Async and subsetting

[cmheazel]

Simple Async and Subsetting have been proposed additions to common. They are needed by API-Coverages. Should we include them in the current releases and if so which one (Part 1 or 2)

[jerstlouis]

Async

The async & job management capabilities of OGC API - Processes, which already had the /jobs end-point moved out of /processes in anticipation of that, would be great, but should probably be its own Common part. This could then also be used with OGC API - Coverages. That defines both polling and callbacks (different approach than simple responeHandler?). It could also potentially lighten the OGC API - Processes specifications to refer to the Common building block in a future version. Async response could be controller with Prefer: header as done with processes (see also #231), i.e. async response if set to respond-async or if processing will take longer than specified wait: delay. Relevant Processes conformance classes:

• Jobs list
• Dismiss
• Callbacks

Subsetting

• One aspect is simply describing additional dimensions (as discussed in Spatial extent / Temporal interval one vs. multiple array issues, and an interoperable approach to extensibility #91, as well as Update Coverages to reflect Common envelope as part of extent property dimensions ogcapi-coverages#100 and Align extent definition with approach taken in EDR ogcapi-coverages#96), which really is just about clarifying the schema defined in extent.yaml in terms of how you add dimensions beyond spatial and temporal (see envelope.yaml). I still think this could be done in the Core conformance class of Part 2 (since they are optional additional members), unless the reason not to do this is to accommodate services that decided to define additional members another way.
• The subsetting capability would make sense as a separate conformance class of Part 2 that defines the behavior of the subset query parameter.
• In addition to Coverages, subset is also being proposed for:
  • Maps, as an alternative to bbox (see Move partitioning conformance classes to Part 1 & add subset query parameter ogcapi-maps#76),
  • Features, for clipping as opposed to bbox intersecting (see Implementations for new task "Geometry simplification" ogcapi-features#526 and Support for clipping feature geometries ogcapi-features#530),
  • Tiles, for additional dimensions beyond the 2 of the TileMatrixSet (see How to support time in this API? ogcapi-tiles#66).