resources are tested, for example for accessibility or other
quality assurance testing, it may be significant to record the exact
headers exchanged between the server and the client during the
testing. Without a record of the exchanged headers, it may not be
possible to re-identify the exact resource (or representation of the
resource) that has been tested. The terms provided by this document
allow quality assurance tools to record the HTTP exchange between a
client and a server, for example to record the POST parameters or the
headers used during content negotiation. The terms provided by this
document can be used in combination with the W3C Evaluation And
Report Language (EARL) [EARL].
Precising Conformance Claims
Conformance claims that are made about a Web resource or group of Web
resource, are sometimes only applicable under certain constraints.
For example, conformance of a Web site to the W3C Web Content
Accessibility Guidelines (WCAG) [WCAG], may only be applicable for a
certain language of the Web site that is using language negotiation.
When provding machine-readable conformance claims, for example using
the W3C Protocol for Describing Web Resources (POWDER): Description
Resources [POWDER-DR], it is important to precise any such
constraints that may apply.
Debugging Web Applications
Web applications using client-side scripting such as AJAX may
exchange additional HTTP messages with the server without using a
different URI. In order to debug such Web applications, it must be
possible to reconstruct the exact history of the states through which
the Web application passed. Web authoring tools that are designed to
develop and debug Web applications could use the terms provided by
this document to record the exact HTTP messages exchanged bewteen a
client and a server. This information could be provided to the
developer as a log to help debug errors in the Web application..
Indexing Information Resources
When indexing RDF information resources that are available through
the HTTP protocol (also called "scuttering" in Semantic Web
parlance), it is often useful to record information about the HTTP
request and response messages that were exchanged, along with the
data for later use. In some instances, different representations of
the RDF information may be retrieved from the server depending on the
HTTP headers and paramters exchanged. The terms provided by this
document can be used to supplement the collected data with the HTTP
messages as part of a comprehensive indexing repository.
1.3 Limitations
There are also notable schema limitations with regards to security and
privacy since the content recorded by this vocabulary could potentially
contain sensitive information, for example authentication information in
HTTP headers or other information (login user name, passwords, and so on)
within the body of the message. Since the schema of this document is
limited to terms defined by the HTTP vocabulary, security and privacy
considerations need to be made at the application level. For example,
certain parts of the data may be restricted to appropriate user permissions
or obfuscated.
2 Classes
This section defines RDF classes for the HTTP 1.1 specification according
to [RFC2616].
2.1 Connection Class
A connection that is used for the HTTP transfer.
Related Properties
Domain of:
http:connectionAuthority
http:requests
Range of: none
Examples
Example 2.1: A Connection resource.
<http:Connection rdf:ID="conn">
<http:connectionAuthority
>www.example.org:80</http:connectionAuthority>
<http:requests rdf:parseType="Collection">
<http:Request rdf:ID="req0"/>
<http:Request rdf:ID="req1"/>
</http:requests>
</http:Connection>
2.2 Message Class
An HTTP message.
Related Properties
Domain of:
http:httpVersion
http:headers
http:body
Range of: none
It may be appropriate to provide additional information about the Message
by using the following from external vocabularies:
dct:date external link
Message date (see the usage of this property in requests and
responses).
Examples
Example 2.2: A Message resource.
<http:Message rdf:ID="mess0">
<http:httpVersion>1.1</http:httpVersion>
<dct:date>2007-09-13</dct:date>
<http:headers rdf:parseType="Collection">
<http:MessageHeader rdf:ID="mh0"/>
<http:MessageHeader rdf:ID="mh1"/>
</http:headers>
<http:body>
<cnt:Content rdf:ID="cont0"/>
</http:body>
</http:Message>
There are two subclasses from the http:Message class: http:Request and
http:Response.
2.2.1 Request Class
An HTTP request. The http:Request class is a subclass of the http:Message
class.
Related Properties
Domain of:
http:methodName
http:mthd
http:requestURI
http:resp
Range of: none
The dct:date property when used in a Request resource represents the date
the request was sent by the client.
Examples
Example 2.3: A Request resource.
