Web Services Transfer (WS-Transfer)

Editor's Draft $Date: 2009/03/04 17:38:10 $

Latest version:

http://www.w3.org/TR/ws-transfer

Editors:

Doug Davis, IBM

Ashok Malhotra, Oracle

Katy Warr, IBM

Wu Chou, Avaya


Abstract

This specification describes a general SOAP-based protocol for accessing XML representations of Web service-based resources.

Status of this Document

This document is an editors' copy that has no official standing.

Table of Contents

1 Introduction
   1.1 Requirements
2 Terminology and Notation
   2.1 Terminology
   2.2 XML Namespaces
   2.3 Notational Conventions
   2.4 Compliance
3 Resource Operations
   3.1 Get
   3.2 Put
   3.3 Delete
4 Resource Factory Operations
   4.1 Create
5 Faults
   5.1 InvalidRepresentation
6 Security Considerations
7 Acknowledgements
8 References

Appendices

A XML Schema
B WSDL


1 Introduction

This specification defines a mechanism for acquiring XML-based representations of entities using the Web service infrastructure. It defines two types of entities:

·         Resources, which are entities addressable by an endpoint reference that provide an XML representation

·         Resource factories, which are Web services that can create a new resource from an XML representation

Specifically, it defines two operations for sending and receiving the representation of a given resource and two operations for creating and deleting a resource and its corresponding representation. This specification also defines optional extensions in order to deal with fragment-based access to resources.

It should be noted that the state maintenance of a resource is at most subject to the "best efforts" of the hosting server. When a client receives the server's acceptance of a request to create or update a resource, it can reasonably expect that the resource now exists at the confirmed location and with the confirmed representation, but this is not a guarantee, even in the absence of any third parties. The server may change the representation of a resource, may remove a resource entirely, or may bring back a resource that was deleted.

For instance, the server may store resource state information on a disk drive. If that drive crashes and the server recovers state information from a backup tape, changes that occurred after the backup was made will be lost.

A server may have other operational processes that change resource state information. A server may run a background process that examines resources for objectionable content and deletes any such resources it finds. A server may purge resources that have not been accessed for some period of time. A server may apply storage quotas that cause it to occasionally purge resources.

In essence, the confirmation by a service of having processed a request to create, modify, or delete a resource implies a commitment only at the instant that the confirmation was generated. While the usual case should be that resources are long-lived and stable, there are no guarantees, and clients should code defensively.

There is no requirement for uniformity in resource representations between the messages defined in this specification. For example, the representations required by Create or Put may differ from the representation returned by Get, depending on the semantic requirements of the service. Additionally, there is no requirement that the resource content is fixed for any given endpoint reference. The resource content may vary based on environmental factors, such as the security context, time of day, configuration, or the dynamic state of the service.

As per the SOAP processing model, other specifications may define SOAP headers which may be optionally added to request messages to require the transfer of subsets or the application of transformations of the resource associated with the endpoint reference. When the Action URIs defined by this specification are used, such extension specifications must also allow the basic processing models defined herein.

1.1 Requirements

This specification intends to meet the following requirements:

·         Provide a SOAP-based protocol for managing resources and their representations.

·         Minimize additional mechanism beyond the current Web Services architecture.

·         Define WSDL 1.1 portTypes, for the Web service methods described in this specification, compliant with WS-I Basic Profile 1.1 [WS-I BP 1.1].

·         Define minimum requirements for compliance without constraining richer implementations.

·         Compose with other Web service specifications for secure, reliable, transacted message delivery.

·         Provide extensibility for more sophisticated and/or currently unanticipated scenarios.

·         Support a variety of encoding formats including (but not limited to) both SOAP 1.1 [SOAP 1.1] and SOAP 1.2 [SOAP 1.2] Envelopes.

1.2 Non-Requirements

This specification does not intend to meet the following requirements:

·        Discovery of resources.

2 Terminology and Notation

2.1 Terminology

Resource

A Web service that is addressable by an endpoint reference as defined in WS-Addressing and that can be represented by an XML Infoset using the Get and Put operations defined in this specification.

Resource factory

A Web service that is capable of creating new resources using the Create operation defined in this specification.

Resource representation

The XML representation of the resource that is accessed using the operations defined in the WS-Transfer and WS-ResourceTransfer specifications.

Metadata resource

A resource whose XML representation describes some aspect of the metadata of another resource, such as its WSDL or lifecycle metadata. Each resource may have zero or more metadata resources associated with it.

Fragment

The term "fragment" is used in this specification to mean a part of the resource representation.

EPR

The wsa:EndpointReference (EPR), as defined by WS-Addressing, is a reference to the resource in its entirety. Operations, which are otherwise unconstrained within this specification, are assumed to affect the resource as a whole.

2.2 XML Namespaces

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)

wxf

http://www.w3.org/2009/02/ws-tra

This specification

s

Either SOAP 1.1 or 1.2

SOAP

s11

http://schemas.xmlsoap.org/soap/envelope/

[SOAP 1.1]

s12

http://www.w3.org/2003/05/soap-envelope

[SOAP 1.2]

wsa

http://www.w3.org/2005/08/addressing

[WS-Addressing]

wsdl

http://schemas.xmlsoap.org/wsdl/

[WSDL 1.1]

xs

http://www.w3.org/2001/XMLSchema

XML Schema [XML Schema, Part 1], [XML Schema, Part 2]

wsmex

http://www.w3.org/2009/02/ws-mex

WS-MetadataExchange

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 .

2.3 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 [RFC 2119].

This specification uses the following syntax to define outlines for messages:

·         The syntax appears as an XML instance, but values in italics indicate data types instead of literal values.

·         Characters are appended to elements and attributes to indicate cardinality:

o        "?" (0 or 1)

o        "*" (0 or more)

o        "+" (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.

·         An ellipsis (i.e. "...") indicates a point of extensibility that allows other child or attribute content. Additional children and/or attributes MAY be added 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 it.

·         XML namespace prefixes (see Table 2-1) are used to indicate the namespace of the element being defined.

2.4 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 Table 2-1) within SOAP envelopes unless it is compliant with this specification.

Specifically, a compliant SOAP Node that implements a resource MUST provide the Get operation as defined in this specification, and MAY provide the Put and Delete operations.

Normative text within this specification takes precedence over normative outlines, which in turn takes precedence over the XML Schema and WSDL descriptions.

In any given request-response message exchange, the responses generated by the service server MUST use the same WS-Addressing namespace binding that was used in the request.

x Support for Resource Fragments

Implementations of WS-Transfer may optionally support fragment-based access to resources.  This section describes the key aspects of such support.

x.1 Fragments

Since an EPR refers to a resource as a whole, techniques which are used to reference or access parts of the resource representation are referred to as "fragment access" in that they access fragments of the XML representing the resource.

