Web Services Enumeration (WS-Enumeration)
Latest version:
http://www.w3.org/TR/ws-enumeration
Previous version:
http://www.w3.org/TR/2009/WD-ws-enumeration-20090317
Editors:
Doug Davis, IBM
Ashok Malhotra, Oracle
Katy Warr, IBM
Wu Chou, Avaya
Copyright © 2009 W3C®
(MIT,
ERCIM,
Keio), All Rights Reserved. W3C liability,
trademark
and document
use rules apply.
This specification describes a general
SOAP-based protocol for enumerating a sequence of XML elements that is suitable
for traversing logs, message queues, or other linear information models.
This document is an editors' copy that
has no official standing.
1 Introduction
1.1 Requirements
2 Notations and Terminology
2.1 Notational Conventions
2.2 Considerations on the Use of
Extensibility Points
2.3 XML Namespaces
2.4 Terminology
2.5 Compliance
3 Enumeration Messages
3.1 Enumerate
3.2 Pull
3.3 Renew
3.4 GetStatus
3.5 Release
3.6 EnumerationEnd
4 Faults
4.1 InvalidExpirationTime
4.2 ExpirationTimeExceeded
4.3 UnsupportedExpirationTime
4.4 FilteringNotSupported
4.5 FilterDialectRequestedUnavailable
4.6 CannotProcessFilter
4.7 InvalidEnumerationContext
4.8 TimedOut
4.9 UnusableEPR
4.10 EndToNotSupported
4.11 EmptyFilter
5 Security Considerations
6 WS-Enumeration Metadata
6.1 Enumeration Assertion
7 Acknowledgements
8 References
8.1 Normative References
8.2 Informative References
A XML Schema
B WSDL
C Action Tables
D Change Log
There are numerous applications for which a
simple single-request/single-reply metaphor is insufficient for transferring
large data sets over SOAP. Applications that do not fit into this simple paradigm
include streaming, traversal, query, and enumeration.
This specification defines a simple
SOAP-based protocol for enumeration that allows the data source to provide a
session abstraction, called an enumeration context, to a consumer that
represents a logical cursor through a sequence of data items. The consumer can
then request XML element information items using this enumeration context over
the span of one or more SOAP messages.
Somewhere, state MUST be maintained regarding
the progress of the iteration. This state MAY be maintained between requests by
the data source being enumerated or by the data consumer. WS-Enumeration allows
the data source to decide, on a request-by-request basis, which party will be
responsible for maintaining this state for the next request.
In its simplest form, WS-Enumeration defines
an operation, Enumerate, used to establish the creation of an enumeration
session and another operation, Pull, which allows a data source, in the context
of a specific enumeration, to produce a sequence of XML elements in the body of
a SOAP message. Each subsequent Pull operation returns the next N elements in
the aggregate sequence.
A data source MAY provide a custom mechanism
for starting a new enumeration. For instance, a data source that provides
access to a SQL database can support a SELECT operation that performs a
database query and uses an explicit database cursor to iterate through the
returned rows. In general, however, it is simpler if all data sources support a
single, standard operation to start an enumeration. This specification defines
such an operation, Enumerate, that data sources MUST
implement for starting a new enumeration of a data source. The Enumerate
operation is used to create new enumeration contexts for subsequent traversal/retrieval.
Each Enumerate operation results in a distinct enumeration context, each with
its own logical cursor/position.
Note that different enumerations of the same
data source can produce different results; this can happen even for two enumeration
contexts created concurrently by a single consumer using identical Enumerate
requests. In general, the consumer of an enumeration SHOULD NOT ought
not to make any assumptions about the ordering or completeness of
the enumeration; the returned data items represent a selection by the data
source of items it wishes to present to that consumer at that time in that
order, with no guarantee that every available item is returned or that the
order in which items is returned has any semantic meaning whatsoever (of
course, any specific data source can provide strong guarantees, if so desired).
In particular, note that the very act of enumerating the contents of a data
source can modify the contents of the data source; for instance, a queue might
be represented as a data source such that items that are returned in a Pull
response are removed from the queue.
This specification intends to meet the
following requirements:
·
Support enumeration of data sources that
cannot practically fit into a single SOAP message.
·
Support both server-side and client-side
enumeration state maintenance.
·
Minimize additional mechanism beyond the
current web service architecture.
This section specifies the notations,
namespaces, and terminology used in this specification.
The keywords "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 [RFC
2119].
This
specification uses the following syntax to define normative outlines for
messages:
·
The syntax appears as an XML instance, but
values in italics indicate data types instead of values.
·
Characters are appended to elements and attributes
to indicate cardinality:
·
"?" (0 or 1)
·
"*" (0 or more)
·
"+" (1 or more)
·
The character "|" is used to
indicate a choice between alternatives.
·
The characters "(" and
")" are used to indicate that contained items are to be treated as a
group with respect to cardinality or choice.
·
The characters "[" and
"]" are used to call out references and property names.
·
Ellipsis (i.e.
"...") indicate points of extensibility.
·
XML namespace prefixes (see Table 2-1) are used to indicate the namespace of the
element being defined.
In
addition to Message Information Header properties [WS-Addressing],
this specification uses the following properties to define messages:
[Headers]
Unordered message headers.
[Action]
The value to be used for the wsa:Action
IRI.
[Body]
A message body.
These
properties bind to a SOAP Envelope as follows:
<s:Envelope>
<s:Header>
[Headers]
<wsa:Action>[Action]</wsa:Action>
...
</s:Header>
<s:Body>[Body]</s:Body>
</s:Envelope>
This
specification can be used in terms of XML Information Set (Infoset) [XML Infoset], even though the specification uses XML
1.0 terminology. Valid Infoset for this specification is the one serializable
in XML 1.0, hence the use of XML 1.0.
The
term "generate" is used in relation to the various faults defined by
this specification to imply that a fault is produced and no futher processing
SHOULD be performed. In these cases the fault SHOULD be transmitted. However,
there might be reasons when a compliant implementation can choose not to
transmit the fault - for example, security concerns - in these situations the
fault MAY NOT be transmitted.
The elements defined in this specification
MAY be extended at the points indicated by their outlines and schema.
Implementations MAY add child elements and/or attributes at the indicated
extension points but MUST NOT contradict the semantics of the parent and/or
owner, respectively. If a receiver does not recognize an extension, the
receiver SHOULD ignore that extension. Senders MAY indicate the presence of an
extension that has to be understood through the use of a corresponding SOAP
Header with a soap:mustUnderstand attribute with the
value "1".
In cases where it is either desirable or
necessary for the receiver of a request that has been extended to indicate that
it has recognized and accepted the semantics associated with that extension, it
is RECOMMENDED that the receiver add a corresponding extension to the response
message. The definition of an extension SHOULD clearly specify how the
extension that appears in the response correlates with that in the
corresponding request.
Extension elements and attributes MUST NOT
use the Web Services Enumeration namespace URI.
The XML namespace URI that MUST be used by
implementations of this specification is:
Table 2-1 lists XML namespaces that are used in this
specification. The choice of any namespace prefix is arbitrary and not
semantically significant.
|
Table 2-1: Prefixes and XML namespaces used in this
specification |
||
|
Prefix |
XML Namespace |
Specification(s) |
|
wsen |
This
specification |
|
|
s |
SOAP 1.2 [SOAP12] |
|
|
s11 |
SOAP 1.1 [SOAP11] |
|
|
wsa |
WS-Addressing [WS-Addressing] |
|
|
xs |
XML Schema [XMLSchema - Part 1], [XMLSchema
- Part 2] |
|
|
wsdl |
WSDL/1.1 [WSDL11] |
|
The
working group intends to update the value of the Web Services Enumeration
namespace URI each time a new version of this document is published until such
time that the document reaches Candidate Recommendation status. Once it has
reached Candidate Recommendation status, the working group intends to maintain
the value of the Web Services Enumeration namespace URI that was assigned in
the Candidate Recommendation unless significant changes are made that impact
the implementation or break post-CR implementations of the specification. Also
see http://www.w3.org/2001/tag/doc/namespaceState.html
and http://www.w3.org/2005/07/13-nsuri
.
