This specification defines the OSLC Change Management domain, a RESTful web services interface for the management of product change requests, activities, tasks and relationships between those and related resources such as requirements, test cases, or architectural resources. To support these scenarios, this specification defines a set of HTTP-based RESTful interfaces in terms of HTTP methods: GET, POST, PUT and DELETE, HTTP response codes, content type handling and resource formats.

Introduction

This specification defines the OSLC Change management domain as a RESTful web services interface for the management of product change requests, activities, tasks and relationships between those and related resources such as project, category, release and plan. To support these scenarios, this specification defines a set of HTTP-based RESTful interfaces in terms of HTTP methods: GET, POST, PUT and DELETE, HTTP response codes, content type handling and resource formats.

The intent of this specification is to define the capabilities needed to support integration scenarios defined by the OASIS OSLC Open Project and not to provide a comprehensive interface to Change Management. The resource formats and operations may not match exactly the native models supported by change management servers but are intended to be compatible with them. The approach to supporting these scenarios is to delegate operations, as driven by server contributed user interfaces, as much as possible and not require a server to expose its complete data model and application logic.

Terminology

Terminology uses and extends the terminology and capabilities of [[!OSLCCore3]].

Change Request Resource
A request for change to an application or product. Typically a product request for enhancement, a report for a resolution of a product defect or simply a bug report.
Client
An implementation of the OSLC Change Management specifications as a client. OSLC CM Clients consume services provided by servers.
Server
An implementation of the OSLC Change Management specifications as a server. OSLC CM clients consume services provided by Servers. The use of the terms Client and Server are intended to distinguish typical consumers and providers of OSLC resources in a distributed environment based on REST. A particular application component could be a client for some OSLC domain services and a server for the same or another domain.

References

Base Requirements

The following sub-sections define the mandatory and optional requirements for an OSLC Requirements Management (OSLC RM) server.

Base Compliance

This specification is based on [[!OSLCCore3]]. OSLC CM servers MUST be compliant with both the core specification, MUST follow all the mandatory requirements in the normative sections of this specification, and SHOULD follow all the guidelines and recommendations in both these specifications.

An OSLC CM server MUST implement the domain vocabulary defined in OSLC Change Management Version 3.0. Part 2: Vocabulary

The following table summarizes the requirements from OSLC Core Specification as well as some additional requirements specific to the CM domain. Note that this specification further restricts some of the requirements for OSLC Core Specification. See the previous sections in this specification or the OSLC Core Specification to get further details on each of these requirements.

Requirement Meaning
Unknown properties and content OSLC servers MAY ignore unknown content and OSLC clients MUST preserve unknown content
Resource Operations OSLC service MUST support resource operations via standard HTTP operations
Resource Paging OSLC servers MAY provide paging for resources but only when specifically requested by client
Partial Resource Representations OSLC servers MUST support request for a subset of a resource’s properties via the oslc.properties URL parameter retrieval via HTTP GET
Partial Update OSLC servers MAY support partial update of resources using [[LDPPatch]], or via HTTP PUT.
Discovery OSLC servers SHOULD provide a ServiceProvider resource for Core v2 compatibility, MAY provide a ServiceProviderCatalog, and MAY provide other forms of discovery described in Core 3.0 Discovery.
Creation Factories OSLC servers MUST provide LDPC creation factories to enable resource creation of Change Management resources via HTTP POST
Query Capabilities OSLC servers SHOULD provide query capabilities to enable clients to query for resources
Query Syntax OSLC query capabilities SHOULD support the OSLC Core Query Syntax and MAY use other query syntax
Delegated UI Dialogs OSLC Services MUST offer delegated UI dialogs (creation and selections) specified via OSLC Core 3.0 Delegated Dialogs and SHOULD include discovery through a ServiceProvider resource for OSLC v2 compatibility
UI Preview OSLC Services SHOULD offer UI previews for resources that may be referenced by other resources specified via OSLC Core 3.0 Preview and SHOULD include discovery through a server resource for OSLC v2 compatibility
Authentication OSLC Services SHOULD follow the recommendations for Authentication specified in [[!OSLCCore3]]
Error Responses OSLC Services SHOULD provide error responses using OSLC Core 3.0 defined error formats
Turtle Representations OSLC servers MUST provide a Turtle representation for HTTP GET requests and SHOULD support Turtle representations on POST and PUT requests.
RDF/XML Representations OSLC servers SHOULD provide an RDF/XML representation for HTTP GET requests and SHOULD support RDF/XML representations on POST and PUT requests for compatibility with Change Management 2.0.
XML Representations OSLC servers SHOULD provide a XML representation for HTTP GET, POST and PUT requests that conform to the Core 2.0 Guidelines for XML.
JSON Representations OSLC servers MUST provide JSON-LD representations for HTTP GET, POST and PUT requests that conform to the Core Guidelines for JSON-LD
HTML Representations OSLC servers SHOULD provide HTML representations for HTTP GET requests