<http:Request rdf:ID="reqs0">
<http:abs_path>/</http:abs_path>
<http:methodName>GET</http:methodName>
<http:mthd rdf:resource="http://www.w3.org/2008/http-methods#GET
"/>
<http:resp rdf:resource="#resp0"/>
<dct:date>2007-09-13</dct:date>
<http:httpVersion>1.1</http:httpVersion>
<http:headers rdf:parseType="Collection">
<http:MessageHeader rdf:about="#mh0"/>
<http:MessageHeader rdf:about="#mh1"/>
</http:headers>
</http:Request>
2.2.2 Response Class
An HTTP response. The http:Response class is a subclass of the http:Message
class.
Related Properties
Domain of:
http:statusCodeNumber
http:sc
http:reasonPhrase
Range of:
http:resp
The dct:date property when used in a Response resource represents the date
the response was received by the client.
Examples
Example 2.4: A Response resource.
<http:Response rdf:ID="resp0">
<http:httpVersion>1.1</http:httpVersion>
<dct:date>2008-01-11</dct:date>
<http:statusCodeNumber>200</http:statusCodeNumber>
<http:sc rdf:resource="
http://www.w3.org/2008/http-statusCodes#statusCode200"/>
<http:headers rdf:parseType="Collection">
<http:MessageHeader rdf:about="#mh2"/>
<http:MessageHeader rdf:about="#mh3"/>
</http:headers>
<http:body>
<cnt:Content rdf:ID="cont0"/>
</http:body>
</http:Response>
2.3 MessageHeader Class
A header in an HTTP message.
Related Properties
Domain of:
http:fieldName
http:hdrName
http:fieldValue
http:headerElements
Range of: none
Examples
Example 2.5: A MessageHeader resource.
<http:MessageHeader rdf:ID="mh0">
<http:fieldValue>text/html, image/png,
image/gif;q=0.8</http:fieldValue>
<http:fieldName>Accept</http:fieldName>
<http:hdrName rdf:resource="
http://www.w3.org/2008/http-headers#accept"/>
<http:headerElements rdf:parseType="Collection">
<http:HeaderElement rdf:about="#he0"/>
<http:HeaderElement rdf:about="#he1"/>
<http:HeaderElement rdf:about="#he2"/>
</http:headerElements>
</http:MessageHeader>
2.4 HeaderElement Class
An element in a header value, if a Message Header value can be decomposed
into several parts.
Related Properties
Domain of:
http:elementName
http:elementValue
http:params
Range of: none
Examples
Example 2.6: A HeaderElement resource.
<http:HeaderElement rdf:ID="he0">
<http:elementName>image/gif</http:elementName>
<http:params rdf:parseType="Collection">
<http:Parameter rdf:ID="param0"/>
</http:params>
</http:HeaderElement>
2.5 Parameter Class
A parameter in a Header Element.
Related Properties
Domain of:
http:paramName
http:paramValue
Range of: none
Examples
Example 2.7: A Parameter resource.
<http:Parameter rdf:ID="param0">
<http:paramName>q</http:paramName>
<http:paramValue>0.8</http:paramValue>
</http:Parameter>
2.6 Method Class
The HTTP 1.1 specification defines eight methods: OPTIONS, GET, HEAD, POST,
PUT, DELETE, TRACE, CONNECT. The RDF graph available in RDF/XML at
http://www.w3.org/2008/http-methods provides http:Method resources for each
of these to be used as objects for the http:mthd property. A resource of
type http:Method represents the name of a method used with HTTP.
Related Properties
Domain of: none
Range of:
http:mthd
2.7 StatusCode Class
[HTTP Status Codes] is a registry for status codes too be used in HTTP. The
RDF graph available in RDF/XML at http://www.w3.org/2008/http-statusCodes
provides http:StatusCode resources for each of these to be used as objects
for the http:sc property. A resource of type http:StatusCode represents a
status code.
Related Properties
Domain of: none
Range of:
http:sc
2.8 HeaderName Class
Header names to be used in HTTP are registered by the IANA (see [RFC4229],
[Permanent Headers], and [Provisional Headers]). The RDF graph available in
RDF/XML at http://www.w3.org/2008/http-headers provides http:HeaderName
resources for each of these to be used as objects for the http:hdrName
property. A resource of type http:HeaderName represents the name of a
header used with HTTP.
Related Properties
Properties defined by this document:
Domain of: none
Range of:
http:hdrName
3 Properties
This section defines RDF properties for the HTTP 1.1 specification
according to [RFC2616].
