'Lookup the full set of options for a Filter Widget
- for Subscriptions we don\'t want to see just the options available in current data'

@staticmethod
def _options(fieldname):

    db = current.db
    if (fieldname == 'location_id'):
        table = current.s3db.gis_location
        query = ((table.deleted == False) & (table.level == 'L1'))
        rows = db(query).select(table.id)
        options = [row.id for row in rows]
    return options
