Network Working Group J. Reschke
Internet-Draft greenbytes
Expires: August 6, 2004 February 6, 2004
Datatypes for WebDAV properties
draft-reschke-webdav-property-datatypes-06
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Copyright Notice
Copyright (C) The Internet Society (2004). All Rights Reserved.
Abstract
This specification extends the Web Distributed Authoring Protocol
(WebDAV) to support both datatyping and some amount of meta
information on property values. Protocol elements are defined to let
clients and servers specify the datatype and meta information of a
property, and to instruct the WebDAV method PROPFIND to return
datatype and meta information.
Distribution of this document is unlimited. Please send comments to
the Distributed Authoring and Versioning (WebDAV) working group at
w3c-dist-auth@w3.org [1], which may be joined by sending a message
with subject "subscribe" to w3c-dist-auth-request@w3.org [2].
Discussions of the WEBDAV working group are archived at URL: http://
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lists.w3.org/Archives/Public/w3c-dist-auth/.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Notational Conventions . . . . . . . . . . . . . . . . . . . 4
3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1 Data types . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.2 Property flags . . . . . . . . . . . . . . . . . . . . . . . 6
3.2.1 pf:hidden . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2.2 pf:protected . . . . . . . . . . . . . . . . . . . . . . . . 6
3.3 Property display names . . . . . . . . . . . . . . . . . . . 6
3.3.1 pf:property-displayname-set property (computed) . . . . . . 6
4. Changes for PROPPATCH method . . . . . . . . . . . . . . . . 7
4.1 Marshalling type information . . . . . . . . . . . . . . . . 7
4.1.1 Example for successful PROPPATCH . . . . . . . . . . . . . . 8
4.1.2 Example for failed PROPPATCH . . . . . . . . . . . . . . . . 9
4.1.3 Example for succesful PROPPATCH where type information
was not preserved . . . . . . . . . . . . . . . . . . . . . 10
4.2 Marshalling property flag information . . . . . . . . . . . 11
4.2.1 Example for successful PROPPATCH . . . . . . . . . . . . . . 11
4.2.2 Example for failed PROPPATCH . . . . . . . . . . . . . . . . 12
5. Changes for PROPFIND method . . . . . . . . . . . . . . . . 13
5.1 Marshalling of datatype information . . . . . . . . . . . . 13
5.1.1 Example for PROPFIND/prop . . . . . . . . . . . . . . . . . 14
5.2 Marshalling of property flags . . . . . . . . . . . . . . . 15
5.2.1 Example for PROPFIND/prop . . . . . . . . . . . . . . . . . 15
6. Compatibility Considerations . . . . . . . . . . . . . . . . 16
6.1 Datatype marshalling . . . . . . . . . . . . . . . . . . . . 16
6.2 Property flags . . . . . . . . . . . . . . . . . . . . . . . 17
6.3 New live properties . . . . . . . . . . . . . . . . . . . . 17
7. Internationalization Considerations . . . . . . . . . . . . 17
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . 17
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 17
Normative References . . . . . . . . . . . . . . . . . . . . 17
Informative References . . . . . . . . . . . . . . . . . . . 18
Author's Address . . . . . . . . . . . . . . . . . . . . . . 19
A. Example: marshalling of array-typed properties . . . . . . . 19
A.1 Setting of array-typed property . . . . . . . . . . . . . . 20
A.2 Getting an array-typed property . . . . . . . . . . . . . . 21
A.3 Optional DASL operators for queries on array-typed
properties . . . . . . . . . . . . . . . . . . . . . . . . . 22
A.3.1 sap:some-eq . . . . . . . . . . . . . . . . . . . . . . . . 22
A.3.2 sap:some-gt . . . . . . . . . . . . . . . . . . . . . . . . 23
A.3.3 sap:some-gte . . . . . . . . . . . . . . . . . . . . . . . . 23
A.3.4 sap:some-like . . . . . . . . . . . . . . . . . . . . . . . 23
A.3.5 sap:some-lt . . . . . . . . . . . . . . . . . . . . . . . . 23
A.3.6 sap:some-lte . . . . . . . . . . . . . . . . . . . . . . . . 23
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A.3.7 sap:some-ne . . . . . . . . . . . . . . . . . . . . . . . . 23
B. Change Log (to be removed by RFC Editor before
publication) . . . . . . . . . . . . . . . . . . . . . . . . 23
B.1 Since 'draft-reschke-webdav-property-datatypes-00' . . . . . 23
B.2 Since 'draft-reschke-webdav-property-datatypes-01' . . . . . 24
B.3 Since 'draft-reschke-webdav-property-datatypes-02' . . . . . 24
B.4 Since 'draft-reschke-webdav-property-datatypes-03' . . . . . 24
B.5 Since 'draft-reschke-webdav-property-datatypes-04' . . . . . 24
B.6 Since 'draft-reschke-webdav-property-datatypes-05' . . . . . 24
Intellectual Property and Copyright Statements . . . . . . . 25
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1. Introduction
This specification builds on the infrastructure provided by the
WebDAV Distributed Authoring Protocol, adding support for data-typed
properties, some property flags and display names for properties.
