The Dependency Injection Container

Containers serve as a central place to store and manage providers. You also define your dependency graph in the containers.

While providers can be defined outside of containers with that depends, this is not recommended if you want to use any context features

Quickstart

Define a container by subclassing BaseContainer and define your providers as class attributes.

from that_depends import BaseContainer

class Container(BaseContainer):
    # define your providers here

Then you can build your dependency graph within the container:

from that_depends import providers

class Container(BaseContainer):
    config = providers.Singleton(Config)
    session = providers.Factory(create_db_session, config=config.db) # (1)!

    user_repository = providers.Factory(
        UserRepository, 
        session=session.cast, # (3)!
        config.users
    ) # (2)!

1. The configuration will be resolved and then the .db attribute will be passed to the create_db_session creator as a keyword argument when resolving the session provider.
2. Depends on both the session and configuration providers.
3. Providers have the cast property that will change their type to the return type of their creator, use it to prevent type errors.