As a developer, I want the administration of the entity state to be simplified.
The management of the entity state using generic containers "Core" and "Value" is unnecessarily complicated. Typically, entities should be simple POJOs. If a generic representation of the state is required for persistence purposes, it can be created quickly and easily via entity-specific adapters that collect or initialize the properties of an entity in a hashmap. Then, this would be an implementation detail of a particular adapter, but should not be part of the general API.
Decision from mdm Hackathon (23.10.2017):
we will stay with the current approach.
for the mandatory attributes there exist getters and setters.
with the current approach the additional attributes and relations can be accessed via the core, and the core also provides the file link infos and the access to stores. So the core is a wrapper for the proposed hashmaps.
removing the core from the BaseEntity would mean to restructure the store design.
The fundamental design of the core / value concept, including the stores should be rethought. Especially the stores for entitys and relations (MutableStore, PermanentStore, ChildrenStore) and their behaviour is unintuitive. For example at the moment it is not transparent, if a relation is not set or is not yet loaded. Further analysis for restructuring is recommended, but exceeds the scope of current sprints.