8. Open Layers laboratory

This is a proposal of a complete exercise that covers the contents learned on this workshop. Take your time to do all the steps.

8.1. Basics: Map configuration and controls


Estimated duration: 30 minutes

  • Set projection to EPSG:900913 and displayProjection to EPSG:4326
  • Restrict the map extent of the map to a bounding box (coordinates must be in EPSG:900913)
  • Add two raster layers as overlays:
    • an Open MapQuest layer
    • The states WMS layer from geoserver
  • Set tile size to 512 * 512
  • Set the states WMS layer singleTile property to true (see the different labelling options)
  • Set the transparency of the MapQuest layer to 50%
  • Add the layerswitcher control
  • Avoid the OSM layer to appear in the layerswitcher
  • Add the zoombox control
  • Add the mouseposition control


Open MapQuest uses this array of OSM urls:

var arrayOSM = ["http://otile1.mqcdn.com/tiles/1.0.0/osm/${z}/${x}/${y}.jpg",

8.2. Medium: Adding vector layers and advanced controls


Estimated duration: 1 hour

  • Add a gml layer with projection: “EPSG:4326”. Take it from: data/europe.gml
  • Add a kml layer with projection: “EPSG:4326”. Take it from data/global_undersea.kml
  • Add two wfs layers (polygons and points) with projection: “EPSG:4326”: cartaro:capitals and topp:states.
  • Add the editing toolbar
  • Change the position and/or theme of the layerswitcher
  • Add the DynamicMeasure control from the extras folder. Configure it to measure distances and areas
  • Add buttons for switching distance and area measure controls. You will need to add an OpenLayers.Control.Panel, and define the displayClass of the DynamicMeasureControl. Also create those styles with CSS
  • Add the FeaturePopup control from the extras folder and configure it for the cities layer You’ll need to define templates. See the documentation of the FeaturePopup Control

8.3. Advanced: Styling


Estimated duration: 2 hours

  • Filter wfs: Filter countries of the states layer with a MALE population greater than 700000
  • Set the stylemap of the citiesLayer:
    • Add a default and a select style, a label and fillColors
  • Register to the featureselected event of the states layer and show an alert with the ID of the feature
  • Create a function to add unique values styles to a layer given its name and a feature attribute name. Apply it to the gml layer, with the property UN
  • Use a AnimatedClusterStrategy in the points layer
  • Rules
result of the exercise

Result of the laboratory