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67 lines
2.3 KiB
ReStructuredText
67 lines
2.3 KiB
ReStructuredText
Advanced usage
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==============
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Current section of documentation describes advanced usage of
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*Dependency Injector*.
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@inject decorator
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-----------------
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.. currentmodule:: dependency_injector.injections
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:py:func:`inject` decorator is a part of
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:py:mod:`dependency_injector.injections` module.
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:py:func:`inject` decorator can be used for making *inline* dependency
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injections. It *patches* decorated callable in such way that dependency
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injection will be done during every call of decorated callable.
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:py:func:`inject` takes a various number of positional and keyword arguments
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that are used as decorated callable injections. Every time, when
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:py:func:`inject` is called, positional and keyword argument injections would
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be passed as an callable arguments.
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Such behaviour is very similar to the standard Python ``functools.partial``
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object, except of one thing: all injectable values are provided
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*"as is"*, except of providers (subclasses of
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:py:class:`dependency_injector.providers.Provider`). Providers
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will be called every time, when injection needs to be done. For example,
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if injectable value of injection is a
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:py:class:`dependency_injector.providers.Factory`, it will provide new one
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instance (as a result of its call) every time, when injection needs to be done.
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:py:func:`inject` behaviour with context positional and keyword arguments is
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very like a standard Python ``functools.partial``:
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- Positional context arguments will be appended after :py:func:`inject`
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positional injections.
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- Keyword context arguments have priority on :py:func:`inject` keyword
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injections and will be merged over them.
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Example:
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.. literalinclude:: ../../examples/advanced_usage/inject_simple.py
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:language: python
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:linenos:
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Example of usage :py:func:`inject` decorator with Flask:
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.. literalinclude:: ../../examples/advanced_usage/inject_flask.py
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:language: python
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:linenos:
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@inject decorator with classes
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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:py:func:`inject` could be applied for classes. In such case, it will look for
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class ``__init__()`` method and pass injection to it. If decorated class has
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no ``__init__()`` method, appropriate
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:py:exc:`dependency_injector.errors.Error` will be raised.
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Example of usage :py:func:`inject` with Flask class-based view:
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.. literalinclude:: ../../examples/advanced_usage/inject_flask_class_based.py
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:language: python
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:linenos:
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