ATG Component layering and how it works?

The config files (.properties) are layered in ATG. If the same .property files is present in modules which are dependent, then it will merge the property values.

Scenario #1:
Module A has X.properties with values name and age and depends on Module B which has X.properties with age and address.

When Module A component is involved it takes the values of age (overridden in A) and name from X.properties of A and address from X.properties of B.

Scenario #2:
Multi value property
#1    X.properties in the config of component contains
              vehicles=car, bike
        X.properties in the localconfig contains
              vehicles=bus
Then when this is used in the jsp then only bus is selected.

#2 To add all items, then, we need to use the below notation in the overridden file:
               vehicles+=bus

#3 If we need car and bus and bike to be removed then, we need to use the below notation in the overridden file:
              vehicles+=bus
              vehicles-=bike