Although servers must support XML content in property values, it may
be desirable to persist values as scalar values when possible, and to
expose the data's type when the property value is returned to the
client. The client is free to ignore this information, but it may be
able to take advantage of it when modifying a property.
On the other hand, when setting new properties, it can be desirable
to pass data type information along with the value. A server can take
advantage of this information to optimize storage and to perform
additional parsing (for instance of dates). Servers that support
searching can also take advantage of known data types when doing
comparisons and sorting.
Furthermore, it may be desirable to add some amount of additional
meta information to properties in order to enable generic WebDAV
clients to provide a meaningful user interface for editing these
properties. In particular, clients can take advantage of knowing that
particular properties are not generally suitable for edits through
humans ("hidden"), or that they can not be changed ("protected").
Finally, generic clients that allow editing of arbitrary properties
need to display a "display name" for each property. This document
defines a new protected live property, "pf:property-displayname-set",
that provides this information.
2. Notational Conventions
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 [RFC2119].
The term "property element" refers to the XML element that identifies
a particular property, for instance
<getcontentlength xmlns="DAV:" />
The term "prop element" is used for the WebDAV "prop" element as
defined in section 12.11 of [RFC2518].
The XML representation of schema components uses a vocabulary
identified by the namespace name "http://www.w3.org/2001/XMLSchema".
For brevity, the text and examples in this specification use the
prefix "xs:" to stand for this namespace; in practice, any prefix can
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be used. "XML Schema: Structures" ([XS1]) also defines several
attributes for direct use in any XML documents. These attributes are
in a different namespace named "http://www.w3.org/2001/
XMLSchema-instance". For brevity, the text and examples in this
specification use the prefix "xsi:" to stand for this latter
namespace; in practice, any prefix can be used.
This document defines extension elements and attributes that could
ultimately become part of the core WebDAV protocol. Being just an
individual submission, it currently defines them in the proprietary
namespace
http://sapportals.com/xmlns/cm/webdav
instead of the "DAV:" namespace. It uses a prefix of "pf:" for
referring to elements or attributes in this namespace. However,
WebDAV server and clients are free to use any prefix, provided that
there is a namespace declaration that binds the prefix to the URI of
the same namespace.
3. Overview
3.1 Data types
Although WebDAV property types can be anything that can be marshalled
as content of an XML element, in many cases they actually are simple
types like integers, booleans or dates. "XML Schema Part 2:
Datatypes" [XS2] defines a set of simple types which can be used as a
basis for supplying type information to attributes.
Data type information is represented using the attribute "type" from
the XML Schema namespace "http://www.w3.org/2001/XMLSchema-instance".
In XML Schema, data types are qualified names, and the XML Schema
recommendation defines a set of built-in datatypes (section 3 of
[XS2]), defined in the namespace "http://www.w3.org/2001/XMLSchema".