3.1 body Property
This property relates a resource object of the type Message to a resource
object of the type cnt:Content or a subclass thereof to be the Message's
entity body as defined in [RFC2616]. HTTP bodies are series of bytes. Thus
for the resource object, it is appropriate to point to a
cnt:ContentAsBase64 resource (see [Content-in-RDF] for more information on
content representations using the Resource Desription Framework (RDF)).
Domain:
http:Message
Range:
cnt:ContentAsBase64 external link
Examples
Example 3.1: The entity body of a message.
<http:Message rdf:ID="mess0">
<http:body>
<cnt:ContentAsBase64 rdf:ID="cont0-bin"/>
</http:body>
</http:Message>
3.2 connectionAuthority Property
Connection authority - server host and port for a connection.
Domain:
http:Connection
Range:
Literal
3.3 elementName Property
Header element name (Literal).
Domain:
http:HeaderElement
Range:
Literal
3.4 elementValue Property
Header element value (Literal).
Domain:
http:HeaderElement
Range:
Literal
3.5 fieldName Property
Header name (Literal).
Domain:
http:MessageHeader
Range:
Literal
3.6 fieldValue Property
Header value (Literal).
Domain:
http:MessageHeader
Range:
Literal
3.7 headers Property
HTTP headers sent with the message.
Domain:
http:Message
Range:
unspecified
3.8 headerElements Property
Header value elements.
Domain:
http:MessageHeader
Range:
unspecified
3.9 hdrName Property
This property relates a resource of type http:MessageHeader to a resource
of type http:HeaderName.
Domain:
http:MessageHeader
Range:
http:HeaderName
3.10 httpVersion Property
Property representing the HTTP version number as a Literal (the format is
'digit.digit').
Domain:
http:Message
Range:
Literal
3.11 mthd Property
HTTP method.
Domain:
http:Request
Range:
http:Method
3.12 methodName Property
HTTP method name (Literal).
Domain:
http:Request
Range:
Literal
3.13 params Property
Header element parameters.
Domain:
http:HeaderElement
Range:
unspecified
3.14 paramName Property
Parameter name.
Domain:
http:Parameter
Range:
Literal
3.15 paramValue Property
Parameter value.
Domain:
http:Parameter
Range:
Literal
3.16 reasonPhrase Property
Reason phrase sent by the server.
Domain:
http:Response
Range:
Literal
3.17 requests Property
HTTP requests sent via the connection.
Domain:
http:Connection
Range:
unspecified
3.18 requestURI Property
The request URI as specified in section 5.1.2 of [RFC2616]. This vocabulary
defines the following sub-properties:
http:absoluteURI
http:abs_path
http:authority
Domain:
http:Request
Range:
Literal
Examples
Example 3.2: The use of the requestURI property.
<http:Request>
<http:methodName>OPTIONS</http:methodName>
<http:requestURI>*</http:requestURI>
...
</http:Request>
3.18.1 absoluteURI Property
Request URI that is an absolute URI.
Conformance Note: The object for this property must be a Literal (absolute
URI).
Examples
Example 3.3: The use of the absoluteURI property.
<http:Request>
<http:methodName>GET</http:methodName>
<http:absoluteURI
>http://www.example.org:80/foo/bar</http:absoluteURI>
...
</http:Request>
3.18.2 abs_path Property
Request URI that is an absolute path.
Conformance Note: The object for this property must be a Literal (absolute
path).
Examples
Example 3.4: The use of the abs_path property.
<http:Request>
<http:methodName>GET</http:methodName>
<http:abs_path>/foo/bar</http:abs_path>
...
</http:Request>
3.18.3 authority Property
Request URI that is an authority.
Conformance Note: The object for this property must be a Literal (host and
optional port number).
Examples
Example 3.5: The use of the authority property.
<http:Request>
<http:methodName>CONNECT</http:methodName>
<http:authority>www.example.org:80</http:authority>
...
</http:Request>
3.19 resp Property
This property relates a resource of type http:Request to a resource of type
http:Response.
Domain:
http:Request
Range:
http:Response
3.20 sc Property
This property relates a resource of type http:Response to a resource of
type http:StatusCode.
Domain:
http:Response
Range:
http:StatusCode
3.21 statusCodeNumber Property
The status code sent by the server (Literal).
Domain:
http:Response
Range:
Literal
4 Conformance
This section describes conformance with this HTTP-in-RDF specification. It
differentiates between the following entities:
[Editor's note: The working group asks for comments about a more colloquial
word for "HTTP-in-RDF Graph".]
