Package com.ibm.soa.parlayx21.common

Common Data Types.

See:
          Description

Class Summary
ChargingInformation For the services that include charging as an inline message part the charging information is provided in this data structure.
ChargingInformation_Deser  
ChargingInformation_Helper  
ChargingInformation_Ser  
PolicyException_Deser  
PolicyException_Helper  
PolicyException_Ser  
ServiceError The service error structure provides error information.
ServiceError_Deser  
ServiceError_Helper  
ServiceError_Ser  
ServiceException_Deser  
ServiceException_Helper  
ServiceException_Ser  
SimpleReference The simple reference that refers to a remote web service object.
SimpleReference_Deser  
SimpleReference_Helper  
SimpleReference_Ser  
TimeMetric The time metric lists a particular time metric.
TimeMetric_Deser  
TimeMetric_Helper  
TimeMetric_Ser  
TimeMetrics The time metrics lists the types of values.
 

Exception Summary
PolicyException  
PolicyException_DeserProxy  
ServiceException  
ServiceException_DeserProxy  
 

Package com.ibm.soa.parlayx21.common Description

Common Data Types.

Common Data Types

For common data types associated with this package see Common Data Types.

Scope

The present document is part 1 of the Stage 3 Parlay X 2 Web Services specification for Open Service Access (OSA).

The OSA specifications define an architecture that enables application developers to make use of network functionality through an open standardized interface, for example, the OSA APIs.

The present document specifies the Common aspects of the Parlay X 2 Web Services. The following are defined here:
  * Name spaces.
  * Data definitions.
  * Fault definitions.
  * WSDL Description of the interfaces.

References

The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
  * References are either specific (identified by date of publication and/or edition number or version number) or nonspecific.
  * For a specific reference, subsequent revisions do not apply.
  * For a non-specific reference, the latest version applies.

Referenced documents which are not found to be publicly available in the expected location might be found at http://docbox.etsi.org/Reference.

[1] ETSI TR 121 905: "Universal Mobile Telecommunications System (UMTS); Vocabulary for 3GPP Specifications (3GPP TR 21.905)".

[2] W3C Recommendation (2 May 2001): "XML Schema Part 2: Datatypes".

NOTE: Available at http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/.

[3] IETF RFC 2806: "URLs for Telephone Calls".

NOTE: Available at http://www.ietf.org/rfc/rfc2806.txt.

IETF RFC 3966: "The tel URI for Telephone Numbers". NOTE: Available at http://www.ietf.org/rfc/rfc3966.txt.[JR1]

[4] IETF RFC 3261: "SIP: Session Initiation Protocol".

NOTE: Available at http://www.ietf.org/rfc/rfc3261.txt.

[5] WS-I Basic Profile Version 1.0: "Final Material".

NOTE: Available at http://www.ws-i.org/Profiles/BasicProfile-1.0-2004-04-16.html.

[6] W3C Note (15 March 2001): "Web Services Description Language (WSDL) 1.1".

NOTE: Available at http://www.w3.org/TR/2001/NOTE-wsdl-20010315.

[7] OASIS Standard 200401 (March 2004): "Web Services Security: SOAP Message Security 1.0 (WS-Security 2004)".

NOTE: Available at http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-soap-message-security-1.0.pdf.

[8] W3C Recommendation (12 February 2002): "XML-Signature Syntax and Processing".

NOTE: Available at http://www.w3.org/TR/2002/REC-xmldsig-core-20020212/.

[9] ISO 4217: "Codes for the representation of currencies and funds".

[10] IETF RFC 3986: "Uniform Resource Identifier (URI): Generic Syntax".

NOTE: Available at http://www.ietf.org/rfc/rfc3986.txt.

Definitions and abbreviations

Definitions

For the purposes of the present document, the following terms and definitions apply:
application: computer program that accesses a Web Service
SOAP: not an acronym, protocol used for XML messaging
Web Service: software system designed to support interoperable machine-to-machine interaction over a network
Web Service Provider: entity which provides Web Services interfaces to capabilities offered
Web Service Requester: entity which operates Applications that access Web Services

Abbreviations

For the purposes of the present document, the abbreviations defined in TR 121 905 [1] and the following apply:
3GPP Third Generation Partnership Project
ETSI European Telecommunications Standards Institute
IP Internet Protocol
IT Information Technology
OASIS Organization for the Advancement of Structured Information Standards
OSA Open Service Access
RFC Request For Comment
SIP Session Initiation Protocol
SLA Service Level Agreement
UDDI Universal Description Discovery and Integration
URI Uniform Resource Identifier
W3C World Wide Web Consortium
WSDL Web Service Definition Language
WS-I Web Services-Interoperability Organization
XML Extensible Markup Language

Use of Web Services technologies

Web Service message content

SOAP

All Web Service messages SHALL send and accept messages that conform to the SOAP use defined in the WS-I Basic Profile [5], using the document/literal encoding style.

XML

All Web Service messages SHALL send and accept messages that conform to the XML use defined in the WS-I Basic Profile [5].

HTTP

All Web Service messages SHALL send and accept messages that conform to the HTTP use defined in the WS-I Basic Profile [5].

Web Service interface definitions

All Parlay X 2 Web Services are defined according to the following.

WSDL

All Web Service interfaces SHALL be defined using WSDL 1.1 as defined in the WSDL specification [6] and be conformant to the WSDL use defined in WS-I Basic Profile [5].

See clause 12 for detailed information on the WSDL style to be followed by Parlay X 2 Web Services.

