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&wsenu.name; &wsenu.w3c-designation; &wsenu.status; &wsenu.day; &wsenu.month; &wsenu.year; &wsenu.dated; http://www.w3.org/TR/&wsenu.shortname; &prev.wsenu.dated; Doug Davis IBM Ashok Malhotra Oracle Katy Warr IBM Wu Chou Avaya

This is the First Public Working Draft.

Publication as a Working Draft does not imply endorsement by the W3C Membership. This is a draft document and can be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

This specification describes a general SOAP-based protocol for enumerating a sequence of XML elements from a SOAP enabled information source.

English

Last Modified: $Date: 2011/12/09 16:23:38 $
Composable Architecture

By using the XML, SOAP , , and WSDL extensibility models, the Web service specifications (WS-*) are designed to be composed with each other to provide a rich set of tools for the Web services environment. This specification specifically relies on other Web service specifications to provide secure, reliable, and/or transacted message delivery and to express Web service and client policy.

Introduction

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 or 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 Enumerate 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 mandates that data sources MUST implement the Enumerate operation for starting a new enumeration of a data source. Each new enumeration 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. The ordering or completeness of the enumeration is undefined; 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 Enumerate response are removed from the queue.

Requirements

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.

Notations and Terminology

This section specifies the notations, namespaces, and terminology used in this specification.

Notational Conventions

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 .

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 ) are used to indicate the namespace of the element being defined.

In addition to Message Information Header properties , this specification uses the following properties to define messages:

Unordered message headers.

The value to be used for the wsa:Action IRI.

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) , 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 further 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 service MAY choose not to transmit the fault.

Considerations on the Use of Extensibility Points

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.

Terminology

The Web service that is requesting the data enumeration from the data source

A Web service that supports traversal using enumeration contexts via the Enumerate operation defined in this specification

A session context that represents a specific traversal through a logical sequence of XML element information items using the Enumerate operation defined in this specification

Compliance

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 ) 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 conform to the WS-Addressing specifications and be sent to a Web service that is addressable by an EPR (see ).

Unless otherwise noted, all IRIs are absolute IRIs and IRI comparison MUST be performed according to 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.

Implementations are expected to support both UTF-8 and UTF-16 as described in XML 1.0.

Implementations of this specification MUST conform to the corrected version of WSDL as defined by the 'WSDL Correction' sections of WS-I Basic Profile 1.2 and WS-I Basic Profile 2.0 .

XML Namespaces

The XML namespace URI that MUST be used by implementations of this specification is:

http://www.w3.org/&wsenu.nsprefix;/ws-enu

lists XML namespaces that are used in this specification. The choice of any namespace prefix is arbitrary and not semantically significant.

Prefixes and XML namespaces used in this specification
Prefix XML Namespace Specification(s)
wsen http://www.w3.org/&wsenu.nsprefix;/ws-enu This specification
s http://www.w3.org/2003/05/soap-envelope SOAP 1.2
s11 http://schemas.xmlsoap.org/soap/envelope/ SOAP 1.1
wsa http://www.w3.org/2005/08/addressing WS-Addressing
wsp http://www.w3.org/ns/ws-policy WS-Policy
xs http://www.w3.org/2001/XMLSchema XML Schema ,
wsdl http://schemas.xmlsoap.org/wsdl WSDL/1.1

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 .

Enumeration Messages

Enumeration contexts represent a specific traversal through a sequence of XML information items. A Enumerate operation can be used to establish an enumeration context from a data source. A subsequent Enumerate 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 a Enumerate operation. The consumer then passes that XML data back to the data source in subsequent Enumerate requests. Optionally, the data source MAY return an updated enumeration context in the Enumerate 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 items is explicitly allowed; however, no further operations MUST be issued after a Release.

An enumeration context can become invalid for any reason including:

Enumeration completed (i.e. an EndOfSequence has been returned in a Enumerate response)

Enumeration released

Enumeration expired

Enumeration context replaced in the response to another Enumerate request

Enumeration ended (i.e. as indicated via an EnumerationEnd message from data source)

As the last item indicates, the data source MAY invalidate an enumeration context at any time.

When processing a Enumerate, 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 EnumerateResponse or RenewResponse.

Once a consumer determines that an enumeration context is invalid, it MUST NOT issue any more WS-Enumeration request messages referencing that enumeration context.

Enumerate

The Enumerate operation is initiated by sending a Enumerate request message to the data source. This operation MUST be supported by compliant data sources. The Enumerate request message MUST be of the following form:

[Action] http://www.w3.org/&wsenu.nsprefix;/ws-enu/Enumerate [Body] <wsen:Enumerate ...> ( <wsen:NewContext ...> <wsen:EndTo>endpoint-reference</wsen:EndTo> ? <wsen:Expires BestEffort="xs:boolean"? ...> (xs:dateTime | xs:duration) </wsen:Expires> ? <wsen:Filter Dialect="xs:anyURI"?> xs:any </wsen:Filter> ? xs:any* </wsen:NewContext> | <wsen:EnumerationContext ...>...</wsen:EnumerationContext> ) <wsen:MaxTime>xs:duration</wsen:MaxTime> ? <wsen:MaxItems>xs:long</wsen:MaxItems> ? <wsen:MaxCharacters>xs:long</wsen:MaxCharacters> ? xs:any* </wsen:Enumerate>

The following describes additional, normative constraints on the outline listed above:

This OPTIONAL element contains the information necessary to create a new Enumeration. Note, a Enumerate request MUST have either a wsen:EnumerationContext element or a wsen:NewContext element.

This OPTIONAL element denotes where to send an EnumerationEnd message if the enumeration is terminated unexpectedly (see ). 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. Unless some mechanism is used to indicate otherwise, the messages sent to this endpoint MUST use the same version of SOAP that was used for the Enumerate message.

If the data source does not support the use of the EndTo EPR, the data source MUST generate a wsen:EndToNotSupported fault.

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.

This OPTIONAL element can be used by the consumer to indicate the expiration time of the requested enumeration. A value of PT0S indicates a request for an infinite expiration time (i.e. an enumeration that never expires).

The absence of the wsen:Expires element indicates that the expiration value will be chosen by the data source. This value is communicated via the wsen:GrantedExpires element (see below).

If the wsen:Expires element is present and the data source is not able to grant an expiration time that matches the specified value then it MUST generate a wsen:UnsupportedExpirationValue fault.

The value of the wsen:Expires element 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.

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.