HTTP-in-RDF Graph
An individual file or collection of files that contain HTTP-in-RDF
data
HTTP-in-RDF Producer
A software tool or Web-based application that produces HTTP-in-RDF
data
HTTP-in-RDF Consumer
A software tool or Web-based application that processes HTTP-in-RDF
data
4.1 Conforming HTTP-in-RDF graphs
Graphs conforming to this HTTP-in-RDF specification must meet the following
requirements:
1. A Connection must have exactly one connection authority (specified by
http:connectionAuthority).
2. A Connection may have one collection of Requests (referenced by
http:requests).
3. A Message must have exactly one HTTP version (specified by
http:httpVersion).
4. A Message may have one collection of Message Headers (referenced by
http:headers).
5. A Message may have one message body (referenced by http:body).
6. A Message may have one date (specified by dct:date external link).
7. A Request must have exactly one method name (specified by
http:methodName).
8. A Request must have exactly one request URI (specified by
http:requestURI).
9. A Request may be connected to one Method (referenced by http:mthd).
10. A Request may be connected to one Response (referenced by
http:resp).
11. A Response must have exactly one status code number (specified
by http:statusCodeNumber).
12. A Response must have exactly one reason phrase (specified by
http:reasonPhrase).
13. A Response may be conected to one Status Code (referenced by
http:sc).
14. A Message Header must have exactly one field name (specified by
http:fieldName).
15. A Message Header must have exactly one field value (specified
by http:fieldValue).
16. A Message Header may be connected to one Header Name
(referenced by http:hdrName).
17. A Message Header may have one collection of Header Elements
(referenced by http:headerElements).
18. A Header Element must have exactly one header element name
(specified by http:elementName).
19. A Header Element may have one header element value (specified
by http:elementValue).
20. A Header Element may have one collection of Parameters
(referenced by http:params).
21. A Parameter must have exactly one parameter name (specified by
http:paramName).
22. A Parameter must have exactly one parameter value (specified by
http:paramValue).
23. The objects for the headers property must be an RDF Collection
of Message Headers.
24. The objects for the http:headerElements property must be an RDF
Collection of Header Elements.
25. The object for the http:params property must be an RDF
Collection of Parameters.
26. The object for the http:requests property must be an RDF
Collection of Requests.
27. Every instance of cnt:ContentAsBase64 external linkmust conform
with the respective specification.
4.2 Conforming Producers
Producers conforming to this HTTP-in-RDF specification must meet the
following requirements:
1. A Producer must generate conforming graphs
2. A Producer must be able to generate graphs in RDF/XML serialization
and should also support other RDF serializations
3. A Producer must generate all of the terms summarized in Appendix B:
Terms for which there is information available to it
4.3 Conforming Consumers
Consumers conforming to this HTTP-in-RDF specification must meet the
following requirements:
1. A Consumer must process conforming graphs
2. A Consumer must process graphs in any RDF/XML serialization and
should also support other RDF serializations
3. A Consumer must process all of the terms summarized in Appendix B:
Terms for which there is information available to it
Appendix A: A practical Example
The following example shows an RDF/XML representation of an HTTP request
and response pair.
Scenario Description
A client sends two requests to a server at www.example.org port 80 via HTTP
1.1 GET. With each request, it sends request headers. The first request is
for a resource in the document root (/), the second for a resource at
/image. While handling the second request the server performs content
negotiation respecting the request's Accept header and so sends a PNG
image. This is indicated by the response's Vary header.