Consumer
The Web service that
is requesting the data enumeration from the data source
Data Source
A Web service that
supports traversal using enumeration contexts via the Enumerate operation
defined in this specification
Enumeration context
A session context
that represents a specific traversal through a logical sequence of XML element
information items using the Pull operation defined in this specification
An implementation is not compliant with this
specification if it fails to satisfy one or more of the MUST or REQUIRED level
requirements defined herein. A SOAP Node MUST NOT use the XML namespace
identifier for this specification (listed in 2.3
XML Namespaces) within SOAP Envelopes unless it is compliant with this
specification.
Normative
text within this specification takes precedence over the XML Schema and WSDL
descriptions, which in turn take precedence over outlines, which in turn take
precedence over examples.
All
messages defined by this specification MUST be sent to a Web service that is
addressable by an EPR (see [WS-Addressing]).
Unless
otherwise noted, all IRIs are absolute IRIs and IRI comparison MUST be
performed according to [RFC 3987] section 5.3.1.
For
any message defined by this specification, any OPTIONAL elements or attributes
in the message MAY be used by senders of the message,
however receivers of those messages MUST support those OPTIONAL elements and
attributes, unless other behavior is explicitly defined by this specification.
Enumeration contexts represent a specific
traversal through a sequence of XML information items. An Enumerate operation MAY can be
used to establish an enumeration context from a data source. A Pull operation
is used to fetch information items from a data source according to a specific
enumeration context. A Release operation is used to tell a data source that the
consumer is abandoning an enumeration context before it has completed the
enumeration.
Enumeration contexts are represented as XML
data that is opaque to the consumer. Initially, the consumer gets an enumeration
context from the data source by means of an Enumerate operation. The consumer
then passes that XML data back to the data source in the Pull request.
Optionally, the data source MAY return an updated enumeration context in the
Pull response; when present, this new enumeration context MUST replace the old
one on the consumer, and MUST be passed to the data source in all future
requests until and unless the data source again returns an updated enumeration
context.
Callers MAY issue a Release operation against
a valid enumeration context at any time, which causes the enumeration context
to become invalid and allows the data source to free up any resources it might
have allocated to the enumeration. Issuing a Release operation prior to
reaching the end of the sequence of elements is explicitly allowed; however, no
further operations MUST be issued after a Release.
An enumeration context can become invalid for
any reason including:
1.
Enumeration completed (i.e. an EndOfSequence
has been returned in a Pull response)
2.
Enumeration released
3.
Enumeration expired
4.
Enumeration ended (i.e. ended via an
EnumerationEnd message from data source
5.
Enumeration context replaced in the response
to another Pull request
In addition, the data source MAY invalidate
an enumeration context at any time, as necessary.
When processing a Pull, Renew, GetStatus or
Release operation, a data source MUST generate an wsen:InvalidEnumerationContext
fault if it determines that the enumeration context supplied by the consumer in
the request is invalid.
Note that the data source might not be able
to determine that an enumeration context is invalid, especially if all of the
state associated with the enumeration is kept in the enumeration context and
refreshed on every PullResponse or RenewResponse.
This specification defines the Enumerate
operation to start an enumeration. This operation MUST be supported by
compliant data sources. A data source MAY provide other mechanisms for
starting an enumeration and receiving an enumeration context.
The Enumerate operation is initiated by
sending an Enumerate request message to the data source. The Enumerate request
message MUST be of the following form:
[Action]
http://www.w3.org/2009/09/ws-enu/Enumerate
[Body]
<wsen:Enumerate
...>
<wsen:EndTo>endpoint-reference</wsen:EndTo>
?
<wsen:Expires
min="(xs:dateTime
| xs:duration)"?
max="(xs:dateTime
| xs:duration)"?
exact="xs:boolean"? ...>
(xs:dateTime | xs:duration)
</wsen:Expires>
?
<wsen:Filter
Dialect="xs:anyURI"?>
xs:any
</wsen:Filter> ?
xs:any*
</wsen:Enumerate>
The following describes additional, normative
constraints on the outline listed above:
[Body]/wsen:Enumerate/wsen:EndTo
This OPTIONAL element
denotes where to send an EnumerationEnd message if the enumeration is
terminated unexpectedly (see 3.6
EnumerationEnd). If present, this element MUST be of type wsa:EndpointReferenceType. Default is to not send this message.
The endpoint to which the EndTo EPR refers MUST support the
EnumerationEndPortType portType.
If the data source does not support the use of the EndTo
EPR, the data source MUST generate a wsen:EndToNotSupported
fault.
[Body]/wsen:Enumerate/wsen:Expires
This OPTIONAL element can be used by the consumer to
indicate the expiration time of the requested enumeration. The value of this
element indicates the desired expiration time for the enumeration. The implied
default is indefinite (no expiry). The value of this element MUST be between
the values of the @min and @max attributes inclusive. If the request is
malformed, the data source MUST generate a wsen:InvalidExpirationTime
fault.
If the wsen:Expires element is present and the data
source is not able to grant an expiry time within range indicated by the @min
and @max attribute values, it MUST generate a wsen:ExpirationTimeExceeded
fault.
The value of the wsen:Expires
element as well as those of its @min and @max attributes MAY be either a
duration (xs:duration) or a specific time (xs:dateTime). Data sources MUST
accept duration values and MAY accept specific time values. Upon receiving a
request that contains specific time values, a data source that does not support
such value types MUST fail the request and generate a wsen:UnsupportedExpirationType
fault.
The value types in a wsen:Expires
element MAY differ among the element and its attributes. For example, the
element value can be a duration while the @max attribute
can be a specific time. Regardless of the value types, it MUST be true that
wsen:Expires/@min <= wsen:Expires <=
wsen:Expires/@max as interpreted by the data source at the time the
wsen:Enumerate request is processed. If this is not true, the request MUST fail
and the receiver MUST generate a wsen:InvalidExpirationTime
fault.
If a consumer chooses to use specific time values in a
request, it is RECOMMENDED that these values include a time zone component.
Specific time values that lack a time zone MUST be interpreted in the local
time zone of the receiver.
[Body]/wsen:Enumerate/wsen:Expires@min
The implied default is PT0S. This specifies the minimum
expiration time that the consumer is willing to accept.
[Body]/wsen:Enumerate/wsen:Expires@max
The implied default is indefinite (no expiry). This
specifies the maximum expiration time that the consumer is willing to accept.
[Body]/wsen:Enumerate/wsen:Expires@exact
The default value is "false" in which case this
attribute has no effect. If this attribute value is "true" both @min
and @max attributes MUST be ignored and are treated as if they had the same
value as the wsen:Expires element.
[Body]/wsen:Enumerate/wsen:Filter
This OPTIONAL element contains a Boolean predicate in
some dialect (see [[Body]/wsen:Enumerate/wsen:Filter/@Dialect ]) that all elements of interest MUST
satisfy. The resultant enumeration context MUST NOT return elements for which
this predicate expression evaluates to the value false. If this element is
absent, then the implied value is the expression true(),
indicating that no filtering is desired.
If the data source does not support filtering, the
request MUST fail, and the data source MUST generate a wsen:FilteringNotSupported
fault.
If the data source supports filtering but cannot honor
the requested filter dialect, the request MUST fail, and the data source MUST
generate a wsen:FilterDialectRequestedUnavailable
fault.
If the data source supports filtering and the requested
dialect but cannot process the requested filter content, the request MUST fail,
and the data source MUST generate a wsen:CannotProcessFilter
fault.
It is possible for an Enumerate request to contain a
filter that will never evaluate to true for the lifetime of the enumeration. If
a data source detects this condition it MUST generate a wsen:EmptyFilter
fault in response to the Enumerate request message.
[Body]/wsen:Enumerate/wsen:Filter/@Dialect
Implied value is
"http://www.w3.org/2009/09/ws-enu/Dialects/XPath10".
If filtering is
supported, then support for the XPath 1.0 dialect (described below) is
RECOMMENDED. Alternate filter dialects can be defined. Such dialect definitions
MUST include sufficient information for proper application. For example, it
would need to define the context (which data) over which the filter operates.
