# OpenMNND WFS

This example shows the use of a WFS service rendered using the OpenLayers vector library.

This is an example that shows rendering a WFS service using OpenLayer vectors in the browser. The OpenLayers code will download the GML from the WFS service for each layer, parse it and create features using the OL vector library to draw the features on the map. For more information on the vector library, please visit vector support wiki. In this example there are 4 layers shown on the map. The base layer and parcel layer are created from a WMS service using the OpenLayers.Layer.WMS object. The streams, roads, and plat layers are drawn from a WFS service using the OpenLayers.Layer.WFS object.

Rendering WFS layers into vectors is possible, but you need to be cautions when showing the features on the map. Testing has shown that when you renderer more than 200 vectors in the browser the performance decreases dramatically. Also features that have a lot of vertices can cause performance issues. In this example the parcel layer is rendered as a WMS layer because at the time of developing this example there where a handful of features that had too many vertices to render without killing the browser resources. There are a number of properties that can be set for each WFS layer, such color and line weight using style properties such as strokeColor and strokeWidth. You can also get feature attributes from the WFS services using the extractAttribute property. View the source to see the example code.

- Streams: Feature Count 0
- Plat: Feature Count 0
- Roads: Feature Count 0

- select road
- select polygon