To avoid unnecessary verbosity, data type information should only be
supplied if it adds usable information to the protocol. In
particular, type information is not required for live properties
defined in WebDAV [RFC2518] and for properties of type "xs:string".
A server may implement any combination of datatypes, both from the
XML Schema recommendation and possibly from other namespaces.
Note that a particular property can be typed for a number of reasons:
o The property is a live property with server-defined semantics and
value space.
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o The property may have been set using a non-WebDAV protocol that
the server understands in addition to WebDAV.
o The type may have been specified in an extended PROPPATCH method
as defined in Section 4.
3.2 Property flags
This specification defines semantics for two specific property flags.
3.2.1 pf:hidden
pf:hidden = "false" | "true"
This is a (boolean) display hint for generic user agents. When set to
"false", it indicates that it is generally not useful to allow users
to modify this property.
3.2.2 pf:protected
pf:protected = "false" | "true"
When set to "true", this flag indicates that this property is
protected (as defined in [RFC3253], section 1.4.2). A user agent may
display this property, but should not allow edits on it.
3.3 Property display names
For the purpose of marshalling property displayname information, this
specification introduces a new computed resource property. In
accordance to [RFC3253], this property SHOULD not returned upon an
PROPFIND/allprop request.
3.3.1 pf:property-displayname-set property (computed)
<!ELEMENT pf:property-displayname-set (pf:property-displayname*)>
<!ELEMENT pf:property-displayname (prop, pf:displayname)>
The pf:property-displayname-set contains display information about
properties defined on the resource. The set may not be complete (if
the server doesn't have display information for particular
properties).
prop: ANY, see RFC2518
The DAV:prop element contains exactly one property element
identifying the resource property to which the
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pf:property-displayname element applies.
<!ELEMENT pf:displayname (#PCDATA) >
The pf:displayname element contains the display name for the
property. Servers MUST indicate the human language of the description
using the xml:lang attribute and SHOULD consider the HTTP
Accept-Language request header when selecting one of multiple
available languages.
4. Changes for PROPPATCH method
4.1 Marshalling type information
If the property element has an XML attribute named "xsi:type", the
server may use this information to select an optimized representation
for storing the property value. For instance, by specifying a type as
"xs:boolean", the client declares the property value to be of type
boolean (as defined in [XS2]). The server may choose any suitable
internal format for persisting this property, and in particular is
allowed to fail the request if the format given does not fit the
format defined for this type.
The server should indicate successful detection and parsing of the
typed value by setting the xsi:type attribute on the property element
in the response body (this implies that it should return a
MULTISTATUS status code and a <multistatus> response body).
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4.1.1 Example for successful PROPPATCH
>>Request
PROPPATCH /bar.html HTTP/1.1
Host: example.org
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:propertyupdate xmlns:D="DAV:"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:Z="http://ns.example.org/standards/z39.50">
<D:set>
<D:prop>
<Z:released xsi:type="xs:boolean">false</Z:released>
</D:prop>
</D:set>
</D:propertyupdate>
>>Response
HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:Z="http://ns.example.org/standards/z39.50">
<D:response>
<D:href>http://example.org/bar.html</D:href>
<D:propstat>
<D:prop><Z:released xsi:type="xs:boolean" /></D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>
In this cases, the xsi:type attribute on the element "Z:released"
indicates that the server indeed has understood the submitted data
type information.
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4.1.2 Example for failed PROPPATCH
>>Request
PROPPATCH /bar.html HTTP/1.1
Host: example.org
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:propertyupdate xmlns:D="DAV:"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:Z="http://ns.example.org/standards/z39.50">
<D:set>
<D:prop>
<Z:released xsi:type="xs:boolean">t</Z:released>
</D:prop>
</D:set>
</D:propertyupdate>
>>Response
HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:"
xmlns:Z="http://ns.example.org/standards/z39.50">
<D:response>
<D:href>http://example.org/bar.html</D:href>
<D:propstat>
<D:prop><Z:released/></D:prop>
<D:status>HTTP/1.1 422 Unprocessable Entity</D:status>
<D:responsedescription>
Does not parse as xs:boolean
</D:responsedescription>
</D:propstat>
</D:response>
</D:multistatus>
In this case the request failed because the supplied value "t" is not
a valid representation for a boolean value.