[Body]/wsen:Enumerate/wsen:Filter/@Dialect="
http://www.w3.org/2009/09/ws-enu/Dialects/XPath10
Value of [Body]/wsenu:Enumerate/wsen:Filter
is an XPath [XPath1.0] predicate expression
(PredicateExpr); the context of the expression is:
·
Context Node: any XML element that could be
returned as a direct child of the wsen:Items element.
·
Context Position: 1.
·
Context Size: 1.
·
Variable Bindings: None.
·
Function Libraries: Core Function Library [XPath1.0].
·
Namespace Declarations: The [in-scope
namespaces] property [XML Infoset] of [Body]/wsen:Enumerate/wsen:Filter.
The namespace bindings are evaluated against any
namespace declarations that are in scope where the XPath expression appears
within the SOAP message. Note that the evaluation of expressions that rely on
such context dependent bindings is fragile in the face of transformations that
alter namespace prefixes. Such transformations might occur during the
transmission, processing, storage, or retrieval of a request. Clients that wish
to isolate expressions from the effects of any changes to the namespace
prefixes in the containing SOAP message are advised to construct expressions in
a manner that avoids the use of namespace prefixes. For example, use an
expression such as "/a[namespace-uri()='http://www.example.com']"
not "/ns1:a".
Other
components of the outline above are not further constrained by this
specification.
If
included within the Enumerate request message, the wsen:EndTo
SHOULD have some cursory validity checking performed before the Enumerate
response is returned. While not all errors can be detected prior to sending a
message to that EPR, some obvious ones can be detected. For example, an
unsupported transport specified within the wsa:Address
IRI. Detecting these errors during Enumerate processing will lessen the chances
of the consumer creating an unusable enumeration. If this check is performed
and a problem is detected then the data source MUST generate a wsen:UnusableEPR fault rather than returning the
EnumerateResponse message.
Upon
successful processing of an Enumerate request message, a data source is
expected to create an enumeration context and return that context in an
Enumerate response message, which MUST adhere to the following form:
[Action]
http://www.w3.org/2009/09/ws-enu/EnumerateResponse
[Body]
<wsen:EnumerateResponse ...>
<wsen:GrantedExpires ...>
(xs:dateTime | xs:duration)
</wsen:GrantedExpires> ?
<wsen:EnumerationContext
...>...</wsen:EnumerationContext>
xs:any*
</wsen:EnumerateResponse>
The
following describes additional, normative constraints on the outline listed
above:
[Body]/wsen:EnumerateResponse/wsen:GrantedExpires
The expiration time assigned by the
data source. The expiration time MAY be either a specific time or a
duration but MUST be of the same type as the wsen:Expires
element of the corresponding request. If the corresponding request did not
contain a wsen:Expires element, this element MUST be a
duration (xs:duration).
When expressed as a duration, the wsen:GrantedExpires
element designates a time interval that began at the moment the enumeration is
created. Although this specification cannot dictate when, during the processing
of a Enumerate request, an enumeration is created, the data source MUST start
the expiration interval at or before it transmits the wsen:EnumerateResponse
message.
If this element does not appear, then the enumeration
will not expire. That is, the enumeration has an indefinite lifetime. It will
terminate when the end of the enumeration is reached, or if the consumer sends
a Release request, or by the data source at any time for reasons such as
connection termination, resource constraints, or system shut-down.
[Body]/wsen:EnumerateResponse/wsen:EnumerationContext
The required EnumerationContext element contains the XML
representation of the new enumeration context. The consumer is required to pass
this XML data in Pull requests for this enumeration context, until and unless a
PullResponse or RenewResponse message updates the enumeration context.
Example 3-1 lists a sample Enumerate request.
(01) <s:Envelope
xmlns:S="http://www.w3.org/2003/05/soap-envelope"
(02)
xmlns:wsa="http://www.w3.org/2005/08/addressing"
(03) xmlns:wsen="http://www.w3.org/2009/09/ws-enu">
(04) <s:Header>
(05) <wsa:Action>
(06)
http://www.w3.org/2009/09/ws-enu/Enumerate
(07) </wsa:Action>
(08) <wsa:MessageID>
(09) uuid:e7c5726b-de29-4313-b4d4-b3425b200839
(10) </wsa:MessageID>
(11)
<wsa:To>http://www.example.com/relayAgent/enum19</wsa:To>
(12) <wsa:ReplyTo>
(13) <wsa:Address>
(14)
http://www.w3.org/2005/08/addressing/anonymous
(15) </wsa:Address>
(16) </wsa:ReplyTo>
(17) </s:Header>
(18) <s:Body>
(19) <wsen:Enumerate>
(20) <wsen:Expires
min="PT10M"> PT10M </wsen:Expires>
(21) </wsen:Enumerate>
(22) </s:Body>
(23) </s:Envelope>
Lines (05-07) in Example
3-1 indicate this message is an Enumerate request and that the data source
is expected to respond with an Enumerate response message. The wsen:Expires
element on line (20) indicates that the consumer would like an enumeration
context that will be good for at least 10 minutes; that is, it expects to
complete its enumeration within a 10 minute period. No wsen:Filter
element is present, so the resultant enumeration context is expected to return
all available elements.
Example 3-2 lists a response to the request in Example 3-1.
Example 3-2:
Response to Enumerate request
(01) <s:Envelope
xmlns:S='http://www.w3.org/2003/05/soap-envelope'
(02) xmlns:wsen='http://www.w3.org/2009/09/ws-enu'
(03) xmlns:wsa='http://www.w3.org/2005/08/addressing'>
(04) <s:Header>
(05) <wsa:Action>
(06)
http://www.w3.org/2009/09/ws-enu/EnumerateResponse
(07) </wsa:Action>
(08) <wsa:RelatesTo>
(09) uuid:e7c5726b-de29-4313-b4d4-b3425b200839
(10) </wsa:RelatesTo>
(11) <wsa:To>
(12)
http://www.w3.org/2005/08/addressing/anonymous
(13) <wsa:To>
(14) </s:Header>
(15) <s:Body>
(16) <wsen:EnumerateResponse>
(17) <wsen:Expires>
PT15M </wsen:Expires>
(18) <wsen:EnumerationContext>
(19) 123
(20) </wsen:EnumerationContext>
(21) </wsen:EnumerateResponse>
(22) </s:Body>
(23) </s:Envelope>
Lines (05-07) in Example
3-2 indicate this message is an Enumerate response message. Line (17)
indicates that the data source has actually created an enumeration context with
a lifetime of 15 minutes. Lines (18-20) are the XML representation of the
enumeration context that supports the Pull operation defined below.
The Pull operation is initiated by sending a
Pull request message to the data source. This operation MUST be supported by
compliant data sources. The Pull request message MUST be of the following form:
[Action]
http://www.w3.org/2009/09/ws-enu/Pull
[Body]
<wsen:Pull
...>
<wsen:EnumerationContext
...>...</wsen:EnumerationContext>
<wsen:MaxTime>xs:duration</wsen:MaxTime>
?
<wsen:MaxElements>xs:long</wsen:MaxElements>
?
<wsen:MaxCharacters>xs:long</wsen:MaxCharacters>
?
xs:any*
</wsen:Pull>
The following describes additional, normative
constraints on the outline listed above:
[Body]/wsen:Pull/wsen:EnumerationContext
This required
element contains the XML data that represents the current enumeration context.
[Body]/wsen:Pull/wsen:MaxTime
This OPTIONAL
element (of type xs:duration) indicates the maximum
amount of time the initiator is willing to allow the data source to assemble
the Pull response. When this element is absent, the data source is not required
to limit the amount of time it takes to assemble the Pull response. The data
source MUST recognize the wsen:MaxTime element and
return a wsen:TimedOut fault if no elements are available prior to the request
message's deadline.
This is useful with
data sources that accumulate elements over time and package them into a single
Pull response.
[Body]/wsen:Pull/wsen:MaxElements
This OPTIONAL
element (of type xs:long) indicates the number of
items (child elements of wsen:Items in the Pull response) the consumer is willing
to accept. When this element is absent, its implied value is 1. Implementations
MUST NOT return more than this number of elements in the Pull response message.
