public void updateCustomField(CustomField field) throws ApplicationException {
   if (field == null
       || ConvertUtil.isNullOrEmpty(field.getEntityName())
       || ConvertUtil.isNullOrEmpty(field.getFieldName())
       || ConvertUtil.isNullOrEmpty(field.getSourceFieldName())) {
     log.info("The custom field to be updated is invalid: " + field);
     throw new ApplicationException(
         "Unable to update custom field with an invalid custom field definition.");
   }
   Entity entity = findLatestEntityVersionByName(field.getEntityName());
   EntityAttribute attrib = null;
   for (EntityAttribute item : entity.getAttributes()) {
     if (item.getName().equalsIgnoreCase(field.getFieldName()) && item.getDateVoided() == null) {
       attrib = item;
     }
   }
   if (attrib == null) {
     log.info("The user attempted to update a field that does not exist.");
     throw new ApplicationException("Unable to update an unknown custom field definition.");
   }
   attrib.setFunctionParameters(serializeParameters(field.getConfigurationParameters()));
   attrib.setDateChanged(new Date());
   attrib.setSourceName(field.getSourceFieldName());
   attrib.setTransformationFunction(field.getTransformationFunctionName());
   attrib.setUserChangedBy(Context.getUserContext().getUser());
   try {
     entityDefinitionDao.updateEntity(entity);
     // Generate a notification event to inform interested listeners via the lightweight mechanism
     // that this event has occurred.
     Context.notifyObserver(ObservationEventType.CUSTOM_FIELD_UPDATE_EVENT, field);
   } catch (DaoException e) {
     log.error("Failed while updating a custom field: " + e, e);
     throw new ApplicationException("Failed while updating the custom field: " + e.getMessage());
   }
 }
 private EntityAttribute buildAttributeFromCustomField(Entity entity, CustomField field) {
   EntityAttribute attrib = new EntityAttribute();
   EntityAttributeDatatype type = getDatatypeByCode(EntityAttributeDatatype.STRING_DATATYPE_CD);
   attrib.setDatatype(type);
   attrib.setDateCreated(new Date());
   attrib.setDescription(field.getFieldName());
   attrib.setDisplayName(field.getFieldName());
   attrib.setDisplayOrder(1000);
   attrib.setEntity(entity);
   attrib.setFunctionParameters(serializeParameters(field.getConfigurationParameters()));
   attrib.setIndexed(false);
   attrib.setSearchable(false);
   attrib.setCaseInsensitive(false);
   attrib.setIsCustom(true);
   attrib.setName(field.getFieldName());
   attrib.setSourceName(field.getSourceFieldName());
   attrib.setTransformationFunction(field.getTransformationFunctionName());
   attrib.setUserCreatedBy(Context.getUserContext().getUser());
   return attrib;
 }
 @SuppressWarnings("unchecked")
 public void update(Observable o, Object eventData) {
   if (!(o instanceof EventObservable)
       || eventData == null
       || !(eventData instanceof CustomField)) {
     log.warn("Received unexpected event with data of " + eventData);
     return;
   }
   EventObservable event = (EventObservable) o;
   CustomField customField = (CustomField) eventData;
   Map<String, List<CustomField>> customFieldsListByEntityName =
       (Map<String, List<CustomField>>)
           Context.getConfiguration()
               .lookupConfigurationEntry(
                   customField.getEntityName(),
                   ConfigurationRegistry.CUSTOM_FIELD_LIST_BY_ENTITY_NAME_MAP);
   Map<String, Map<String, CustomField>> customFieldsMapByEntityName =
       (Map<String, Map<String, CustomField>>)
           Context.getConfiguration()
               .lookupConfigurationEntry(
                   customField.getEntityName(),
                   ConfigurationRegistry.CUSTOM_FIELD_MAP_BY_ENTITY_NAME_MAP);
   List<CustomField> fieldList = customFieldsListByEntityName.get(customField.getEntityName());
   Map<String, CustomField> fieldMap =
       customFieldsMapByEntityName.get(customField.getEntityName());
   if (event.getType() == ObservationEventType.CUSTOM_FIELD_ADD_EVENT) {
     log.debug(
         "A new custom field was added; we need to update the in-memory registry: " + customField);
     fieldList.add(customField);
     fieldMap.put(customField.getFieldName(), customField);
   } else if (event.getType() == ObservationEventType.CUSTOM_FIELD_UPDATE_EVENT) {
     log.debug(
         "A custom field was updated; we need to update the in-memory registry: " + customField);
     boolean found = false;
     for (CustomField item : fieldList) {
       if (item.getFieldName().equals(customField.getFieldName())) {
         found = true;
         item.setConfigurationParameters(customField.getConfigurationParameters());
         item.setSourceFieldName(customField.getSourceFieldName());
         item.setTransformationFunctionName(customField.getTransformationFunctionName());
         log.debug(
             "As a result of an update custom field event, update field "
                 + item
                 + " in the list.");
       }
     }
     if (!found) {
       log.warn(
           "Received an event to update an existing custom field but the field is not found in the registry.");
     }
     fieldMap.put(customField.getFieldName(), customField);
   } else if (event.getType() == ObservationEventType.CUSTOM_FIELD_DELETE_EVENT) {
     log.debug(
         "A new custom field was deleted; we need to update the in-memory registry: "
             + customField);
     CustomField foundField = null;
     for (CustomField item : fieldList) {
       if (item.getFieldName().equals(customField.getFieldName())) {
         foundField = item;
       }
     }
     if (foundField != null) {
       fieldList.remove(foundField);
       log.debug(
           "As a result of a delete custom field event, deleted field "
               + foundField
               + " from the list.");
     }
     fieldMap.remove(customField.getFieldName());
   }
 }