Note that similar error conditions can occur in the standard WebDAV
protocol even though no data type was specified: for instance, when a
client tries to set a live property for which only a certain value
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space is allowed.
4.1.3 Example for succesful PROPPATCH where type information was not
preserved
>>Request
PROPPATCH /bar.html HTTP/1.1
Host: example.org
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:propertyupdate xmlns:D="DAV:"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:Z="http://ns.example.org/standards/z39.50">
<D:set>
<D:prop>
<Z:released xsi:type="Z:custom">t</Z:released>
</D:prop>
</D:set>
</D:propertyupdate>
>>Response
HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:Z="http://ns.example.org/standards/z39.50">
<D:response>
<D:href>http://example.org/bar.html</D:href>
<D:propstat>
<D:prop><Z:released/></D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>
In this case the request succeeded, but the server did not know how
to handle the data type "Z:custom". Therefore no data type
information was returned in the response body.
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4.2 Marshalling property flag information
If the property element has an XML attribute named "pf:hidden", the
server should persist this as part of the property value.
On the other hand, an XML attribute named "pf:protected" SHOULD be
ignored, because protected properties MUST NOT be modifiable by
PROPPATCH.
4.2.1 Example for successful PROPPATCH
>>Request
PROPPATCH /bar.html HTTP/1.1
Host: example.org
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:propertyupdate xmlns:D="DAV:"
xmlns:pf="http://sapportals.com/xmlns/cm/webdav"
xmlns:Z="http://ns.example.org/standards/z39.50">
<D:set>
<D:prop>
<Z:author pf:hidden="false">Joe User</Z:author>
<Z:int-doc-id pf:hidden="true">ADJSTCR</Z:int-doc-id>
</D:prop>
</D:set>
</D:propertyupdate>
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>>Response
HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:"
xmlns:Z="http://ns.example.org/standards/z39.50">
<D:response>
<D:href>http://example.org/bar.html</D:href>
<D:propstat>
<D:prop>
<Z:author />
<Z:int-doc-id />
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>
4.2.2 Example for failed PROPPATCH
>>Request
PROPPATCH /bar.html HTTP/1.1
Host: example.org
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:propertyupdate xmlns:D="DAV:"
xmlns:pf="http://sapportals.com/xmlns/cm/webdav"
xmlns:Z="http://ns.example.org/standards/z39.50">
<D:set>
<D:prop>
<Z:author pf:hidden="flase">Joe User</Z:author>
</D:prop>
</D:set>
</D:propertyupdate>
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>>Response
HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:"
xmlns:Z="http://ns.example.org/standards/z39.50">
<D:response>
<D:href>http://example.org/bar.html</D:href>
<D:propstat>
<D:prop><Z:author/></D:prop>
<D:status>HTTP/1.1 422 Unprocessable Entity</D:status>
<D:responsedescription>
Does not parse as xs:boolean
</D:responsedescription>
</D:propstat>
</D:response>
</D:multistatus>
In this case the request failed because the supplied value "flase" is
not a valid value for pf:hidden.
5. Changes for PROPFIND method
5.1 Marshalling of datatype information
PROPFIND is extended to return the data type information for
properties unless one of the following conditions is met:
o The data type MUST be different from "xs:string" (because this can
be considered the default data type).
o The property's data type MUST not be defined in [RFC2518] (because
these types are already well-defined).
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5.1.1 Example for PROPFIND/prop
>>Request
PROPFIND /bar.html HTTP/1.1
Host: example.org
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:"
xmlns:Z="http://ns.example.org/standards/z39.50">
<D:prop>
<D:getcontenttype/>
<Z:released/>
</D:prop>
</D:propfind>
>>Response
HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:"
xmlns:Z="http://ns.example.org/standards/z39.50"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xs="http://www.w3.org/2001/XMLSchema">
<D:response>
<D:href>http://example.org/bar.html</D:href>
<D:propstat>
<D:prop>
<D:getcontenttype>text/html</D:getcontenttype>
<Z:released xsi:type="xs:boolean">1</Z:released>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>
This example shows that the property value "true" is returned with
the correct data type information, and that the server chose one of
the two possible representations defined in XML Schema. It also shows
that data type information is not returned for "D:getcontenttype", as
this property's data type is already defined in [RFC2518].