Resulting RDF/XML
<?xml version="1.0" encoding="utf-8"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:http="http://www.w3.org/2006/http#"
xmlns:cnt="http://www.w3.org/2008/content#"
xmlns:dct="http://purl.org/dc/terms/">
<http:Connection rdf:ID="conn">
<http:connectionAuthority
>www.example.org:80</http:connectionAuthority>
<http:requests rdf:parseType="Collection">
<http:Request rdf:about="#req0"/>
<http:Request rdf:about="#req1"/>
</http:requests>
</http:Connection>
<http:Request rdf:about="#req0">
<http:httpVersion>1.1</http:httpVersion>
<http:methodName>GET</http:methodName>
<http:mthd rdf:resource="http://www.w3.org/2008/http-methods#GET"/>
<http:abs_path>/</http:abs_path>
<http:headers rdf:parseType="Collection">
<http:MessageHeader>
<http:fieldName>Host</http:fieldName>
<http:hdrName rdf:resource="
http://www.w3.org/2008/http-headers#host"/>
<http:fieldValue>www.example.org</http:fieldValue>
</http:MessageHeader>
<http:MessageHeader>
<http:fieldName>User-Agent</http:fieldName>
<http:hdrName rdf:resource="
http://www.w3.org/2008/http-headers#user-agent"/>
<http:fieldValue>My User Agent</http:fieldValue>
</http:MessageHeader>
<http:MessageHeader>
<http:fieldName>Accept</http:fieldName>
<http:hdrName rdf:resource="
http://www.w3.org/2008/http-headers#accept"/>
<http:fieldValue>text/html, image/png,
image/gif;q=0.8</http:fieldValue>
<http:headerElements rdf:parseType="Collection">
<http:HeaderElement>
<http:elementName>text/html</http:elementName>
</http:HeaderElement>
<http:HeaderElement>
<http:elementName>image/png</http:elementName>
</http:HeaderElement>
<http:HeaderElement>
<http:elementName>image/gif</http:elementName>
<http:params rdf:parseType="Collection">
<http:Parameter>
<http:paramName>q</http:paramName>
<http:paramValue>0.8</http:paramValue>
</http:Parameter>
</http:params>
</http:HeaderElement>
</http:headerElements>
</http:MessageHeader>
</http:headers>
<http:resp rdf:resource="#resp0"/>
</http:Request>
<http:Request rdf:about="#req1">
<http:httpVersion>1.1</http:httpVersion>
<http:methodName>GET</http:methodName>
<http:mthd rdf:resource="http://www.w3.org/2008/http-methods#GET"/>
<http:abs_path>/image</http:abs_path>
<http:headers rdf:parseType="Collection">
<http:MessageHeader>
<http:fieldName>Host</http:fieldName>
<http:hdrName rdf:resource="
http://www.w3.org/2008/http-headers#host"/>
<http:fieldValue>www.example.org</http:fieldValue>
</http:MessageHeader>
<http:MessageHeader>
<http:fieldName>User-Agent</http:fieldName>
<http:hdrName rdf:resource="
http://www.w3.org/2008/http-headers#user-agent"/>
<http:fieldValue>My User Agent</http:fieldValue>
</http:MessageHeader>
<http:MessageHeader>
<http:fieldName>Accept</http:fieldName>
<http:hdrName rdf:resource="
http://www.w3.org/2008/http-headers#accept"/>
<http:fieldValue>image/png, image/gif;q=0.8</http:fieldValue>
<http:headerElements rdf:parseType="Collection">
<http:HeaderElement>
<http:elementName>image/png</http:elementName>
</http:HeaderElement>
<http:HeaderElement>
<http:elementName>image/gif</http:elementName>
<http:params rdf:parseType="Collection">
<http:Parameter>
<http:paramName>q</http:paramName>
<http:paramValue>0.8</http:paramValue>
</http:Parameter>
</http:params>
</http:HeaderElement>
</http:headerElements>
</http:MessageHeader>
</http:headers>
<http:resp rdf:resource="#resp1"/>
</http:Request>
<http:Response rdf:ID="resp0">
<http:httpVersion>1.1</http:httpVersion>
<http:statusCodeNumber>200</http:statusCodeNumber>
<http:sc rdf:resource="http://www.w3.org/2008/http-statusCodes#200
"/>
<http:reasonPhrase>OK</http:reasonPhrase>
<http:headers rdf:parseType="Collection">
<http:MessageHeader>
<http:fieldName>Date</http:fieldName>
<http:hdrName rdf:resource="
http://www.w3.org/2008/http-headers#date"/>
<http:fieldValue>.......</http:fieldValue>
</http:MessageHeader>
<http:MessageHeader>
<http:fieldName>Content-Type</http:fieldName>
<http:hdrName rdf:resource="
http://www.w3.org/2008/http-headers#content-type"/>
<http:fieldValue>text/html; charset=utf-8</http:fieldValue>
<http:headerElements rdf:parseType="Collection">
<http:HeaderElement>
<http:elementName>text/html</http:elementName>
<http:params rdf:parseType="Collection">