Security for Parlay X 2 Web Services

If a message contains an identifier and/or credentials representing the sender of the message then these SHALL be provided in a manner prescribed by WS-Security [7].

Encryption of message content MAY be required by the Web Service Provider. If this is required, then this SHALL be accomplished in one of the following manners:
  * Use of a Virtual Private Network, to be administered independent of the Web Service implementation.
  * Use of Transport Level Security using HTTP over TLS as specified in the WS-I Basic Profile [5].

Integrity of the message content MAY be required by the Web Service Provider. If this is required, then this SHALL be accomplished using XML Digital Signature [8].

XML data types

Where possible standard XML Schema data types are used, as defined in section 3 (Built-in datatypes) in XML Schema [2].

Detailed service description

Address data items

Addresses, unless the specification provides specific additional instruction, MUST conform to the address portion of the URI definition provided in RFC 28063966 [3] for 'tel:' addresses, or RFC 3261 [4] for 'sip:' addresses or the definition given below for shortcodes or aliased addresses. Optional additions to the address portion of these URI definitions MUST NOT be considered part of the address accepted by the Parlay X 2 Web Services interfaces, and an implementation MAY choose to reject an address as invalid if it contains any content other than the address portion.

When processing a 'tel:' URI, as specified in RFC 28063966 [3], Parlay X 2 Web Services MUST accept national addresses (those not starting with '+' and a country code) and MUST accept international addresses (those starting with '+' and a country code).

When specified in the definition of a service operation, the URI may contain wildcard characters in accordance with the appropriate specification (for example, RFC 28063966 [3] or RFC 3261 [4]).

Shortcodes are short telephone numbers, usually 4 to 6 digits in length reserved for telecom service providers' own functionality. They shall be differentiated from national addresses by the use of a 'short:' rather than 'tel:' URI scheme. The short code defined in the URI consists of a string of digits with no non-digit characters.

Support for aliases in addresses is provided by use of the URI defined in RFC 3986 [10]. This allows for arbitrary data to be submitted to the Parlay X Web Service interface. The following is an example of how this could be applied: :

An alias is generally a relatively short character string that holds a scrambled address such that only the application identified in the URI can expand it.

Charging

Web Services may use a Web Service Provider to deliver content or function. In some cases, the producer of the content or capability will wish to use a bill-on-behalf-of capability offered by the Web Service Provider to charge for the content/function provided. For those services where the charge is part of a single activity, providing the charging related information as part of the message is very efficient.

An example is a messaging service, where a sports business collects information and distributes short messages with sports scores to its subscribers. The sports business has an agreement with a Web Service Provider where the charges for the messages are included in the bill provided by the Web Service Provider (thus the Web Service Provider is billing on behalf of the sports business.

To enable this capability to be provided across a variety of services in a consistent manner, thus making implementation easy and efficient, the information to be provided in the Web Service message for charging information is defined as part of the Parlay X Web Services Framework.

Charging data type

The charging information is provided in an XML data type, using the following schema:

<xsd:complexType name="ChargingInformation"> <xsd:sequence> <xsd:element name="description" type="xsd:string"/> <xsd:element name="currency" type="xsd:string" minOccurs="0" maxOccurs="1"/> <xsd:element name="amount" type="xsd:decimal" minOccurs="0" maxOccurs="1"/> <xsd:element name="code" type="xsd:string" minOccurs="0" maxOccurs="1"/> </xsd:sequence> </xsd:complexType>

The application accessing the Web Service provides this information:
  * Description text, which will often be used to provide billing text. This text does not have specific required content, but would likely include information on the business, the content or service provided, and a transaction identifier. Credit card statements are a good example of description text provided by different companies.
  * Currency in which the charge is to be applied. Values for the currency field are defined by ISO 4217 [9].
  * Defines the amount to be charged.
  * Code specifies a charging code which references a contract under which this charge is applied. The code identifier is provided by the Web Service Provider.

The charging information provided may not be acceptable to the Web Service Provider. For example, the Web Service Provider may limit the amount that may be specified for a particular Web Service or for a particular Web Service Requester. If the information provided is not acceptable, an appropriate fault message may be returned to the Web Service Requester (SVC0007 is defined as a generic charging fault).

Exception definition

Exceptions are defined with three data items.

The first data item is a unique identifier for the message. This allows the receiver of the message to recognize the message easily in a language-neutral manner. Thus applications and people seeing the message do not have to understand the message text to be able to identify the message. This is very useful for customer support as well, since it does not depend on the reader to be able to read the language of the message.

The second data item is the message text, including placeholders (marked with %) for additional information. This form is consistent with the form for internationalization of messages used by many technologies (operating systems, programming environments, etc.). Use of this form enables translation of messages to different languages independent of program changes. This is well suited for Web Services messages, as a programming language is not defined.

The third data item is a list of zero or more strings that represent the content to put in each placeholder defined in the message in the second data item.

Service exception

When a service is not able to process a request, and retrying the request with the same information will also result in a failure, and the issue is not related to a service policy issue, then the service will issue a fault using the ServiceException fault message. A Service Exception uses the letters 'SVC' at the beginning of the message identifier.

Examples of service exceptions include invalid input, lack of availability of a required resource or a processing error.

Policy exception

When a service is not able to complete because the request fails to meet a policy criteria, then the service will issue a fault using the PolicyException fault message. To clarify how a Policy Exception differs from a Service Exception, consider that all the input to an operation may be valid as meeting the required input for the operation (thus no Service Exception), but using that input in the execution of the service may result in conditions that require the service not to complete. A Policy Exception uses the letters 'POL' at the beginning of the message identifier.