Implementations MAY return fewer than this number based on either the wsen:MaxTime timeout, the wsen:MaxCharacters size limit, or
implementation-specific constraints.
[Body]/wsen:Pull/wsen:MaxCharacters
This OPTIONAL
element (of type xs:long) indicates the maximum size
of the returned elements, in Unicode characters, that the initiator is willing
to accept. When this element is absent, the data source is not required to
limit the number of characters in the Pull response. Implementations MUST NOT
return a Pull response message whose wsen:Items
element, and all of its children, is larger than MaxCharacters. Implementations
MAY return a smaller message based on the wsen:MaxTime
timeout, the wsen:MaxElements limit, or implementation-specific constraints.
Even if a Pull
request contains a MaxCharacters element, the consumer MUST be prepared to
receive a Pull response that contains more data characters than specified, as
XML canonicalization or alternate XML serialization algorithms can change the
size of the representation.
It can happen that
the next item the data source would return to the consumer is larger than
MaxCharacters. In this case, the data source MAY skip the item, or MAY return
an abbreviated representation of the item that fits inside MaxCharacters. If
the data source skips the item, it MAY return it as part of the response to a
future Pull request with a larger value of MaxCharacters, or it MAY omit it
entirely from the enumeration. If the oversized item is the last item to be
returned for this enumeration context and the data source skips it, it MUST
include the wsen:EndOfSequence item in the Pull
response and invalidate the enumeration context. See the discussion of wsen:EndOfSequence below.
Other components of the outline above are not
further constrained by this specification.
Upon receipt of a Pull request message, the
data source MAY wait as long as it deems necessary (but not longer than the
value of the wsen:MaxTime element, if present) to
produce a message for delivery to the consumer. The data source MUST recognize
the wsen:MaxTime element and return a wsen:TimedOut
fault if no elements are available prior to the request message's deadline.
Note, however, that this fault SHOULD NOT cause the enumeration context to
become invalid (of course, the data source MAY invalidate the enumeration context
for other reasons). That is, the requestor can issue additional Pull requests
using this enumeration context after receiving this fault.
Upon successful processing of a Pull request
message, a data source is expected to return a Pull response message, which
MUST adhere to the following form:
[Action]
http://www.w3.org/2009/09/ws-enu/PullResponse
[Body]
<wsen:PullResponse
...>
<wsen:EnumerationContext
...>...</wsen:EnumerationContext> ?
<wsen:Items>
<xs:any>
enumeration-specific element </xs:any> +
</wsen:Items>
?
<wsen:EndOfSequence/>
?
xs:any*
</wsen:PullResponse>
The following describes additional, normative
constraints on the outline listed above:
[Body]/wsen:PullResponse/wsen:EnumerationContext
The OPTIONAL EnumerationContext
element, if present, contains a new XML representation of the current
enumeration context. The consumer MUST replace the prior representation with
the contents of this element.
[Body]/wsen:PullResponse/wsen:Items/xs:any
The OPTIONAL Items
element contains one or more enumeration-specific elements, one for each
element being returned.
[Body]/wsen:PullResponse/wsen:EndOfSequence
This OPTIONAL
element indicates that no more elements are available from this enumeration and
the enumeration context sent by the consumer in the request becomes invalid.
Note that at least one of wsen:Items or wsen:EndOfSequence MUST appear. It is possible for
both to appear if items are returned and the sequence is exhausted. Similarly,
wsen:EnumerationContext and wsen:EndOfSequence MUST
NOT both appear; neither can appear, or one without the other, but not both in
the same PullResponse.
Example 3-3 lists a Pull request.
(01) <s:Envelope xmlns:S="http://www.w3.org/2003/05/soap-envelope"
(02)
xmlns:wsa="http://www.w3.org/2005/08/addressing"
(03)
xmlns:wsen="http://www.w3.org/2009/09/ws-enu">
(04) <s:Header>
(05) <wsa:Action>
(06)
http://www.w3.org/2009/09/ws-enu/Pull
(07) </wsa:Action>
(08) <wsa:MessageID>
(09) uuid:e7c5726b-de29-4313-b4d4-b3425b200839
(10) </wsa:MessageID>
(11)
<wsa:To>http://www.example.com/relayAgent</wsa:To>
(12) <wsa:ReplyTo>
(13) <wsa:Address>
(14) http://www.w3.org/2005/08/addressing/anonymous
(15) </wsa:Address>
(16) </wsa:ReplyTo>
(17) </s:Header>
(18) <s:Body>
(19) <wsen:Pull>
(20) <wsen:EnumerationContext>123</wsen:EnumerationContext>
(21) <wsen:MaxTime>P30S</wsen:MaxTime>
(22) <wsen:MaxElements>10</wsen:MaxElements>
(23) </wsen:Pull>
(24) </s:Body>
(25) </s:Envelope>
Lines (05-07) in Example
3-3 indicate this message is a Pull request and that the data source is
expected to respond with a Pull response message. Line (21) indicates that the
response message SHOULD be generated no more than 30 seconds after receipt of
the Pull request message. Line (22) indicates that no more than 10 elements can
be returned in the body of the Pull response message.
Example 3-4 lists a response to the request in Example 3-3.
Example 3-4:
Response to Pull request
(01) <s:Envelope
xmlns:S="http://www.w3.org/2003/05/soap-envelope"
(02) xmlns:wsen="http://www.w3.org/2009/09/ws-enu"
(03)
xmlns:wsa="http://www.w3.org/2005/08/addressing">
(04) <s:Header>
(05) <wsa:Action>
(06)
http://www.w3.org/2009/09/ws-enu/PullResponse
(07) </wsa:Action>
(08) <wsa:RelatesTo>
(09) uuid:e7c5726b-de29-4313-b4d4-b3425b200839
(10) </wsa:RelatesTo>
(11) <wsa:To>
(12)
http://www.w3.org/2005/08/addressing/anonymous
(13) <wsa:To>
(14) </s:Header>
(15) <s:Body>
(16) <wsen:PullResponse>
(17) <wsen:Items
xmlns:xx="http://fabrikam123.example.com/schema/log">
(18) <xx:LogEntry
id="1">System booted</xx:LogEntry>
(19) <xx:LogEntry
id="2">AppX started</xx:LogEntry>
(20) <xx:LogEntry
id="3">John Smith logged on</xx:LogEntry>
(21) <xx:LogEntry
id="4">AppY started</xx:LogEntry>
(22) <xx:LogEntry
id="5">AppX crashed</xx:LogEntry>
(23) </wsen:Items>
(24) <wsen:EndOfSequence/>
(25) </wsen:PullResponse>
(26) </s:Body>
(27) </s:Envelope>
Lines (05-07) in Example
3-4 indicate this message is a Pull response message. Lines (18-22) are the
five elements returned by this Pull request. The presence of a wsen:EndOfSequence element (line (24)) indicates that no more
elements are available and that the enumeration context is now invalid.
The
consumer MUSTSHOULD NOT
issue additional Pull request messages after a Pull response containing a wsen:EndOfSequence element has been returned. Similarly, upon
receipt of a Pull response containing a wsen:EndOfSequence
element, the consumer MUSTSHOULD
NOT issue a Release operation to signal that the enumeration context is no
longer needed.
To update, or renew, the expiration for an
enumeration, a Renew request message is sent to the data source. This operation
MUST be supported by compliant data sources. The Renew request message MUST be
of the following form:
[Action]
http://www.w3.org/2009/09/ws-enu/Renew
[Body]
<wsen:Renew
...>
<wsen:EnumerationContext
...>...</wsen:EnumerationContext>
<wsen:Expires
min="(xs:dateTime
| xs:duration)"?
max="(xs:dateTime
| xs:duration)"?
exact="xs:boolean"? ...>
(xs:dateTime | xs:duration)
</wsen:Expires>
?
xs:any*
</wsen:Renew>
Components of the outline listed above are
additionally constrained as for a request to create an enumeration (see 3.1 Enumerate) with the following addition(s):
[Body]/wsen:Renew/wsen:EnumerationContext
This REQUIREDrequired
element contains the XML data that represents the current enumeration context.