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5.2 Marshalling of property flags
Marshalling of property flags is triggered by adding extension
elements to the PROPFIND request body accordingly.
<!ELEMENT propfind ((allprop | propname | prop),
pf:include-hidden-flag+,
pf:include-protected-flag+ ) >
<!ELEMENT pf:include-hidden-flag EMPTY >
<!ELEMENT pf:include-protected-flag EMPTY >
Presence of a pf:include-hidden-flag element in the request body
indicated that the server SHOULD include the flag pf:hidden on all
properties. Presence of a pf:include-protected-flag element in the
request body indicated that the server SHOULD include the flag
pf:protected on all properties.
5.2.1 Example for PROPFIND/prop
>>Request
PROPFIND /bar.html HTTP/1.1
Host: example.org
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:"
xmlns:pf="http://sapportals.com/xmlns/cm/webdav"
xmlns:Z="http://ns.example.org/standards/z39.50">
<D:prop>
<D:getcontenttype/>
<D:getetag/>
<Z:author/>
</D:prop>
<pf:include-hidden-flag/>
<pf:include-protected-flag/>
</D:propfind>
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>>Response
HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:"
xmlns:pf="http://sapportals.com/xmlns/cm/webdav"
xmlns:Z="http://ns.example.org/standards/z39.50">
<D:response>
<D:href>http://example.org/bar.html</D:href>
<D:propstat>
<D:prop>
<D:getcontenttype
pf:hidden="false"
pf:protected="true">text/html</D:getcontenttype>
<D:getetag
pf:hidden="true"
pf:protected="true">"abc"</D:getetag>
<Z:author
pf:hidden="false"
pf:protected="false">Joe User</Z:author>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>
6. Compatibility Considerations
6.1 Datatype marshalling
This part of this specification does not introduce any new protocol
elements, nor does it change the informal WebDAV DTD. It merely
specifies additional server semantics for the case where clients
submit additional data type information in an attribute on the
property element (previously undefined), and adds an additional
attribute on property elements upon PROPFIND.
Clients not aware of datatype handling should not supply the
"xsi:type" attribute on property elements (after all, this attribute
belongs to the XML Schema-Instance namespace which has been defined
for exactly this purpose). Old clients should also ignore additional
attributes on property elements returned by PROPFIND (and similar
methods), although the WebDAV specification only defines this
behaviour for unknown elements (and is silent about unknown
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attributes).
Servers not aware of datatype handling either drop the "xsi:type"
attribute, or persist it along with the property value. However, they
will never indicate successful parsing of the data type by returning
back the type in the response to PROPPATCH.
6.2 Property flags
Property flags are only reported upon special request and thus are
never seen by old clients. The PROPFIND request body has been
extended according to the WebDAV XML extensibility rules defined in
[RFC2518], section 14.
Clients not aware of property flags should not supply the attributes
on property elements. This follows from the property flag namespace
being controlled by the authors of this specification.
Servers not aware of property flags either drop them or persist them
along with the property value. No harm is done, unless the client
supplied erroneous values.
6.3 New live properties
The introduction of new WebDAV properties does not affect
compatibility with existing implementations at all.
7. Internationalization Considerations
This proposal builds on [RFC2518], and inherits its
internationalizability.
8. IANA Considerations
This proposal does not introduce any new IANA considerations, since
it does not specify any new namespaces (in the general sense), but
merely uses existing ones.
9. Acknowledgements
This draft has benefited from thoughtful discussion by Stefan Eissing
and Eric Sedlar.
Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
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[RFC2518] Goland, Y., Whitehead, E., Faizi, A., Carter, S. and D.
