Source code for websauna.system.admin.modeladmin

"""Automatic admin and CRUD for SQLAlchemy models."""
# Standard Library
import string
import typing as t

# Pyramid
import venusian
from pyramid.interfaces import IRequest

# Websauna
from websauna.system.admin.interfaces import IAdmin
from websauna.system.admin.interfaces import IModelAdmin
from websauna.system.core.traversal import Resource
from websauna.system.crud.sqlalchemy import CRUD as CRUD
from websauna.system.crud.sqlalchemy import Resource as AlchemyResource

# We enforce some best practices to readable URL names of model admins. This is an arbitrary choice of the author.
ALLOWED_TRAVERSE_ID_CHARACTERS = string.ascii_lowercase + string.digits + "-"

[docs]class ModelAdmin(CRUD): """Resource presenting one model in admin interface. Provide automatized list, show add, edit and delete actions for an SQLAlchemy model which declares admin interface. """ #: Title used in breadcrumbs, other places title = None #: Model must be set by subclass model = None def __init__(self, request): super(ModelAdmin, self).__init__(request)
[docs] def get_model(self): assert self.model, "Model must be set by a subclass as a class attribute" return self.model
#: Our resource factory
[docs] class Resource(AlchemyResource):
[docs] def get_admin(self): return self.__parent__.get_admin()
[docs] def get_admin(self) -> IAdmin: """Get Admin resource object.""" return self.__parent__.__parent__
[docs] def get_title(self) -> str: if self.title: return self.title return
[docs]class ModelAdminRoot(Resource): """Admin resource under which all model admins lurk. To get access this resource: """
[docs] def get_title(self): return "Models"
[docs] def get_model_admins(self): """List all registered model admin classes. :yield: (model_id, IModelAdmin) tuples """ for model_id, model_cls in self.request.registry.getAdapters([self.request], IModelAdmin): yield(model_id, model_cls)
def __getitem__(self, item): """Traverse to model admins. """ registry = self.request.registry model_admin_resource = registry.queryAdapter(self.request, IModelAdmin, name=item) if not model_admin_resource: raise RuntimeError("Did not find model admin with id: {}".format(item)) Resource.make_lineage(self, model_admin_resource, item) return model_admin_resource
[docs] def items(self) -> t.List[t.Tuple[str, ModelAdmin]]: for id, model_cls in self.get_model_admins(): yield id, self[id]
[docs]def model_admin(traverse_id: str) -> type: """Class decorator to mark the class to become part of model admins. ``Configure.scan()`` must be run on this module for the implementation to be picked up. If there is already an existing model admin with same ``model``, then the existing model admin is overwritten. :param traverse_id: Under which URL id this model appears in the admin interface. Allowed to contain lowercase letters, dash and digits. This will be available as ``ModelAdmin.__name__`` instance attribute. :param model_cls: Which model class this admin resource is controlling """ assert all(c in ALLOWED_TRAVERSE_ID_CHARACTERS for c in traverse_id), "traverse_id may only contain lowercase letters, digits and a dash: {}".format(traverse_id) def _inner(cls): "The class decorator example" def register(scanner, name, wrapped): config = scanner.config # We can look up midels by model = getattr(cls, "model", None) assert model, "Class {} must declare model attribute".format(cls) registry = config.registry # Purge existing model admin registry.unregisterAdapter(required=(IRequest,), provided=IModelAdmin) registry.registerAdapter(cls, required=(IRequest,), provided=IModelAdmin, name=traverse_id) registry.model_admin_ids_by_model[model] = traverse_id venusian.attach(cls, register, category='websauna') return cls return _inner
[docs]def configure_model_admin(config): """Sets up model -> model admin registry.""" config.registry.model_admin_ids_by_model = {}