Work item: Produce schemas for GetMap, GetFeatureInfo and GetCapabilities requests for POST/XML

[joanma747]

Discussed in the 2020-11-26 SWG meeting.

The schemas OGC have are http://schemas.opengis.net/ows/2.0/owsGetCapabilities.xsd contain GetCapabilities request (and response) http://schemas.opengis.net/sld/1.1/ contains GetMap for 1.1 but not for 1.3

DGIWG is asking for them.

One possibility is to adopt the ones in: https://schemas.cubewerx.com/schemas/wms/ that seem to be ok. Please note they use SLD 1.0 (not 1.1) and that GetFeautureInfo uses X,Y instead of I,J . som other corrections might be required.

Gobe takes action to create a GitHub space for this work item. WE will find out the exact procedure to send schemas to OGC without needing to create a WMS 1.3.1 document.

[ghobona]

@joanma747 I added the date of the SWG meeting to the post.

[ghobona]

Cc: @dsarafinof @StefStr @luciocola

[ghobona]

A Gitlab repository has been created for the WMS schemas.

You can opt into to the repository at https://portal.ogc.org/?m=projects&a=view&project_id=274

[ghobona]

Found that the schema for GetMap requests exists in the SLD XSDs at http://schemas.opengis.net/sld/1.1/GetMap.xsd

[ghobona]

The schema files of OWS Common 2.0 provide a GetCapabilities type that was intended to be used by different service types, including WMS.

See the attached screenshot, taken from http://schemas.opengis.net/ows/2.0/owsGetCapabilities.xsd

[ghobona]

There does not appear to be an XML schema definition for WMS GetFeatureInfo. There is one for WMTS. Comparing the WMTS GetFeatureInfo schema (see left of attached screenshot) to the WMS GetFeatureInfo KVP parameters (see top-right of attached screenshot), we could create a WMS GetFeatureInfo element that is similar to the WMTS one but uses the sld:GetMap element and adds additional elements for Querylayer, FeatureCount and Exceptions. Effectively, we would arrive at a structure that is similar to the Deegree approach (see bottom-right of attached screenshot), though excluding the Vendor element which appears to be Deegree specific.

[StefStr]

Using OWS Common 2.0 for GetCapabilities and OWS 1.1 for GetFeatureInfo does not seem to be the best approach. I would recommend to align WMTS and WMS as much as possible, also with respect to the OWS version used. Looking at the WMTS GetFeatureInfo example this could mean to work with OWS 1.1.

Comments welcome.

[ghobona]

No objection to using GetCapabilities from OWS Common 1.1.

[dsarafinof]

The OWS common version to be used has too be clear and harmonized (for all WMS 1.3 request, and the same for WMTS). About WMS 1.3, it's not based on any OWS-Common and everything has been integrated (thanks to ISO work ;) but it does rely (from what i understood on OWS 1.0, same as for SLD 1.1, which extends WMS 1.3 check the getmap XSD for example http://schemas.opengis.net/sld/1.1/GetMap.xsd. WMTS relies on OWS-1.1

[ghobona]

@StefStr @dsarafinof

The initial draft of the Best Practice document is at https://portal.ogc.org/files/?artifact_id=96292

It is in the Portal folder https://portal.ogc.org/index.php?m=projects&a=view&project_id=274&tab=2&artifact_id=56443

The asciidoc source files are at https://gitlab.ogc.org/ogc/wms-schemas

To access the Gitlab repo, you will need to opt-in at https://portal.ogc.org/?m=projects&a=view&project_id=274

Note that the source files use the new Metanorma OGC document template. More information about Metanorma is at https://www.metanorma.com/author/ogc/authoring/

If you find any issues with the template, please raise them on the metanorma-ogc issues board and Cc me in through my GitHub handle (@ghobona).

The next step is to create an XSD file that offers the wms:GetFeatureInfo and wms:GetFeatureInfoResponse.

@StefStr @dsarafinof Are you happy to take over the document from this point and to discuss the requirements with the SWG?