OperationsMetadata in JSON Service Metadata document in JSON

78 Copyright © 2015 Open Geospatial Consortium. Figure 12: OWS Common OperationsMetadata UML diagram The structure is presented in JSON-LD as a context and an example: { context: { ows: http:www.opengis.netows2.0, mywfs: http:www.BlueOx.orgmywfs2.5, id: id, name: id, type: type, operation: ows:OperationsMetadataOperation, DCP: _:, HTTP: _:, Get: _:, href: Copyright © 2015 Open Geospatial Consortium. 79 { id: ows:href, type: id }, noValues: ows:noValues, defaultValue: ows:defaultValue, constraints: ows:constraint }, id: mywfs:operationsMetadataDemo1, type: ows:OperationsMetadata, operation: [ { name: mywfs:operationDemo1GetCapabilities, type: ows:Operation, DCP: [ { HTTP: { Get: { name: mywfs:operationDemo1GetCapabilitiesmethod, type: ows:RequestMethod, href: http:www.BlueOx.orgmywfs2.5? } } }] }, { name: mywfs:OperationDemo1NoOp, type: ows:Operation, DCP: [ { HTTP: { Get: { name: mywfs:OperationDemo1NoOpmethod, type: ows:RequestMethod, href: http:www.BlueOx.orgmywfs2.5? } } }] } ], constraints: [ { name: mywfs:OperationsMetadataConstraintImplementsBasicWFS, type: ows:Domain, noValues: , defaultValue: TRUE 80 Copyright © 2015 Open Geospatial Consortium. }, { name: mywfs:OperationsMetadataConstraintImplementsTransactionalWFS, type: ows:Domain, noValues: , defaultValue: TRUE }] } That can be automatically transformed to RDF like this: http:www.BlueOx.orgmywfs2.5operationsMetadataDemo1 http:www.w3.org19990222-rdf-syntax-nstype http:www.opengis.netows2.0OperationsMetadata . http:www.BlueOx.orgmywfs2.5operationsMetadataDemo1 http:www.opengis.netows2.0OperationsMetadataOperation http:www.BlueOx.orgmywfs2.5operationDemo1GetCapabilities . http:www.BlueOx.orgmywfs2.5operationsMetadataDemo1 http:www.opengis.netows2.0OperationsMetadataOperation http:www.BlueOx.orgmywfs2.5OperationDemo1NoOp . http:www.BlueOx.orgmywfs2.5OperationDemo1NoOp http:www.w3.org19990222-rdf-syntax-nstype http:www.opengis.netows2.0Operation . http:www.BlueOx.orgmywfs2.5OperationDemo1NoOpmethod http:www.opengis.netows2.0href http:www.BlueOx.orgmywfs2.5? . http:www.BlueOx.orgmywfs2.5OperationDemo1NoOpmethod http:www.w3.org19990222-rdf-syntax-nstype http:www.opengis.netows2.0RequestMethod . http:www.BlueOx.orgmywfs2.5operationDemo1GetCapabilities http:www.w3.org19990222-rdf-syntax-nstype http:www.opengis.netows2.0Operation . http:www.BlueOx.orgmywfs2.5operationDemo1GetCapabilitiesmethod http:www.opengis.netows2.0href http:www.BlueOx.orgmywfs2.5? . http:www.BlueOx.orgmywfs2.5operationDemo1GetCapabilitiesmethod http:www.w3.org19990222-rdf-syntax-nstype http:www.opengis.netows2.0RequestMethod . http:www.BlueOx.orgmywfs2.5operationsMetadataDemo1 http:www.opengis.netows2.0constraint http:www.BlueOx.orgmywfs2.5OperationsMetadataConstraintImp lementsBasicWFS . http:www.BlueOx.orgmywfs2.5operationsMetadataDemo1 http:www.opengis.netows2.0constraint http:www.BlueOx.orgmywfs2.5OperationsMetadataConstraintImp lementsTransactionalWFS . http:www.BlueOx.orgmywfs2.5OperationsMetadataConstraintImplemen tsBasicWFS http:www.opengis.netows2.0defaultValue TRUE . http:www.BlueOx.orgmywfs2.5OperationsMetadataConstraintImplemen tsBasicWFS http:www.opengis.netows2.0noValues . Copyright © 2015 Open Geospatial Consortium. 81 http:www.BlueOx.orgmywfs2.5OperationsMetadataConstraintImplemen tsBasicWFS http:www.w3.org19990222-rdf-syntax-nstype http:www.opengis.netows2.0Domain . http:www.BlueOx.orgmywfs2.5OperationsMetadataConstraintImplemen tsTransactionalWFS http:www.opengis.netows2.0defaultValue TRUE . http:www.BlueOx.orgmywfs2.5OperationsMetadataConstraintImplemen tsTransactionalWFS http:www.opengis.netows2.0noValues . http:www.BlueOx.orgmywfs2.5OperationsMetadataConstraintImplemen tsTransactionalWFS http:www.w3.org19990222-rdf-syntax- nstype http:www.opengis.netows2.0Domain .

