Aliases

rodi supports service resolution by name and by aliases, in the following example a service UsingAlias is properly resolved, by explicitly defined aliases example and settings.

from rodi import Container


class UsingAlias:

    def __init__(self, example, settings):
        self.example = example
        self.settings = settings


class Foo:

    def __init__(self):
        pass


class ContainerSettings:

    def __init__(self, setting_one, setting_two):
        self.setting_one = setting_one
        self.setting_two = setting_two


container = Container()

container.add_exact_transient(UsingAlias)
container.add_exact_transient(Foo)
container.add_instance(ContainerSettings('aaa', 'bbb'))

# arrange an exact alias for UsingAlias class init parameter:
container.add_alias('example', Foo)
container.add_alias('settings', ContainerSettings)

services = container.build_provider()
u = services.get(UsingAlias)

assert isinstance(u, UsingAlias)
assert isinstance(u.example, Foo)
assert isinstance(u.settings, ContainerSettings)

Automatically generated aliases

When registering container, aliases are inferred by type name. Such aliases are used when type hints are missing from constructors (__init__ methods). If aliases are ambiguous, because they can refer to more than one type, an exception is thrown when building a service services.

Example of inferred aliases:

Type name	Aliases
CatsRepository	cats_repository, CatsRepository, catsrepository
ICatsRepository	icats_repository, ICatsRepository, icatsrepository
HTTPContext	http_context, HTTPContext, httpcontext
Foo	foo, Foo

Exact aliases

rodi also supports to define exact aliases, that take precedence over inferred ones.

container.set_alias('example', ExampleType)

Disabling aliases

It is possible to disable aliases, using strict mode when instantiating a Container:

container = Container(strict=True)