Other
components of the outline above are not further constrained by this
specification.
If
the data source accepts a request to renew an enumeration, it MUST reply with a
response of the following form:
[Action]
http://www.w3.org/2009/09/ws-enu/RenewResponse
[Body]
<wsen:RenewResponse ...>
<wsen:GrantedExpires ...>
(xs:dateTime | xs:duration)
</wsen:GrantedExpires> ?
<wsen:EnumerationContext
...>...</wsen:EnumerationContext> ?
xs:any*
</wsen:RenewResponse>
Components
of the outline listed above are constrained as for a response to an Enumerate
request (see 3.1 Enumerate) with the following
addition:
[Body]/wsen:RenewResponse/wsen:EnumerationContext
This element is OPTIONAL in this response.
If
the data source chooses not to renew this enumeration, the request MUST fail,
and the data source MUST generate a SOAP 1.1 Server fault or a SOAP 1.2
Receiver fault indicating that the renewal was not accepted.
Other
components of the outline above are not further constrained by this
specification.
To get the status of an enumeration, the
consumer sends a GetStatus request message to the data source. This operation
MUST be supported by compliant data sources. The message MUST be of the
following form:
[Action]
http://www.w3.org/2009/09/ws-enu/GetStatus
[Body]
<wsen:GetStatus
...>
<wsen:EnumerationContext
...>...</wsen:EnumerationContext> ?
xs:any*
</wsen:GetStatus>
Components of the outline listed above are
additionally constrained as for a request to renew an enumeration (see 3.3 Renew). Other components of the outline above are
not further constrained by this specification.
If
the enumeration is valid the data source MUST reply with a response of the
following form:
[Action]
http://www.w3.org/2009/09/ws-enu/GetStatusResponse
[Body]
<wsen:GetStatusResponse ...>
<wsen:GrantedExpires ...>
(xs:dateTime | xs:duration)
</wsen:GrantedExpires> ?
xs:any*
</wsen:GetStatusResponse>
Components
of the outline listed above are constrained as for a response to a renew
request (see 3.3 Renew). Other components of the
outline above are not further constrained by this specification.
This
operation is safe; it will not result in any side effect imputable to the
requester. This means that in case of an underlying protocol error that might
get unnoticed, resending the same request can be done automatically.
The Release operation is initiated by sending
a Release request message to the data source. This operation MUST be supported
by compliant data sources. The Release request message MUST be of the following
form:
[Action]
http://www.w3.org/2009/09/ws-enu/Release
[Body]
<wsen:Release
...>
<wsen:EnumerationContext
...>...</wsen:EnumerationContext>
xs:any*
</wsen:Release>
The following describes additional, normative
constraints on the outline listed above:
[Body]/wsen:Release/wsen:EnumerationContext
This REQUIREDrequired
element contains the XML data that represents the enumeration context being
abandoned.
Other components of the outline above are not
further constrained by this specification.
Upon successful processing of a Release
request message, a data source MUSTis
expected to return a Release response message, which MUST adhere
to the following form:
[Action]
http://www.w3.org/2009/09/ws-enu/ReleaseResponse
[Body]
<wsen:ReleaseResponse
...>
xs:any*
</wsen:ReleaseResponse>
Example 3-5 lists a Release request.
(01) <s:Envelope
xmlns:S="http://www.w3.org/2003/05/soap-envelope"
(02) xmlns:wsa="http://www.w3.org/2005/08/addressing"
(03)
xmlns:wsen="http://www.w3.org/2009/09/ws-enu">
(04) <s:Header>
(05) <wsa:Action>
(06)
http://www.w3.org/2009/09/ws-enu/Release
(07) </wsa:Action>
(08) <wsa:MessageID>
(09) uuid:e7c5726b-de29-4313-b4d4-b3425b200839
(10) </wsa:MessageID>
(11)
<wsa:To>http://www.example.com/relayAgent</wsa:To>
(12) <wsa:ReplyTo>
(13) <wsa:Address>
(14)
http://www.w3.org/2005/08/addressing/anonymous
(15) </wsa:Address>
(16) </wsa:ReplyTo>
(17) </s:Header>
(18) <s:Body>
(19) <wsen:Release>
(20) <wsen:EnumerationContext>123</wsen:EnumerationContext>
(21) </wsen:Release>
(22) </s:Body>
(23) </s:Envelope>
Lines (05-07) in Example
3-5 indicate this message is a Release request and that the data
source is expected to respond with a Release response message.
Line (20) identifies the enumeration context to be released.
Example 3-6 lists a response to the request in Example 3-5.
(01) <s:Envelope
xmlns:S="http://www.w3.org/2003/05/soap-envelope"
(02)
xmlns:wsen="http://www.w3.org/2009/09/ws-enu"
(03) xmlns:wsa="http://www.w3.org/2005/08/addressing">
(04) <s:Header>
(05) <wsa:Action>
(06)
http://www.w3.org/2009/09/ws-enu/ReleaseResponse
(07) </wsa:Action>
(08) <wsa:RelatesTo>
(09) uuid:e7c5726b-de29-4313-b4d4-b3425b200839
(10) </wsa:RelatesTo>
(11) <wsa:To>
(12)
http://www.w3.org/2005/08/addressing/anonymous
(13) <wsa:To>
(14) </s:Header>
(15) <s:Body>
(16) <wsen:ReleaseResponse/>
(17) </s:Body>
(18) </s:Envelope>
Lines (05-07) in Example
3-6 indicate this message is a Release response message.
If the data source terminates an
enumeration unexpectedly, and it supports the use of the EndTo EPR, and the
EndTo EPR was present in the Enumerate message for that enumeration (see 3.1 Enumerate), the EnumerationEnd message MUST be
sent to the endpoint reference indicated by that EPR. The message MUST be of
the following form:
[Action]
http://www.w3.org/2009/09/ws-enu/EnumerationEnd
[Body]
<wsen:EnumerationEnd ...>
<wsen:Code>
( http://www.w3.org/2009/09/ws-enu/SourceShuttingDown |
http://www.w3.org/2009/09/ws-enu/SourceCancelling |
xs:anyURI )
</wsen:Code>
<wsen:Reason xml:lang="language identifier" >
xs:string
</wsen:Reason> ?
xs:any*
</wsen:EnumerationEnd>
The
following describes additional, normative constraints on the outline listed
above:
[Body]/wsen:EnumerationEnd/wsen:Code
= "http://www.w3.org/2009/09/ws-enu/SourceShuttingDown"
This value MUST be used if the data source terminated the
enumeration because the source is being shut down in a controlled manner; that
is, if the data source is being shut down but has the opportunity to send an
EnumerationEnd message before it exits.
[Body]/wsen:EnumerationEnd/wsen:Code
= "http://www.w3.org/2009/09/ws-enu/SourceCancelling"
This value MUST be used if the data source terminated the
enumeration for some other reason before it expired.
[Body]/wsen:EnumerationEnd/wsen:Reason
This OPTIONAL element contains text, in the language
specified by the @xml:lang attribute, describing the
reason for the unexpected enumeration termination.
Other
components of the outline above are not further constrained by this
specification.
All fault messages defined in this
specification MUST be sent according to the rules and usage described in [WS-Addressing 1.0 SOAP Binding] Section 6 for encoding
SOAP 1.1 and SOAP 1.2 faults. The [Action] property below MUST be used
for faults defined in this specification:
The
definitions of faults in this section use the following properties:
[Code] The fault code.
[Subcode] The fault subcode.
[Reason] The English language reason element.
[Detail] The detail element. If
absent, no detail element is defined for the fault.
For
SOAP 1.2, the [Code] property MUST be either "Sender" or
"Receiver". These properties are serialized into text XML as follows:
|
Sender
|
Receiver
|
|
|
SOAP 1.2 |
s12:Sender |
s12:Receiver |
The properties above bind to a SOAP 1.2 fault
as follows:
<s12:Envelope>
<s12:Header>
<wsa:Action>
[Action] </wsa:Action>
<!--
Headers elided for brevity. -->
</s12:Header>
<s12:Body>
<s12:Fault>
<s12:Code>
<s12:Value>[Code]</s12:Value>
<s12:Subcode>
<s12:Value>[Subcode]</s12:Value>
</s12:Subcode>
</s12:Code>
<s12:Reason>
<s12:Text
xml:lang="en">[Reason]</s12:Text>
</s12:Reason>
<s12:Detail>
[Detail]
...