This specification defines an extensible mechanism for designating the expression syntax by which the fragment is identified or computed, and defines several such standard expression syntaxes or "dialects".

x.2 Expression Dialects

The dialects defined below are used to form an expression that can be evaluated with respect to the XML document that represents the resource. The de-referenced value of the expression is the part of the XML that is of interest. The expression may form a logical "pointer" to the fragment of XML that is of interest or, depending on the dialect, may form a query that can be applied to the XML document to produce an evaluated result. It is important to understand that these expression dialects simply identify the appropriate fragment of the resource representation and that the [Action] itself defines what will happen to the referenced fragment.

The definition of each dialect must clearly specify how the result of evaluating an expression against a resource representation is serialized to XML and should specify any dialect-specific behavior for operations that access the resource representation.

x.2.1 QName Dialect[I1] 

The QName expression dialect is a simple dialect for expressions that uses a QName to reference the immediate children of the root element of the resource representation. Consider the resource described in Example 2-1.

In this example, the QName dialect can define references to the elements <DiskCapacity>, <DiskFreeSpace>, <SerialNumber>, <LastAuditDate> and all <Volume> elements. The QName dialect cannot define direct references to the elements <Drive>, <Label>, <TotalCapacity> and <FreeSpace> - since they are not direct children of the Disk (root) element of the resource - or to specific <Volume> elements. Example 4-1, below, shows an example usage of this dialect. This dialect is useful for simple resources with no XPath processing capability.

The QName dialect MUST be indicated by using the URI:

http://www.w3.org/2009/02/ws-tra/ExpressionDialect/QName

Note that the expression MUST evaluate to zero or more entire elements, each including the element name, any attributes and its entire content. The QName dialect does not support computed values.

x.2.2 XPath Level 1 Dialect

The XPath Level 1 expression dialect uses an XPath to reference specific fragments of the resource representation. The XPath is logically applied to the XML representation of the resource and the resulting node-set is the resource fragment which is the subject of the message containing the expression. Example 2-2 shows an example usage of this dialect. This dialect is useful for resources with limited XPath processing capability which do not need to support returning values computed from their resource representation.

The XPath Level 1 dialect is defined in Appendix I of this specification. An implementation that uses the XPath Level 1 dialect MUST support the expressions whose syntax is described by the BNF in Appendix I. It MAY support additional expressions defined by XPath 1.0.

An XPath Level 1 expression is an expression whose context is:

·         Context Node: the root element of the XML representation of the resource

·         Context Position: 1

·         Context Size: 1

·         Variable Binding: None

·         Node Tests: NameTest and the text NodeType

·         Function Libraries: None

·         Namespace Declarations: Any namespace declarations in-scope where the XPath expression appears

Consider the resource described in Example 2-1. The XPath Level 1 dialect can define references to any element, attribute or value in the resource representation.

The XPath Level 1 dialect MUST be indicated by using the URI:

http://www.w3.org/2009/02/ws-tra/ExpressionDialect/XPath-Level-1

Expressions in this dialect MUST NOT evaluate to more than a single node. The XPath Level 1 dialect does not support computed values. Text and attribute nodes MUST be serialized using the same serialization as for the XPath 1.0 dialect.

x.2.3 XPath 1.0 Dialect

The XPath 1.0 expression dialect uses an XPath to reference specific fragments of the resource representation. The XPath is logically applied to the XML representation of the resource and the result of the XPath is returned as the value for that expression. The XPath 1.0 dialect supports a wider set of XPath function libraries than the XPath Level 1 dialect. Example 4-3, below, shows an example usage of this dialect. This dialect is useful for resources with full XPath processing capability or which need to support returning values computed from their resource representation.

An XPath 1.0 expression is an expression whose context is:

·         Context Node: the root element of the XML representation of the resource

·         Context Position: 1

·         Context Size: 1

·         Variable Binding: None

·         Function Libraries: Core function library

·         Namespace Declarations: Any namespace declarations in-scope where the XPath expression appears

Consider the resource described in Example 2-1. The XPath 1.0 dialect can define references to any element, attribute or value in the resource representation and can also be used to compute values from the resource representation.

The XPath 1.0 dialect MUST be indicated by using the URI:

http://www.w3.org/TR/1999/REC-xpath-19991116

Implementations that support the full XPath 1.0 dialect MUST support the XPath Level 1 dialect.

Note that the expression may evaluate to one of four possible types: a node-set, a Boolean, a number or a string. The latter three types are the results of evaluating a computed expression. They are serialized by performing the following conversion and then wrapping the result in the wst:Result element:

·         Boolean - converted to an xs:boolean

·         string - convert to an xs:string

·         number - convert to an xs:double

A node-set is zero or more elements, attributes or text values of elements. A node-set is serialized into XML by concatenating each node and enclosing it in the wst:Result wrapper XML element for which schema validation is suppressed. Element nodes in a node-set are serialized directly into their XML representation. For attributes and text nodes in the node-set, a wrapper element is used to enclose these values to distinguish them from other such nodes in the serialized result.

Attribute nodes in XPath are represented in the following form:

name="value"

Serialization of an attribute node separates the name from the value using the following element:

(01) <wst:AttributeNode name="attribute name">
(02)   attribute value
(03) </wst:AttributeNode>

The following describes additional constraints on the outline listed above:

wst:AttributeNode

This element is used to serialize an attribute node in a node-set and MUST contain the value portion of the attribute node.

wst:AttributeNode/@name

This attribute MUST be the name portion of the attribute node.

Text nodes are serialized in the following form:

(01) <wst:TextNode>
(02)   text value
(03) </wst:TextNode>

The following describes additional constraints on the outline listed above:

wst:TextNode

This element is used to serialize a text node in a node-set and MUST contain the text value.

Given the following XML as an example document.

(01) <a xmlns="example">
(02)   <b>1</b>
(03)   <c x="y">2</c>
(04) </a>

The result of the XPath "/a/b | /a/b/text() | /a/c/@x" would be serialized as the following:

(01) <wst:Result>
(02)   <b>1</b>
(03)   <wst:TextNode>1</wst:TextNode>
(04)   <wst:AttributeNode name="x">y</wst:AttributeNode>
(05) </wst:Result>

The nodes in the node-set MAY be serialized in any order.

The WS-Transfer global element definition wst:NodeSet can also be used as the wrapper element when serializing these node-sets outside of a WS-T result.

An XPath 1.0 expression may evaluate to multiple nodes; because of this the XPath 1.0 dialect MUST NOT be used with a "Put" or "Create" operation.

3 Resource Operations

3.1 Get

This specification defines one Web service operation (Get) for fetching a one-time snapshot of the representation of a resource.

The Get request message MUST be of the following form:

 

<s:Envelope ...> 

  <s:Header ...>

    <wsa:Action>

      http://www.w3.org/2009/02/ws-tra/Get

    </wsa:Action>

    <wsa:MessageID>xs:anyURI</wsa:MessageID>

    <wsa:To>xs:anyURI</wsa:To>

    ...