<http:Parameter>
<http:paramName>charset</http:paramName>
<http:paramValue>utf-8</http:paramValue>
</http:Parameter>
</http:params>
</http:HeaderElement>
</http:headerElements>
</http:MessageHeader>
</http:headers>
<http:body>
<cnt:ContentAsBase64 rdf:ID="cont0-bin">
<cnt:bytes rdf:datatype="
http://www.w3.org/2001/XMLSchema#base64Binary"
>ajrq9qguojbglj48z..........</cnt:bytes>
</cnt:ContentAsBase64>
</http:body>
</http:Response>
<cnt:XMLContent rdf:ID="cont0-xml">
<dct:source rdf:resource="#cont0-bin"/>
<cnt:xmlLeadingMisc rdf:parseType="Literal"><!-- This is the start
of the document -->
</cnt:xmlLeadingMisc>
<cnt:docTypeDecl>
<cnt:DocTypeDecl>
<cnt:dtdName>html</cnt:dtdName>
<cnt:publicId>-//W3C//DTD XHTML 1.0 Strict//EN</cnt:publicId>
<cnt:systemId rdf:datatype="
http://www.w3.org/2001/XMLSchema#anyURI"
>http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd</cnt:systemId>
</cnt:DocTypeDecl>
</cnt:docTypeDecl>
<cnt:xmlRest rdf:parseType="Literal"><html xmlns="
http://www.w3.org/1999/xhtml" lang="en">
<head>
<title>My document</title>
</head>
<body>
<p><!-- ...... --></p>
</body>
</html></cnt:xmlRest>
</cnt:XMLContent>
<http:Response rdf:ID="resp1">
<http:httpVersion>1.1</http:httpVersion>
<http:statusCodeNumber>200</http:statusCodeNumber>
<http:sc rdf:resource="http://www.w3.org/2008/http-statusCodes#200
"/>
<http:reasonPhrase>OK</http:reasonPhrase>
<http:headers rdf:parseType="Collection">
<http:MessageHeader>
<http:fieldName>Date</http:fieldName>
<http:hdrName rdf:resource="
http://www.w3.org/2008/http-headers#date"/>
<http:fieldValue>.......</http:fieldValue>
</http:MessageHeader>
<http:MessageHeader>
<http:fieldName>Content-Type</http:fieldName>
<http:hdrName rdf:resource="
http://www.w3.org/2008/http-headers#content-type"/>
<http:fieldValue>image/png</http:fieldValue>
</http:MessageHeader>
<http:MessageHeader>
<http:fieldName>Vary</http:fieldName>
<http:hdrName rdf:resource="
http://www.w3.org/2008/http-headers#vary"/>
<http:fieldValue>accept</http:fieldValue>
<http:headerElements rdf:parseType="Collection">
<http:HeaderElement>
<http:elementName>accept</http:elementName>
</http:HeaderElement>
</http:headerElements>
</http:MessageHeader>
</http:headers>
<http:body>
<cnt:ContentAsBase64>
<cnt:bytes rdf:datatype="
http://www.w3.org/2001/XMLSchema#base64Binary"
>qouh3908t38hohfrf..........</cnt:bytes>
</cnt:ContentAsBase64>
</http:body>
</http:Response>
</rdf:RDF>
Appendix B: Terms
The following terms are defined by this specification:
Classes
|------------+-----+------------+--------+-------------------------------|
| Class name |Label| Comment |Refineme| Related properties |
| | | | nts | |
|------------+-----+------------+--------+-------------------------------|
|Classes in |
|the |
|HTTP-in-RDF |
|namespace |
|------------+-----------------------------------------------------------
|http:Connect|Conne|A connection|- |http:connectionAuthority, |
|ion |ction|used for | |http:requests |
| | |HTTP | | |
| | |transfer. | | |
|------------+-----+------------+--------+-------------------------------|
|http:HeaderE|Heade|A part of a |- |http:elementName, |
|lement |r |deconstructe| |http:elementValue, http:params |
| |Eleme|d header | | |
| |nt |value. | | |
|------------+-----+------------+--------+-------------------------------|
|http:HeaderN|Heade|The header |- | |
|ame |r |name. | | |
| |Name | | | |
|------------+-----+------------+--------+-------------------------------|
|http:Message|Messa|An HTTP |http:Req|http:httpVersion, dct:date, |
| |ge |message. |uest, |http:body, http:headers |
| | | |http:Res| |
| | | |ponse | |
|------------+-----+------------+--------+-------------------------------|
|http:Message|Messa|A header in |- |http:fieldName, http:fieldValue|
|Header |ge |an HTTP | |, http:hdrName, |
| |Heade|message. | |http:headerElements |
| |r | | | |
|------------+-----+------------+--------+-------------------------------|
|http:Method |Metho|The HTTP |- | |
| |d |method used | | |
| | |for a | | |
| | |request. | | |
|------------+-----+------------+--------+-------------------------------|
|http:Paramet|Param|A parameter |- |http:paramName, http:paramValue|