Specification Versioning

This specification follows the specification version guidelines given in [OSLCCore3].

Namespaces

In addition to the namespace URIs and namespace prefixes oslc, rdf, dcterms and foaf defined in the [OSLCCore3], OSLC CM defines the namespace URI of http://open-services.net/ns/cm# with a namespace prefix of oslc_cm.

This specification also uses these namespace prefix definitions:

Resource Formats

In addition to the requirements for resource representations in [[!OSLCCore3]], this section outlines further refinements and restrictions.

For HTTP GET requests on all OSLC CM and OSLC Core defined resource types,

For HTTP PUT/POST request formats for resource type of ChangeRequest:

For HTTP GET response formats for Query requests,

CM servers MUST provide Turtle and JSON-LD, SHOULD provide RDF/XML, XML, and MAY provide Atom Syndication Format XML representations.

When CM clients request:

  • text/turtle CM servers MUST respond with Turtle representation.
  • application/ld+json CM servers MUST respond with JSON-LD representation.
  • application/rdf+xml CM servers SHOULD respond with RDF/XML representation without restrictions.
  • application/xml CM servers SHOULD respond with OSLC-defined abbreviated XML representation as defined in the OSLC Core Representations Guidance
  • application/atom+xml CM servers SHOULD respond with Atom Syndication Format XML representation as defined in the OSLC Core Representations Guidance
  • The Atom Syndication Format XML representation SHOULD use RDF/XML representation without restrictions for the atom:content entries representing the resource representations.

See Query Capabilities for additional information when Resource Shapes affect representation.

Content Negotiation

[[!OSLCCore3]] specifies RDF representations (and specifically Turtle and JSON-LD) as a convention that all OSLC server implementations minimally provide and accept. OSLC CM server implementations are strongly encouraged to adopt this convention. Future versions of this specification are expected to require RDF representations for all operations and relax requirements for specialized XML representations.

XML Representation - identified by the application/xml content type. Format representation rules are outlined in Core OSLC Core Resource Formats section

RDF/XML Representation - identified by the application/rdf+xml content type. No additional guidance is given.

JSON-LD Representation - identified by the application/ld+json content type. Format representation rules are specified in JSON-LD 1.0.

Atom Syndication Format XML Representation - identified by the application/atom+xml content type. Format representation rules are outlined in Core OSLC Core Resource Formats section.

Authentication

[[!OSLCCore3]] specifies the recommended OSLC authentication mechanisms. In addition to the OSLC Core authentication requirements, OSLC CM servers SHOULD support [[!OpenIDConnect]].

Error Responses

[[!OSLCCoreVocab]] specifies the OSLC Core error responses. OSLC CM puts no additional constraints on error responses.

Pagination

OSLC CM servers SHOULD support pagination of query results and MAY support pagination of a single resource's properties as defined by [[!OSLCCore3]].

Requesting and Updating Properties

Requesting a Subset of Properties

A client MAY request a subset of a resource's properties as well as properties from a referenced resource. In order to support this behavior a server MUST support the oslc.properties and oslc.prefix URL parameter on a HTTP GET request on individual resource request or a collection of resources by query. If the oslc.properties parameter is omitted on the request, then all resource properties MUST be provided in the response.

Updating a Subset of Properties

A client MAY request that a subset of a resource's properties be updated by using the [[LDPPatch]] PATCH method.

For compatibility with [[!OSLCCore2]], CM servers class='conformance' also support partial update by identifying those properties to be modified using the oslc.properties URL parameter on a HTTP PUT request.

If the parameter oslc.properties contains a valid resource property on the request that is not provided in the content, the server MUST set the resource's property to a null or empty value. If the parameter oslc.properties contains an invalid resource property, then a 409 Conflict MUST be returned.