  </s:Header>

  <s:Body ...>

 

    <wst:Get ExpressionDialect="xs:anyURI"? ...>

      <wst:Expression ...> ... </wst:Expression> +

      |

       xs:any *

    </wst:Get>

  </s:Body>

</s:Envelope>

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

/s:Envelope/s:Header/wsa:Action

This required element MUST contain the value http://www.w3.org/2009/02/ws-tra/Get. If a SOAP Action URI is also present in the underlying transport, its value MUST convey the same value.

/s:Envelope/s:Body/wst:Get@DialectExpressionDialect

This OPTIONAL attribute, when present, indicates that fragment retrieval is being performed and also indicates which expression dialect will be used to identify the fragment(s) of the resource representation to retrieve. When this attribute is present, the only children elements of the wst:Get element MUST be wst:Expression elements, and there MUST be at least one.  When this attribute is not present then ...<<we default back to current ws-transfer where the first child is the actual XML of the resource and 2+ children are ignored>>. This attribute MUST be present when the message contains a wst:Expression element. A resource MUST generate an UnsupportedDialectFault if it does not support the specified Dialect.  << add text that a fault MUST be generated if it doesn't support Fragments at all>>

/s:Envelope/s:Body/wst:Get/wst:Expression

When present, this optional element identifies a fragment in the resource to be sent in the response. Absence of this element is equivalent to an Expression that identifies the entire resource representation. The value of this element MUST conform to the dialect specified in /s:Envelope/s:Body/wst:Get@ExpressionDialect attribute. A resource MUST generate an InvalidExpressionFault if the expression is invalid. If the expression syntax is not valid with respect to the dialect then a resource SHOULD specify a fault detail of "InvalidExpressionSyntax". If the expression value is not valid for the resource type then the resource SHOULD specify a fault detail of "InvalidExpressionValue".

If a resource cannot return a value for a requested fragment then it MUST generate a GetFault.

If the request contains more Expression elements than the resource supports the resource MUST return a fault which SHOULD be wst:MultipartLimitExceededFault.

A Get request MUST be targeted at the resource whose representation is desired as described in 2 Terminology and Notation of this specification.

There are no body blocks defined by default for a Get Request. As per the SOAP processing model, other specifications may introduce various types of extensions to the semantics of this message which are enabled through headers tagged with s:mustUnderstand="true". Such extensions may define how resource or subsets of it are to be retrieved or transformed prior to retrieval. Specifications which define such extensions MUST allow processing the basic Get request message without those extensions. Since the response may not be sent to the original sender, extension specifications should consider adding a corresponding SOAP header value in the response to signal to the receiver that the extension is being used.

Implementations may respond with a fault message using the standard fault codes defined in WS-Addressing (e.g., wsa:ActionNotSupported). Other components of the outline above are not further constrained by this specification.

If the resource accepts a Get request, it MUST reply with a response of the following form:

<s:Envelope ...> 

  <s:Header ...>

    <wsa:Action>

      http://www.w3.org/2009/02/ws-tra/GetResponse

    </wsa:Action>

    <wsa:RelatesTo>xs:anyURI</wsa:RelatesTo>

    <wsa:To>xs:anyURI</wsa:To>

    ...

  </s:Header>

  <s:Body ...>

    <wst:GetResponse ...>

      <wst:ResourceFragment> xs:any </wst:ResourceFragment> +

      |

      xs:any+

    </wst:GetResponse>

  </s:Body>

</s:Envelope>

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

/s:Envelope/s:Header/wsa:Action

This required element MUST contain the value http://www.w3.org/2009/02/ws-tra/GetResponse. If a SOAP Action URI is also present in the underlying transport, its value MUST convey the same value.

/s:Envelope/s:Body/wst:GetResponse/wst:ResourceFragment

This OPTIONAL element, when present, encompasses a single fragment response corresponding to a wst:Expression in the original request and MUST contain the fragment of the resource representation identified by the wst:Expression. If the request contained a wst:Get@ExpressionDialect attribute then the response MUST contain an equal number of wst:Result elements.

 

/s:Envelope/s:Body/xs:anychild::*[position()=1]

If the request message did not include the Dialect attribute, then tThe representation itself MUST be the initial child element of the wst:GetResponseSOAP:Body  element of the response message. The presence of subsequent child elements is service-specific and MAY be controlled by the presence or extension-specific SOAP headers in the original request.

 

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

The following shows a sample SOAP envelope containing a Get request:

<s:Envelope 

    xmlns:s="http://www.w3.org/2003/05/soap-envelope"

    xmlns:wsa="http://www.w3.org/2005/08/addressing"

    xmlns:xxx="http://fabrikam123.example.com/resource-model" >

  <s:Header>

    <wsa:ReplyTo>

      <wsa:Address>

        http://www.fabrikam123.example.org/pullport

      </wsa:Address>

    </wsa:ReplyTo>

    <wsa:To>http://www.example.org/repository</wsa:To>

    <xxx:CustomerID>732199</xxx:CustomerID>

    <xxx:Region>EMEA</xxx:Region>

    <wsa:Action>

      http://www.w3.org/2009/02/ws-tra/Get

    </wsa:Action>

    <wsa:MessageID>

      uuid:00000000-0000-0000-C000-000000000046

    </wsa:MessageID>

  </s:Header>

  <s:Body/>

</s:Envelope>

The following shows the corresponding response message:

<s:Envelope 

    xmlns:s="http://www.w3.org/2003/05/soap-envelope"

    xmlns:wsa="http://www.w3.org/2005/08/addressing"

    xmlns:xxx="http://fabrikam123.example.com/resource-model" >

  <s:Header>

    <wsa:To>http://www.fabrikam123.example.org/pullport</wsa:Address>

    <wsa:Action>

      http://www.w3.org/2009/02/ws-tra/GetResponse

    </wsa:Action>

    <wsa:MessageID>

      uuid:0000010e-0000-0000-C000-000000000046

    </wsa:MessageID>

    <wsa:RelatesTo>

      uuid:00000000-0000-0000-C000-000000000046

    </wsa:RelatesTo>

  </s:Header>

  <s:Body>

    <xxx:Customer>

      <xxx:first>Roy</xxx:first><xxx:last>Hill</xxx:last>

      <xxx:address>123 Main Street</xxx:address>

      <xxx:city>Manhattan Beach</xxx:city>

      <xxx:state>CA</xxx:state>

      <xxx:zip>90266</xxx:zip>

    </xxx:Customer>

  </s:Body>

</s:Envelope>

In this example, the representation of the resource is the following XML element:

  <xxx:Customer>

    <xxx:first>Roy</xxx:first><xxx:last>Hill</xxx:last>

    <xxx:address>123 Main Street</xxx:address>

    <xxx:city>Manhattan Beach</xxx:city>

    <xxx:state>CA</xxx:state>

    <xxx:zip>90266</xxx:zip>

  </xxx:Customer>

3.2 Put

This specification defines one Web service operation (Put) for updating a resource by providing a replacement representation. A resource MAY accept updates that provide different XML representations than that returned by the resource; in such a case, the semantics of the update operation is defined by the resource.