|er |eter |for a part | | |
| | |of a header | | |
| | |value | | |
|------------+-----+------------+--------+-------------------------------|
|http:Request|Reque|An HTTP |- |http:methodName, |
| |st |request. | |http:requestURI, http:mthd, |
| | | | |http:resp |
|------------+-----+------------+--------+-------------------------------|
|http:Respons|Respo|An HTTP |- |http:statusCodeNumber, |
|e |nse |response. | |http:reasonPhrase, http:sc |
|------------+-----+------------+--------+-------------------------------|
|http:StatusC|Statu|The status |- | |
|ode |s |code of an | | |
| |Code |HTTP | | |
| | |response. | | |
|------------+-----+------------+--------+-------------------------------|
Properties
|--------------+-------+------------------------+---------+--------------|
|Property name | Label | Comment | Domain | Range |
|--------------+-------+------------------------+---------+--------------|
|Properties in |
|the |
|HTTP-in-RDF |
|namespace |
|--------------+---------------------------------------------------------
|http:body |Entity |The entity body of an |http:Mess|cnt:ContentAsB|
| |body |HTTP message. |age |ase64 |
|--------------+-------+------------------------+---------+--------------|
|http:connectio|Connect|The authority of a |http:Conn|RDF Literal |
|nAuthority |ion |connection used for the |ection | |
| |authori|HTTP transfer | | |
| |ty | | | |
|--------------+-------+------------------------+---------+--------------|
|http:elementNa|Header |The name of a header |http:Head|RDF Literal |
|me |element|element |erElement| |
| |name | | | |
|--------------+-------+------------------------+---------+--------------|
|http:elementVa|Header |The value of a header |http:Head|RDF Literal |
|lue |element|element. |erElement| |
| |value | | | |
|--------------+-------+------------------------+---------+--------------|
|http:fieldName|Field |The name of an HTTP |http:Mess|RDF Literal |
| |name |header field. |ageHeader| |
|--------------+-------+------------------------+---------+--------------|
|http:fieldValu|Field |The value of an HTTP |http:Mess|RDF Literal |
|e |value |header field. |ageHeader| |
|--------------+-------+------------------------+---------+--------------|
|http:headerEle|Header |The deconstructed parts |http:Mess|Collection of |
|ments |element|of an HTTP header value.|ageHeader|http:HeaderEle|
| |s | | |ment |
|--------------+-------+------------------------+---------+--------------|
|http:hdrName |Header |The name of an HTTP |http:Mess|http:HeaderNam|
| |name |header. |ageHeader|e |
|--------------+-------+------------------------+---------+--------------|
|http:headers |Headers|The headers in an HTTP |http:Mess|Collection of |
| | |message. |age |http:MessageHe|
| | | | |ader |
|--------------+-------+------------------------+---------+--------------|
|http:httpVersi|HTTP |The HTTP version of an |http:Mess|RDF Literal |
|on |Version|HTTP message. |age | |
|--------------+-------+------------------------+---------+--------------|
|http:mthd |Method |The HTTP method used for|http:Requ|http:Method |
| | |the HTTP request. |est | |
|--------------+-------+------------------------+---------+--------------|
|http:methodNam|Method |The HTTP method name |http:Requ|RDF Literal |
|e |name |used for the HTTP |est | |
| | |request. | | |
|--------------+-------+------------------------+---------+--------------|
|http:paramName|Paramet|The name of a parameter |http:Para|RDF Literal |
| |er name|in a part of a |meter | |
| | |deconstructed HTTP | | |
| | |header value. | | |
|--------------+-------+------------------------+---------+--------------|
|http:params |Paramet|The parameters in a part|http:Head|Collection of |
| |ers |of a deconstructed HTTP |erElement|http:Parameter|
| | |header value. | | |
|--------------+-------+------------------------+---------+--------------|
|http:paramValu|Paramet|The value of a parameter|http:Para|RDF Literal |
|e |er |in a part of a |meter | |
| |value |deconstructed HTTP | | |
| | |header value. | | |
|--------------+-------+------------------------+---------+--------------|
|http:reasonPhr|Reason |The reason phrase |http:Resp|RDF Literal |
