MapServer OpenLayers Viewer

MapServer (since the 6.0 release) provides a simple, built-in method for testing a mapfile using OpenLayers. This feature is for testing/development purposes only, and not for production or deploying full-featured sites. You can preview, test, and navigate a mapfile by accessing a special url which will return a built-in OpenLayers template.

Notitie

This feature was discussed in rfc 63 and in the ticket https://github.com/MapServer/MapServer/issues/3549

Using the OpenLayers viewer

Opening the OpenLayers viewer in your browser

Assuming you are running mapserver on your local machine, and you have the Itasca demo setup, a basic url would be (split into two lines for readability):

http://localhost/cgi-bin/mapserv?mode=browse&template=openlayers
     &layer=lakespy2&layer=dlgstln2&map=/var/www/workshop/itasca.map

Here is a quick breakdown of that url:

• Basic Parameters for activating the OpenLayers browser:

  template=openlayers
  mode=browse
  

• Basic Map / Layer Parameters:

  map=/var/www/workshop/itasca.map
  layer=lakespy2
  layer=dlgstln2
  

That’s it!

Opening the OpenLayers viewer in the form of a WMS request

This feature is useful when debugging WMS requests. You can write one of these by hand, or copy the URL for a WMS tile. Running the following should give you a simple OpenLayers demo around the BBOX (split into several lines for readability):

http://localhost/cgi-bin/mapserv?map=/var/www/workshop/itasca.map
     &LAYERS=lakespy2&VERSION=1.1.1&SERVICE=WMS&REQUEST=GetMap
     &FORMAT=application/openlayers&WIDTH=512&HEIGHT=512&SRS=EPSG:26915
     &BBOX=429956.19803725,5231780.0814818,444078.32296225,5245902.2064068

Here is a quick breakdown of the interesting parts of that URL:

• Special Parameter for activating the OpenLayers viewer:

  FORMAT=application/openlayers
  

• Basic MapServer Parameters:

  map=/var/www/workshop/itasca.map
  

• Basic WMS parameters:

  #Layers, our bounding box and projection
  LAYERS=lakespy2
  BBOX=429956.19803725,5231780.0814818,444078.32296225,5245902.2064068
  SRS=EPSG:26915
  
  #Version and other WMS request params
  SERVICE=WMS
  VERSION=1.1.1
  REQUEST=GetMap
  WIDTH=512
  HEIGHT=512
  TRANSPARENT=true
  

Customizing settings

• environment variables:

  MS_OPENLAYERS_JS_URL - The URL to the OpenLayers javascript library. Per default the library loaded from the MapServer web server.