The Put request message MUST be of the following form:

<s:Envelope ...> 

  <s:Header ...>

    <wsa:Action>

      http://www.w3.org/2009/02/ws-tra/Put

    </wsa:Action>

    <wsa:MessageID>xs:anyURI</wsa:MessageID>

    <wsa:To>xs:anyURI</wsa:To>

    ...

  </s:Header>

  <s:Body...>

    <wst:Put ExpressionDialect="xs:anyURI"? ...>

      <wst:Fragment @Mode="xs:anyURI">

        <wst:Expression> xs:any </wst:Expression>[I2] 

        <wst:Value ...> xs:any </wst:Value> ?

      </wst:Fragment>

      | xs:any +

    </wst:Put>

  </s:Body>

</s:Envelope> 

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

/s:Envelope/s:Header/wsa:Action

This required element MUST contain the value http://www.w3.org/2009/02/ws-tra/Put. If a SOAP Action URI is also present in the underlying transport, its value MUST convey the same value.

/s:Envelope/s:Body/wst:Put@ExpressionDialect

 

This OPTIONAL attribute, when present, indicates that a fragment update is being performed and also indicates which expression dialect will be used to identify the fragment(s) of the resource representation to be updated. This attribute MUST be present when the message contains a /s:Envelope/s:Body/wst:Put/wst:Fragment
element.   << add text to say that a fault MUST be generated if it doesn't support fragments at all>>

 

/s:Envelope/s:Body/wst:Put/wst:Fragment

 

This optional element encompasses a single update to be performed on the resource. Upon successful completion of a Put operation, the resource representation MUST appear as though the fragment updates occurred in the order specified in the Put operation. If there are multiple Fragment elements then, for the first fragment, the resource representation is the original resource representation (before applying the Put changes). For subsequent fragments, the resource representation is the intermediate representation resulting from applying the previous fragments.

 

If the request contains more Fragment elements than the resource supports the resource MUST return a fault which SHOULD be wst:MultipartLimitExceededFault.

 

If this element is present, other (non-Fragment) children following this element SHOULD be ignored by the service.[I3] 

 

 

 

/s:Envelope/s:Body/wst:Put/wst:Fragment@Mode

This attribute indicates the type of update to be performed on this fragment. A resource MUST generate a ResourceValidityFault if the result of executing this operation would cause the resource representation to become invalid. A resource MAY support only a subset of the Modes defined within this specification. A resource that does not support a specified Mode MUST generate a PutModeUnsupportedFault.

A value of "http://www.w3.org/2009/02/ws-tra/Remove" indicates that the fragment MUST be deleted if it is present. The expression dialect indicated in this operation MAY place additional constraints on the definition of this Mode. Note that, in order to delete the resource itself, a WS-Transfer "Delete" message is used.

A value of "http://www.w3.org/2009/02/ws-tra/Modify" means that the fragment MUST be replaced by removing any fragment that already exists and inserting the specified value in its place. If the expression resolves to nothing then this fragment element does not result in any change to the resource representation. The expression dialect indicated in this operation MAY place additional constraints on the definition of this Mode. A fragment with no wst:Expression MUST specify this Mode.

A value of "http://www.w3.org/2009/02/ws-tra/Insert" indicates that the fragment MUST be added to the resource representation. If the expression targets a repeated element (maxOccurs > 1), the fragment MUST be added at the end. If the expression targets a non-repeated element (maxOccurrs = 1) that already exists, the resource MUST generate a FragmentAlreadyExistsFault. If the expression targets an existing item of a repeated element, the fragment MUST be added before the existing item.

 

/s:Envelope/s:Body/wst:Put/wst:Fragment/wst:Expression

This element contains the expression that identifies a fragment of the resource representation to be updated.

 

The value of this element MUST conform to the dialect specified in the /s:Envelope/s:Body/wst:Put@ExpressionDialect

attribute. A resource MUST generate an InvalidExpressionFault if the expression is invalid. If the expression syntax is not valid with respect to the dialect then a resource SHOULD specify a fault detail of "InvalidExpressionSyntax". If the expression value is not valid for the resource type then the resource SHOULD specify a fault detail of "InvalidExpressionValue".

 

/s:Envelope/s:Body/wst:Put/wst:Fragment/wst:Value

This element contains the data to be written to the resource representation. If the /s:Envelope/s:Body/wst:Put/wst:Fragment@Modeattribute is "http://www.w3.org/2009/02/ws-tra/Insert" or "http://www.w3.org/2009/02/ws-tra/Modify" then this element MUST be present. If the [Body]/wst:Put/Fragment/@Mode attribute is "http://www.w3.org/2009/02/ws-tra/Remove" then this element MUST NOT be present. A resource MUST generate an InvalidPutSyntaxFault if it receives a message with a Value cardinality that is not valid for the Mode attribute.

 

 

/s:Envelope/s:Body/wst:Put/xs:anychild::*[position()=1]

This OPTIONAL element MUST contain tThe representation to be used for the update MUST be the initial child element of the s:Body element of the request message. All other children SHOULD be ignored by the service. This element MUST NOT be present if a wst:Fragment element is present.

A Put request MUST be targeted at the resource whose representation is desired to be replaced, as described in 2 Terminology and Notation of this specification. As per the SOAP processing model, other specifications MAY introduce various types of extensions to this message which are enabled through headers tagged with s:mustUnderstand="true". Such extensions may require that a full or partial update should be accomplished using symbolic, instruction-based, or other methodologies.

Extension specifications MAY also define extensions to the original Put request, enabled by OPTIONAL SOAP headers, which control the nature of the response, as discussed in remarks on the PutResponse below.

Specifications which define any of these extensions MUST allow processing the Put message without such extensions.

In addition to the standard fault codes defined in WS-Addressing, implementations MAY use the fault code wxf:InvalidRepresentation if the presented representation is invalid for the target resource. See Section 5. Other components of the outline above are not further constrained by this specification.

If a resource encounters a failure while processing the fragments in a Put request, it MUST generate a PutFault. The resource SHOULD ensure that its representation is unchanged from prior to the request, although atomic behavior is not required of resource implementations. The resource SHOULD include a wsrt:SideAffects element in the fault detail to indicate whether any changes occurred.

A successful Put operation updates the current representation associated with the targeted resource.

If the resource accepts a Put request and performs the requested update, it MUST reply with a response of the following form:

<s:Envelope ...> 

  <s:Header ...>

    <wsa:Action>

      http://www.w3.org/2009/02/ws-tra/PutResponse

    </wsa:Action>

    <wsa:RelatesTo>xs:anyURI</wsa:RelatesTo>

    <wsa:To>xs:anyURI</wsa:To>

    ...

  </s:Header>

  <s:Body ...>

    <wst:PutResponse ...>

      xs:any ?

    </wst:PutResponse>

  </s:Body>

</s:Envelope> 

/s:Envelope/s:Header/wsa:Action

This required element MUST contain the value http://www.w3.org/2009/02/ws-tra/PutResponse. If a SOAP Action URI is also present in the underlying transport, its value MUST convey the same value.