</s12:Detail>
</s12:Fault>
</s12:Body>
</s12:Envelope>
The properties bind to a SOAP 1.1 fault as
follows:
<s11:Envelope>
<s11:Body>
<s11:Fault>
<faultcode>[Subcode]</faultcode>
<faultstring xml:lang="en">[Reason]</faultstring>
<detail>
[Detail]
...
</detail>
</s11:Fault>
</s11:Body>
</s11:Envelope>
This fault MUST be
generated when a request specified an expiration that is malformed.
|
[Code] |
s12:Sender |
|
[Subcode] |
wsen:InvalidExpirationTime |
|
[Reason] |
Invalid expiration time. |
|
[Detail] |
|
This fault MUST be
generated when a request specifies an expiration that is not within the min/max
range.
|
[Code] |
s12:Sender |
|
[Subcode] |
wsen:ExpirationTimeExceeded |
|
[Reason] |
The expiration time requested is not
within the min/max range. |
|
[Detail] |
|
This fault MUST be
generated when the Enumerate expiration time that is specified is not a duration.
|
[Code] |
s12:Sender |
|
[Subcode] |
wsen:UnsupportedExpirationTime |
|
[Reason] |
Unsupported expiration time. |
|
[Detail] |
|
This fault MUST
generated when the data source does not support filters.
|
[Code] |
s12:Sender |
|
[Subcode] |
wsen:FilteringNotSupported |
|
[Reason] |
Filtering not supported. |
|
[Detail] |
|
This fault MUST be
generated when the data source does not support the requested filter dialect.
|
[Code] |
s12:Sender |
|
[Subcode] |
wsen:FilterDialectRequestedUnavailable |
|
[Reason] |
Filer dialect requested unavailable. |
|
[Detail] |
<wsen:SupportedDialect> + |
This fault MUST be
generated when the data source can not process the filter content.
|
[Code] |
s12:Sender |
|
[Subcode] |
wsen:CannotProcessFilter |
|
[Reason] |
Cannot filter as requested. |
|
[Detail] |
|
This fault MUST be
generated when the enumeration context is invalid.
|
[Code] |
s12:Receiver |
|
[Subcode] |
wsen:InvalidEnumerationContext |
|
[Reason] |
Text explaining why the enumeration
context is no longer valid, or "Invalid
enumeration context" if no
additional information is available. |
|
[Detail] |
|
This fault MUST be generated when the data
source times out during the processing of a Pull operation, if the wsen:MaxTime is reached.
|
[Code] |
s12:Receiver |
|
[Subcode] |
wsen:TimedOut |
|
[Reason] |
Timeout. |
|
[Detail] |
|
This fault MUST be generated when a
data source detects that the wsen:EndTo EPR is
unusable.
|
[Code] |
s12:Sender |
|
[Subcode] |
wsen:UnusableEPR |
|
[Reason] |
The wsen:EndTo
EPR is unusable. |
|
[Detail] |
Details as to why the EPR is unusable. |
This fault MUST be generated by an data
source that does not support /wsen:Enumerate/wsen:EndTo
semantics, in response to a enumerate request that contains a wsen:EndTo
element.
|
[Code] |
s12:Sender |
|
[Subcode] |
wsen:EndToNotSupported |
|
[Reason] |
wsen:EndTo semantics is not supported. |
|
[Detail] |
none |
This fault MUST be generated when a
data source detects a wsen:Enumerate request
containing a filter that, for whatever reason, will never evaluate to true.
|
[Code] |
s12:Sender |
|
[Subcode] |
wsen:EmptyFilter |
|
[Reason] |
The wsen:Filter
would result in zero data items. |
|
[Detail] |
The wsen:Filter
value. |
It is strongly RECOMMENDED that the
communication between services be secured using the mechanisms described in [WS-Security].
In
order to properly secure messages, the body (even if empty) and all relevant
headers need to be included in the signature. Specifically, the WS-Addressing
header blocks, WS-Security timestamp, and any header blocks resulting from a <wsa:ReferenceParameters> in references need
to be signed along with the body in order to "bind" them together and
prevent certain types of attacks.
If
a requestor is issuing multiple messages to a Web service, such as when a
consumer is enumerating a data source, it is RECOMMENDED that a security
context be established using the mechanisms described in [WS-SecureConversation]. It is often
appropriate to establish a security context that is used both for the
initiation of enumeration (i.e., the Enumerate request or an equivalent service-specific
request) and the actual enumeration itself (i.e., the Pull requests). It is
further RECOMMENDED that if shared secrets are used, message-specific derived
keys SHOULD be used to protect the secret from crypto attacks.
The
access control semantics of data sources is out-of-scope of this specification
and are specific to each data source. Similarly, any protection mechanisms on
data source independent of their transfer (e.g. embedded signatures and
encryption) are also out-of-scope.
It
is RECOMMENDED that the security considerations of WS-Security also be
considered.
While
a comprehensive set of attacks is not feasible, the following list summarizes
common classes of attacks that apply to this protocol and identifies the
mechanism(s) to prevent/mitigate the attacks.
·
Replay - Messages, or
portions of messages, can be replayed in an attempt to gain access or disrupt
services. Freshness checks such as timestamps, digests, and sequences can be
used to detect duplicate messages.
·
Invalid tokens - There are a
number of token attacks including certificate authorities, false signatures,
and PKI attacks. Care SHOULD be taken to ensure each token is valid (usage
window, digest, signing authority, revocation, ...),
and that the appropriate delegation policies are in compliance.
·
Man-in-the-middle - The message
exchanges in this specification could be subject to man-in-the-middle attacks
so care SHOULD be taken to reduce possibilities here such as establishing a
secure channel and verifying that the security tokens user represent identities
authorized to speak for, or on behalf of, the desired resource reference.
·
Message alteration - Alteration is
prevented by including signatures of the message information using WS-Security.
Care SHOULD be taken to review message part references to ensure they haven't
been forged (e.g. ID duplication).
·
Message disclosure - Confidentiality
is preserved by encrypting sensitive data using WS-Security.
·
Key integrity - Key integrity is
maintained by using the strongest algorithms possible (by comparing secured
policies - see [WS-Policy] and [WS-SecurityPolicy]) and by using derived keys ([WS-SecureConversation]).
·
Authentication - Authentication is
established using the mechanisms described in WS-Security and WS-Trust. Each
message is authenticated using the mechanisms described in WS-Security.
·
Accountability - Accountability is
a function of the type of and string of the key and algorithms being used. In
many cases, a strong symmetric key provides sufficient accountability. However,
in some environments, strong PKI signatures are required.
·
Availability - All reliable
messaging services are subject to a variety of availability attacks. Replay
detection is a common attack and it is RECOMMENDED that this be addressed by
the mechanisms described in WS-Security. Other attacks, such as network-level
denial of service attacks are harder to avoid and are outside the scope of this
specification. That said, care SHOULD be taken to
ensure that minimal state is saved prior to any authenticating sequences.
An endpoint MAY indicate that it supports
WS-Enumeration, or its features, by including the WS-Enumeration Policy
assertion within its WSDL. By doing so the endpoint is indicating that the
corresponding WS-Enumeration operations are supported by that endpoint even
though they do not explicitly appear in its WSDL.
The WS-Enumeration WSDL containing the
operations indicated by the Enumeration Assertion MAY be exposed as described
in WS-MetadataExchange [WS-MetadataExchange]
Section 9. This WS-Enumeration WSDL can be annotated to indicate any endpoint
specific metadata that might be needed by clients interacting with this
service. For example, the WSDL MAY have policy assertions that indicate a
particular security mechanism used to protect the WS-Enumeration operations
supported by this endpoint.
The mechanism for indicating that a
binding or endpoint conforms to the WS-Enumeration specification is through the
use of the Web Services Policy - Framework [WS-Policy]
and Web Services Policy - Attachment [WS-Policy
Attachment] specifications.