Jensen, "HTTP Extensions for Distributed Authoring --
WEBDAV", RFC 2518, February 1999.
[RFC3253] Clemm, G., Amsden, J., Ellison, T., Kaler, C. and J.
Whitehead, "Versioning Extensions to WebDAV", RFC 3253,
March 2002.
[XML] Bray, T., Paoli, J., Sperberg-McQueen, C., Maler, E. and
F. Yergeau, "Extensible Markup Language (XML) 1.0 (Third
Edition)", W3C REC-xml-20040204, February 2004, <http://
www.w3.org/TR/2004/REC-xml-20040204>.
[XS1] Thompson, H., Beech, D., Maloney, M., Mendelsohn, N. and
World Wide Web Consortium, "XML Schema Part 1:
Structures", W3C REC-xmlschema-1-20010502, May 2001,
<http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/>.
[XS2] Biron, P., Malhotra, A. and World Wide Web Consortium,
"XML Schema Part 2: Datatypes", W3C
REC-xmlschema-2-20010502, May 2001, <http://www.w3.org/TR/
2001/REC-xmlschema-2-20010502/>.
Informative References
[SEARCH] Reschke, J., Ed., Reddy, S., Davis, J. and A. Babich,
"WebDAV SEARCH", ID draft-reschke-webdav-search-06,
February 2004, <http://greenbytes.de/tech/webdav/
draft-reschke-webdav-search-06.html>.
[SOAP11] Box, D., Ehnebuske, D., Kakivaya, G., Layman, A.,
Mendelsohn, N., Nielsen, H., Thatte, S., Winer, D. and
World Wide Web Consortium, "Simple Object Access Protocol
1.1", W3C NOTE-SOAP-20000508, May 2000, <http://www.w3.org/
TR/2000/NOTE-SOAP-20000508>.
URIs
[1] <mailto:w3c-dist-auth@w3.org>
[2] <mailto:w3c-dist-auth-request@w3.org?subject=subscribe>
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Author's Address
Julian F. Reschke
greenbytes GmbH
Salzmannstrasse 152
Muenster, NW 48159
Germany
Phone: +49 251 2807760
Fax: +49 251 2807761
EMail: julian.reschke@greenbytes.de
URI: http://greenbytes.de/tech/webdav/
Appendix A. Example: marshalling of array-typed properties
As an example for more complex data types, this section shows
marshalling of array-typed properties as implemented in the WebDAV
protocol adapters of SAP Portal's Enterprise Portal System (release
5.0).
As XML Schema [XS2] does not define simple types for arrays, it
builds on the predefined array types used in [SOAP11]. These in turn
can be based on the simple types defined in XML Schema.
Note the following special properties of SOAP-encoded arrays:
1. They require an additional "arrayType" attribute to specify the
array length and the base type.
2. The names of the individual children of the property element
aren't relevant as the type information is already encoded on the
property element itself. It is however recommended to use
identical element names for all array members.
