Isolating declarative code to preserve customizations

Embodiments provide a software model which allows a user to modify a software program in substantially the same manner as the original programmer or developer. In one embodiment, declarative code and user customizations are isolated from other code and structure of the software program. The isolated customizations can be quickly and efficiently examined to determine whether any changes or other modifications have been made to the software program. Additionally, the isolated changes can be efficiently located and applied when updating or upgrading the software program to persist any customized changes made to the software program.