Wednesday, November 23, 2011

Configurators Love Esri's URL Parameters (Part 1: One Parameter, Lots of Map Apps)

URL parameters are no big deal for web map programmers.  They use URL parameters all the time to configure complex web applications at use-time.   But they're a big deal for Configurators  --  map makers who are only programmer wannabes.  We could never make a living programming.  But we can do a lot of web mapping by reconfiguring other people's code.

Esri has opened up lots of possibilities for Configurators.  It's possible for Configurators to adapt the Esri Javascript API code samples, but the learning curve is steep.   Their Flex Viewer is easier to configure.  Just change XML tag content.  Easiest of all are the web map apps at  Once the map is authored, the unique map ID can be sent to several pre-built viewers.

San Mateo County (Calif.) took advantage of web map parameter to create a Public Maps Gallery that gives users several viewing options.  We authored our web maps at to show map services on the County GIS server.  Then we sent the web map unique ID as a URL parameter to several different map viewers.

The map of Whitehouse Creek - Parcels Adjacent to Rare Species Habitat is a good example.

Additional map viewer options appear at the bottom of this simple viewer:

  • Full-Service Map Viewer ( is the standard Javascript map viewer hosted at
  • Presentation Map is ArcGIS Explorer Online map viewer at, built with Microsoft Silverlight.  This map viewer requires the Silverlight plug-in.  It has many advanced features for configuring the map layers and popups, and for creating online presentations for “telling the story with maps.”
  • SMC Flex Map is Esri’s ArcGIS Server Map Viewer for Flex, which has been locally configured and hosted on the San Mateo County web server.
  • SmartPhone Map is a simple Javascript map viewer template hosted at  We could have customized and hosted this on the San Mateo Countyweb server instead.  Its simple format is useful for small-format mobile devices.  But this template has no capability to turn map layers on/off, so it's limited to showing only those map layers the map author made visible when the web map was saved.

There are some gotchas with the URL parameter for the unique map ID.  You can see this by comparing the map ID parameter that is actually sent in the URL for each of the map viewers.  More about this in my next post.

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