injectable 3.3.0

Dependency Injection for Humans™

Injectable: Dependency Injection for Humans™

Injectable is an elegant and simple Dependency Injection framework built with Heart and designed for Humans.

from injectable import Autowired, autowired from typing import List from models import Database from messaging import Broker class Service: @autowired def __init__( self, database: Autowired(Database), message_brokers: Autowired(List[Broker]), ): pending = database.retrieve_pending_messages() for broker in message_brokers: broker.send_pending(pending) from abc import ABC class Broker(ABC): def send_pending(messages): ...

from injectable import injectable @injectable class Database: ... from messaging import Broker from injectable import injectable @injectable class KafkaProducer(Broker): ... from messaging import Broker from injectable import injectable @injectable class SQSProducer(Broker): ...

Features you’ll love ❤️

• Autowiring: injection is transparent to the function. Just decorate the function with @autowired and annotate parameters with Autowired, that’s it.

• Automatic dependency discovery: just call InjectionContainer.load() at the root of your project or pass the root path as an argument. All classes decorated with @injectable will be automatically discovered and ready for injection.

• Qualifier overloading: declare as many injectables as you like for a single qualifier or extending the same base class. You can inject all of them just by specifying a typing.List to Autowired: deps: Autowired(List["qualifier"]).

• Transparent lazy initialization: passing the argument lazy=True for Autowired will make your dependency to be initialized only when actually used, all in a transparent fashion.

• Singletons: decorate your class with @injectable(singleton=True) and only a single instance will be initialized and shared for injection.

• Namespaces: specify different namespaces for injectables as in @injectable(namespace="foo") and then just use them when annotating your parameters as in dep: Autowired(..., namespace="foo").

• Linters friendly: Autowired is carefully designed to comply with static linter analysis such as PyCharm’s to preserve the parameter original type hint.

These are just a few cool and carefully built features for you. Check out our docs!

Changelog

3.3.0 (2020-04-20)

• Include the injectable.testing utilities to ease mocking injectables.

3.2.1 (2020-04-19)

• InjectionContainer::load is more resilient against duplicated injectables

  registering

3.2.0 (2020-04-15)

• Support for optional injection in declarative fashion: Autowired(Optional[...])

3.1.4 (2020-04-15)

• Fix Autowired(List[...]) not working with qualifiers

3.1.3 (2020-04-15)

• Fix Windows injectables not being loaded.

3.1.2 (2020-04-14)

• Remove unused inspect imports.

3.1.1 (2020-04-13)

• Fix bug of scanning the same module more than once when InjectionContainer.load()

  is called multiple times with different relative search paths.

3.1.0 (2020-04-13)

• Added @injectable_factory decorator for declaring injectable factory methods

• Include the console output in the examples

3.0.1 (2020-04-13)

• Fix package content missing

3.0.0 (2020-04-12)

• Drop support for autowiring without previous initialization of the InjectionContainer

• Refactor @autowired decorator for working with the Autowired type annotation

• Added @injectable decorator for registering injectables to the InjectionContainer

• Support for qualifiers, groups and namespaces

• Added Autowired type annotation for marking parameters for autowiring

• Added inject and inject_multiple as service locators

• Added InjectionContainer for registering injectables

• Official support for Python 3.7 and 3.8

• Official support for Ubuntu, Windows and MacOS

• Drop Python 3.4 and 3.5 official support

• General code refactoring

• Official documentation

• Added usage examples

2.0.0 (2018-02-24)

• Drop Python 3.3 official support

1.1.2 (2018-02-24)

• Support for dependencies of classes without signature

• Fix bug of builtin types not being accepted for injectable dependencies

1.1.1 (2018-02-23)

• Statically infer dependency’s constructor suitability for injection instead of using

  trial instantiation

• Fix bug of raising TypeError when injectable fails on the trial dependency

  instantiation which can happen when the dependency does provide a default constructor with no arguments but the running environment (possibly a test suite environment) will make the instantiation fail

1.1.0 (2018-02-10)

• Enable the use of @autowired decorator without parenthesis

1.0.1 (2018-02-10)

• Fixes required dependency lazy_object_proxy not being installed when installing

  injectable through pip

1.0.0 (2018-02-06)

• First stable release

0.2.0 (2018-02-06)

• Support for lazy dependency initialization

• Support for type annotations with strings

0.1.1 (2018-02-05)

• Python 3.3 and 3.4 support

0.1.0 (2018-02-05)

• First beta release