This
specification defines a policy assertion (wsenu:DataSource).
The wsenu:DataSource policy assertion applies to the
endpoint policy subject.
For
WSDL 1.1, these assertions MAY be attached to wsdl11:port
or wsdl11:binding. For WSDL 2.0, they MAY be attached to wsdl20:endpoint or wsdl20:binding. A policy expression containing
the wsenu:DataSource policy assertion MUST NOT be
attached to a wsdl:portType or wsdl20:interface.
The
wsenu:DataSource policy assertion is a nested policy
container assertion. The meaning of this assertion, when present in a policy
alternative, is that WS-Enumeration is required to communicate with the subject
and that the subject is a WS-Enumeration data source.
In
order to indicate that the subject supports WS-Enumeration but does not require
its use, an additional policy alternative SHOULD be provided which does not
contain this assertion. The compact authoring style for an OPTIONAL policy
assertion (the wsp:Optional attribute) provided by
WS-Policy MAY be used to indicate two policy alternatives, one which contains
the policy assertion, and another which does not.
The
normative outline of this assertion is:
<wsenu:DataSource
...>
<wsenu:FilterDialect
...> xs:anyURI
</wsenu:FilterDialect> *
<wsenu:MaxExpires
...> xs:duration
</wsenu:MaxExpires> ?
<wsenu:MaxTime
...> xs:duration
</wsenu:MaxTime> ?
<wsenu:MaxElements
...> xs:long
</wsenu:MaxElements> ?
<wsenu:MaxCharacters
...> xs:long </wsenu:MaxCharacters>
?
<wsenu:EndToSupported
.../> ?
...
</wsenu:DataSource>
The
following describes additional, normative constraints on the outline listed
above:
/wsenu:DataSource
A policy assertion that specifies that WS-Enumeration
protocol MUST be used when communicating with this endpoint. This assertion has
Endpoint Policy Subject.
/wsenu:DataSource/wsenu:FilterDialect
When present, this OPTIONAL parameter indicates support
for the specified Filter Dialect IRI.
/wsenu:DataSource/wsenu:MaxExpires
When present, this OPTIONAL parameter indicates the
maximum lifetime of enumerations that this endpoint will support. The implied
default is indefinite (no expiry). Note: a value of "PT0S" indicates
that this endpoint supports enumerations with an infinite lifetime.
/wsenu:DataSource/wsenu:MaxTime
When present, this OPTIONAL parameter indicates the
maximum MaxTime value supported by this endpoint. The implied default is
indefinite (no expiry). Note: a value of "PT0S" indicates that this
endpoint supports any duration value.
/wsenu:DataSource/wsenu:MaxElements
When present, this OPTIONAL parameter indicates the
maximum MaxElements value supported by this endpoint. The value specified MUST
be greater than zero.
/wsenu:DataSource/wsenu:MaxCharacters
When present, this OPTIONAL parameter indicates the
maximum MaxCharacters value supported by this endpoint. The value specified
MUST be greater than zero.
/wsenu:DataSource/wsenu:EndToSupported
When present, this OPTIONAL parameter indicates support
for the /wsen:Enumerate/wsen:EndTo semantics. That is,
when an enumerate request contains a wsen:EndTo
element, a EnumerationEnd message will be sent to the EPR contained in the
wsen:EndTo element, if the enumeration terminates unexpectedly.
This specification has been developed as a
result of joint work with many individuals and teams, including: Ashok Malhotra
(Oracle Corp.), Asir Vedamuthu (Microsoft Corp.), Bob Freund (Hitachi, Ltd.),
Doug Davis (IBM), Fred Maciel (Hitachi, Ltd.), Geoff Bullen (Microsoft Corp.),
Gilbert Pilz (Oracle Corp.), Greg Carpenter (Microsoft Corp.), Jeff Mischkinsky
(Oracle Corp.), Katy Warr (IBM), Li Li (Avaya Communications), Mark Little (Red
Hat), Prasad Yendluri (Software AG), Ram Jeyaraman (Microsoft Corp.), Sreedhara
Narayanaswamy (CA), Sumeet Vij (Software AG), Vikas Varma (Software AG), Wu
Chou (Avaya Communications), Yves Lafon (W3C).
Key words for use in RFCs to Indicate Requirement
Levels ,
A non-normative copy of the XML
schema is listed below for convenience.
targetNamespace='http://www.w3.org/2009/09/ws-enu'
xmlns:tns='http://www.w3.org/2009/09/ws-enu'
xmlns:wsa='http://www.w3.org/2005/08/addressing'
xmlns:xs='http://www.w3.org/2001/XMLSchema'
elementFormDefault='qualified'
<xs:import
namespace='http://www.w3.org/XML/1998/namespace'
schemaLocation='http://www.w3.org/2001/xml.xsd'
/>
namespace='http://www.w3.org/2005/08/addressing'
schemaLocation='http://www.w3.org/2005/08/addressing/ws-addr.xsd'
/>
<!-- Types and
global elements -->
<xs:complexType
name='FilterType' mixed='true'>
<xs:any
namespace='##other' processContents='lax'
minOccurs='0'
maxOccurs='unbounded' />
<xs:attribute
name='Dialect' type='xs:anyURI' use='optional'
default='http://www.w3.org/2009/09/ws-enu/Dialects/XPath10'/>
<xs:anyAttribute
namespace='##other' processContents='lax' />
<xs:simpleType
name='PositiveDurationType'>
<xs:restriction
base='xs:duration'>
<xs:minExclusive
value='P0Y0M0DT0H0M0S' />
<xs:simpleType
name='NonNegativeDurationType'>
<xs:restriction
base='xs:duration'>
<xs:minInclusive
value='P0Y0M0DT0H0M0S' />
<simpleType name='DurationDateTime'>
<xs:union
memberTypes='xs:dateTime tns:NonNegativeDurationType' />
<xs:complexType
name='MiniExpirationType'>
<xs:extension
base='tns:DurationDateTime'>
<xs:anyAttribute
namespace='##other' processContents='lax'/>
<xs:complexType
name='ExpirationType'>
<xs:extension
base='tns:MiniExpirationType'>
<xs:attribute
name='min' type='tns:DurationDateTime' use='optional'/>
<xs:attribute
name='max' type='tns:DurationDateTime' use='optional'/>
<xs:anyAttribute
namespace='##other' processContents='lax'/>
<xs:complexType
name='EnumerationContextType'>
<xs:complexContent
mixed='true'>
<xs:restriction
base='xs:anyType'>
<xs:any
namespace='##other' processContents='lax'
minOccurs='0'
maxOccurs='unbounded' />
<xs:anyAttribute
namespace='##other' processContents='lax' />
<xs:complexType
name='ItemListType'>
<xs:sequence
maxOccurs='unbounded'>
<xs:any
namespace='##other' processContents='lax'
minOccurs='0'
maxOccurs='unbounded' />
<xs:complexType
name='LanguageSpecificStringType'>
<xs:extension
base='xs:string'>
<xs:attribute
ref='xml:lang' />
<xs:anyAttribute
namespace='##other' processContents='lax' />
<xs:element
name='EndTo' type='wsa:EndpointReferenceType'
<xs:element
name='Expires' type='tns:ExpirationType'
<xs:element
name='Filter' type='tns:FilterType'
<xs:any
namespace='##other' processContents='lax'
minOccurs='0'
maxOccurs='unbounded' />
<xs:anyAttribute
namespace='##other' processContents='lax' />
<!-- Used for a
fault response -->
<xs:element
name='SupportedDialect' type='xs:anyURI' />
<xs:element
name='EnumerateResponse'>
<xs:element
name='GrantedExpires' type='tns:MiniExpirationType'
<xs:element
name='EnumerationContext'
type='tns:EnumerationContextType'