Examples of policy exceptions include privacy violations, requests not permitted under a governing service agreement or input content not acceptable to the service provider.

Namespaces

The namespace for the common data types is: http://www.csapi.org/schema/parlayx/common/v2_1

The namespace for the common faults is: http://www.csapi.org/wsdl/parlayx/common/v2_0/faults

The 'xsd' namespace is used in the present document to refer to the XML Schema data types defined in XML Schema [2]. The use of the name 'xsd' is not semantically significant.

Sequence diagrams

Not applicable.

XML Schema data type definition

TimeMetrics enumeration

List of time metric values.


Millisecond Millisecond
Second Second
Minute Minute
Hour Hour
Day Day
Week Week
Month Month
Year Year

TimeMetric structure

For services that provide service based on a time interval or duration or similar metric, this type is used to specify the time metric.


metric TimeMetrics Metric to use for time measurement


units xsd:int Number of units of TimeMetrics

ChargingInformation structure

For services that include charging as an inline message part the charging information is provided in this data structure.


Description xsd:string

Description text to be use for information and billing text
currency xsd:string

Currency identifier as defined in ISO 4217 [99]
amount xsd:decimal

Amount to be charged
code xsd:string

Charging code, referencing a contract under which the charge is applied

ServiceError structure

Some of the services that process requests for both single addresses and group of addresses return a fault message for the single request, and a data item for the group response. This data structure allows the data item returned for a group response to contain the same level of information as the fault message response.


messageId xsd:string

Message identifier (take from fault definitions)

text xsd:string

Message text, with replacement variables marked with %#
variables xsd:string [0..unbounded]

Variables to substitute into Text string

SimpleReference structure

For those services that require a reference to a Web Service, the information required to create the endpoint information is contained in this type.


endpoint xsd:anyURI

Endpoint address
interfaceName xsd:string

Name of interface
correlator xsd:string

Correlation information

Web Service interface definition

Not applicable.

Fault definitions

ServiceException

Faults related to the operation of the service, not including policy related faults, result in the return of a ServiceException message. Service exception messages use the reserved message identifier 'SVC', and are defined with numbers from 0001 to 0999, with numbers 0001 to 0199 reserved for common exceptions and 0200 to 0999 for Parlay X 2 Web Services specification use. Numbers from '1000' to '9999' may be used by third parties.


messageId xsd:string

Message identifier, with prefix SVC
text xsd:string

Message text, with replacement variables marked with %#
variables xsd:string [0..unbounded]

Variables to substitute into Text string

SVC0001: Service error


messageId SVC0001
text A service error occurred. Error code is %1
variables %1 Error code from service - meaningful to support, and may be documented in product documentation

SVC0002: Invalid input value


messageId SVC0002
text Invalid input value for message part %1
variables %1 - message part

SVC0003: Invalid input value with list of valid values


messageId SVC0003
text Invalid input value for message part %1, valid values are %2
variables %1 - message part %2 - list of valid values

SVC0004: No valid addresses


messageId SVC0004
text No valid addresses provided in message part %1
variables %1 - message part

SVC0005: Duplicate correlator


messageId SVC0005
text Correlator %1 specified in message part %2 is a duplicate
variables %1 - correlator %2 - message part

SVC0006: Invalid group


messageId SVC0006
text Group %1 in message part %2 is not a valid group
variables %1 - identifier for the invalid group %2 - message part

SVC0007: Invalid charging information


messageId SVC0007
text Invalid charging information
variables None

SVC0008: Overlapping Criteria

message Id SVC0008
text Overlapped Criteria %1
variables %1 Message part with the overlapped criteria

PolicyException

Faults related to policies associated with the service, result in the return of a PolicyException message. Policy exception messages use the reserved message identifier 'POL', and are defined with numbers from 0001 to 0999, with numbers 0001 to 0199 reserved for common exceptions and 0200 to 0999 for Parlay X 2 Web Services specification use. Numbers from '1000' to '9999' may be used by third parties.


messageId xsd:string

Message identifier, with prefix POL
text xsd:string

Message text, with replacement variables marked with %#
variables xsd:string [0..unbounded]

Variables to substitute into Text string

POL0001: Policy error


messageId POL0001
text A policy error occurred. Error code is %1
variables %1 Error code from service - meaningful to support, and may be documented in product documentation

POL0002: Privacy error


messageId POL0002
text Privacy verification failed for address %1, request is refused
variables %1 - address privacy verification failed for

POL0003: Too many addresses


messageId POL0003
text Too many addresses specified in message part %1
variables %1 - message part

POL0004: Unlimited notifications not supported


messageId POL0004
text Unlimited notification request not supported
variables None

POL0005: Too many notifications requested


messageId POL0005
text Too many notifications requested
variables None

POL0006: Groups not allowed


messageId POL0006
text Group specified in message part %1 not allowed
variables %1 - message part

POL0007: Nested groups not allowed


messageId POL0007
text Nested group specified in message part %1 not allowed
variables %1 - message part

POL0008: Charging not supported


messageId POL0008
text Charging is not supported
variables None

POL0009: Invalid frequency requested


messageId POL0009
text Invalid frequency requested
variables None

Fault number ranges by service

The following table includes fault number ranges are reserved for use by specific Parlay X 2 Web Services.
Web Service SVC range POL range
Third Party Call 0260 to 0264


Multimedia Conference

0240 to 0244
Short Messaging 0280 to 0284


Terminal Status

0200 to 0204
Terminal Location 0200 to 0204 0230 to 0234
Payment 0270 to 0274


Account Management 0250 to 0254 0220 to 0224 Address List Management

0210 to 0214
Presence 0220 to 0224

Service policies

Not applicable.

