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Connect to a WFS service

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A Web Feature Service (WFS) is a web service for querying spatial data that has a standardized API defined by the Open Geospatial Consortium (OGC). The WfsClient class in the spatial IO module lets developers connect to a WFS service and query data from the service.

The WfsClient class supports the following features:

  • Supported versions: 1.0.0, 1.1.0, and 2.0.0

  • Supported filter operators: binary comparisons, logic, math, value, and bbox.

  • Requests are made using HTTP GET only.

  • Supported operations:

    Operation Description
    GetCapabilities Generates a metadata document with valid WFS operations and parameters
    GetFeature Returns a selection of features from a data source
    DescribeFeatureType Returns the supported feature types

Using the WFS client

The atlas.io.ogc.WfsClient class in the spatial IO module makes it easy to query a WFS service and convert the responses into GeoJSON objects. This GeoJSON object can then be used for other mapping purposes.

The Simple WFS example sample shows how to easily query a Web Feature Service (WFS) and renders the returned features on the map. For the source code for this sample, see Simple WFS example source code.

A screenshot that shows the results of a WFS overlay on a map.

Supported filters

The specification for the WFS standard makes use of OGC filters. The WFS client supports the following filters, assuming that the service being called also supports these filters. Custom filter strings can be passed into the CustomFilter class.

Logical operators

  • And
  • Or
  • Not

Value operators

  • GmlObjectId
  • ResourceId

Math operators

  • Add
  • Sub
  • Mul
  • Div

Comparison operators

  • PropertyIsEqualTo
  • PropertyIsNotEqualTo
  • PropertyIsLessThan
  • PropertyIsGreaterThan
  • PropertyIsLessThanOrEqualTo
  • PropertyIsGreaterThanOrEqualTo
  • PropertyIsLike
  • PropertyIsNull
  • PropertyIsNil
  • PropertyIsBetween

WFS service explorer

The WFS service explorer sample is a simple tool for exploring WFS services on Azure Maps. For the source code for this sample, see WFS service explorer source code.

A screenshot that shows a simple tool for exploring WFS services on Azure Maps.

To access WFS services hosted on non-CORS enabled endpoints, a CORS enabled proxy service can be passed into the proxyService option of the WFS client as shown in the following example.

//Create the WFS client to access the service and use the proxy service settings
client = new atlas.io.ogc.WfsClient({
    url: url,
    proxyService: window.location.origin + '/YourCorsEnabledProxyService.ashx?url='
});

Next steps

Learn more about the classes and methods used in this article:

WfsClient

WfsServiceOptions

See the following articles for more code samples to add to your maps:

Leverage core operations

Supported data format details