wfs

WFS 1.1

Web Feature Service support: feature-level access to vector layers as GML or GeoJSON. Parsing and response generation live in qgis_render::server::wfs; the server module drives it.

use qgis_render::server::{Server, WfsRequest};

let response = server.handle_wfs(WfsRequest::parse(query_string)?)?;
// response.content_type == "application/json"

Requests

REQUEST	Purpose	Response
GetCapabilities	Describe the service and the published feature types.	XML
DescribeFeatureType	Field names and types for one feature type.	XML schema
GetFeature	Return features, optionally filtered.	GML 3 or GeoJSON

GetFeature parameters

Parameter	Example	Description
TYPENAME	buildings	Feature type, as advertised in capabilities.
OUTPUTFORMAT	application/json	application/json or text/xml; subtype=gml/3.1.1.
MAXFEATURES	100	Cap on the number of features returned.
STARTINDEX	200	Skip the first N features (paging).
BBOX	14,50,15,51	Spatial filter in the type’s CRS.
FILTER	OGC XML filter	Attribute and spatial filter.
PROPERTYNAME	name,height	Restrict the returned fields.
RESULTTYPE	hits	Return only numberMatched instead of features.

curl 'http://localhost:8080/wfs?SERVICE=WFS&VERSION=1.1.0&REQUEST=GetFeature&TYPENAME=buildings&OUTPUTFORMAT=application/json&MAXFEATURES=2'

The GeoJSON response carries paging metadata:

{
  "type": "FeatureCollection",
  "features": [],
  "numberMatched": 48392,
  "numberReturned": 2,
  "links": [
    { "href": "/wfs?...&STARTINDEX=0", "rel": "self" },
    { "href": "/wfs?...&STARTINDEX=2", "rel": "next" }
  ]
}

Filtering

# Bounding box
curl 'http://localhost:8080/wfs?SERVICE=WFS&REQUEST=GetFeature&TYPENAME=buildings&BBOX=14,50,15,51&OUTPUTFORMAT=application/json'

# Attribute filter (OGC XML)
curl 'http://localhost:8080/wfs?SERVICE=WFS&REQUEST=GetFeature&TYPENAME=buildings&OUTPUTFORMAT=application/json' \
  --data-urlencode 'FILTER=<Filter><PropertyIsGreaterThan><PropertyName>height</PropertyName><Literal>50</Literal></PropertyIsGreaterThan></Filter>'

The XML filter is translated into a FeatureRequest and pushed down to the provider, so it filters in the database rather than in memory where the layer allows it.

Counting without transferring

curl 'http://localhost:8080/wfs?SERVICE=WFS&REQUEST=GetFeature&TYPENAME=buildings&RESULTTYPE=hits&FILTER=...'

Errors

Malformed requests return an OGC ExceptionReport:

<ExceptionReport version="1.1.0">
  <Exception exceptionCode="InvalidParameterValue" locator="TYPENAME">
    Unknown feature type: roads
  </Exception>
</ExceptionReport>

See also

• server — request dispatch and configuration
• features — the request model filters are translated to
• wms — map images rather than features
• Server Overview — OGC API Features, the modern alternative