aggregate.rst

Aggregate provider

:py:class:`Aggregate` provider aggregates a group of other providers.

.. currentmodule:: dependency_injector.providers

.. literalinclude:: ../../examples/providers/aggregate.py
   :language: python
   :lines: 3-
   :emphasize-lines: 24-27

Each provider in the Aggregate is associated with a key. You can call aggregated providers by providing their key as a first argument. All positional and keyword arguments following the key will be forwarded to the called provider:

yaml_reader = container.config_readers("yaml", "./config.yml", foo=...)

You can also retrieve an aggregated provider by providing its key as an attribute name:

yaml_reader = container.config_readers.yaml("./config.yml", foo=...)

To retrieve a dictionary of aggregated providers, use .providers attribute:

container.config_readers.providers == {
    "yaml": <YAML provider>,
    "json": <JSON provider>,
}

Note

You can not override the Aggregate provider.

Note

When you inject the Aggregate provider, it is passed "as is".

To use non-string keys or string keys with . and -, provide a dictionary as a positional argument:

aggregate = providers.Aggregate({
    SomeClass: providers.Factory(...),
    "key.with.periods": providers.Factory(...),
    "key-with-dashes": providers.Factory(...),
})

.. seealso::
   :ref:`selector-provider` to make injections based on a configuration value, environment variable, or a result of a callable.

   ``Aggregate`` provider is different from the :ref:`selector-provider`. ``Aggregate`` provider doesn't select which provider
   to inject and doesn't have a selector. It is a group of providers and is always injected "as is". The rest of the interface
   of both providers is similar.

Note

Aggregate provider is a successor of :ref:`factory-aggregate-provider` provider. Aggregate provider doesn't have a restriction on the provider type, while FactoryAggregate aggregates only Factory providers.

.. disqus::