def filters_from_args(request_args):
    """
    Helper to centralize reading filters from url params
    """
    timespans_id = request_args['timespanId'] if 'timespanId' in request_args else None
    snapshots_id = request_args['snapshotId'] if 'snapshotId' in request_args else None
    foci_id = request_args['focusId'] if 'focusId' in request_args else None
    q = request_args['q'] if ('q' in request_args) and (request_args['q'] != 'undefined') else None
    return snapshots_id, timespans_id, foci_id, q