/s:Envelope/s:Body/wst:PutResponse/child::*[position()=1]xs:any

If the request Body contained a /s:Envelope/s:Body/wst:Create/wst:Fragment  element, then the new representation MUST be omitted in the response. The absence of the resource representation in the response is in recognition of the potentially large amount of data that may be returned, which may have been the reason a fragment Put was used instead of sending the entire resource representation.  [I4] 

If the request Body did not contain a wst:Fragment element, By default, a service MUST return the current representation of the resource as the initial child of the s:Body element if the updated representation differs from the representation sent in the Put request message. The presence of additional child elements which contain other information pertaining to the update is service-specific.

As an optimization and as a service to the requester, the s:Body element of the response message SHOULD be empty if the updated representation does not differ from the representation sent in the Put request message; that is, if the service accepted the new representation verbatim.

Such a response (an empty s:Body) implies that the update request was successful in its entirety (assuming no intervening mutating operations are performed). A service MAY return the current representation of the resource as the initial child of the s:Body element even in this case, however.

Extension specifications MAY define extensions to the original Put request, enabled by OPTIONAL header values, which specifically control the presence, absence, or format of the updated representation or other child elements in the PutResponse in order to optimize the response. In the absence of such headers, the behavior MUST be as described above. Specifications which define any of these extensions MUST allow processing the Put message without such extensions. Since the response may not be sent to the original sender, extension specifications should consider adding a corresponding SOAP header value in the response to signal to the receiver that the extension is being used.

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

The following shows a sample SOAP envelope containing a Put request:

<s:Envelope 

    xmlns:s="http://www.w3.org/2003/05/soap-envelope"

    xmlns:wsa="http://www.w3.org/2005/08/addressing"

    xmlns:xxx="http://fabrikam123.example.com/resource-model" >

  <s:Header>

    <wsa:ReplyTo>

      <wsa:Address>

        http://www.fabrikam123.example.org/sender

      </wsa:Address>

    </wsa:ReplyTo>

    <wsa:To>http://www.example.org/pushport</wsa:To>

    <xxx:CustomerID>732199</xxx:CustomerID>

    <xxx:Region>EMEA</xxx:Region>

    <wsa:Action>

      http://www.w3.org/2009/02/ws-tra/Put

    </wsa:Action>

    <wsa:MessageID>

      uuid:00000000-0000-0000-C000-000000000047

    </wsa:MessageID>

  </s:Header>

  <s:Body>

    <xxx:Customer>

      <xxx:first>Roy</xxx:first><xxx:last>Hill</xxx:last>

      <xxx:address>321 Main Street</xxx:address>

      <xxx:city>Manhattan Beach</xxx:city>

      <xxx:state>CA</xxx:state>

      <xxx:zip>90266</xxx:zip>

    </xxx:Customer>

  </s:Body>

</s:Envelope>

The following shows the corresponding response message indicating success:

<s:Envelope 

    xmlns:s="http://www.w3.org/2003/05/soap-envelope"

    xmlns:wsa="http://www.w3.org/2005/08/addressing"

    xmlns:xxx="http://fabrikam123.example.com/resource-model" >

  <s:Header>

    <wsa:To>http://www.fabrikam123.example.org/sender</wsa:Address>

    <wsa:Action>

      http://www.w3.org/2009/02/ws-tra/PutResponse

    </wsa:Action>

    <wsa:MessageID>

      uuid:0000010e-0000-0000-C000-000000000047

    </wsa:MessageID>

    <wsa:RelatesTo>

      uuid:00000000-0000-0000-C000-000000000047

    </wsa:RelatesTo>

  </s:Header>

  <s:Body/>

</s:Envelope>

3.3 Delete

This specification defines one Web service operation (Delete) for deleting a resource in its entirety.

Extension specifications MAY define extensions to the Delete request, enabled by OPTIONAL header values, which specifically control preconditions for the Delete to succeed and which may control the nature or format of the response. Since the response may not be sent to the original sender, extension specifications should consider adding a corresponding SOAP header value in the response to signal to the receiver that the extension is being used.

The Delete request message MUST be of the following form:

<s:Envelope ...> 

  <s:Header ...>

    <wsa:Action>

      http://www.w3.org/2009/02/ws-tra/Delete

    </wsa:Action>

    <wsa:MessageID>xs:anyURI</wsa:MessageID>

    <wsa:To>xs:anyURI</wsa:To>

    ...

  </s:Header>

  <s:Body ...>

    <wst:Delete ...>

      xs:any *

    </wst:Delete>

  </s:Body>

</s:Envelope> 

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

/s:Envelope/s:Header/wsa:Action

This required element MUST contain the value http://www.w3.org/2009/02/ws-tra/Delete. If a SOAP Action URI is also present in the underlying transport, its value MUST convey the same value.

A Delete request MUST be targeted at the resource to be deleted as described in 2 Terminology and Notation of this specification.

There are no body blocks defined for a Delete Request.

Implementations may respond with a fault message using the standard fault codes defined in WS-Addressing (e.g., wsa:ActionNotSupported). Other components of the outline above are not further constrained by this specification.

A successful Delete operation invalidates the current representation associated with the targeted resource.

If the resource accepts a Delete request, it MUST reply with a response of the following form:

<s:Envelope ...> 

  <s:Header ...>

    <wsa:Action>

      http://www.w3.org/2009/02/ws-tra/DeleteResponse

    </wsa:Action>

    <wsa:RelatesTo>xs:anyURI</wsa:RelatesTo>

    <wsa:To>xs:anyURI</wsa:To>

    ...

  </s:Header>

  <s:Body ...>

    <wst:DeleteResponse>

      xs:any ?

    </wst:DeleteResponse>

  </s:Body>

</s:Envelope> 

/s:Envelope/s:Header/wsa:Action

This required element MUST contain the value http://www.w3.org/2009/02/ws-tra/DeleteResponse. If a SOAP Action URI is also present in the underlying transport, its value MUST convey the same value.

By default, there are no s:Body blocks defined for a Delete response. Specifications which define extensions for use in the original Delete request which control the format of the response MUST allow processing the Delete message without such extensions.

