OSLC Core properties used by all Configuration Management resources
Prefixed Name |
Occurs |
Read-only |
Value-type |
Representation |
Description |
OSLC Core: Common Properties |
|
|
|
|
|
rdf:type |
one-or-many |
unspecified |
Resource |
Reference |
The resource type URIs. |
dcterms:contributor |
zero-or-many |
unspecified |
Resource |
Either |
Contributor or contributors to resource (reference: Dublin Core). It is likely that the target resource will be an foaf:Person but that is not necessarily the case. |
dcterms:created |
zero-or-one |
True |
DateTime |
n/a |
Timestamp of resource creation (reference: Dublin Core) |
dcterms:creator |
zero-or-many |
unspecified |
Resource |
Either |
Creator or creators of resource (reference: Dublin Core). It is likely that the target resource will be an foaf:Person but that is not necessarily the case. |
dcterms:description |
zero-or-one |
unspecified |
XMLLiteral |
n/a |
Descriptive text (reference: Dublin Core) about resource represented as rich text in XHTML content. SHOULD include only content that is valid and suitable inside an XHTML <div> element. |
dcterms:identifier |
exactly-one |
True |
String |
n/a |
A unique identifier for a resource. Assigned by the service provider when a resource is created. Not necessarily intended for end-user display. |
dcterms:modified |
zero-or-one |
True |
DateTime |
n/a |
Timestamp of latest resource modification (reference: Dublin Core) |
dcterms:subject |
zero-or-many |
unspecified |
String |
n/a |
Tag or keyword for a resource. Each occurrence of a dcterms:subject property denotes an additional tag for the resource. |
dcterms:title |
exactly-one |
unspecified |
XMLLiteral |
n/a |
Title (reference: Dublin Core) of the resource represented as rich text in XHTML content. |
W3C Provenance Properties |
|
|
|
|
|
prov:wasDerivedFrom , prov:wasRevisionOf |
zero-or-many |
unspecified |
Resource |
Either |
Previous versions or revisions of this resource. |
prov:wasGeneratedBy |
zero-or-many |
unspecified |
Resource |
Either |
A change set or similar activity that generated this resource. It is likely that the target resource will be an oslc_config:ChangeSet but that is not necessarily the case. |
Concept resources and version resources
A GET on the URI of a concept resource will resolve that URI to an appropriate state of (version of) a concept resource for the appropriate configuration context (see later). The returned resource will contain RDF statements about both the version resource and the concept resource; most statements will use the concept resource as the subject, because it is the state of (properties of) the concept resource that are defined by a version resource.
We use the dcterms:isVersionOf
property to relate the version resource itself to its concept resource.
As an example, GET http://example.com/conceptResourceA in one configuration context might return:
:conceptResourceA-version23
dcterms:isVersionOf :conceptResourceA .
:conceptResourceA
a :someType ;
dcterms:title "Concept Resource A" ;
:color "blue" ;
dcterms:description "Concept resource A as it appears in the state with the URI :conceptResourceA-version23" .
while in a different configuration context it might return:
:conceptResourceA-version17
dcterms:isVersionOf :conceptResourceA .
:conceptResourceA
a :someType ;
dcterms:title "Concept Resource A" ;
:color "red" ;
dcterms:description "Concept resource A as it appears in the state with the URI :conceptResourceA-version17" .
TBD: while the Linked Data Platform indicates that every concept resource should define at least one rdf:type
, it is not clear if we always need to define a separate type for the version resource itself. This should be discussed with the Core workgroup.
Configuration Item
Resources of any type may appear as configuration items - resource that appear as members of configurations or change sets. Configuration items MAY have any of the common properties shown above, and MAY have any other properties. Configuration items that represent versions of a concept resource MUST have the dcterms:isVersionOf
property referencing that concept resource.