This OPTIONAL attribute, when present with a value of 'true', indicates that the data source MUST grant an expiration time that is its best effort to match the requested expiration time. Default value of this attribute is "false" in which case the data source MUST grant the requested expiration time or fault the enumeration request as defined above.

This OPTIONAL element contains a Boolean predicate in some dialect (see ) that all items of interest MUST satisfy. The resultant enumeration context MUST NOT return items 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 a 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 during the processing of the Enumerate request it MUST generate a wsen:EmptyFilter fault in response to the Enumerate request message. If, after the EnumerateResponse message has been sent, the data source determines that the filter will never evaluate to true for the lifetime of the enumeration, or if there is an error within the filter expression, the enumeration MUST be terminated. In this case if an EndTo was provided, then a EnumerationEnd message MUST be sent with a Reason value of "http://www.w3.org/&wsenu.nsprefix;/ws-evt/SourceCancelling".

Implied value is "http://www.w3.org/&wsenu.nsprefix;/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.

Value of [Body]/wsen:Enumerate/wsen:NewContext/wsen:Filter is an XPath 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 .

Namespace Declarations: The [in-scope namespaces] property of [Body]/wsen:Enumerate/wsen:NewContext/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 "/*[local-name()='a' and namespace-uri()='http://www.example.com']" not "/ns1:a".

This filter dialect is the same as the XPath 1.0 filter dialect except that it uses instead of XPath 1.0 as the expression language.

This OPTIONAL element contains the XML data that represents the current enumeration context. Note, a Enumerate request MUST have either a wsen:EnumerationContext element or a wsen:NewContext element.

This OPTIONAL element (of type xs:duration) indicates the maximum amount of time the consumer is willing to allow the data source to assemble the Enumerate response. When this element is absent, the data source is NOT REQUIRED to limit the amount of time it takes to assemble the Enumerate response. The data source MUST recognize the wsen:MaxTime element. If no items are available prior to the request message's deadline, the data source MUST return an EnumerationResponse message that contains a wsen:Items element with no child elements present.

This is useful with data sources that accumulate items over time and package them into a single Enumerate response.

This OPTIONAL element (of type xs:long) indicates the number of items (child elements of wsen:Items in the Enumerate 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 items in the Enumerate 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.

Note that a value of zero MAY, along with a wsen:NewContext element, be used to create a new enumeration without retrieving any of the data items.

If the data source does not support returning items in response to a Enumerate request that also created a new enumeration, and the Enumerate request did not include a wsen:MaxItems with a value of zero, then the data source MUST generate a wsen:MaxItemsMustBeZero fault.

This OPTIONAL element (of type xs:long) indicates the maximum size of the returned items, in Unicode characters, that the consumer is willing to accept. When this element is absent, the data source is NOT REQUIRED to limit the number of characters in the Enumerate response. Implementations MUST NOT return a Enumerate 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:MaxItems limit, or implementation-specific constraints.

Even if a Enumerate request contains a MaxCharacters element, the consumer MUST be prepared to receive a Enumerate response that contains more data characters than specified, as XML canonicalization or alternate XML serialization algorithms can change the size of the representation.

When compiling the list of items to return, if the next item would cause the wsen:Items array to be larger than the MaxCharacters value and the wsen:Items array is not empty then the data source MUST return the current list of items back to the client, saving that next item for a subsequent enumerate request. If, however, the wsen:Items array is empty the data source MUST skip the item and MUST NOT return it as part of the enumeration.

Other components of the outline above are not further constrained by this specification.

Upon successful processing of a Enumerate request message, a data source MUST return a Enumerate response message of the following form:

[Action] http://www.w3.org/&wsenu.nsprefix;/ws-enu/EnumerateResponse [Body] <wsen:EnumerateResponse ...> <wsen:GrantedExpires ...> (xs:dateTime | xs:duration) </wsen:GrantedExpires> <wsen:EnumerationContext ...>...</wsen:EnumerationContext> ? <wsen:Items Reason="xs:anyURI"?> <xs:any> enumeration-specific element </xs:any> * </wsen:Items> ? <wsen:EndOfSequence/> ? xs:any* </wsen:EnumerateResponse>

The following describes additional, normative constraints on the outline listed above:

This element is 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 wse:GrantedExpires element designates the amount of time remaining on this enumeration as measured from the moment the request message was processed. Although this specification cannot dictate when, during the processing of a request message a enumeration's remaining time is determined, the data source MUST measure the expiration duration from a time that is at or before the transmission of the response message.

A wsen:GrantedExpires value of PT0S indicates that the enumeration will never expire. 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.

Note that a wsen:GrantedExpires element MUST only appear in a EnumerateResponse message if the corresponding Enumerate request message included a wsen:NewContext element.

The OPTIONAL EnumerationContext element, if present, contains a XML representation of the enumeration context. The consumer MUST replace the prior representation, if any, with the contents of this element.

The OPTIONAL Items element contains zero or more enumeration-specific elements, one for each item being returned.

Implied value is "http://www.w3.org/&wsenu.nsprefix;/ws-enu/TimedOut".

The OPTIONAL Reason attribute indicates the reason that the wsen:Items element has no child elements. Alternate Reason values can be defined. The Reason attribute MUST NOT be present if the wsen:Items element has one or more child elements.

This value MUST be used if no items are available prior to the Enumeration request message's deadline.

This OPTIONAL element indicates that no more items 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 EnumerateResponse.

lists a sample Enumerate request that establishes a new context.

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/&wsenu.nsprefix;/ws-enu"> (04) <s:Header> (05) <wsa:Action> (06) http://www.w3.org/&wsenu.nsprefix;/ws-enu/Enumerate (07) </wsa:Action> (08) <wsa:MessageID> (09) urn: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:NewContext> (21) <wsen:Expires> PT10M </wsen:Expires> (22) </wsen:NewContext> (23) <wsen:MaxItems> 0 </wsen:MaxItems> (24) </wsen:Enumerate> (25) </s:Body> (26) </s:Envelope>

Lines (05-07) in indicate this message is a Enumerate request and that the data source is expected to respond with a Enumerate response message. The wsen:Expires element on line (21) indicates that the consumer would like an enumeration context that will be good for 10 minutes. No wsen:Filter element is present, so the resultant enumeration context is expected to return all available items. Line (23) indicates that the Enumerate response is not to include any items from the enumeration - this operation is just estalishing the enumeration context.

lists a response to the request in .

