Missing shared interface for objects from database or index

[matthias-ronge]

Database objects (Project, Process, etc.) and their representatives in the search engine index (ProjectDTO, ProcessDTO, etc.) do not have a common interface.

Goal: To add a common interface to each pair of classes. The interface should only give readable access to the content, that is, it should only have getters (because calling a setter on an index object will not update the database) and then all methods that only need read access to an object (which are most), should only take interface objects as parameters. This should reduce the number of cases in which a database object is loaded for an index object, only to be passed on to a method, because the method signature requires a database objekt and not makes use of a common interface; although all the necessary data would be available in the index.