WSDL usage and style

Parlay X 2 Web Services definitions:
  * SHALL specify services using document forms as described in clause 12.1.
  * SHALL use namespaces as defined in clause 12.2.
  * SHALL follow the authoring style as defined in clause 12.3.
  * SHALL follow data type definitions as defined in clause 12.4.
  * SHALL define messages and interfaces as defined in clause 12.5 using document/literal definitions.
  * SHALL define bindings and services as defined in clause 12.6 using document/literal definitions.

Service definition and documents

Service definitions are expressed using the facilities of WSDL. While it is possible to produce a single document that represents an entire service definition, this is not a desirable approach for any non-trivial Web Service.

Decomposition provides the following benefits:
  * XML Schema is used for data type definitions.
  * Faults that are shared across interfaces are defined independently.
  * Service interface definitions are defined independent of bindings.
  * Bindings are defined independently and consistent with UDDI best practices.

Following these conventions improves the overall definition and maintenance process and improves deployment by supporting separation of interface and binding.

Interface sets

A Web Service definition may contain one or more interfaces (or portTypes in WSDL 1.1 [6]). The characteristics of the Web Service being considered will determine whether one interface or multiple interfaces are appropriate.

The term Interface Set will be used to describe the group of interfaces that comprise a Web Service. The Interface Set provides a mechanism to group a set of related interfaces using well defined conventions for document and namespace naming.

For reference, other technologies group related interfaces using 'module' or 'package' conventions, achieving a similar result for organizing related interfaces.

Preparing for document definition

To provide a consistent use of naming within document sets, and across document sets, a number of conventions are defined that rely on a small amount of preparation to be done before creating the documents.

For each Interface Set, a Base Name is selected. For each interface within the Interface Set, a Short Name is selected. These names will be used as part of a common naming convention for the related set of documents defined and for definition naming within the documents. This approach ensures name consistency through Web Service evolution, whether it starts with one interface or multiple interfaces.

An example will demonstrate the naming convention. A group of interfaces for a short messaging service (SMS) are defined. This Web Service contains multiple interfaces.
  * An Interface Set is defined (SMS Interface Set).
  * The Base Name for the Interface Set is assigned the name 'sms'.

* Each interface within the Interface Set is assigned a Short Name:

- The SendSms interface is assigned the Short Name 'send'.

- The RetrieveSms interface is assigned the Short Name 'retrieve'.

Base Names and Short Names are always defined using only lower case letters, numbers or underscore characters. They must not start with a non-alphabetic character. An underscore should be used to separate words when the name consists of multiple words. These restrictions apply since these names are used in the construction of file names and URI content.

With these preparations complete, the document set may be created.

Documents

There are four document types that can be utilized in a Web Service definition. Each has a specific role, and contributes to the goal of supporting a well organized and useful decomposition of the individual elements of a Web Service definition.

Types definition document

The Type Definitions Document contains data type definitions within a schema namespace.

When the document is related to a specific Interface Set, it will use the Base Name with the suffix '_types' and the extension '.xsd'. When the Type Definitions Document is used across multiple Interface Sets, it will use an independent name with the suffix '_types' and the extension '.xsd'.

The present document is optional, since not all services will define new data types.

Shared faults document

The Shared Faults Document contains fault definitions that are shared across multiple interfaces in an Interface Set, or across Interface Sets.

The faults are defined within their own namespace within the WSDL definition namespace. The document name for the present document will use the suffix '_faults' and the extension 'wsdl'. The first part of the name of the document is based on its usage, with the following guidance:
  * If it is used by multiple Interface Sets, an independent name reflective of the faults defined will be chosen by the author.
  * If it used only by multiple interfaces within an Interface Set, then the Base Name will be used for the first part of the name.

The present document is optional, since not all WSDL definitions will define faults that are shared with other WSDL definitions.

Service interface document

The Service Interface Document contains the message and interface (portTypes in WSDL 1.1 [6]) definitions. One interface definition is included in each document. The present document may import Type Definition Documents and Shared Faults Documents. The present document may be used for a variety of Service Bindings Documents without change.

The document name for the present document will use the suffix '_interface' and the extension 'wsdl'. The name of the document is determined as follows:
  * For each interface in an Interface Set, the name is a combination of the Base Name followed by an underscore followed by the Short Name for the interface defined in the present document. Thus multiple documents will have the same Base Name as the first portion of the name and the individual interface Short Name as the second portion.

Service bindings document

The Service Bindings Document contains both the binding to be used and the service definition associated with the binding. One service definition is defined in each document. The present document imports one Service Interface Document.

The document name for the present document will use the suffix '_service' with the extension 'wsdl'. Optionally, text representing the specific binding may be added immediately before the '_service' suffix. The name of the document is determined as follows:
  * For each interface in an Interface Set, the name is a combination of the Base Name followed by an underscore followed by the Short Name for the interface defined in the present document. Thus multiple documents will have the same Base Name as the first portion of the name and the individual interface Short Name as the second portion.

Document separation rationale

The four document types approach satisfies a number of desirable goals for WSDL creation, use and maintenance.
  * Types and shared faults are defined in common documents, eliminating redundant definitions.
  * Interfaces are defined in individual documents, providing easier reading (only relevant message definitions in same document), while using a naming convention that group related interfaces together.
  * Services are defined in individual documents, providing easy consumption by service registries and easy creation of alternate binding documents. Like the interface documents, the naming conventions for these documents group related services together.