Response to Enumerate request (01) <s:Envelope xmlns:S='http://www.w3.org/2003/05/soap-envelope' (02) xmlns:wsen='http://www.w3.org/&wsenu.nsprefix;/ws-enu' (03) xmlns:wsa='http://www.w3.org/2005/08/addressing'> (04) <s:Header> (05) <wsa:Action> (06) http://www.w3.org/&wsenu.nsprefix;/ws-enu/EnumerateResponse (07) </wsa:Action> (08) <wsa:RelatesTo> (09) urn: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:GrantedExpires> PT10M </wsen:GrantedExpires> (18) <wsen:EnumerationContext> (19) 123 (20) </wsen:EnumerationContext> (21) </wsen:EnumerateResponse> (22) </s:Body> (23) </s:Envelope>

Lines (05-07) in indicate this message is a Enumerate response message. Line (17) indicates that the data source has created an enumeration context with a lifetime of 10 minutes. Lines (18-20) are the XML representation of the enumeration context that supports the Enumerate operation defined below.

lists a Enumerate request that uses the enumeration context established in the previous example.

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/&wsenu.nsprefix;/ws-enu"> (04) <s:Header> (05) <wsa:Action> (06) http://www.w3.org/&wsenu.nsprefix;/ws-enu/Enumerate (07) </wsa:Action> (08) <wsa:MessageID> (09) urn: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:Enumerate> (20) <wsen:EnumerationContext>123</wsen:EnumerationContext> (21) <wsen:MaxTime>P30S</wsen:MaxTime> (22) <wsen:MaxItems>10</wsen:MaxItems> (23) </wsen:Enumerate> (24) </s:Body> (25) </s:Envelope>

Lines (05-07) in indicate this message is a Enumerate request and that the data source is expected to respond with a Enumerate response message. Line (21) indicates that the response message SHOULD be generated no more than 30 seconds after receipt of the Enumerate request message. Line (22) indicates that no more than 10 items can be returned in the body of the Enumerate response message.

lists a response to the request in .

Response to Enumerate request (01) <s:Envelope xmlns:S="http://www.w3.org/2003/05/soap-envelope" (02) xmlns:wsen="http://www.w3.org/&wsenu.nsprefix;/ws-enu" (03) xmlns:wsa="http://www.w3.org/2005/08/addressing"> (04) <s:Header> (05) <wsa:Action> (06) http://www.w3.org/&wsenu.nsprefix;/ws-enu/EnumerateResponse (07) </wsa:Action> (08) <wsa:RelatesTo> (09) urn: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: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:EnumerateResponse> (26) </s:Body> (27) </s:Envelope>

Lines (05-07) in indicate this message is a Enumerate response message. Lines (18-22) are the five items returned by this Enumerate request. The presence of a wsen:EndOfSequence element (line (24)) indicates that no more items are available and that the enumeration context is now invalid.

Renew

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/&wsenu.nsprefix;/ws-enu/Renew [Body] <wsen:Renew ...> <wsen:EnumerationContext ...>...</wsen:EnumerationContext> <wsen:Expires BestEffort="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 ) with the following addition(s):

This REQUIRED 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/&wsenu.nsprefix;/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 a Enumerate request (see ) with the following addition:

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.

GetStatus

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/&wsenu.nsprefix;/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 ). 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/&wsenu.nsprefix;/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 ). 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 consumer. This means that in case of an underlying protocol error that might get unnoticed, resending the same request can be done automatically.

Release

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/&wsenu.nsprefix;/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:

This REQUIRED 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 MUST return a Release response message of the following form:

[Action] http://www.w3.org/&wsenu.nsprefix;/ws-enu/ReleaseResponse [Body] <wsen:ReleaseResponse ...> xs:any* </wsen:ReleaseResponse>

lists a Release request.

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/&wsenu.nsprefix;/ws-enu"> (04) <s:Header> (05) <wsa:Action> (06) http://www.w3.org/&wsenu.nsprefix;/ws-enu/Release (07) </wsa:Action> (08) <wsa:MessageID> (09) urn: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 indicate this message is a Release request. Line (20) identifies the enumeration context to be released.

lists a response to the request in .

Response to Release request (01) <s:Envelope xmlns:S="http://www.w3.org/2003/05/soap-envelope" (02) xmlns:wsen="http://www.w3.org/&wsenu.nsprefix;/ws-enu" (03) xmlns:wsa="http://www.w3.org/2005/08/addressing"> (04) <s:Header> (05) <wsa:Action> (06) http://www.w3.org/&wsenu.nsprefix;/ws-enu/ReleaseResponse (07) </wsa:Action> (08) <wsa:RelatesTo> (09) urn: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 indicate this message is a Release response message.

EnumerationEnd

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 ), the EnumerationEnd message MUST be sent to the endpoint reference indicated by that EPR.

Note, a enumeration context expiring as expected is not considered to be an unexpected termination, therefore a EnumerationEnd message MUST NOT be sent in this case.

The message MUST be of the following form:

[Action] http://www.w3.org/&wsenu.nsprefix;/ws-enu/EnumerationEnd [Body] <wsen:EnumerationEnd ...> <wsen:Code> ( http://www.w3.org/&wsenu.nsprefix;/ws-enu/SourceShuttingDown | http://www.w3.org/&wsenu.nsprefix;/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:

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.

This value MUST be used if the data source terminated the enumeration for some other reason before it expired.

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.

Faults

All fault messages defined in this specification MUST be sent according to the rules and usage described in 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:

http://www.w3.org/&wsenu.nsprefix;/ws-enu/fault

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.

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> <s12:Header> <wsa:Action> [Action] </wsa:Action> <!-- Headers elided for brevity. --> </s12:Header> <s11:Body> <s11:Fault> <faultcode>[Subcode]</faultcode> <faultstring xml:lang="en">[Reason]</faultstring> <detail> [Detail] ... </detail> </s11:Fault> </s11:Body> </s11:Envelope> UnsupportedExpirationValue

This fault MUST be generated when a request specifies an expiration that is not within the min/max range.

[Code] s12:Sender
[Subcode] wsen:UnsupportedExpirationValue
[Reason] The expiration time requested is not within the min/max range.
[Detail]
UnsupportedExpirationType

This fault MUST be generated when a request specifies an expiration time and the data source is only capable of accepting expiration durations; for instance, if the data source does not have access to absolute time.

[Code] s12:Sender
[Subcode] wsen:UnsupportedExpirationType
[Reason] Only expiration durations are supported.
[Detail]
FilteringNotSupported

This fault MUST generated when the data source does not support filters.

[Code] s12:Sender
[Subcode] wsen:FilteringNotSupported
[Reason] Filtering not supported.
[Detail]
FilterDialectRequestedUnavailable

This fault MUST be generated when the data source does not support the requested filter dialect.