/>
<xs:any
namespace='##other' processContents='lax'
minOccurs='0'
maxOccurs='unbounded' />
<xs:anyAttribute
namespace='##other' processContents='lax' />
<xs:element
name='EnumerationContext'
type='tns:EnumerationContextType'
/>
<xs:element
name='MaxTime' type='tns:PositiveDurationType'
<xs:element
name='MaxElements' type='xs:positiveInteger'
<xs:element
name='MaxCharacters' type='xs:positiveInteger'
<xs:element
name='EndToSupported' type='tns:Empty' minOccurs='0' />
<xs:any
namespace='##other' processContents='lax'
minOccurs='0'
maxOccurs='unbounded' />
<xs:anyAttribute
namespace='##other' processContents='lax' />
<xs:element
name='PullResponse'>
<xs:element
name='EnumerationContext'
type='tns:EnumerationContextType'
<xs:element
name='Items' type='tns:ItemListType'
<xs:element
name='EndOfSequence' minOccurs='0' />
<xs:anyAttribute
namespace='##other' processContents='lax' />
<xs:element
name='EnumerationContext'
type='tns:EnumerationContextType'
/>
<xs:element
name='Expires' type='tns:ExpirationType'
<xs:any
namespace='##other' processContents='lax'
minOccurs='0'
maxOccurs='unbounded' />
<xs:anyAttribute
namespace='##other' processContents='lax' />
<xs:element
name='RenewResponse'>
<xs:element
name='GrantedExpires' type='tns:MiniExpirationType'
<xs:element
name='EnumerationContext'
type='tns:EnumerationContextType'
<xs:any
namespace='##other' processContents='lax'
minOccurs='0'
maxOccurs='unbounded' />
<xs:anyAttribute
namespace='##other' processContents='lax' />
<xs:element
name='EnumerationContext'
type='tns:EnumerationContextType'
/>
<xs:any
namespace='##other' processContents='lax'
minOccurs='0'
maxOccurs='unbounded' />
<xs:anyAttribute
namespace='##other' processContents='lax' />
<xs:element
name='GetStatusResponse'>
<xs:element
name='GrantedExpires' type='tns:MiniExpirationType'
<xs:any
namespace='##other' processContents='lax'
minOccurs='0'
maxOccurs='unbounded' />
<xs:anyAttribute
namespace='##other' processContents='lax' />
<xs:element
name='EnumerationContext'
type='tns:EnumerationContextType'
/>
<xs:anyAttribute
namespace='##other' processContents='lax' />
<xs:element
name='ReleaseResponse'>
<xs:any
namespace='##other' processContents='lax'
minOccurs='0'
maxOccurs='unbounded' />
<xs:anyAttribute
namespace='##other' processContents='lax' />
<!--
EnumerationEnd message -->
<xs:element
name='EnumerationEnd'>
<xs:element
name='Code' type='tns:OpenEnumerationEndCodeType' />
<xs:element
name='Reason' type='tns:LanguageSpecificStringType'
minOccurs='0'
maxOccurs='unbounded' />
<xs:any
namespace='##other' processContents='lax'
minOccurs='0'
maxOccurs='unbounded' />
<xs:anyAttribute
namespace='##other' processContents='lax' />
<xs:simpleType
name='EnumerationEndCodeType'>
<xs:restriction
base='xs:anyURI'>
'http://www.w3.org/2009/09/ws-enu/SourceShuttingDown'
/>
'http://www.w3.org/2009/09/ws-enu/SourceCancelling'
/>
<xs:simpleType
name='OpenEnumerationEndCodeType'>
<xs:union
memberTypes='tns:EnumerationEndCodeType xs:anyURI' />
<xs:complexType
name='Duration'>
<xs:extension
base='tns:NonNegativeDurationType'>
<xs:anyAttribute
namespace='##other'/>
<xs:extension
base='xs:anyURI'>
<xs:anyAttribute
namespace='##other'/>
<xs:anyAttribute
namespace='##other'/>
<xs:element
name='DataSource'>
<xs:element
name='FilterDialect' type='tns:URI' minOccurs='0'
<xs:element
name='MaxExpires' type='tns:Duration' minOccurs='0'/>
<xs:element
name='MaxTime' type='tns:Duration' minOccurs='0'/>
<xs:element
name='MaxElements' type='tns:Long' minOccurs='0'/>
<xs:element
name='MaxCharacters' type='tns:Long' minOccurs='0'/>
<xs:any
namespace='##other' processContents='lax' minOccurs='0'
<xs:anyAttribute
namespace='##other' processContents='lax' />
A non-normative
copy of the WSDL description is listed below for convenience.
targetNamespace='http://www.w3.org/2009/09/ws-enu'
xmlns:wsa='http://www.w3.org/2005/08/addressing'
xmlns:wsam='http://www.w3.org/2007/05/addressing/metadata'
xmlns:wsdl='http://schemas.xmlsoap.org/wsdl/'
xmlns:wsen='http://www.w3.org/2009/09/ws-enu'
xmlns:xs='http://www.w3.org/2001/XMLSchema'
>
namespace='http://www.w3.org/2009/09/ws-enu'
schemaLocation='http://www.w3.org/2009/09/ws-enu/enumeration.xsd'
/>
<wsdl:message
name='EnumerateMessage'>
<wsdl:part
name='Body' element='wsen:Enumerate' />
<wsdl:message
name='EnumerateResponseMessage'>
<wsdl:part
name='Body' element='wsen:EnumerateResponse' />
<wsdl:message
name='PullMessage'>
<wsdl:part
name='Body' element='wsen:Pull' />
<wsdl:message
name='PullResponseMessage'>
<wsdl:part
name='Body' element='wsen:PullResponse' />
<wsdl:message
name='RenewMessage' >
<wsdl:part
name='Body' element='wsen:Renew' />
<wsdl:message
name='RenewResponseMessage' >
<wsdl:part
name='Body' element='wsen:RenewResponse' />
<wsdl:message
name='GetStatusMessage' >
<wsdl:part
name='Body' element='wsen:GetStatus' />
<wsdl:message
name='GetStatusResponseMessage' >
<wsdl:part
name='Body' element='wsen:GetStatusResponse' />
<wsdl:message
name='ReleaseMessage'>
<wsdl:part
name='Body' element='wsen:Release' />
<wsdl:message
name='ReleaseResponseMessage'>
<wsdl:part
name='Body' element='wsen:ReleaseResponse' />
<wsdl:message
name='EnumerationEndMessage' >
<wsdl:part
name='Body' element='wsen:EnumerationEnd' />
<wsdl:portType
name='DataSource'>
<wsdl:operation
name='EnumerateOp'>
message='wsen:EnumerateMessage'
wsam:Action='http://www.w3.org/2009/09/ws-enu/Enumerate'
/>
message='wsen:EnumerateResponseMessage'
wsam:Action='http://www.w3.org/2009/09/ws-enu/EnumerateResponse'
/>
<wsdl:operation
name='PullOp'>
wsam:Action='http://www.w3.org/2009/09/ws-enu/Pull'
/>
message='wsen:PullResponseMessage'
wsam:Action='http://www.w3.org/2009/09/ws-enu/PullResponse'
/>
<wsdl:operation
name='RenewOp' >
wsam:Action='http://www.w3.org/2009/09/ws-enu/Renew'
/>
message='wsen:RenewResponseMessage'
wsam:Action='http://www.w3.org/2009/09/ws-enu/RenewResponse'
/>
<wsdl:operation
name='GetStatusOp' >
message='wsen:GetStatusMessage'
wsam:Action='http://www.w3.org/2009/09/ws-enu/GetStatus'
/>
message='wsen:GetStatusResponseMessage'
wsam:Action='http://www.w3.org/2009/09/ws-enu/GetStatusResponse'
/>
<wsdl:operation
name='ReleaseOp'>
wsam:Action='http://www.w3.org/2009/09/ws-enu/Release'
/>
message='wsen:ReleaseResponseMessage'
wsam:Action='http://www.w3.org/2009/09/ws-enu/ReleaseResponse'
/>
<wsdl:portType
name='EnumerationEndPortType'>
<wsdl:operation
name='EnumerationEndOp' >
message='wsen:EnumerationEndMessage'
wsam:Action='http://www.w3.org/2009/09/ws-enu/EnumerationEnd'
/>
Note:
this is a work in progress and may change before long
·
Actions
are represented as columns.
·
Empty
box indicates that the spec is silent for the specified trigger/action pair.
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