By following this approach, the document decomposition supports modularization for reuse goals, in a manner that reflects a useful level of granularity, and useful document form for use with tools and for deployment use.

Document version identifier

Just like namespaces may have naming conflicts, document names may also have naming conflicts. It is not always predictable how documents will be stored and used, or when multiple versions of a service may be co-deployed. For this reason, documents may include version identifiers in their naming.

Documents may be assigned a version identifier, corresponding to version information provided in the namespace (see clause 12.2.3 for more information on the version identifier).

If used, the identifier is added to the end of the name following an underscore. For example, a namespace version of v2_0 would be expressed as _2_0 added to the end of the document name and before its extension.

Document naming example

Using the SMS Interface Set described previously, the following document set would be produced. Additional assumptions for this example are that there are some data type definitions and that multiple interfaces in the Interface Set use a common set of faults.

The names provided include the use of version identifiers, where this Web Service is at the v1_0 level.
  * One Type Definitions Document - sms_types_1_0.xsd.
  * One Shared Faults Document - sms_faults_1_0.wsdl.
  * Two Service Interface Documents - sms_send_interface_1_0.wsdl and sms_retrieve_interface_1_0.wsdl.
  * Two Service Bindings Documents - sms_send_service_1_0.wsdl and sms_retrieve_service_1_0.wsdl.

The two Service Interface Documents import the Type Definition Document and Shared Faults Document. The two Service Bindings Documents import their respective Service Interface Document.

Service definitions for notification patterns

A Service Interface Document provides the messages and interfaces for a Web Service. It does not distinguish any deployment relationship, though there are specific uses intended for some Web Services definitions.

A common message pattern, defined in the Message Patterns section, is notification. The Web Service has a corresponding facility, such as a Web page, that provides the information required to define the notification, and a WSDL definition that represents the notification definition.

For message patterns that include notifications, the Web Service definition approach is the same, but the roles of the Web Service Provider and Web Service Requestor become a peer-to-peer or a producer-consumer relationship instead of a requestor-provider relationship.

To provide a practical example, the SMS Interface Set described previously will be extended to include two additional interfaces - RegisterSms and SmsNotify. The interfaces will use the Short Names 'register' and 'notify' respectively.

The RegisterSms interface will reuse the current Type Definitions Document (sms_types.xsd) and Shared Faults Document (sms_faults.wsdl), and adds its own Service Interface Document (sms_register_interface.wsdl) and Service Bindings Document (sms_register_service.wsdl).

The SmsNotify interface will reuse the current Type Definitions Document (sms_types.xsd) and Shared Faults Document (sms_faults.wsdl), and adds its own Service Interface Document (sms_notify_interface.wsdl) and Service Bindings Document (sms_notify_service.wsdl).

The RegisterSms interface is deployed in the same manner as the SendSms and RetrieveSms services at the Web Service Provider. The Web Service Requestor uses the RegisterSms interface to indicate the criteria to be used to determine when a notification is appropriate to send.

Although the notification will be delivered to the entity that had been using the SMS Interface Set in a requestor role, the definition of the SmsNotify service is consistent with the other services in the Interface Set. The only difference is that at the time of deployment, the SmsNotify implementation will be deployed in the environment of the entity that deploys the requester side of the other SMS Interface Set interfaces.

Following this approach, a consistent use of document conventions simplifies the process of defining Web Services, regardless of the deployment configurations or roles that deployed services may assume.

Namespaces

The definitions tag has a number of attributes for namespace definitions. These definitions will include a set of common definitions and WSDL specific definitions. The common definitions will be provided in all WSDL documents.

Namespaces for Parlay X 2 Web Services

For Parlay X 2 Web Services, the scheme is 'http', domain is www.csapi.org, and root is parlayx. Thus for XML Schema namespaces 'http://www.csapi.org/schema/parlayx' is the base name, and for WSDL 'http://www.csapi.org/wsdl/parlayx' is the base name.

Use of namespaces

Correct use of namespaces is essential for both creating WSDL that will be usable by a variety of tools, and creating references that allow use of reusable content across the set of documents for a Web Service.

The following are the key namespaces defined:
  * XML Schema namespaces for data type definitions.
  * Shared fault namespaces, for easy sharing of common fault definitions.
  * WSDL interface namespace for Web Service interface definitions.
  * WSDL schema local interface namespace for XML Schema definitions contained in the WSDL interface definition.
  * WSDL binding namespace for service bindings definitions.

Each namespace has a distinct role. Managing them in a consistent way provides highly flexible definitions, while ensuring easy use by WSDL creators and readers.

Namespace elements

The namespace definition includes three defined elements - the hierarchical name element, the version element and the namespace type element.

The hierarchical name element provides a fully qualified name in a hierarchical form for the namespace. This element is the Web Service specific information.

If a namespace contains a version number it will be a separate namespace element, immediately following the hierarchical name element, and preceding the namespace type. Version numbers are recommended, and are used in the examples.

A version number is based on release numbering, consisting of the lowercase letter 'v', followed by a number indicating major version number, followed by an underscore '_', followed by a minor version number. Any numbering beyond the minor version number follows the same convention with an underscore separator. Numbers are not limited to single digits.

Following the version number is the namespace type, which is always the last element in the namespace. The namespace type is one of 'faults' for Shared Faults Documents, 'interface' or 'local' for Service Interface Documents, or 'service' for Service Bindings Documents. The Type Definitions Document does not have a namespace type; since it does not share its namespace 'schema' (XML Schema definitions in the Service Interface Document use the 'local' namespace type).