[Code] s12:Sender
[Subcode] wsen:FilterDialectRequestedUnavailable
[Reason] Filter dialect requested unavailable.
[Detail] <wsen:SupportedDialect> + OPTIONAL; repeating; one per filter dialect supported by the receiver
CannotProcessFilter

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]
InvalidEnumerationContext

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]
UnusableEPR

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.
EndToNotSupported

This fault MUST be generated by a data source that does not support /wsen:Enumerate/wsen:NewContext/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
EmptyFilter

This fault MUST be generated when a data source detects a 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.
MaxItemsMustBeZero

This fault MUST be generated by a data source that does not support returning items in a Enumerate response and the Enumerate request did not include a wsen:MaxItems with a value of zero.

[Code] s12:Sender
[Subcode] wsen:MaxItemsMustBeZero
[Reason] wsen:MaxItems must be zero when creating a new enumeration.
[Detail] none
Security Considerations

This specification considers two sets of security requirements, those of the applications that use the WS-Enumeration protocol and those of the protocol itself.

This specification makes no assumptions about the security requirements of the applications that use WS-Enumeration. However, once those requirements have been satisfied within a given operational context, the addition of WS-Enumeration to this operational context can not undermine the fulfillment of those requirements; the use of WS-Enumeration SHOULD NOT create additional attack vectors within an otherwise secure system.

The material below is not a "check list". There are many other security concerns that need to be considered when implementing or using this protocol. Implementers and users of this protocol are urged to perform a security analysis to determine their particular threat profile and the appropriate responses to those threats.

Creating Enumeration Contexts

An enumeration represents a logical cursor through a sequence of data items. If the information in these items is sensitive, it is advisable to for Data Sources to authenticate and authorize Consumers as part of the processing of the Enumerate request. Note that a Data Source might authorize retrievals on a per-item basis after the enumeration has been created. This might be necessary in cases where the sensitivity of the information requested might not be known at the time the Enumerate request is processed or varies during the lifetime of the enumeration.

Protecting Enumeration Contexts

Once created, it is advisable to treat Enumeration Contexts as protected resources. Renew, GetStatus, and Release requests ought to be authenticated and authorized (for example, the identity of the requester ought to be checked against the identity of the entity that performed the original Enumerate request). Likewise EnumerationEnd messages ought to be authenticated and authorized (for example, the identity of the sender ought to be checked against the identity the entity that sent the original EnumerateResponse message). Note that authentication and authorization policies (i.e. the rules that define which entities are allowed to perform which requests and the mechanisms by which the identities of these entities are discovered and verified) are particular to individual deployments.

Enumeration Contexts are also sensitive because of the way they are used to maintain or reference the state of active Enumerations. Attackers able to snoop or guess the value of an Enumeration Context could use this information to Enumerate data items in that Enumeration. To defend against the misuse of snooped/guessed Enumeration Contexts, Data Sources are advised to authenticate and authorize clients sending Enumerate requests.

Endpoint Verification

Data Source implementations that perform validity checks on the EndTo EPR used in the Enumerate request are advised that such checks can be misused to obtain information about a target network. For example, suppose a Data Source implementation verifies the address of EndTo EPRs by attempting to create a connection to this EPR's address and faulting the Enumerate request if a connection cannot be created. When deployed within a DMZ, such a Data Source could be exploited by a malicious Consumer to probe for other, non-visible hosts by guessing target addresses and using them in Enumerate requests. Note that, even if the returned fault does not provide connection information, the time the Data Source spends processing the Enumerate request might betray the existence or non-existence of a host at the target address.

Implementations that perform validity checks on the EndTo EPR are advised to provide a means to disable such checks in environments where these types of attacks are an issue.

WS-Enumeration Metadata

An endpoint MAY indicate its support of WS-Enumeration, or its features, by including the WS-Enumeration DataSource 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 are implicit and do not explicitly appear in its WSDL (i.e. the WS-Enumeration operations do not appear in the WSDL that MAY be retrievable by using a WS-MetadataExchange GetWSDL to that endpoint).

The WS-Enumeration WSDL containing the operations indicated by the Enumeration Assertion MAY be exposed by including the WSDL as a child of the DataSource Policy assertion or by including a reference to it using the mex:Location or mex:Reference element (as described in 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 the WS-Enumeration operations. 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.

Enumeration Assertion

Services indicate support for the WS-Enumeration's definition of a data source through the use of the Web Services Policy - Framework and Web Services Policy - Attachment specifications.

This specification defines a policy assertion (wsen:DataSource). The normative outline of this assertion is:

<wsen:DataSource ...> <wsen:FilterDialect URI="xs:anyURI" ...> xs:any* </wsen:FilterDialect> * <wsen:DateTimeSupported .../> ? <wsen:Expires min="xs:duration"? max="xs:duration"? .../> ? <wsen:MaxTime ...> xs:duration </wsen:MaxTime> ? <wsen:MaxItems ...> xs:long </wsen:MaxItems> ? <wsen:MaxCharacters ...> xs:long </wsen:MaxCharacters> ? <wsen:EndToSupported .../> ? <wsen:ItemsOnNewContextSupported .../> ? xs:any* </wsen:DataSource>

The following describes additional, normative constraints on the outline listed above:

This policy assertion has Endpoint Policy Subject. When present in a policy alternative, it indicates that the subject is a data source and the WS-Enumeration protocol MUST be used when communicating with this endpoint.

When present, this OPTIONAL parameter indicates support for the specified Filter Dialect IRI.

This extensibility point allows for additional FilterDialect specific metadata to be included within the policy assertion. Any metadata that appears is scoped to the use of the specified FilterDialect URI.

When present, this OPTIONAL parameter indicates support for expiration time expressed as specific time (rather than duration).

When present, this OPTIONAL parameter indicates the minimum and maximum enumeration expiration times that this endpoint will support. When the OPTIONAL 'min' attribute is absent then the data source MUST not impose a lower bound on the accepted Expires values. The implied default value for the OPTIONAL 'max' attribute is infinite (or PT0S). In all cases, the 'min' value MUST be less than or equal to the 'max' value.

When present, this OPTIONAL parameter indicates the maximum MaxTime value supported by this endpoint. The implied default is infinite. Note: a value of "PT0S" indicates that this endpoint supports any duration value.

When present, this OPTIONAL parameter indicates the maximum MaxItems value supported by this endpoint. The value specified MUST be greater than zero.