Updating Multi-Valued Properties

For multi-valued properties that contain a large number of values, it may be difficult and inefficient to add or remove property values. OSLC CM servers MAY provide support for a partial update of the multi-valued properties as defined by draft specification [[LDPPatch]]. CM servers MAY also support partial updates through HTTP PUT where only the updated properties are included in the entity request body.

Status, State and State Predicates

Probably the most important property of a Change Request is the status property. "Status" specifies the location of a Change Request in a workflow. The oslc_cm:status property is a typically read-only string that servers can set to describe the status of a ChangeRequest. In queries the oslc_cm:status property can be used to filter change request (e.g. all change requests that are "fixed") and may be used to perform state transitions (not part of this specification) on a change request, e.g. closing a change request as "fixed".

The problem is that different CM servers may use different properties (or even a set of properties) and different values to represent the change request's state. Even providing access to meta data does not help because knowing all possible state values does not reveal the semantics of a state.

[[OSLCCM20]] introduced State Predicates to define single-value often read-only Boolean properties on a Change Request resource that allow servers to translate their specific status string values into a standard boolean state predicate value. For example, a CM server could set oslc_cm:status to "BeingInvestigated", and map this status to the following state predicate values:

An attempt to update read-only predicates SHOULD be answered with a 409 Conflict HTTP status code. Their presence in a resource representation used for an update via PUT MUST NOT prevent the resource from being updated. Predicates MUST be queryable. The Change Request resource definition sections defines the complete set of predicates.

OSLC CM 3.0 provides a similar means of defining a set of standard states that is also extensible. The oslc_cm:state property can have a value of type oslc_cm:State which represents an enumeration of individuals representing a standard set of ChangeRequest states. Servers MAY define additional individuals to extend the states of different ChangeRequest types and lifecycles.

Labels for Relationships

Change Management relationships to other resources are represented by RDF properties. Instances of a relationship - often called links - are RDF triples with a subject URI, a predicate that is the property, and a value (or object) that is the URI of target resource. When a link is to be presented in a user interface, it may be helpful to display an informative and useful textual label instead of or in addition to the URI of the predicate and or object. There are three items that clients could display:

Turtle example using a reified statement:

@prefix ns0: <http://open-services.net/ns/cm#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix dcterms: <http://purl.org/dc/terms/> .

<http://example.com/bugs/4321>
  a <http://open-services.net/ns/cm#ChangeRequest> ;
  ns0:relatedChangeRequest <http://anotherexample.com/defects/123> .

<http://njh.me/#link1>
  a rdf:Statement ;
  rdf:subject <http://example.com/bugs/4321> ;
  rdf:predicate ns0:relatedChangeRequest ;
  rdf:object <http://anotherexample.com/defects/123> ;
  dcterms:title "Defect 123: Problems during install" .

JSON-LD example using reified statement:

{
  "@context": {
    "dcterms": "http://purl.org/dc/terms/",
    "rdf": "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
    "oslc": "http://open-services.net/ns/core#",
    "oslc_cm": "http://open-services.net/ns/cm#"
  },
  "@id": "http://example.com/bugs/4321",
  "@type": "oslc_cm:ChangeRequest",
  "oslc_cm:relatedChangeRequest": {
    "@id": "http://anotherexample.com/defects/123",
    "dcterms:title": "Defect 123: Problems during install"
  }
}

Vocabulary Terms and Constraints

OSLC Change Management Version 3.0. Part 2: Vocabulary Defines the vocabulary terms and constraints for OSLC Change Management resources. These terms and constraints are specified according to [[!OSLCCoreVocab]].

CM Server Capabilities

Server Resources

OSLC CM servers MUST support OSLC Discovery capabilities defined by [[!OSLCCore3]].

OSLC CM servers MAY provide a ServiceProvider Resource that can be retrieved at a implementation dependent URI.

OSLC CM servers MAY provide a ServiceProviderCatalog Resource that can be retrieved at a implementation dependent URI.

OSLC CM servers MAY provide a oslc:serviceProvider property for their defined resources that will be the URI to a ServiceProvider Resource.

OSLC CM servers MUST supply a value of http://open-services.net/ns/cm# for the property oslc:domain on either oslc:Service or oslc:ServiceProviderCatalog resources.

OSLC CM servers MAY allow ChangeRequest state change through [[OSLCActions]].

