Allow WFS search channels to set region based on property

[jampukka]

Currently single fixed value can be configured as the value for region per WFS search channel (https://github.com/oskariorg/oskari-server/blob/2.8.1/service-search-wfs/src/main/java/fi/nls/oskari/search/channel/WFSSearchChannel.java#L112). We should extend this to allow admin to configure a property to be used for extracting region from a Feature.

In addition I propose we allow providing simple (possibly even localized in the future) mapping configuration to optionally alter the value. This could be used to for example map municipality codes (091) to human readable region names (Helsinki).

[ZakarFin]

Sounds good. I would make the 091 -> Helsinki mapping a bit more generic than just for the search functionality. Maybe some simple code list config for the WFS-layer/vector source at first that could then be extended to use an external file/service for the code values? Possibly some plugin/hook mechanism that enables that kind of extension?

[jampukka]

Right, then I think we should split the work in three separate parts

1. Add support for selecting property to use to extract value for region in WFSSearchChannel
2. Change WFSSearchChannel to use OskariWFSClient (extending search channel support to OGC API Features + GML only WFS)
3. Add support for codelists / value transformation mapping support to vector layers and OskariWFSClient

Each part could be added separately and each provide extra value.

[ZakarFin]

And maybe part 4 as an optional external source for codelists that can also be added later on. In part 3 I would like to keep the value mapping/codelists out of OskariWFSClient and instead make the client aware of the mapping. So getting features from the service would return the actual values and mapping codes to user-friendly values would be done on the UI.

[ZakarFin]

There's an action route that is used to fetch coverage data for layers etc. The same route could be extended and used to pass the codelists to frontend for vector sources: https://github.com/oskariorg/oskari-server/blob/master/control-base/src/main/java/org/oskari/control/layer/DescribeLayerHandler.java

[jampukka]

I'll implement 1 soon. Users can get around of 3 and 4 outside of Oskari (doing it at the service level) so that lowers their priority a little.

[rekjuh]

@jampukka like the other issue I just commented on: what's the situation with this? You made a PR on 2022 with the mention on this but is there still something you'd like the Oskari team to work on? If you wish to keep this open and get updates, please create a new issue here: https://github.com/oskariorg/oskari-documentation/issues