When present, this OPTIONAL parameter indicates the maximum MaxCharacters value supported by this endpoint. The value specified MUST be greater than zero.

When present, this OPTIONAL parameter indicates support for the /wsen:Enumerate/wsen:NewContext/wsen:EndTo semantics. That is, when a 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.

When present, this OPTIONAL parameter indicates support for the Enumerate operation creating a new enumeration context and returning an initial set of items in the Enumerate response message. When a data source does not support this feature, all consumers MUST include a wsen:MaxItems with a value of zero in Enumerate requests that create new enumeration contexts.

This extensibility point allows for additional WS-Enumeration specific metadata to be included within the policy assertion - e.g. WS-Enumeration WSDL, or nested policy assertions related to the WS-Enumeration message exchanges. Any metadata that appears is scoped to the operations and features of the WS-Enumeration specification.

Acknowledgements

This specification has been developed as a result of joint work with many individuals and teams, including: Alessio Soldano (Red Hat), Ashok Malhotra (Oracle Corp.), Asir Vedamuthu (Microsoft Corp.), Bob Freund (Hitachi, Ltd.), Bob Natale (MITRE Corp.), David Snelling (Fujitsu, 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), Martin Chapman (Oracle Corp.), Paul Fremantle (WSO2), Paul Nolan (IBM), Prasad Yendluri (Software AG), Ram Jeyaraman (Microsoft Corp.), Sreedhara Narayanaswamy (CA), Sumeet Vij (Software AG), Tom Rutt (Fujitsu, Ltd.), Vikas Varma (Software AG), Wu Chou (Avaya Communications), Yves Lafon (W3C/ERCIM).

References Normative References WS-I Profile, Basic Profile Version 1.2 , R. Chumbley, et al, Editors. Web Services Interoperability Organization (WS-I), 9 November 2010. WS-I Profile, Basic Profile Version 2.0 , R. Chumbley, et al, Editors. Web Services Interoperability Organization (WS-I), 9 November 2010. Key words for use in RFCs to Indicate Requirement Levels , S. Bradner, Author. Internet Engineering Task Force, March 1997. Internationalized Resource Identifiers (IRIs) , M. Duerst and M. Suignard, Authors. Internet Engineering Task Force, January 2005. W3C Note, "Simple Object Access Protocol (SOAP) 1.1" , D. Box, et al, Editors. World Wide Web Consortium (W3C), 8 May 2000. W3C Recommendation, "SOAP Version 1.2 Part 1: Messaging Framework" , M. Gudgin, M. Hadley, N. Mendelsohn, J-J. Moreau, H. Frystyk Nielson, Editors. World Wide Web Consortium (W3C), 27 April 2007. W3C Recommendation, "Web Services Addressing 1.0 (WS-Addressing)" , M. Gudgin, M. Hadley, T. Rogers, Editors. World Wide Web Consortium (W3C), 9 May 2006. W3C Recommendation, "Web Services Addressing 1.0 - SOAP Binding" , M. Gudgin, M. Hadley, T. Rogers, Editors. World Wide Web Consortium (W3C), 9 May 2006. W3C Recommendation, "Web Services Policy (WS-Policy) 1.5 - Framework" , A. Vedamuthu, et al., Editors. World Wide Web Consortium (W3C), 4 September 2007. W3C Recommendation, "Web Services Policy (WS-Policy) 1.5 - Attachment" , A. Vedamuthu, et al., Editors. World Wide Web Consortium (W3C), 4 September 2007. W3C Note, "Web Services Description Language (WSDL) 1.1" , E. Christensen, et al., Editors. World Wide Web Consortium (W3C), 15 March 2001 W3C Recommendation, "XML Information Set (Second Edition)" , J. Cowan, R. Tobin, Editors. World Wide Web Consortium (W3C), 4 February 2004. W3C Recommendation, "XML Schema Part 1: Structures (Second Edition)" , H. Thompson, et al., Editors. World Wide Web Consortium (W3C), 28 October 2004. W3C Recommendation, "XML Schema Part 2: Datatypes (Second Edition)" , P. Biron, A. Malhotra, Editors. World Wide Web Consortium (W3C), 28 October 2004. W3C Recommendation, "XML Path Language (XPath) Version 1.0" , J. Clark, S. DeRose, Editors. World Wide Web Consortium (W3C), 16 November 1999. W3C Recommendation, "XML Path Language (XPath) 2.0" , A. Berglund, et al., Editors. World Wide Web Consortium (W3C), 23 January 2007. Informative References W3C Working Group Draft, "Web Services Metadata Exchange (WS-MetadataExchange) 1.1" , D. Davis, et al., Editors. World Wide Web Consortium (W3C), 15 September 2009. XML Schema

A normative copy of the XML Schema , description for this specification can be retrieved from the following address:

http://www.w3.org/&wsenu.nsprefix;/ws-enu/enumeration.xsd

A non-normative copy of the XML schema is listed below for convenience.