10.1.1.4 Contents section in Service Metadata in JSON

The Contents section of the service metadata document is more ambiguous in OWS Common because it depends deeply on the nature of the service. OWS Common only specifies that a list of resource descriptions will be includes if calls each one “datasetSummary”. A dataset summary should have an id, a title, an abstract, some keywords, a Bounding Box in WGS84 and Bounding Boxes in other CRS’s. All this elements are also present in OWS Context. This ER is proposing to use a OWS Context encodings for this section. Since OWS Context in GeoJSON has already been drafted, we thing that adopting it will help to reduce redundancies and increase interoperability. Recommendation 25: Consider OWS Context as the Contents section of service metadata document. In particular adopt the OWS Context JSON encoding in the JSON encoding of OWS Common. Target: OWS Common

10.1.2 JSON GetCapabilities request

Subclause 7.2.4 on OWS Common is considering a XML encoding for GetCapabilities. In our opinion, we should avoid creating a JSON request for GetCapabilities and limit JSON usage in combination with REST requests or KVP request. Recommendation 26: OWS Common should recommend a REST requests for GetCapabilities and should recommend JSON as a default request. Target: OWS Common

10.1.3 JSON requests

For complex requests, we may consider the need for a JSON encoding. In this case, OWS Common defines a minimum set of parameters in subclause 9.2.1. OWS Common should provide a context fragment defining them. Recommendation 27: Define the OWS Common minimum set of parameters in a request as a context fragment. A JSON schema can also be provided. Target: OWS Common 82 Copyright © 2015 Open Geospatial Consortium.

10.1.4 JSON exception

Subclause 7.4.1 on OWS Common defines an exception report for GetCapabilities and Clause 8 the general rules of the exceptions. In our opinion, we should avoid creating a JSON exception for GetCapabilities and limit ourselves to use the HTTP error levels and appropriate descriptions for them in a more RESTful style.

10.1.5 JSON responses

JSON responses can be provided also when currently an XML response is possible. In this case, the standard will provide a context fragment and eventually a JSON Schema.

10.1.6 Bounding Boxes

Subclause 10.2 on OWS Common defines how to use Bounding Boxes in OWS Common. SubClause 10.2.2 and in the case of JSON encoding whenever possible we should use GeoJSON bbox. Subclause 10.2.1 defines a generic bounding box. CRSbbox: { crs: http:www.opengis.netdefcrsOGC1.3CRS84, LowerCorner: POINT-180 -90, UpperCorner: POINT180 90 }

10.2 JSON in Web Map Services

This subclause discusses how to include JSON in the WMS service.

10.2.1 JSON in GetCapabilities response

The subclause 10.1.1 already discuses this topic in a more general way.

10.2.2 JSON for WMS GetMap response

In the past, several discussions suggested the need to be able on how to get metadata about individual maps returned by a WMS service. A JSON response can be a opportunity to do so: To request a JSON response in GetMap you only have to request the right format: ?service=WMSrequest=GetMapformat=applicationjson Then, the response can contain some information about the map and the map image itself embedded or linked.