Filtered OGC API Features layers

[jampukka]

Support for Filtered WFS-layers was added in #228, however the support wasn't added to OGC API Features layers. Currently a filter configured as documented here https://oskari.org/documentation/examples/oskari-filter is just silently ignored if the layer in question is of type WFS3/OGC API Features.

OGC API Features - Part 3: Filtering (& CQL2) isn't finished so supporting all features designed in #228 can't be done fully server-side. But even after it gets finished most services won't support all conformance classes inside Part 3: Filtering. These conformance classes determine which sort of filtering capabilities the service does support. We need to be able to determine which ones the server does support and send them as part of the request. The ones that aren't supported by that specific service should be post-filtered in Oskari server.

It would make sense to add support for simple query parameters as defined inPart 1: Core. This would allow combining equal to, in (arguable, but many support /items?foo=1,2,3,4 as 'foo' IN (1,2,3,4), and bbox filters in a simple (non-nested) AND which in total most probably covers large portion of use-cases for this whole functionality.

[jampukka]

Working on this issue on oskariorg/oskari-server#816

Current progress using tieviiva (road links) from https://avoin-paikkatieto.maanmittauslaitos.fi/maastotiedot/features/v1/collections/tieviiva which supports filtering only on kohdeluokka (category)

CQL Filter "kohdeluokka" IN (12111, 12112), Layer Attributes configured as:

{
  "filter": {
    "property": {
      "in": ["12111","12112"],
      "key": "kohdeluokka"
    }
  }
}

---

CQL Filter "kohdeluokka" IN (12111, 12112) AND nimi_suomi = 'Länsiväylä', Layer Attributes configured as:

{
  "filter": {
    "AND": [
      {
        "in": ["12111","12112"],
        "key": "kohdeluokka"
      },
      {
        "value": "Länsiväylä",
        "key": "nimi_suomi"
      }
    ]
  },
  "queryables": [
    "kohdeluokka"
  ]
}

Generated OAPIF query is https://avoin-paikkatieto.maanmittauslaitos.fi/maastotiedot/features/v1/collections/tieviiva/items?limit=1000&bbox=24.780370%2C60.206566%2C24.930547%2C60.245707&kohdeluokka=12111,12112. The nimi_suomi = 'Länsiväylä' part is evaluated at oskari-server side for each feature while reading them from the response.

[ZakarFin]

I wonder how and if this works with the newly merged oskariorg/oskari-frontend#2368

[rekjuh]

@jampukka what's the current situation with this issue? We're moving all the issues to Oskari-documentation repo. If you wish to keep this open and get updates, please create a new issue here: https://github.com/oskariorg/oskari-documentation/issues