<xs:schema targetNamespace='http://www.w3.org/&wsenu.nsprefix;/ws-enu' xmlns:tns='http://www.w3.org/&wsenu.nsprefix;/ws-enu' xmlns:wsa='http://www.w3.org/2005/08/addressing' xmlns:xs='http://www.w3.org/2001/XMLSchema' elementFormDefault='qualified' blockDefault='#all'> <xs:import namespace='http://www.w3.org/XML/1998/namespace' schemaLocation='http://www.w3.org/2001/xml.xsd' /> <xs:import namespace='http://www.w3.org/2005/08/addressing' schemaLocation='http://www.w3.org/2006/03/addressing/ws-addr.xsd' /> <!-- Types and global elements --> <xs:complexType name='FilterType' mixed='true'> <xs:sequence> <xs:any namespace='##other' processContents='lax' minOccurs='0' maxOccurs='unbounded' /> </xs:sequence> <xs:attribute name='Dialect' type='xs:anyURI' use='optional' default='http://www.w3.org/&wsenu.nsprefix;/ws-enu/Dialects/XPath10'/> <xs:anyAttribute namespace='##other' processContents='lax' /> </xs:complexType> <xs:simpleType name='PositiveDurationType'> <xs:restriction base='xs:duration'> <xs:minExclusive value='P0Y0M0DT0H0M0S' /> </xs:restriction> </xs:simpleType> <xs:simpleType name='NonNegativeDurationType'> <xs:restriction base='xs:duration'> <xs:minInclusive value='P0Y0M0DT0H0M0S' /> </xs:restriction> </xs:simpleType> <xs:simpleType name='DurationDateTime'> <xs:union memberTypes='xs:dateTime tns:NonNegativeDurationType' /> </xs:simpleType> <xs:complexType name='MiniExpirationType'> <xs:simpleContent> <xs:extension base='tns:DurationDateTime'> <xs:anyAttribute namespace='##other' processContents='lax'/> </xs:extension> </xs:simpleContent> </xs:complexType> <xs:complexType name='ExpirationType'> <xs:simpleContent> <xs:extension base='tns:MiniExpirationType'> <xs:attribute name='BestEffort' type='xs:boolean' use='optional'/> <xs:anyAttribute namespace='##other' processContents='lax'/> </xs:extension> </xs:simpleContent> </xs:complexType> <xs:complexType name='EnumerationContextType'> <xs:complexContent mixed='true'> <xs:restriction base='xs:anyType'> <xs:sequence> <xs:any namespace='##other' processContents='lax' minOccurs='0' maxOccurs='unbounded' /> </xs:sequence> <xs:anyAttribute namespace='##other' processContents='lax' /> </xs:restriction> </xs:complexContent> </xs:complexType> <xs:complexType name='ItemListType'> <xs:sequence maxOccurs='unbounded'> <xs:any namespace='##other' processContents='lax' minOccurs='0' maxOccurs='unbounded' /> </xs:sequence> <xs:attribute name='Reason' type='xs:anyURI' use='optional'/> </xs:complexType> <xs:complexType name='LanguageSpecificStringType'> <xs:simpleContent> <xs:extension base='xs:string'> <xs:attribute ref='xml:lang' /> <xs:anyAttribute namespace='##other' processContents='lax' /> </xs:extension> </xs:simpleContent> </xs:complexType> <!-- Used for a fault response --> <xs:element name='SupportedDialect' type='xs:anyURI' /> <!-- Enumerate request --> <xs:element name='Enumerate'> <xs:complexType> <xs:sequence> <xs:choice> <xs:element name='NewContext'> <xs:complexType> <xs:sequence> <xs:element name='EndTo' type='wsa:EndpointReferenceType' minOccurs='0' /> <xs:element name='Expires' type='tns:ExpirationType' minOccurs='0' /> <xs:element name='Filter' type='tns:FilterType' minOccurs='0' /> <xs:any namespace='##other' processContents='lax' minOccurs='0' maxOccurs='unbounded' /> </xs:sequence> <xs:anyAttribute namespace='##other' processContents='lax' /> </xs:complexType> </xs:element> <xs:element name='EnumerationContext' type='tns:EnumerationContextType' /> </xs:choice> <xs:element name='MaxTime' type='tns:PositiveDurationType' minOccurs='0' /> <xs:element name='MaxItems' type='xs:positiveInteger' minOccurs='0' /> <xs:element name='MaxCharacters' type='xs:positiveInteger' minOccurs='0' /> <xs:element name='EndToSupported' type='tns:Empty' minOccurs='0' /> <xs:any namespace='##other' processContents='lax' minOccurs='0' maxOccurs='unbounded' /> </xs:sequence> <xs:anyAttribute namespace='##other' processContents='lax' /> </xs:complexType> </xs:element> <!-- Enumerate response --> <xs:element name='EnumerateResponse'> <xs:complexType> <xs:sequence> <xs:element name='GrantedExpires' type='tns:MiniExpirationType' /> <xs:element name='EnumerationContext' type='tns:EnumerationContextType' minOccurs='0' /> <xs:element name='Items' type='tns:ItemListType' minOccurs='0' /> <xs:element name='EndOfSequence' minOccurs='0' /> </xs:sequence> <xs:anyAttribute namespace='##other' processContents='lax' /> </xs:complexType> </xs:element> <!-- Renew request --> <xs:element name='Renew'> <xs:complexType> <xs:sequence> <xs:element name='EnumerationContext' type='tns:EnumerationContextType' /> <xs:element name='Expires' type='tns:ExpirationType' minOccurs='0' /> <xs:any namespace='##other' processContents='lax' minOccurs='0' maxOccurs='unbounded' /> </xs:sequence> <xs:anyAttribute namespace='##other' processContents='lax' /> </xs:complexType> </xs:element> <!-- Renew response --> <xs:element name='RenewResponse'> <xs:complexType> <xs:sequence> <xs:element name='GrantedExpires' type='tns:MiniExpirationType' /> <xs:element name='EnumerationContext' type='tns:EnumerationContextType' minOccurs='0' /> <xs:any namespace='##other' processContents='lax' minOccurs='0' maxOccurs='unbounded' /> </xs:sequence> <xs:anyAttribute namespace='##other' processContents='lax' /> </xs:complexType> </xs:element> <!-- GetStatus request --> <xs:element name='GetStatus'> <xs:complexType> <xs:sequence> <xs:element name='EnumerationContext' type='tns:EnumerationContextType' /> <xs:any namespace='##other' processContents='lax' minOccurs='0' maxOccurs='unbounded' /> </xs:sequence> <xs:anyAttribute namespace='##other' processContents='lax' /> </xs:complexType> </xs:element> <!-- GetStatus response --> <xs:element name='GetStatusResponse'> <xs:complexType> <xs:sequence> <xs:element name='GrantedExpires' type='tns:MiniExpirationType' /> <xs:any namespace='##other' processContents='lax' minOccurs='0' maxOccurs='unbounded' /> </xs:sequence> <xs:anyAttribute namespace='##other' processContents='lax' /> </xs:complexType> </xs:element> <!-- Release request --> <xs:element name='Release'> <xs:complexType> <xs:sequence> <xs:element name='EnumerationContext' type='tns:EnumerationContextType' /> </xs:sequence> <xs:anyAttribute namespace='##other' processContents='lax' /> </xs:complexType> </xs:element> <!-- Release response --> <xs:element name='ReleaseResponse'> <xs:complexType> <xs:sequence> <xs:any namespace='##other' processContents='lax' minOccurs='0' maxOccurs='unbounded' /> </xs:sequence> <xs:anyAttribute namespace='##other' processContents='lax' /> </xs:complexType> </xs:element> <!-- EnumerationEnd message --> <xs:element name='EnumerationEnd'> <xs:complexType> <xs:sequence> <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:sequence> <xs:anyAttribute namespace='##other' processContents='lax' /> </xs:complexType> </xs:element> <xs:simpleType name='EnumerationEndCodeType'> <xs:restriction base='xs:anyURI'> <xs:enumeration value= 'http://www.w3.org/&wsenu.nsprefix;/ws-enu/SourceShuttingDown' /> <xs:enumeration value= 'http://www.w3.org/&wsenu.nsprefix;/ws-enu/SourceCancelling' /> </xs:restriction> </xs:simpleType> <xs:simpleType name='OpenEnumerationEndCodeType'> <xs:union memberTypes='tns:EnumerationEndCodeType xs:anyURI' /> </xs:simpleType> <!-- Policy --> <xs:complexType name='Duration'> <xs:simpleContent> <xs:extension base='tns:NonNegativeDurationType'> <xs:anyAttribute namespace='##other'/> </xs:extension> </xs:simpleContent> </xs:complexType> <xs:complexType name='URI'> <xs:simpleContent> <xs:extension base='xs:anyURI'> <xs:anyAttribute namespace='##other'/> </xs:extension> </xs:simpleContent> </xs:complexType> <xs:complexType name='Long'> <xs:simpleContent> <xs:extension base='xs:long'> <xs:anyAttribute namespace='##other'/> </xs:extension> </xs:simpleContent> </xs:complexType> <xs:complexType name='Empty'> <xs:sequence/> <xs:anyAttribute namespace='##other' processContents='lax'/> </xs:complexType> <xs:element name='DataSource'> <xs:complexType> <xs:sequence> <xs:element name='FilterDialect' minOccurs='0' maxOccurs='unbounded'> <xs:complexType> <xs:sequence> <xs:any namespace='##other' processContents='lax' minOccurs='0' maxOccurs='0'/> </xs:sequence> <xs:attribute name='URI' type='xs:anyURI' use='required' /> <xs:anyAttribute namespace="##other" processContents='lax'/> </xs:complexType> </xs:element> <xs:element name='DateTimeSupported' type='tns:Empty' minOccurs='0'/> <xs:element name='Expires' minOccurs='0'> <xs:complexType> <xs:attribute name='min' type='xs:duration' use='optional'/> <xs:attribute name='max' type='xs:duration' use='optional'/> </xs:complexType> </xs:element> <xs:element name='MaxTime' type='tns:Duration' minOccurs='0'/> <xs:element name='MaxItems' type='tns:Long' minOccurs='0'/> <xs:element name='MaxCharacters' type='tns:Long' minOccurs='0'/> <xs:any namespace='##other' processContents='lax' minOccurs='0' maxOccurs='unbounded'/> </xs:sequence> <xs:anyAttribute namespace='##other' processContents='lax' /> </xs:complexType> </xs:element> </xs:schema> WSDL

