def optionally_many_from_arguments(
cls: Type[T],
arguments: QueryString,
available: Optional[Dict[str, T]] = None,
key: str = 'order_by',
fallback_to: Optional[T] = None) -> Optional[List[T]]:
if available is None:
if not isinstance(cls.available, dict):
raise RuntimeError('implement .available order by values')
available = cls.available
values = arguments.parse_string(key).split(',')
if values is None or len(values) < 1:
return fallback_to
parsed: List[T] = []
for term in values:
if term not in available.keys():
raise BadRequest('Invalid {k} value. Valid values: {v}'.format(
k=key, v=', '.join(available.keys())))
parsed.append(available[term])
continue
return parsed
def from_arguments(cls: Type[T],
arguments: QueryString,
max_length: int = 64,
min_length: int = 3,
key: str = 'fragment') -> T:
fragment = arguments.parse_string(key=key,
max_length=max_length,
min_length=min_length,
allow_whitespace=True)
return cls(fragment)