This module will contain a Complex Observation Handler used to store unstructured data in the form of a complex observation to any storage systems suited for the purpose. The handler will be able to select a storage DAO according to the MIME type of the data that it's passed. So, for instance, a serialized object can be saved to a NoSQL database and large binary data can be saved to a distributed file/storage system.
It should be noted that there is no such thing in OpenMRS-core as a Complex Note as yet. We propose to get a ComplexData field included in the Note object and for the core to provide a ComplexNoteHandler interface. Any note with a non-null ComplexData property will be handled by a complexNoteHandler.
Design
Implementing the ComplexObsHandler (and ComplexNoteHandler in the future)
public class UnstructuredDataHandler extends AbstractHandler implements ComplexObsHandler {
@Override
public Obs saveObs(Obs obs) throws APIException {
String contentType = getContentType(obs.getComplexData().getTitle());
if (UnstructuredDAOUnstructuredDataHandler.getUnstructuredDAO(contentType).saveObs(obs)){
obs.setComplexData(null);
obs.setValueComplex(obs.getTitle());
} else {
throw new UnstructuredDataStorageException();
}
return obs;
}
@Override
public boolean purgeComplexData(Obs obs) {
String contentType = getContentType(obs.getComplexData().getTitle());
return UnstructuredDAOUnstructuredDataHandler.getUnstructuredDAO(contentType).purgeObs(obs);
}
@Override
public Obs getObs(Obs obs, String view) {
String contentType = getContentType(obs.getComplexData().getTitle());
return UnstructuredDAOUnstructuredDataHandler.getUnstructuredDAO(contentType).getObs(obs);
}
String getContentType(String title){
//do parsing here
}
}
Interfaces
public interface UnstructuredDataHandler {
/** To be called by the ComplexObsHandler/ComplexNoteHandler */
UnstructuredDAO getUnstructuredDAO(String contentType);
/** For each DAO a call to this method will be added in the ModuleActivator willStart() method */
void RegisterUnstructuredDAO (String contentType, UnstructuredDAO prototype) throws AlreadyRegisteredException;
/** For each DAO a call to this method will be added in the ModuleActivator willStop() method */
void DeregisterUnstructuredDAO(String contentType);
}
public interface UnstructuredDAO {
Boolean saveObs(Obs obs);
Boolean saveNote(Note note);
Boolean purgeObs(Obs obs);
Boolean purgeNote(Note note);
Note getNote(Note note);
Obs getObs(Obs obs);
}
THIS PAGE IS A WORK IN PROGRESS