A normative copy of the WSDL description for this specification can be retrieved from the following address:

http://www.w3.org/&wsenu.nsprefix;/ws-enu/enumeration.wsdl

A non-normative copy of the WSDL description is listed below for convenience.

<wsdl:definitions targetNamespace='http://www.w3.org/&wsenu.nsprefix;/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/&wsenu.nsprefix;/ws-enu' xmlns:xs='http://www.w3.org/2001/XMLSchema' > <wsdl:types> <xs:schema> <xs:import namespace='http://www.w3.org/&wsenu.nsprefix;/ws-enu' schemaLocation='http://www.w3.org/&wsenu.nsprefix;/ws-enu/enumeration.xsd' /> </xs:schema> </wsdl:types> <wsdl:message name='EnumerateMessage'> <wsdl:part name='Body' element='wsen:Enumerate' /> </wsdl:message> <wsdl:message name='EnumerateResponseMessage'> <wsdl:part name='Body' element='wsen:EnumerateResponse' /> </wsdl:message> <wsdl:message name='RenewMessage' > <wsdl:part name='Body' element='wsen:Renew' /> </wsdl:message> <wsdl:message name='RenewResponseMessage' > <wsdl:part name='Body' element='wsen:RenewResponse' /> </wsdl:message> <wsdl:message name='GetStatusMessage' > <wsdl:part name='Body' element='wsen:GetStatus' /> </wsdl:message> <wsdl:message name='GetStatusResponseMessage' > <wsdl:part name='Body' element='wsen:GetStatusResponse' /> </wsdl:message> <wsdl:message name='ReleaseMessage'> <wsdl:part name='Body' element='wsen:Release' /> </wsdl:message> <wsdl:message name='ReleaseResponseMessage'> <wsdl:part name='Body' element='wsen:ReleaseResponse' /> </wsdl:message> <wsdl:message name='EnumerationEndMessage' > <wsdl:part name='Body' element='wsen:EnumerationEnd' /> </wsdl:message> <wsdl:portType name='DataSource'> <wsdl:operation name='EnumerateOp'> <wsdl:input message='wsen:EnumerateMessage' wsam:Action='http://www.w3.org/&wsenu.nsprefix;/ws-enu/Enumerate' /> <wsdl:output message='wsen:EnumerateResponseMessage' wsam:Action='http://www.w3.org/&wsenu.nsprefix;/ws-enu/EnumerateResponse' /> </wsdl:operation> <wsdl:operation name='RenewOp' > <wsdl:input message='wsen:RenewMessage' wsam:Action='http://www.w3.org/&wsenu.nsprefix;/ws-enu/Renew' /> <wsdl:output message='wsen:RenewResponseMessage' wsam:Action='http://www.w3.org/&wsenu.nsprefix;/ws-enu/RenewResponse' /> </wsdl:operation> <wsdl:operation name='GetStatusOp' > <wsdl:input message='wsen:GetStatusMessage' wsam:Action='http://www.w3.org/&wsenu.nsprefix;/ws-enu/GetStatus' /> <wsdl:output message='wsen:GetStatusResponseMessage' wsam:Action='http://www.w3.org/&wsenu.nsprefix;/ws-enu/GetStatusResponse' /> </wsdl:operation> <wsdl:operation name='ReleaseOp'> <wsdl:input message='wsen:ReleaseMessage' wsam:Action='http://www.w3.org/&wsenu.nsprefix;/ws-enu/Release' /> <wsdl:output message='wsen:ReleaseResponseMessage' wsam:Action='http://www.w3.org/&wsenu.nsprefix;/ws-enu/ReleaseResponse' /> </wsdl:operation> </wsdl:portType> <wsdl:portType name='EnumerationEndPortType'> <wsdl:operation name='EnumerationEndOp' > <wsdl:input message='wsen:EnumerationEndMessage' wsam:Action='http://www.w3.org/&wsenu.nsprefix;/ws-enu/EnumerationEnd' /> </wsdl:operation> </wsdl:portType> </wsdl:definitions> Action Tables

The purpose of the action tables is to illustrate, via a separate means from the normative text, the allowable order and interactions of various messages and activities. The action tables are not intended to constrain implementations beyond those necessary to insure this ordering.