Namespace usage

Why namespace versions are used

Maintaining a version number as part of the namespace enables multiple versions of a specification to be identified easily, both by human inspection (reading namespace information) and by machine inspection (parsing namespace).

In addition to the version information being contained in the namespace, the Parlay X Web Services WSDL documents also incorporate this same version number in the document file name.

These two mechanisms enable each specification document version to be uniquely identified, ensuring correct composition of documents even when multiple versions are present in a system.

When namespace versions are changed

When a specification document, or one of its dependent documents, changes then the version for the specification document is incremented. Incrementing of the major version or minor version number is dependent on the nature of the change (typically major version number changes at a release cycle, minor version number changes within a release cycle). For example, if a specification has a types definition document and an interface definition document, then,

If the types definitions document is updated, its version will be incremented. Since the interface definition is dependent on the types definition document, its version will be incremented as well.

If the interface definition document is updated, but there are no changes to the types definition document, then only the interface definition document version is incremented (since the types definition document is not dependent on the interface definition document).

For common documents that are used across multiple specifications, a change in the common document will require updating the specification documents that are dependent on the common document (to update the reference to the common document) and thus their document versions will be incremented as well.

Benefit of managing namespace versions

Two primary benefits are realized by managing namespace versions.
  * Clearly identified specification documents for the specification reader, developer or machine (for discovery).
  * Possibility to have coexisting implementations of multiple versions of the same specification, since all artefacts are isolated and uniquely identifiable.

Common namespaces

Each document type has some common namespaces will be used in every instance of that document type. Type Definition Documents xmlns:xsd=http://www.w3.org/2001/XMLSchema

Shared Faults Documents and Service Interface Documents xmlns="http://schemas.xmlsoap.org/wsdl/" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:xsd=http://www.w3.org/2001/XMLSchema

Service Bindings Documents for SOAP over HTTP xmlns="http://schemas.xmlsoap.org/wsdl/" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:xsd=http://www.w3.org/2001/XMLSchema

Other bindings will have other namespace definitions that will be common to all Service Bindings Documents using that binding.

Target namespace

The target namespace defines the namespace that is the default namespace for the elements within a document. A special case is the target namespace defined for the schema section within the wsdl:types section of a Service Interface Document, where the target namespace applies specifically to the XML Schema definitions within this section.

The base namespace for WSDL related elements is http://www.example.com/wsdl. For sub-namespaces, they will extend this namespace. All elements defined within the root namespace are defined within this base target namespace.

For example target namespaces may include:
  * Root namespace, http://www.example.com/wsdl/v1_0/service.
  * Sub-namespace, http://www.example.com/wsdl/accounts/v1_0/service.
  * Multi-level sub-namespace, http://www.example.com/wsdl/accounts/payables/v1_0/service.

The target namespace is the same namespace that will be defined later as the XML Schema or WSDL namespace.

WSDL and Schema namespaces

Namespaces are defined for the WSDL and Schema elements that are defined within the present document, and for those that are referenced by elements in the present document. For each instance, a pair of namespaces may be defined (if applicable). The WSDL namespace is defined with its Short Name. The Schema namespace is defined with the Short Name plus the suffix '_xsd'.

For the WSDL reference used for the present document, the name space definition is the same as the targetNamespace. For the Schema reference, the base namespace is http://www.example.com/schema, with the same hierarchy reference following the base namespace, but without an ending qualifier since the schema namespace is not shared across documents.

EXAMPLES:

Base namespace xmlns:example="http://www.example.com/wsdl/v1_0" xmlns:example_xsd=http://www.example.com/schema/v1_0 <p> Sub-namespace xmlns:accounts="http://www.example.com/wsdl/accounts/v1_0/service" xmlns:accounts_xsd=http://www.example.com/schema/accounts/v1_0

Local namespace use

Within the WSDL service definition, XML Schema is used to define messages. These are defined within the wsdl:types section of the Service Interface Document. Since namespaces must be unique across documents, and within different sections of the same document, a local namespace is used for the XML Schema types defined within the wsdl:types section.

The local namespace definition within a Service Interface Document uses the 'schema' namespace, with the Base Name and Short Name elements followed by the version element and '/local'. The namespace is defined as the Short Name plus '_local_xsd'. This approach guarantees unique and predictable name use.

Examples

Base definitions:

<definitions name="example" targetNamespace="http://www.example.com/wsdl/v1_0/service" xmlns="http://schemas.xmlsoap.org/wsdl/" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:example="http://www.example.com/wsdl/v1_0/service" xmlns:example_xsd="http://www.example.com/schema/v1_0">

Sub-namespace definitions:

<definitions name="accounts" targetNamespace="http://www.example.com/wsdl/accounts/v1_0/service" xmlns="http://schemas.xmlsoap.org/wsdl/" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:example="http://www.example.com/wsdl/v1_0" xmlns:example_xsd="http://www.example.com/schema/v1_0" xmlns:accounts="http://www.example.com/wsdl/accounts/v1_0/service" xmlns:accounts_xsd="http://www.example.com/schema/accounts/v1_0">

Authoring style - Document content and names

General WSDL document information

The following are general guidelines for WSDL document information:
  * WSDL documents will use UTF-8 as their encoding. UTF-16 may also be used if required.
  * A date in a comment at the top of the WSDL document will indicate the last revision date of the definition.