Creation Factories

OSLC CM servers MUST support Creation Factories and list them in the Service Provider Resource as defined by OSLC Core. OSLC CM servers SHOULD support Resource Shapes for Creation Factories as defined in [[!OSLCShapes]]

Query Capabilities

OSLC CM servers SHOULD support the Query Capabilities as defined by [[!OSLCCore3]]. OSLC CM servers SHOULD support Resource Shapes for Query Capability as defined in [[!OSLCShapes]]

The Query Capability, if supported, MUST support these parameters:

  • oslc.where
  • oslc.select
  • oslc.properties
  • oslc.prefix

If shape information is NOT present with the Query Capability, servers SHOULD use these default properties to contain the result:

Delegated UIs

OSLC CM servers MUST support the selection and creation of resources by delegated web-based user interface dialogs Delegated UIs as defined by [[!OSLCCore3]].

OSLC CM servers MAY support the pre-filling of creation dialogs based on the definition at Delegated UIs.

Usage Identifiers

An OSLC CM server can identify or distinguish the usage of various services with additional property values for the OSLC Core defined oslc:usage property on oslc:Dialog, CreationFactory and QueryCapability. The oslc:usage property value of http://open-services.net/ns/core#default will be used to designate the default or primary service to be used by clients when multiple entries are found.

The additional Change Management property values for oslc:usage are:

Version Compatibility with 2.0 Specifications

Deprecated terms

A number of terms introduced in early development of the OSLC Change Management domain were deprecated in the finalized [[OSLCCM20]] specification. These terms are summarized here in order to indicate they remain deprecated.

Prefixed Name Occurs Read-only Value-type Represen-tation Range Description
deprecated dcterms:type zero-or-more unspecified String n/a n/a A short string representation for the type, example Defect.
Relationship properties: This grouping of properties are used to identify relationships between resources managed by other OSLC servers
deprecated oslc_cm:testedByTestCase zero-or-many False Resource Reference any Test case by which this change request is tested. It is likely that the target resource will be an oslc_qm:TestCase, but that is not necessarily the case.
deprecated oslc_cm:affectsTestResult zero-or-many False Resource Reference any Associated QM resource that is affected by this Change Request. It is likely that the target resource will be an oslc_qm:TestResult, but that is not necessarily the case.
deprecated oslc_cm:blocksTestExecutionRecord zero-or-many False Resource Reference any Associated QM resource that is blocked by this Change Request. It is likely that the target resource will be an oslc_cm:TestExecutionRecord, but that is not necessarily the case.
deprecated oslc_cm:relatedTestExecutionRecord zero-or-many False Resource Reference any Related to a QM test execution resource. It is likely that the target resource will be an oslc_qm:TestExecutionRecord, but that is not necessarily the case.
deprecated oslc_cm:relatedTestCase zero-or-many False Resource Reference any Related QM test case resource. It is likely that the target resource will be an oslc_qm:TestCase, but that is not necessarily the case.
deprecated oslc_cm:relatedTestPlan zero-or-many False Resource Reference any Related QM test plan resource. It is likely that the target resource will be an oslc_qm:TestPlan, but that is not necessarily the case.
deprecated oslc_cm:relatedTestScript zero-or-many False Resource Reference any Related QM test script resource. It is likely that the target resource will be an oslc_qm:TestScript, but that is not necessarily the case.

Changes from 2.0

The following lists the significant vocabulary changes that were introduced in this specification. The changes are all upward compatible additions and therefore do not introduce incompatibilities with version 2.0.

Acknowledgements

The following individuals have participated in the creation of this specification and are gratefully acknowledged:

Project Governing Board:

James Amsden, IBM (co-chair)
Andrii Berezovskyi, KTH (co-chair)
Bill Chown, Mentor
Wesley Coelho, Tasktop
Axel Reichwein, Koneksys

Techical Steering Committee:

James Amsden, IBM
Andrii Berezovskyi, KTH
Axel Reichwein, Koneksys

Additional Participants:

Gray Bachelor, IBM
Geoff Clemm, IBM
Peter Hack, IBM
Sam Padget, IBM
Martin Pain, IBM
Brian Steele, IBM
Jad El-Khoury, KTH
Martin Sarabura, PTC
Jory Burson, OASIS
Chet Ensign, OASIS
Carol Geyer, OASIS