We use a Joomla plugin called GoogleMaps to give access to the maps on our site. The author of this excellent plugin, Mike Reumer, has provided good documentation and a number of demonstrations.

To embed a map into a webpage, a text string of which the following is an example, needs to be placed (in curly brackets {...}) in the page at the location where the map is to be displayed:

mosmap mapType='Satellite' |centerlon=-2.412 |centerlat=50.6570 |zoom=14 |kml[0]='/images/Maps/kmlmaps/Footpaths/East_Hill_to_Osmington.kml' |kml[1]='/images/Maps/kmlmaps/Footpaths/East_Hill_to_Osmington_photos.kml' |kmlrenderer='geoxml' |kmlsidebar='left'|kmlsbwidth='200' |kmlfoldersopen='1'

Here "mosmap ..." is an instruction to the plugin to generate a map. The mosmap instruction has many parameters that can be set to define what map is to be displayed, and how it should be formatted. Here are a few of the common parameters:

  • centerlon and centerlat define the centre point of the map to be displayed;
  • zoom defines the zoom factor (between 0 and 21), and therefore the area displayed; a larger zoom factor will display a smaller area with more definition;
  • width and height can be used to alter the size of the map (in pixels) on the user's screen - the defults are 500 pixels and 400 pixels;
  • maptype defines the map type to be displayed; this can be:
    • Normal - a conventional map with roads, places etc.;
    • Satellite - a satellite image;
    • Hybrid - a satellite image with roads, places etc. overlaid;
    • Terrain - a conventional map with a representation of hills, terrain type etc.

The kmlrenderer parameter should be set to 'geoxml' as shown in the example; this selects the software used to render the map.

 

In addition to the map itself, the GoogleMaps plugin can overlay the map with markers of various sorts (lines, polygons, symbols etc.) and also with image overlays (used for example to display historic maps). These overlays are defined by means of kml files, which are "markup language" files designed for geographic purposes. The kml files are text files which define both the overlays and the effects when the overlays are clicked. See here for an overview of the capability of kml files. When a kml file is used in this way, the mosmap instruction should contain some additional parameters:

  • kml (or kml(0), kml(1) etc. to display more than one kml file) specifies the location of the kml file;
  • kmlsidebar specifies where a sidebar should be placed with text descriptions of the markers in the kml file. This can be none, left or right;
  • kmlsbwidth defines the width of the kml sidebar;
  • kmlfoldersopen specifies whether folders (groups of markers defined in the kml file) are open (1) or closed (0) in the sidebar.

Sadly, Mike Reumer is no longer supporting his Google Maps extension. There are no alternatives available with anything like the same functionality, but Google Maps by kksou appears to come fairly close, and I'm in the process of testing it. Here is my first real map, along with its Mike Reumer equivalent: