routers.py

import logging
from django.conf import settings


logger = logging.getLogger(__name__)


class StateDatasetRouter(object):
    """Read/write from speciic State databases"""

    def _db_name(self, model):
        return 'traffic_stops_{}'.format(model._meta.app_label)

    def db_for_read(self, model, **hints):
        """Return state DB if model's app name is a database"""
        state_db = self._db_name(model)
        if state_db in settings.DATABASES:
            name = state_db
        else:
            name = 'default'
        logger.debug('db_for_read({}): {}'.format(state_db, name))
        return name

    def db_for_write(self, model, **hints):
        """Return state DB if model's app name is a database"""
        state_db = self._db_name(model)
        if state_db in settings.DATABASES:
            name = state_db
        else:
            name = 'default'
        logger.debug('db_for_write({}): {}'.format(state_db, name))
        return name

    def allow_syncdb(self, db, model):
        # scenarios:
        #
        # default           traffic_stops_nc    False
        # default           traffic_stops_admin True
        # traffic_stops_nc  traffic_stops_admin False
        # traffic_stops_nc  traffic_stops_nc    True
        #
        name = self._db_name(model)
        if db == 'default':
            if name in settings.DATABASES:
                ret = False
            else:
                ret = True
        else:
            if name in settings.DATABASES:
                ret = True
            else:
                ret = False
        logger.debug('allow_syncdb({}, {}): {}'.format(db, model, ret))
        return ret