# WFS3 - OGC WFS 3.0 service (experimental)

(GDAL/OGR >= 2.3.0)

NOTE: THIS IS BASED ON A DRAFT VERSION OF THE WFS 3.0 SPECIFICATION

This driver can connect to a OGC WFS 3.0 service. It assumes that the service supports OpenAPI 3.0/JSON/GeoJSON encoding for respectively API description, feature collection metadata and feature collection data.

## Dataset name syntax

The syntax to open a WFS datasource is : WFS3:http://path/to/WFS/endpoint

## Layer schema

OGR needs a fixed schema per layer, but WFS 3.0 Core doesn't impose fixed schema. So the driver will retrieve the first page of features (10 features) and establish a schema from this.

## Filtering

The driver will forward any spatial filter set with SetSpatialFilter() to the server. In WFS 3.0 Core, only a subset of attributes allowed by the server can be queried for equalities, potentially combined with a AND logical operator. More complex requests will be partly or completely evaluated on client-side.

Rectangular spatial filtering is forward to the server as well.

## Open options

The following options are available:

- URL=url: URL to the WFS server endpoint. Required when using the "WFS:" string as the connection string.
- PAGE_SIZE=integer: Number of features to retrieve per request. Defaults to 10. Minimum is 1, maximum 10000.
- USERPWD: May be supplied with userid:password to pass a userid and password to the remote server.

## Examples

- Listing the types of a WFS server :

      $ ogrinfo WFS3:https://www.ldproxy.nrw.de/rest/services/kataster

      INFO: Open of `WFS3:http://wfs3hackathon.ldproxy.net/rest/services/de_gn'
            using driver `WFS3' successful.
      1: flurstueck (Multi Polygon)
      2: gebaeudebauwerk (Multi Polygon)
      3: verwaltungseinheit (Multi Polygon)

- Listing the summary information of a WFS layer :

      $ ogrinfo -al -so WFS3:https://www.ldproxy.nrw.de/rest/services/kataster flurstueck

      Layer name: flurstueck
      Metadata:
        TITLE=Flurstück
      Geometry: Multi Polygon
      Feature Count: 9308456
      Extent: (5.612726, 50.237351) - (9.589634, 52.528630)
      Layer SRS WKT:
      GEOGCS["WGS 84",
          DATUM["WGS_1984",
              SPHEROID["WGS 84",6378137,298.257223563,
                  AUTHORITY["EPSG","7030"]],
              AUTHORITY["EPSG","6326"]],
          PRIMEM["Greenwich",0,
              AUTHORITY["EPSG","8901"]],
          UNIT["degree",0.0174532925199433,
              AUTHORITY["EPSG","9122"]],
          AUTHORITY["EPSG","4326"]]
      id: String (0.0)
      aktualit: Date (0.0)
      flaeche: Real (0.0)
      flstkennz: String (0.0)
      land: String (0.0)
      gemarkung: String (0.0)
      flur: String (0.0)
      flurstnr: String (0.0)
      gmdschl: String (0.0)
      regbezirk: String (0.0)
      kreis: String (0.0)
      gemeinde: String (0.0)
      lagebeztxt: String (0.0)
      tntxt: String (0.0)

- Filtering on a property

      $ ogrinfo WFS3:https://www.ldproxy.nrw.de/rest/services/kataster flurstueck -al -q -where "gemarkung = 'Wünnenberg'"
      Layer name: flurstueck
      Metadata:
        TITLE=Flurstück
      OGRFeature(flurstueck):1
        id (String) = DENW19AL0000geMFFL
        aktualit (Date) = 2017/04/26
        flaeche (Real) = 1739
        flstkennz (String) = 05297001600193______
        land (String) = Nordrhein-Westfalen
        gemarkung (String) = Wünnenberg
        flur (String) = 016
        flurstnr (String) = 193
        gmdschl (String) = 05774040
        regbezirk (String) = Detmold
        kreis (String) = Paderborn
        gemeinde (String) = Bad Wünnenberg
        lagebeztxt (String) = Bleiwäscher Straße
        tntxt (String) = Platz / Parkplatz;1739
        MULTIPOLYGON (((8.71191 51.491084,8.7123 51.491067,8.712385 51.491645,8.712014 51.491666,8.711993 51.491603,8.71196 51.491396,8.711953 51.491352,8.71191 51.491084)))

      [...]

- Spatial filtering

      $ ogrinfo WFS3:https://www.ldproxy.nrw.de/rest/services/kataster flurstueck -al -q -spat 8.7 51.4 8.8 51.5

      Layer name: flurstueck
      Metadata:
        TITLE=Flurstück
      OGRFeature(flurstueck):1
        id (String) = DENW19AL0000ht7LFL
        aktualit (Date) = 2013/02/19
        flaeche (Real) = 18
        flstkennz (String) = 05292602900206______
        land (String) = Nordrhein-Westfalen
        gemarkung (String) = Fürstenberg
        flur (String) = 029
        flurstnr (String) = 206
        gmdschl (String) = 05774040
        regbezirk (String) = Detmold
        kreis (String) = Paderborn
        gemeinde (String) = Bad Wünnenberg
        lagebeztxt (String) = Karpke
        tntxt (String) = Fließgewässer / Bach;18
        MULTIPOLYGON (((8.768521 51.494915,8.768535 51.494882,8.768569 51.494908,8.768563 51.494925,8.768521 51.494915)))
      [...]

## See Also

- OGC WFS 3.0 Standard (DRAFT)
- WFS (1.0,1.1,2.0) driver documentation