Names

Names will be normal language names, without prefixes (for example, type or interface markers). The names will be meaningful, and not abbreviated in a way that makes the name hard to understand for users of the WSDL that are not literate in computer programming.

As a guideline, a person using the WSDL will be able to load the WSDL file into an XML viewer and see the names displayed and have reasonable understanding of the content.

This does not preclude the use of commonly understood acronyms within names (for example, ATM) or commonly used abbreviations (for example, max). However, the resulting name must still be meaningful.

Case usage for names

Two general cases are provided for, both using mixed case names; one with a leading capital letter, the other with a leading lowercase letter.

Names for all elements (all cases where the text name='Name' is used) will start with a letter and be mixed case, with the leading letter of each word capitalized. Words will not be separated by white space, underscore, hyphen or other non-letter character.

The following elements will have a leading uppercase letter - simpleType name, complexType name, interface (portType) name, binding name, service name, union element name.

The following elements will have a leading lowercase letter - field names (those names used for elements within other elements), message name (message name portion, service prefix will have uppercase letter if used), message part name, interface operation name, binding operation name.

For example, valid names include 'Name', 'FirstName', 'Name1', 'mixedCaseName'. Invalid names include '1Name', 'NAME', 'nAME'.

Naming conventions for special names

Some names have special meaning, and are often recognized by a naming convention. For example, in some conventions constants are identified by using all upper case letters and underscores between words.

In WSDL, the case usage for names will be followed as described in the previous clause. No other conventions for case usage will be used.

For faults, the fault name will be suffixed with the word 'Exception'.

In many technologies, the return value of an operation is not named. However, in WSDL the response message contains a named part. The part representing the response message content will use the name 'result'.

Document layout

To provide easy and consistent reading of WSDL files, the following layout patterns are recommended.

Each tag level is indented one level relative to the previous tag indent level. The xml tag, date comment and root tag are not indented, they are on the left margin.

Indents of 3 spaces are used, and tabs are not used for storage (store files with spaces).

Namespaces are defined one per line, single spaced, indented one indent level.

Import statements are defined one per line, single spaced, with attributes on the same line.

Each primary element within the schema is separated by one blank line.

Each element within a primary element is single spaced.

Restrictions, extensions and elements are defined on a single line with their attributes.

XML Schema types are laid out according to their respective sections in the present document.

Messages are defined single spaced, with one blank line separating each message definition. Messages with no parts are defined with one tag.

Interfaces (portTypes) are defined with its attributes on a single line, with one blank line separating each interface definition. The first operation starts on the line following the interface definition, with each operation defined single spaced and with a blank line separating each operation definition. Each element defined within an operation (input, output and fault) is defined on a single line with its attributes within one tag.

Bindings will be laid out consistently with interfaces.

Each service is defined single spaced.

Data type definitions

All data type definition examples are shown using XML Schema.

Types section declaration

All data types are defined using XML Schema in the Type Definitions Document.

Base document definition:

<xsd:schema> targetNamespace="http://www.example.com/schema/v1_0" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <p> <p> </xsd:schema>

Sub-namespace document definition:

<xsd:schema> targetNamespace="http://www.example.com/schema/accounts/v1_0" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <p> <p> </xsd:schema>

Optional elements

XML Schema allows elements to be defined as optional, meaning that the element may or may not be present within an XML document. Elements may be declared as optional by use of the minOccurs attribute with a value of zero.

Nillable elements

XML Schema allows elements to be declared as nillable, indicating that the value may be nil (unspecified, not just a zero value).

<xsd:element name="example" type="xsd:int" nillable="true" />

User defined simple data types

User defined simple data types are defined as XML Schema simpleType elements with a name attribute and a restriction to the base XML Schema type. Simple data types do not extend other simple data types.

<xsd:simpleType name="Example"> <xsd:restriction base="xsd:int"/> </xsd:simpleType>

Data structures

Data structures are defined as complex types with a sequence of elements within the complex type.

<xsd:complexType name="Account"> <xsd:sequence> <xsd:element name="name" type="xsd:string"/> <xsd:element name="address" type="example_xsd:Address"/> </xsd:sequence> </xsd:complexType>

Enumerations

Enumerations are defined using XML Schema enumerations. It is suggested that the values listed in an enumeration follow the mixed case usage (Initial capital, capital for each word, lowercase otherwise) and always start with a letter. This will ensure compatibility with programming language usage, and provide consistency in readability of enumerations.

<xsd:simpleType name="Days"> <xsd:restriction base="xsd:string"> <xsd:enumeration value="Sunday"/> <xsd:enumeration value="Monday"/> <xsd:enumeration value="Tuesday"/> </xsd:restriction> </xsd:simpleType>

Enumerations are assigned the literal values from the list provided, not a generated integer representing each enumeration values.

Unions

Unions allow a single data type to have one of a set of values. This is a constructed data type, consisting of an enumeration element that indicates which value is present and the value itself. The enumeration provides a list of possible values, and the union element provides a value that corresponds with each member of the enumeration.

<xsd:simpleType name="PhoneType"> <xsd:restriction base="xsd:string"> <xsd:enumeration value="Home"/> <xsd:enumeration value="Work"/> <xsd:enumeration value="Mobile"/> </xsd:restriction> </xsd:simpleType> <p> <xsd:complexType name="PhoneNumber"> <xsd:sequence> <xsd:element name="UnionElement" type="example_xsd:PhoneType"> <xsd:element name="Home" type="xsd:string" minOccurs="0" maxOccurs="1"/> <xsd:element name="Work" type="xsd:string" minOccurs="0" maxOccurs="1"/> <xsd:element name="Mobile" type="example_xsd:MobileNumber" minOccurs="0" maxOccurs="1"/> </xsd:sequence> </xsd:complexType>

Web Service references

WSDL does not define a data type for a reference to a Web Service; however a data type can be produced that will provide the information necessary for another system to invoke a Web Service. This equivalent is a Web Service reference. This is a precursor to the use of WS-Addressing to provide this capability.

