2016-03-30 17:10:43 +03:00
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Structure of Dependency Injector
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2016-03-31 21:00:48 +03:00
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2016-04-11 23:16:46 +03:00
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.. meta::
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2016-04-23 15:00:06 +03:00
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:keywords: Python,DI,Dependency injection,IoC,Inversion of Control
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2016-04-11 23:16:46 +03:00
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:description: This article describes "Dependency Injector" framework
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components and their interaction between each other.
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Catalogs, providers and injections are the former
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components of the framework.
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2016-03-31 21:00:48 +03:00
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Current section describes *Dependency Injector* main entities and their
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interaction between each other.
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.. image:: /images/internals.png
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:width: 100%
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:align: center
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2016-03-31 21:13:28 +03:00
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There are 3 main entities: providers, injections and catalogs.
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2016-03-31 21:00:48 +03:00
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+ All of the entities could be used in composition with each other or
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separatelly.
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+ Each of the entities could be extended via specialization.
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2016-03-31 21:13:28 +03:00
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Providers
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~~~~~~~~~
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Providers are strategies of accesing objects. For example,
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:py:class:`dependency_injector.providers.Factory` creates new instance
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of provided class every time it is called.
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:py:class:`dependency_injector.providers.Singleton` creates provided
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instance once and returns it on every next call. Providers could be
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injected into each other. Providers could be overridden by another
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providers. Base class is -
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:py:class:`dependency_injector.providers.Provider`.
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Injections
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~~~~~~~~~~
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Injections are instructions for making dependency injections
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(there are several ways how they could be done). Injections are used
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mostly by :py:class:`dependency_injector.providers.Factory` and
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:py:class:`dependency_injector.providers.Singleton` providers, but
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these are not only cases. Base class is -
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:py:class:`dependency_injector.injections.Injection`.
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Catalogs
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~~~~~~~~~
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Catalogs are collections of providers. They are used for grouping
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of providers by some principles. Base class is -
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:py:class:`dependency_injector.catalogs.DeclarativeCatalog`.
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