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

The following shows a sample SOAP envelope containing a Delete request:

<s:Envelope 

    xmlns:s="http://www.w3.org/2003/05/soap-envelope"

    xmlns:wsa="http://www.w3.org/2005/08/addressing"

    xmlns:xxx="http://fabrikam123.example.com/resource-model" >

  <s:Header>

    <wsa:ReplyTo>

      <wsa:Address>

        http://www.fabrikam123.example.org/sender

      </wsa:Address>

    </wsa:ReplyTo>

    <wsa:To>http://www.example.org/pushport</wsa:To>

    <xxx:CustomerID>732199</xxx:CustomerID>

    <xxx:Region>EMEA</xxx:Region>

    <wsa:Action>

      http://www.w3.org/2009/02/ws-tra/Delete

    </wsa:Action>

    <wsa:MessageID>

      uuid:00000000-0000-0000-C000-000000000049

    </wsa:MessageID>

  </s:Header>

  <s:Body/>

</s:Envelope>

The following shows the corresponding response message indicating success:

<s:Envelope 

    xmlns:s="http://www.w3.org/2003/05/soap-envelope"

    xmlns:wsa="http://www.w3.org/2005/08/addressing"

    xmlns:xxx="http://fabrikam123.example.com/resource-model" >

  <s:Header>

    <wsa:To>http://www.fabrikam123.example.org/sender</wsa:Address>

    <wsa:Action>

      http://www.w3.org/2009/02/ws-tra/DeleteResponse

    </wsa:Action>

    <wsa:MessageID>

      uuid:0000010e-0000-0000-C000-000000000049

    </wsa:MessageID>

    <wsa:RelatesTo>

      uuid:00000000-0000-0000-C000-000000000049

    </wsa:RelatesTo>

  </s:Header>

  <s:Body/>

</s:Envelope>

4 Resource Factory Operations

4.1 Create

This specification defines one Web service operation (Create) for creating a resource and providing its initial representation. In some cases, the initial representation MAY constitute the representation of a logical constructor for the resource and may thus differ structurally from the representation returned by Get or the one required by Put. This is because the parameterization requirement for creating a resource is often distinct from the steady-state representation of the resource. Implementations should provide metadata which describes the use of the representation and how it relates to the resource which is created, but such mechanisms are beyond the scope of this specification. The resource factory that receives a Create request will allocate a new resource that is initialized from the presented representation. The new resource will be assigned a service-determined endpoint reference that is returned in the response message.

The Create request message MUST be of the following form:

<s:Envelope ...> 

  <s:Header ...>

    <wsa:Action>

      http://www.w3.org/2009/02/ws-tra/Create

    </wsa:Action>

    <wsa:MessageID>xs:anyURI</wsa:MessageID>

    <wsa:To>xs:anyURI</wsa:To>

    ...

  </s:Header>

  <s:Body ...>

    <wst:Create ExpressionDialect="xs:anyURI"? ...>

      <wst:Metadata> resource metadata </wst:Metadata> ?[I5] 

      <wst:Fragment>

        <wst:Expression> xs:any </wst:Expression>[I6] 

        <wst:Value ...> xs:any </wst:Value>

      </wst:Fragment> *

      | xs:any *

    </wst:Create>

  </s:Body>

</s:Envelope>

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

/s:Envelope/s:Header/wsa:Action

This required element MUST contain the value http://www.w3.org/2009/02/ws-tra/Create. If a SOAP Action URI is also present in the underlying transport, its value MUST convey the same value.

/s:Envelope/s:Body/wst:Create@ExpressionDialect

This OPTIONAL attribute, when present, indicates that a fragment creation is being performed and also indicates which expression dialect will be used to identify the fragment(s) of the resource representation to be updated. This attribute MUST be present when the message contains a /s:Envelope/s:Body/wst:Create/wst:Fragment element. << add text to say that a fault MUST be generated if it doesn't support fragments at all>>

/s:Envelope/s:Body/wst:Create/wst:Metadata

When present this optional element MUST contain at least one wsmex:MetadataSection. This is resource metadata to be created and initialized during the creation of the resource.

A resource factory MUST generate an InvalidMetadataFault if the Create request message contains a wsmex:Dialect that is not supported or if the resource metadata contains values that are not supported for the resource.

This element MAY contain a wsmex:MetadataSection with a wsmex:Dialect of http://www.w3.org/2009/02/ws-tra allowing the requestor to specify desired metadata as defined in this specification (such as lifecycle metadata).

 

/s:Envelope/s:Body/wst:Create/wst:Fragment

This optional element encompasses a single resource fragment to be initialized during the resource creation. If there are multiple Fragment elements then the resource MUST appear to have been created as though each fragment were processed in the sequence specified in the Create message.

If the request contains more Fragment elements than the resource supports the resource MUST return a fault which SHOULD be wst:MultipartLimitExceededFault.

 

/s:Envelope/s:Body/wst:Create/wst:Fragment/wst:Expression

This element contains an expression that identifies a resource fragment to be initialized during resource creation. The expression identifies the fragment in the resource representation as it appears after successful processing of the current fragment. The value of this element MUST conform to the dialect specified in the /s:Envelope/s:Body/wst:Create@ExpressionDialect attribute. A resource factory MUST generate an InvalidExpressionFault if the expression is invalid. If the expression syntax is not valid with respect to the dialect then a resource factory SHOULD specify a fault detail of "InvalidExpressionSyntax". If the expression is not valid for the resource type then the resource factory SHOULD specify a fault detail of "InvalidExpressionValue".

/s:Envelope/s:Body/wst:Create/wst:Fragment/wst:Value

This element contains the data to be written to the resource representation. If the resource factory is unable to write the requested fragment then it MUST generate a CreateFault.

 

/s:Envelope/s:Body/wst:Create/xs:anychild::*[position()=1]

The first child element of the s:Body element MUST NOT be omitted. The contents of this element are service-specific, and MAY contain the literal initial resource representation, a representation of the constructor for the resource, or other instructions for creating the resource. All other children that do not have the wst namespace SHOULD be ignored by the service. This element MUST NOT appear if a wst:Fragment element is present.

Extensions specifications MAY also define extensions to the original Create request, enabled by OPTIONAL SOAP headers, which constrain the nature of the response, as discussed in remarks on the CreateResponse below.Similarly, they may require headers which control the interpretation of the s:Body as part of the resource creation process.

Such specifications MUST also allow processing the Create message without such extensions.

A Create request MUST be targeted at a resource factory capable of creating the desired new resource. This factory is distinct from the resource being created (which by definition does not exist prior to the successful processing of the Create request message).

In addition to the standard fault codes defined in WS-Addressing, implementations MAY use the fault code wfx:InvalidRepresentation if the presented representation is invalid for the target resource. See Section 5.

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

If the resource factory accepts a Create request, it MUST reply with a response of the following form:

<s:Envelope ...> 

  <s:Header ...>

    <wsa:Action>

      http://www.w3.org/2009/02/ws-tra/CreateResponse

    </wsa:Action>

    <wsa:RelatesTo>xs:anyURI</wsa:RelatesTo>

    <wsa:To>xs:anyURI</wsa:To>

    ...

  </s:Header>

  <s:Body ...>

    <wst:CreateResponse ...>

      <wstxf:ResourceCreated>endpoint-reference</wstxf:ResourceCreated>

      xs:any ?

    </wst:CreateResponse>

  </s:Body>

</s:Envelope>

/s:Envelope/s:Header/wsa:Action

This required element MUST contain the value http://www.w3.org/2009/02/ws-tra/CreateResponse. If a SOAP Action URI is also present in the underlying transport, its value MUST convey the same value.

/s:Envelope/s:Body/wst:CreateResponse/wstxf:ResourceCreated

This required element MUST contain a resource reference for the newly created resource. This resource reference, represented as an endpoint reference as defined in WS-Addressing, MUST identify the resource for future Get, Put, and Delete operations.

