python-spanner-orm/spanner_orm/registry.py at main · Global19/python-spanner-orm · GitHub

History

65 lines (49 loc) · 2.08 KB

Raw

# python3

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

# https://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

"""Registers Model classes so they can be referenced elsewhere."""

from typing import Any, Dict, List, Type, Union

import dataclasses

from spanner_orm import error

@dataclasses.dataclass

class RegistryComponent:

references: List[Type[Any]] = dataclasses.field(default_factory=list)

def add(self, reference: Type[Any]) -> None:

self.references.append(reference)

class Registry(object):

def __init__(self):

self._registered = {} # type: Dict[str, RegistryComponent]

def _name_from_class(self, klass: Type[Any]) -> str:

return '{}.{}'.format(klass.__module__, klass.__name__)

def register(self, to_register: Type[Any]) -> None:

name_components = reversed(self._name_from_class(to_register).split('.'))

name = None

for component in name_components:

name = name = '{}.{}'.format(component, name) if name else component

if name not in self._registered:

self._registered[name] = RegistryComponent()

self._registered[name].add(to_register)

def get(self, name: Union[Type[Any], str]) -> Type[Any]:

if isinstance(name, type):

name = self._name_from_class(name)

if name not in self._registered:

raise error.SpannerError(

'{} was not found, verify it has been imported'.format(name))

if len(self._registered[name].references) > 1:

raise error.SpannerError(

'Multiple classes match {}, add more specificity'.format(name))

return self._registered[name].references[0]

_registry = Registry()

def model_registry():

return _registry

python-spanner-orm/spanner_orm/registry.py at main · Global19/python-spanner-orm · GitHub

Expand file tree

Breadcrumbs

registry.py

Latest commit

History

Breadcrumbs

registry.py

File metadata and controls