Configuration
A configuration is a resource with any of the above-listed standard properties, plus the following:
Prefixed Name |
Occurs |
Read-only |
Value-type |
Representation |
Description |
rdf:type |
one-or-many |
unspecified |
Resource |
Reference |
The resource type URIs. A configuration MUST have a resource type of oslc_config:Configuration , and SHOULD have a resource type of ldp:Container or one of its subclasses. The Linked Data Platform container or aggregate is used to indicate the configuration items that are members of (contents of) the configuration. TBD pending W3C review of non-member property retrieval: Note that determining the set of resources in a configuration may be an expensive operation, so clients needing only the non-member properties are advised to GET the related resource formed by appending the query string "non_member_properties" . |
A configuration MAY be a versioned resource, in which case it has a dcterms:isVersionOf
predicate identifying the concept resource. All configurations with the same object value for dcterms:isVersionOf
are versions of the same concept resource - perhaps the same system or component.
Configurations MAY be members of other configurations. TBD: this might be how global configurations are represented at OSLC: as configurations of configurations, but with a possible restriction that the member configurations may not contain overlapping resource sets, and may not allow version skew. That is, a provider is permitted to restrict global configurations such that no two configuration members of a single parent global configuration may select a version of the same concept resource, and hence the global configuration selects only a single version of any given concept resource.
Note that configurations do not have status, workflow, or lifecycle properties; instead, we expect other resources that define such status to link to configurations. These other resources might be Change Requests, or resources from some as-yet undefined OSLC Lifecycle or Process Domain.
The structures commonly known as streams and baselines are represented by configurations linked from a resource with appropriate status values.
TBD:
- Dependencies (configurations on which this configuration depends)
- Dimension values for labeling
Configuration context
A client may request a specific configuration context in one of four ways. TBD: we need to simplify this.
- When performing a GET on a concept URI, add an
X-OSLC-Configuration-Context
header, passing the URI of a configuration resource as the value:
GET /resources/conceptResourceA HTTP/1.1
X-OSLC-Configuration-Context: http://example.com/configurations/myConfiguration1
- When performing a GET on a concept URI, add a query string
oslc_config.context
and the encoded configuration URI to the end of the request URI:
GET /resources/conceptResourceA?oslc_config.context=&3Chttp&3A//example.com/configurations/myConfiguration1&3E HTTP/1.1
- When performing a GET on a configuration URI, add an
X-OSLC-Concept-Resource
header, passing the URI of a concept resource as the value:
GET /configurations/myConfiguration1 HTTP/1.1
X-OSLC-Concept-Resource: http://example.com/resources/conceptResourceA
- When performing a GET on a configuration URI, add a query string
oslc_config.concept_resource
and the encoded concept resource URI to the end of the request URI:
GET /configurations/myConfiguration1?oslc_config.concept_resource=&3Chttp&3A//example.com/resources/conceptResourceA&3E HTTP/1.1
Clients may also use version resource URIs, but are discouraged from persisting such URIs in links, since that reduces the flexibility permitted by configuration management.
Change set
A change set is a resource with any of the above-listed standard properties, plus the following:
Prefixed Name |
Occurs |
Read-only |
Value-type |
Representation |
Description |
rdf:type |
one-or-many |
unspecified |
Resource |
Reference |
The resource type URIs. A change set MUST have a resource type of oslc_config:ChangeSet , and SHOULD have a resource type of ldp:Container or one of its subclasses. The Linked Data Platform container or aggregate is used to indicate the configuration items that are members of (contents of) the change set. For added and modified resources, it is likely that these membership links use version resource URIs or links with a configuration context to point to the version of the resource that is the result of the specified change; the version of the resource before the specified change may then be found using the provenance link prov:wasRevisionOf . TBD pending W3C review of non-member property retrieval: Note that determining the set of resources in a change set may be an expensive operation, so clients needing only the non-member properties are advised to GET the related resource formed by appending the query string "non_member_properties" . |
oslc_config:requiredChangeSet |
zero-or-many |
unspecified |
Resource |
any |
A change set that this change set depends on. It is likely that the target resource will be an oslc_config:ChangeSet but that is not necessarily the case. TBD: why is this property defined? What use case or scenario requires it? |