/s:Envelope/s:Body/wst:CreateResponse/child::*[position()=2]

If the request Body contained either a /s:Envelope/s:Body/wst:Create/wsmex:Metadata or a /s:Envelope/s:Body/wst:Create/wst:Fragment  element, then the new representation MUST be omitted in the response. Otherwise, By default, a service MUST return the current representation of the new resource as the second child of the s:Body element if the created representation logically differs from the representation sent in the Create request message. That is, the initial representation is returned if one or more values present in Create message was specifically overridden with a different value during resource creation. If default values are used to complete a resource creation which were not present in the Create message, then this does not constitute a logical difference. The presence of additional child elements which contain other information pertaining to the result of the Create operation is service-specific.

As an optimization and as a service to the requestor, the s:Body element of the response message SHOULD be empty, other than the ResourceCreated element, if the created representation does not logically differ from the representation sent in the Create request message; that is, if the service accepted the new representation or creation instructions verbatim. Such a response indicates that the request was completely successful (assuming no intervening mutating operations are performed). A service MAY return the current representation of the resource as the initial child of the s:Body element even in this case, however.

Extension specifications MAY define extensions to the original Create request, enabled by OPTIONAL header values, which specifically control the presence, absence, or format of the initial representation or other child elements in the CreateResponse. These headers MAY override the default behavior if they are marked with s:mustUnderstand="true". In the absence of such OPTIONAL headers, the behavior MUST be as described in the previous paragraphs. Since the response may not be sent to the original sender, extension specifications should consider adding a corresponding SOAP header value in the response to signal to the receiver that the extension is being used.

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

The following shows a sample SOAP envelope containing a Create request:

<s:Envelope 

    xmlns:s="http://www.w3.org/2003/05/soap-envelope"

    xmlns:wsa="http://www.w3.org/2005/08/addressing"

    xmlns:xxx="http://fabrikam123.example.com/resource-model" >

  <s:Header>

    <wsa:ReplyTo>

      <wsa:Address>

        http://www.fabrikam123.example.org/sender

      </wsa:Address>

    </wsa:ReplyTo>

    <wsa:To>http://www.example.org/pushport/CustomerSpace</wsa:To>

    <wsa:Action>

      http://www.w3.org/2009/02/ws-tra/Create

    </wsa:Action>

    <wsa:MessageID>

      uuid:00000000-0000-0000-C000-000000000048

    </wsa:MessageID>

  </s:Header>

  <s:Body>

    <xxx:Customer>

      <xxx:first>Roy</xxx:first><xxx:last>Hill</xxx:last>

      <xxx:address>123 Main Street</xxx:address>

      <xxx:city>Manhattan Beach</xxx:city>

      <xxx:state>CA</xxx:state>

      <xxx:zip>90266</xxx:zip>

    </xxx:Customer>

  </s:Body>

</s:Envelope> 

The following shows the corresponding response message indicating success:

<s:Envelope 

    xmlns:s="http://www.w3.org/2003/05/soap-envelope"

    xmlns:wsa="http://www.w3.org/2005/08/addressing"

    xmlns:wxf="http://www.w3.org/2009/02/ws-tra"

    xmlns:xxx="http://fabrikam123.example.com/resource-model" >

  <s:Header>

    <wsa:To>http://www.fabrikam123.example.org/sender</wsa:Address>

    <wsa:Action>

      http://www.w3.org/2009/02/ws-tra/CreateResponse

    </wsa:Action>

    <wsa:MessageID>

      uuid:0000010e-0000-0000-C000-000000000048

    </wsa:MessageID>

    <wsa:RelatesTo>

      uuid:00000000-0000-0000-C000-000000000048

    </wsa:RelatesTo>

  </s:Header>

  <s:Body>

    <wxf:ResourceCreated>

      <wsa:Address>http://www.example.org/pushport</wsa:Address>

      <wsa:ReferenceParameters>

        <xxx:CustomerID>732199</xxx:CustomerID>

        <xxx:Region>EMEA</xxx:Region>

      </wsa:ReferenceParameters>

    </wxf:ResourceCreated>

  </s:Body>

</s:Envelope>

5 Faults

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 SHOULD be used for faults defined in this specification:

http://www.w3.org/2009/02/ws-tra/fault

5.1 InvalidRepresentation

This fault is returned when an incorrect representation is sent in a wxf:Put or wxf:Create message.

[Code]

s:Sender

[Subcode]

wxf:InvalidRepresentation

[Reason]

The supplied representation is invalid

[Detail]

none

5.3 ConcurrencyFault

This fault is generated by a resource to indicate that it was unable to process a message due to concurrent access. A requester might choose to handle this condition by retrying the operation that caused it.

[Action]

http://www.w3.org/2009/02/ws-tra/fault

[Code]

s12:Sender

[Subcode]

wst:ConcurrencyFault

[Reason]

Could not access the resource due to concurrency and/or locking conditions

[Detail]

 

5.4 UnsupportedDialectFault

This fault is generated by a resource to indicate that the expression dialect used to identify a resource fragment is not supported by the resource for the current operation. The fault detail SHOULD contain the Dialect values that the resource does support for the operation.

[Action]

http://www.w3.org/2009/02/ws-tra/fault

[Code]

s12:Sender

[Subcode]

wst:UnsupportedDialectFault

[Reason]

The requested dialect is not supported

[Detail]

<wst:Dialect>xs:anyURI</wst:Dialect> *

5.5 InvalidExpressionFault

This fault is sent by a resource if a <wst:Expression> element has an syntax that is invalid according to the definition of the expression dialect. If the expression syntax is not valid with respect to the dialect then a resource SHOULD specify a fault detail of "InvalidExpressionSyntax", indicating which expression this detail applies to. If the expression is not valid for the resource type then the resource SHOULD specify a fault detail of "InvalidExpressionValue", indicating which expression this detail applies to.

[Action]

http://www.w3.org/2009/02/ws-tra/fault

[Code]

s12:Sender

[Subcode]

wst:InvalidExpressionFault

[Reason]

The specified Expression is not valid

[Detail]

<wst:InvalidExpressionSyntax>
  <wst:Expression>xs:any</wst:Expression> +
</wst:InvalidExpressionSyntax>
|
<wst:InvalidExpressionValue>
  <wst:Expression>xs:any</wst:Expression> +
</wst:InvalidExpressionValue>

5.6 GetFault

This fault is generated by a resource if it is unable to process a valid Get message.

[Action]

http://www.w3.org/2009/02/ws-tra/fault

[Code]

s12:Receiver

[Subcode]

wst:GetFault

[Reason]

Unable to process Get message

[Detail]

 

5.7 ResourceValidityFault

This fault is generated by a resource if the result of processing a Put message would cause the resource representation to become invalid. The fault detail MAY include the wst:Fragment element in the Put message that caused this fault to be generated.