Actions are represented as columns.

Triggers (messages, application actions, timer events) are represented as rows. Triggers are annotated by their type; "[app]" - represents an application action (e.g. a user selecting a "Enumerate" menu item); "[msg]" - represents an incoming, WS-Enumeration defined, message; "[timer]" - represents an internal timer event.

Each cell describes the appropriate action for a given state and trigger. Where the action is dependent upon other factors than the state and trigger (e.g. the value of a fault message), the activity is described in pseudo-code. The section of the specification that describes these activities is displayed in curly brackets (e.g. "{4.2}").

Empty box indicates that the spec is silent for the specified trigger/action pair.

Data Source Action Table
Trigger Action
Trigger has no context Trigger has valid context Trigger has invalid context
Enumerate Request [msg] Create new context If (end of sequence) {   include EndOfSequence   invalidate context } Send EnumerateResponse {} If (end of sequence) {   include EndOfSequence   invalidate context } Send EnumerateResponse {} Generate   InvalidEnumerationContext   Fault {}
Renew Request [msg] Update expiration timer Send RenewReponse {} Generate   InvalidEnumerationContext   Fault {}
GetStatus Request [msg] Send GetStatusResponse {} Generate   InvalidEnumerationContext   Fault {}
Release Request [msg] Send wse:ReleaseResponse Invalidate context {} Generate   InvalidEnumerationContext   Fault {}
Expiration [timer] Invalidate context {}
Shutdown/Error [app] if (EndTo engaged)   send EnumerationEnd Invalidate context {}

Consumer Action Table
Trigger Action
Expiration [timer] Invalidate context {}
EnumerationEnd [msg] Invalidate context {}
Change Log
Data Author Description
2009/03/04 DD Added resolution of issue 6391
2009/03/04 DD Added resolution of issue 6519
2009/03/11 DD Added change log
2009/03/11 DD Added resolution of issue 6641
2009/03/11 DD Added resolution of issue 6425
2009/03/16 KW Added resolution of issue 6587
2009/03/17 DD Added resolution of issue 6399
2009/03/23 DD Added resolution of issue 6666
2009/03/24 DD Added resolution of issue 6648
2009/04/07 DD Added resolution of issue 6499
2009/04/07 DD Added resolution of issue 6726
2009/04/22 KW Added resolution of issue 6739
2009/04/28 DD Added resolution of issue 6787
2009/05/12 DD Added resolution of issue 6860
2009/05/13 DD Added resolution of issue 6696
2009/05/21 DD Added resolution of issue 6674
2009/05/26 KW Added resolution of issue 6920
2009/05/27 DD Added resolution of issue 6906
2009/06/04 DD Added resolution of issue 6916
2009/06/11 DD Added resolution of issue 6956
2009/08/05 DD Added resolution of issue 7159
2009/08/06 DD Added resolution of issue 7192
2009/08/18 DD Added resolution of issue 7206
2009/08/18 DD Added resolution of issue 7193
2009/08/25 DD Added resolution of issue 7365
2009/08/25 DD Added resolution of issue 7270
2009/08/25 DD Added resolution of issue 7235
2009/09/01 DD Added resolution of issue 6427
2009/09/01 DD Added resolution of issue 6701
2009/09/01 DD Added resolution of issue 7430
2009/09/02 DD Added resolution of issue 6694
2009/09/02 DD Added resolution of issue 6533
2009/09/23 DD Added resolution of issue 6568
2009/09/30 DD Added resolution of issue 7716
2009/10/02 DD Added resolution of issue 7426
2009/10/05 DD Added resolution of issues 6403, 6721
2009/10/06 DD Added resolution of issue 7587
2009/10/13 DD Added resolution of issue 7827
2009/10/20 DD Added resolution of issue 7068
2009/10/20 DD Added resolution of issue 7811
2009/10/20 DD Added resolution of issue 7207
2009/10/20 DD Added resolution of issues 7586, 7588, 7828
2009/11/05 DD Added resolution of issue 8075
2009/11/05 DD Added resolution of issue 8069
2009/11/05 DD Added resolution of issue 8076
2009/11/05 DD Added resolution of issue 7912
2009/11/05 DD Added resolution of issues 8070, 8071, 8072
2009/11/06 DD Added resolution of issue 8124
2009/11/06 DD Added resolution of issue 8158
2009/11/06 DD Added resolution of issue 8124
2009/11/17 DD Added resolution of issue 8280
2009/12/01 DD Added resolution of issue 8201
2009/12/08 DD Added resolution of issue 8305
2009/12/08 DD Added resolution of issue 8159
2009/12/08 DD Added resolution of issue 8161
2010/01/19 DD Added resolution of issue 8286
2010/01/19 DD Added resolution of issue 8283
2010/01/26 DD Added resolution of issue 8275
2010/01/28 DD Added resolution of issue 8157
2010/01/28 DD Added resolution of issue 8196
2010/02/05 DD Added resolution of issue 6436
2010/02/08 DD Added resolution of issue 8901
2010/02/09 DD Added resolution of issue 8160
2010/02/09 DD Added resolution of issue 8304
2010/02/23 DD Added resolution of issue 8306
2010/03/09 DD Added resolution of issue 6463, 8031, 8198
2010/03/16 DD Added resolution of issue 8886
2010/03/30 DD Added resolution of issue 9095
2010/03/30 DD Added resolution of issue 9266
2010/04/20 DD Added resolution of issue 9543
2010/05/04 DD Added resolution of issue 9588
2010/05/04 DD Added resolution of issue 9087
2010/05/11 DD Added resolution of issue 9568
2010/05/11 DD Added resolution of issue 9699
2010/05/12 DD Added resolution of issue 9717
2010/05/13 DD Added resolution of issue 9702
2010/06/29 DD Added resolution of issue 9609
2010/08/17 DD Added resolution of issue 10339
2010/11/16 DD Added resolution of issue 10960
2010/11/19 DD Added resolution of issue 8284
2011/01/11 DD Added resolution of issue 11696
2011/02/01 DD Added resolution of issue 11882
2011/02/07 DD Added resolution of issue 11899
2011/02/15 DD Added resolution of issue 12051
2011/02/15 DD Added resolution of issue 11894
2011/02/15 DD Added resolution of issue 12063
2011/02/15 DD Added resolution of issue 11990
2011/02/15 DD Added resolution of issue 11949
2011/03/22 DD Added resolution of issue 12112
2011/03/22 DD Added resolution of issue 11776