The Web Service reference consists of three parts:
  * The URI representing the end point, this is equivalent to the value populated in the section of a WSDL definition.
  * The port type in the reference allows the entity that will be the Web Service Requester to determine which port type or client stub to use.
  * To support stateful references, the additional data element, correlator, is provided. The correlator is opaque to the service receiving the reference; it is meaningful only to the system on which the Web Service is invoked. If a service is stateless, this item will be empty. A correlator should be unique for the service receiving the reference. A means shall be used to guarantee that correlators are unique, incorporating for example message based identifiers or a means agreed between the application and service instance. Note that when requests are retried after certain failure responses that solicit an amendment to a request (for example, a challenge for authentication), these retried requests are not considered new requests, and therefore do not need a new correlator. Implementations may use the form "localid@host". Correlators are case-sensitive and are simply compared byte-by-byte. No provisioning or human interface is required for the selection of the correlator.

<xsd:complexType name="SimpleReference"> <xsd:sequence> <xsd:element name="endpoint" type="xsd:anyURI"/> <xsd:element name="portType" type="xsd:string"/> <xsd:element name="correlator" type="xsd:string"/> </xsd:sequence> </xsd:complexType>

Any additional information necessary required to access the Web Service referred to by a reference, for example, security content, must be provided by the implementation.

Messages and interfaces (PortTypes)

Messages

Messages are used in the operation elements of interfaces (portTypes), providing the definition of the content that is exchanged on input, output and faults.

Document style Web Services

Document style Web Services define one input message and one output message, each with one part that references an element defined with XML Schema. These may be combined with fault messages in the definition of operations within an interface.

The XML Schema elements that define the message parts are defined within the wsdl:types section of the Service Interface Document. These parts may include references to data types defined in Type Definition Documents. Faults specific to the interface defined may also have their messages defined in this manner.

Interfaces (PortTypes)

Interfaces make a set of operations available, and define the messages that will be used for each.

For the request/response message pattern, an interface will have an operation definition that contains a single input message, a single output message and zero or more fault messages, in that order.

Faults (Exceptions)

There are four common types of faults that may be part of interface definitions:

1) SOAP faults, that occur before a message is received by the Web Service.

2) Service faults, that are generated as a result of a system failure, resource failure or rejection of the message (e.g. invalid message content).

3) Policy faults, that are the result of the provider of the Web Service rejecting the request, due to a reason other than those covered by a service fault, and not specific to a service (for example, privacy).

4) Service specific faults, that represent a fault that is not common across services.

In defining interfaces, these faults are represented using the following approach:
  * SOAP faults are not defined in the WSDL, their content is defined independently. Usually these faults are generated by intermediaries or as part of the infrastructure (for example, security subsystem).
  * Every operation shall include a ServiceException, providing a common manner in which these faults can be provided back to the requester.
  * Every operation shall include a PolicyException, providing a common manner in which these faults can be provided back to the requester.
  * Only faults that fall outside the service and policy faults should be provided additional fault definitions - in many cases, no additional fault definitions are required.

By following these guidelines, the following desirable characteristics of Web Services will be provided:
  * Applications, Web Services, and intermediaries can implement consistent handling of classes of faults without specific knowledge of the particular Web Service implementation.
  * Faults can be minimized, allowing service specific faults to be clearly recognized, not cluttered amongst many other common faults.

Even when a Web Service does not initially require a ServiceException or PolicyException, many will be deployed in different places or with additional requirements over time, and will likely require one or both of these over time. Providing these initially reduces the impact of change over time and use.

Also, combining the various service and policy faults into these common fault definitions allows flexible use of the content of the two fault definitions, allowing extensibility over time without impacting the service definition.

Bindings and service definitions

Binding

The binding defines how the WSDL definitions will be utilized in interacting with the network. The binding defines the protocols and operational style of the binding. For example, SOAP over HTTP or SOAP over SMTP for protocols, and document or rpc for style.

While the binding is specific to a technology, unlike the other parts of the WSDL documents, the binding does have influence on the overall service definition. For instance, the choice of SOAP style affects how messages are defined, and the binding choices may determine semantics related to the implementation - for example, some bindings may have limitations in support for asynchronous or reliable messaging.

The present document does not address bindings in detail, as the binding is independent of the WSDL interface definitions. Specific information on use of the SOAP/HTTP binding is covered in the WS-I Basic Profile [5].

Service definition

Services define an endpoint (port), though the address of the endpoint specified in this definition is often replaced at runtime when the discovery step determines that actual location that the service is hosted at.

During development, it is reasonable to use a location that corresponds to a debugging location at which the service will be tested - often pointing to localhost and containing default URL information for a development configuration to be used for testing. For deployment, the location should be a default location for service access.

<wsdl:service name="MessageService"> <wsdl:port binding="msg:MessageServiceBinding" name="MessageService"> <soap:address location="http://www.example.com/services/MessageService"/> </wsdl:port> </wsdl:service>

At runtime, the Web Service Application can determine the soap:address location information through local configuration or through a discovery process, replacing the location information in the default service definition.



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