Source code for aries_cloudagent.config.injection_context

"""Injection context implementation."""

from collections import namedtuple
import copy
from typing import Mapping

from .base import BaseInjector, InjectorError
from .injector import Injector
from .settings import Settings

Scope = namedtuple("Scope", "name injector")

[docs]class InjectionContextError(InjectorError): """Base class for issues in the injection context."""
[docs]class InjectionContext(BaseInjector): """Manager for configuration settings and class providers.""" ROOT_SCOPE = "application" def __init__( self, *, settings: Mapping[str, object] = None, enforce_typing: bool = True ): """Initialize a `ServiceConfig`.""" self._injector = Injector(settings, enforce_typing=enforce_typing) self._scope_name = self.ROOT_SCOPE self._scopes = [] @property def injector(self) -> Injector: """Accessor for scope-specific injector.""" return self._injector @injector.setter def injector(self, injector: Injector): """Setter for scope-specific injector.""" self._injector = injector @property def scope_name(self) -> str: """Accessor for the current scope name.""" return self._scope_name @scope_name.setter def scope_name(self, scope_name: str): """Accessor for the current scope name.""" self._scope_name = scope_name @property def settings(self) -> Settings: """Accessor for scope-specific settings.""" return self.injector.settings @settings.setter def settings(self, settings: Settings): """Setter for scope-specific settings.""" self.injector.settings = settings
[docs] def update_settings(self, settings: Mapping[str, object]): """Update the scope with additional settings.""" if settings: self.injector.settings = self.injector.settings.extend(settings)
[docs] def start_scope( self, scope_name: str, settings: Mapping[str, object] = None ) -> "InjectionContext": """Begin a new named scope. Args: scope_name: The unique name for the scope being entered settings: An optional mapping of additional settings to apply Returns: A new injection context representing the scope """ if not scope_name: raise InjectionContextError("Scope name must be non-empty") if self.scope_name == scope_name: raise InjectionContextError("Cannot re-enter scope: {}".format(scope_name)) for scope in self._scopes: if == scope_name: raise InjectionContextError( "Cannot re-enter scope: {}".format(scope_name) ) result = self.copy() result._scopes.append(Scope(name=self.scope_name, injector=self.injector)) result.scope_name = scope_name if settings: result.update_settings(settings) return result
[docs] def injector_for_scope(self, scope_name: str) -> Injector: """Fetch the injector for a specific scope. Args: scope_name: The unique scope identifier """ if scope_name == self.scope_name: return self.injector for scope in self._scopes: if == scope_name: return scope.injector return None
[docs] async def inject( self, base_cls: type, settings: Mapping[str, object] = None, *, required: bool = True ) -> object: """ Get the provided instance of a given class identifier. Args: cls: The base class to retrieve an instance of settings: An optional mapping providing configuration to the provider Returns: An instance of the base class, or None """ return await self.injector.inject(base_cls, settings, required=required)
[docs] def copy(self) -> "InjectionContext": """Produce a copy of the injector instance.""" result = copy.copy(self) result._injector = self.injector.copy() result._scopes = self._scopes.copy() return result