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A.1 Setting of array-typed property
>>Request
PROPPATCH /bar.html HTTP/1.1
Host: example.org
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8"?>
<propertyupdate xmlns="DAV:"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:Z="http://ns.example.org/standards/z39.50"
xmlns:soap-enc="http://schemas.xmlsoap.org/soap/encoding/">
<set>
<prop>
<Z:refs xsi:type="soap-enc:Array"
soap-enc:arrayType="xs:string[2]">
<xs:string>http://www.w3.org/TR/SOAP</xs:string>
<xs:string>http://www.w3.org/TR/xmlschema-2</xs:string>
</Z:refs>
</prop>
</set>
</propertyupdate>
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>>Response
HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<multistatus xmlns="DAV:"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:Z="http://ns.example.org/standards/z39.50"
xmlns:soap-enc="http://schemas.xmlsoap.org/soap/encoding/">
<response>
<href>http://example.org/bar.html</href>
<propstat>
<prop>
<Z:refs xsi:type="soap-enc:Array"
soap-enc:arrayType="xs:string[2]"/>
</prop>
<status>HTTP/1.1 200 OK</status>
</propstat>
</response>
</multistatus>
A.2 Getting an array-typed property
>>Request
PROPFIND /bar.html HTTP/1.1
Host: example.org
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:"
xmlns:Z="http://ns.example.org/standards/z39.50">
<D:prop>
<Z:refs/>
</D:prop>
</D:propfind>
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>>Response
HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:"
xmlns:Z="http://ns.example.org/standards/z39.50"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:soap-enc="http://schemas.xmlsoap.org/soap/encoding/">
<D:response>
<D:href>http://example.org/bar.html</D:href>
<D:propstat>
<D:prop>
<Z:refs xsi:type="soap-enc:Array"
soap-enc:arrayType="xs:string[2]">
<xs:string>http://www.w3.org/TR/SOAP</xs:string>
<xs:string>http://www.w3.org/TR/xmlschema-2</xs:string>
</Z:refs>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>
A.3 Optional DASL operators for queries on array-typed properties
This section lists a set of proposed optional WebDAV SEARCH [SEARCH]
operators for the DAV:basicsearch grammar (note that the standard
operators for DAV:basicsearch are defined to evalute to UNKNOWN for
properties with mixed/element content).
All of the operators below evaluate to UNKNOWN if the property
doesn't exist or isn't array-typed. Also, the operators support the
"caseless" attribute defined for DAV:basicsearch.
The namespace name for all operators below is "http://sapportals.com/
xmlns/cm/webdav". However for brevity, the prefix "sap" is used.
A.3.1 sap:some-eq
Evaluates to TRUE if at least one of the array members equals the
operand.
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A.3.1.1 Example
<sap:some-eq
xmlns:sap="http://sapportals.com/xmlns/cm/webdav"
xmlns:Z="http://ns.example.org/standards/z39.50"
xmlns="DAV:">
<property><Z:refs/></property>
<literal>http://www.w3.org/TR/xmlschema-2</literal>
</sap:some-eq>
The expression above will evaluate to TRUE for the example from
Appendix A.1.
A.3.2 sap:some-gt
Evaluates to TRUE if at least one of the array members is greater
than the operand.
A.3.3 sap:some-gte
Evaluates to TRUE if at least one of the array members is greater or
equal than the operand.
A.3.4 sap:some-like
Evaluates to TRUE if at least one of the array members is "like" the
operand (similar to DAV:basicsearch's "DAV:like" operator).
A.3.5 sap:some-lt
Evaluates to TRUE if at least one of the array members is less than
the operand.
A.3.6 sap:some-lte
Evaluates to TRUE if at least one of the array members is equal or
less than the operand.
A.3.7 sap:some-ne
Evaluates to TRUE if at least one of the array members does not equal
the operand.
Appendix B. Change Log (to be removed by RFC Editor before publication)
B.1 Since 'draft-reschke-webdav-property-datatypes-00'
Editorial fixes.
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Changed examples to explicitly use utf-8 encoding for HTTP content
type and XML encoding.
Added example for marshalling array-typed properties.
B.2 Since 'draft-reschke-webdav-property-datatypes-01'
Fix width of artwork for IETF compliance.
"Non-normative references" -> "Informative references".
B.3 Since 'draft-reschke-webdav-property-datatypes-02'
Added marshalling for property flags such as "hidden" and
"protected".
Moved array marshalling example into back section.
Added rational and description for pf:property-displayname-set.
Added acknowledgements section.
B.4 Since 'draft-reschke-webdav-property-datatypes-03'
Replaced domain names in examples according to RFC2606: "www.foo.com"
by "example.org", "www.example.com" by "ns.example.org/standards/
z39.50/standards/z39.50" and "www.w3.com/standards/z39.50" by
"ns.example.org/standards/z39.50".
B.5 Since 'draft-reschke-webdav-property-datatypes-04'
Remove superfluous IP and copyright sections. Moved "Introduction"
section to front.
B.6 Since 'draft-reschke-webdav-property-datatypes-05'
Added proposal for DAV:basicsearch operators for array-typed
properties. Update all references.
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