[Action]

http://www.w3.org/2009/02/ws-tra/fault

[Code]

s12:Sender

[Subcode]

wst:ResourceValidityFault

[Reason]

The requested resource modification is not valid.

[Detail]

<wst:Fragment>fragment</wst:Fragmant> ?

5.8 FragmentAlreadyExistsFault

This fault is generated by a resource if a "Put" message specifies the "http://www.w3.org/2009/02/ws-tra/Insert" mode and identifies a non-repeated fragment element (maxOccurrs = 1) that already exists. The fault detail MAY include the wst:Fragment that failed to be processed.

[Action]

http://www.w3.org/2009/02/ws-tra/fault

[Code]

s12:Sender

[Subcode]

wst:FragmentAlreadyExistsFault

[Reason]

The fragment already exists

[Detail]

<wst:Fragment>fragment</wst:Fragment> ?

5.9 PutFault

This fault is generated by a resource if it is unable to process a valid Put message. The fault detail MAY include the wst:Fragment that failed to be processed.

The fault detail SHOULD include a wst:SideAffects element in the fault detail to indicate whether any changes occurred. A value of "true" indicates some changes occurred; a value of "false" indicates no changes occurred. Absence of the element indicates that changes may have occurred.

[Action]

http://www.w3.org/2009/02/ws-tra/fault

[Code]

s12:Receiver

[Subcode]

wst:PutFault

[Reason]

Unable to process Put message

[Detail]

<wst:Fragment>fragment</wst:Fragment> ?
<wst:SideEffects>xs:boolean</wst:SideEffects> ?

5.10 PutModeUnsupportedFault

This fault is generated by a resource if a "Put" message specifies a mode that is not supported by the resource.

[Action]

http://www.w3.org/2009/02/ws-tra/fault

[Code]

s12:Sender

[Subcode]

wst:PutModeUnsupportedFault

[Reason]

The Put mode is not supported

[Detail]

The unsupported Mode URI

5.11 CreateFault

This fault is generated by a resource if it is unable to process a valid Create message. The fault detail MAY include the wst:Fragment that failed to be processed.

[Action]

http://www.w3.org/2009/02/ws-tra/fault

[Code]

s12:Receiver

[Subcode]

wstt:CreateFault

[Reason]

Unable to process Create message

[Detail]

<wstt:Fragment>fragment</wst:Fragment> ?

5.12 InvalidMetadataFault

This fault is generated by a resource factory if a "Create" message contains a wsmex:Dialect that is not supported or if the resource metadata contains values that are not supported for the resource.

[Action]

http://www.w3.org/2009/02/ws-tra/fault

[Code]

s12:Sender

[Subcode]

wst:InvalidMetadataFault

[Reason]

Resource metadata values not supported by resource

[Detail]

 

5.13 MultipartLimitExceededFault

This fault is generated by a resource if a request message exceeds the limit of wst:Expression or wst:Fragment elements supported for the dialect. The fault detail MUST contain the maximum number of wst:Expression or wst:Fragment elements supported for the dialect.

[Action]

http://www.w3.org/2009/02/ws-tra/fault

[Code]

s12:Sender

[Subcode]

wst:MultipartLimitExceededFault

[Reason]

Access to multiple fragments exceeded the supported number of fragments in a single message

[Detail]

<wst:MultipartLimit>xs:positiveInteger</wst:MultipartLimit>

5.14 InvalidPutSyntaxFault

This fault is generated by a resource if a Put request specifying a Mode "http://www.w3.org/2009/02/ws-tra/Remove" contains a wst:Value element or if a Put request specifying a Mode "http://www.w3.org/2009/02/ws-tra/Insert" or "http://www.w3.org/2009/02/ws-tra/Modify" does not contain a wst:Value element.

[Action]

http://www.w3.org/2009/02/ws-tra/fault

[Code]

s12:Sender

[Subcode]

wst:InvalidRemoveSyntaxFault

[Reason]

Invalid syntax used for Put request

[Detail]

 

 

6 Security Considerations

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 resource reference, then it is recommended that a security context be established using the mechanisms described in WS-Trust and WS-SecureConversation. It is further recommended that if shared secrets are used, message-specific derived keys also be used to protect the secret from crypto attacks.

The access control semantics of resource references is out-of-scope of this specification and are specific to each resource reference. Similarly, any protection mechanisms on resource references independent of 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 listing 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.

7 Acknowledgements

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), Sreedhara Narayanaswamy (CA), Sumeet Vij (Software AG), Vikas Varma (Software AG), Wu Chou (Avaya Communications), Yves Lafon (W3C)

8 References

RFC 2119

Key words for use in RFCs to Indicate Requirement Levels , S. Bradner, Harvard University, March 1997. (See http://www.ietf.org/rfc/rfc2119.txt.)

SOAP 1.1

Simple Object Access Protocol (SOAP) 1.1 , D. Box, et al, May 2000. (See http://www.w3.org/TR/2000/NOTE-SOAP-20000508/.)

SOAP 1.2

SOAP Version 1.2 Part 1: Messaging Framework , M. Gudgin, et al, June 2003. (See http://www.w3.org/TR/soap12-part1/.)

WS-Addressing04

D Box et al, W3C Submission, "Web Services Addressing (WS-Addressing)" , May 2006. (See http://www.w3.org/Submission/2004/SUBM-ws-addressing-20040810/.)

WS-Addressing

W3C Recommendation, "Web Services Addressing 1.0 (WS-Addressing)" , May 2006. (See http://www.w3.org/2005/08/addressing/.)

WS-Policy

S. Bajaj, et al, "Web Services Policy Framework (WS-Policy)," , September 2004. (See http://schemas.xmlsoap.org/ws/2004/09/policy.)

WS-SecureConversation

href="http://schemas.xmlsoap.org/ws/2005/02/sc/"> Web Services Secure Conversation Language (WS-SecureConversation) , S. Anderson, et al, February 2005.

WS-Security

Web Services Security: SOAP Message Security 1.0 , OASIS standard. (See http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-soap-message-security-1.0.pdf.)

WS-SecurityPolicy

G. Della-Libera, et al, "Web Services Security Policy Language (WS-SecurityPolicy), Version 1.1" , July 2005. (See http://schemas.xmlsoap.org/ws/2005/07/securitypolicy.)

WSDL 1.1

Web Services Description Language (WSDL) 1.1 , E. Christensen, et al, March 2001. (See http://www.w3.org/TR/2001/NOTE-wsdl-20010315.)

XML Infoset

J. Cowan, et al, "XML Information Set" , February 2004. (See http://www.w3.org/TR/2004/REC-xml-infoset-20040204/.)

XML Schema, Part 1

XML Schema Part 1: Structures , H. Thompson, et al, October 2004. (See http://www.w3.org/TR/2004/REC-xmlschema-1-20041028/.)

XML Schema, Part 2

XML Schema Part 2: Datatypes , James Clark, et al, November 1999. (See http://www.w3.org/TR/2004/REC-xmlschema-2-20041028/.)

WS_I BP …