[hibernate-dev] [OGM] Precedence of options specified on different levels

Hi, In the context of embedded associations for CouchDB [1], I'm working on support for configuring the association storage mode using our new option system [2]. I can see the following "axes" of configuration here: * via annotation - on an association property - on a type * via the option API - on an association property - on a type - on the global level * via a configuration property as given via OgmConfiguration, persistence.xml etc. * on super-types - via annotations or API - on the property or entity level I'm looking now for a sensible and comprehensible algorithm for taking these sources of configuration into account and determining the effective setting for a given association. This could be one way: 1) check API a) look for a setting given via the programmatic API for the given property b) if the property is not configured, look for a setting given for the entity c) if the entity itself is not configured, repeat a) and b) iteratively on super-types if present d) if no type from the hierarchy is configured look for the global setting 2) check annotations if no configuration could be found in 1), do the same for annotations, i.e. a) look for configuration on the given property b) look for configuration on the given entity c) repeat a) and b) iteratively on super-types if present 3) take default value given via OgmConfiguration/persistence.xml etc. This algorithm ensures that: * API configuration always takes precedence over annotation configuration; e.g. if a super-type is configured via the API or the setting is given on the API global level, any annotations are ignored * "More local" configuration takes precedence; i.e. a type's own configuration wins over configuration from super-types, property-level configuration wins over entity-level configuration Note that any setting given via OgmConfiguration/persistence.xml would be handled as last fallback option, i.e. any configuration given via annotations or the API would take precedence over that. I first didn't like that but I came to think it makes sense, if the property name conveys that semantics, e.g. "defaultAssociationStorageMode". Any other thoughts or alternative approaches around this? Thanks, --Gunnar [1] https://hibernate.atlassian.net/browse/OGM-389 [1] https://hibernate.atlassian.net/browse/OGM-208