|ase |phrase |(status text) of an HTTP|onse | |
| | |response. | | |
|--------------+-------+------------------------+---------+--------------|
|http:requests |Request|The HTTP requests made |http:Conn|Collection of |
| |s |via a connection. |ection |http:Request |
|--------------+-------+------------------------+---------+--------------|
|http:requestUR|Request|The request URI of an |http:Requ|RDF Literal |
|I |URI |HTTP request. |est | |
|--------------+-------+------------------------+---------+--------------|
|http:resp |Respons|The HTTP response sent |http:Requ|http:Response |
| |e |in answer to an HTTP |est | |
| | |request. | | |
|--------------+-------+------------------------+---------+--------------|
|http:sc |Status |The status code of an |http:Resp|http:StatusCod|
| |code |HTTP response. |onse |e |
|--------------+-------+------------------------+---------+--------------|
|http:statusCod|Status |The status code number |http:Resp|RDF Literal |
|eNumber |code |of an HTTP response. |onse | |
| |number | | | |
|--------------+-------+------------------------+---------+--------------|
Appendix C: References
[Content-in-RDF]
Representing Content in RDF - Johannes Koch, Carlos A Velasco
(editors). W3C Working Draft 17 July 2008.
[EARL]
Evaluation and Report Language (EARL) Overview - W3C
[HTTP Status Codes]
"HTTP Status Code Registry" - IANA.
[OWL]
Web Ontology Language (OWL) Overview - W3C
[Permanent Headers]
Permanent Message Header Field Names - IANA.
[Provisional Headers]
Provisional Message Header Field Names - IANA.
[POWDER-DR]
Protocol for Web Description Resources (POWDER): Description
Resources - K. Smith, P. Archer, A. Perego (editors). W3C Working
Draft 17 March 2008.
[POWDER-GR]
Protocol for Web Description Resources (POWDER): Grouping of
Resources - P. Archer, A. Perego, K. Smith (editors). W3C Working
Draft 24 March 2008.
[RDF]
Resource Description Framework (RDF) Overview - W3C
[RDF-PRIMER]
RDF Primer. W3C Recommendation, 10 February 2004.
http://www.w3.org/TR/rdf-primer/
[RDFS]
RDF Vocabulary Description Language 1.0: RDF Schema. W3C
Recommendation 10 February 2004.
http://www.w3.org/TR/rdf-schema/
[RFC2119]
Request for Comments (RFC): 2119. Key words for use in RFCs to
Indicate Requirement Levels - IETF March 1997.
[RFC2616]
Hypertext Transfer Protocol -- HTTP/1.1 - R. Fielding, J. Gettys, J.
Mogul, H. Frystyk Nielsen, L. Masinter, P. Leach and T. Berners-Lee.
IETF June 1999.
[RFC4229]
HTTP Header Field Registrations - M. Nottingham, J. Mogul. IETF
December 2005.
[WCAG]
Web Content Accessibility Guidelines (WCAG) Overview - W3C.
[XML]
Extensible Markup Language (XML) 1.0 (Fourth Edition). W3C
Recommendation 16 August 2006, edited in place 29 September 2006.
http://www.w3.org/TR/xml/
Appendix D: Document Changes
[Editor's note: add changes from this version to WD-HTTP-in-RDF-20080908]
Besides several editorial changes, the following is a list of substantial
changes since the 23 March, 2007 Working Draft:
split three RDF models for request methods, header names and status
codes from the HTTP model to be updated separately from external
registries
changed the http:request property to http:requests
introduced the http:Message class to be a base for the http:Request
and http:Response class
changed the http:version property to http:httpVersion
added the dc:date property to the http:Message class
introduced the http:methodName (with object literal), http:mthd (with
object resource from external RDF model for header names) properties
and the http:Method class instead of different http:Request
sub-classes
changed the multiple use of the http:header property to http:headers
with an RDF collection
changed the http:responseCode property to http:sc (with object
literal from external RDF model for status codes), and introduced the
literal http:statusCodeNumber and http:reasonPhrase properties
changed the http:fieldName property to have a object literal
introduced the http:hdrName property having an object resource (from
the external RDF model for header names)
Attachments
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Received on Thursday, 18 June 2009 14:23:38 UTC