Lazy Provider¶

The LazyProvider enables you to reference other providers without explicitly importing them into your module.

This can be helpful if you have a circular dependency between providers in multiple containers.

Creating a Lazy Provider¶

Single import stringSeparate module and provider

from that_depends.experimental import LazyProvider

lazy_p = LazyProvider("my.module.attribute.path")

from that_depends.experimental import LazyProvider

lazy_p = LazyProvider(module_string="my.module", provider_string="attribute.path")

Usage¶

You can use the lazy provider in exactly the same way as you would use the referenced provider.

# first_container.py
from that_depends import BaseContainer, providers, ContextScopes

def my_creator():
    yield 42

class FirstContainer(BaseContainer):
    value_provider = providers.ContextResource(my_creator).with_config(scope=ContextScopes.APP)

You can lazily import this provider:

# second_container.py
from that_depends.experimental import LazyProvider
from that_depends import BaseContainer, providers
class SecondContainer(BaseContainer):
    lazy_value = LazyProvider("first_container.FirstContainer.value_provider")


with SecondContainer.lazy_value.context_sync(force=True):
    SecondContainer.lazy_value.resolve_sync() # 42