Web Feature Service
Written by: Anna Guiles
Wikipedia Definition: The Open Geospatial Consortium Web Feature Service Interface Standard (WFS) provides an interface allowing requests for geographical features across the web using platform-independent calls.
“One can think of geographical features as the "source code" behind a map, whereas the WMS interface or online mapping portals like Google Maps return only an image, which end-users cannot edit or spatially analyze.” WFS allows the user to manipulate the image by adding, deleting, or altering a feature of a map, which was once a picture that could not be changed. Here's an example of how this is done. WFS allows uniform direct access to the features stored on a server. Use a WFS when they want to perform actions such as:
- query a dataset and retrieve the features
- find the feature definition (feature’s property names and types)
- add features to dataset
- delete feature from a dataset
- update feature in a dataset
- lock features to prevent modification
- The link also provides the source code to see how it is done.
WFS uses a bi-directional translation to translate a query from a user to the database, and then translates the database language and information to the user who requested the information in a readable format. The example given in this video is Google Maps. You make a request to see something on Google Earth and then that request goes through WFS and to the Google Database. The database finds the information you want, and translates it into a picture and language you can read.
You can use WFS in QGIS to connect information from a website map directly to your map. The information from the website will show up in your Attribute Table. WFS would be its own layer on top of your map. To use WFS in QGIS you need to install the plug-in. Here is a great step-by-step tutorial on how to add a WFS layer. This is a video tutorial, however, there is no commentary and it is in a foreign language.
Sources and Awesome Links:
http://blog.geoserver.org/2006/11/27/the-wfs-and-wms-services/
http://dev.openlayers.org/releases/OpenLayers-2.13.1/examples/wfs-protocol-transactions.html
http://en.wikipedia.org/wiki/Web_Feature_Service
http://youtu.be/TuxuWAqfaaI
http://www.onegeology.org/wmscookbook/1_4_7.html
http://youtu.be/Ztndmto1aFw