When you save the map theme and the map data, the contents
of the map file are the same as when you save a map theme only, but
instead of storing map data as a set of URLs or pointers, the data
is copied locally. This provides a faster loading time, especially
for raster data, and allows a map to be displayed even if the original
"source data" is not accessible anymore.
However, some operations on the map such as a change
in coordinate system might need this source data to ensure proper
reprojection without loss of precision. If source data is not available,
embedded map elements are reprojected without reading them back from
the original data source.
A use case for this implementation could be if the application
developed using JViews Maps for Defense is used onboard a battle tank with
poor or no connectivity to servers and the command center. The mission
planner who prepares the map for the defense of the city saves the
map data and burns a DVD, which he or she then hands over to the tank
commander.
For more information about saving a map theme and map
data, see
Saving a map.