mirror of
https://github.com/ets-labs/python-dependency-injector.git
synced 2024-11-29 04:53:59 +03:00
Add massive update of README examples
This commit is contained in:
parent
e37a8cee3b
commit
4223a07183
120
README.rst
120
README.rst
|
@ -104,8 +104,124 @@ Dependency injection pattern provides the following advantages:
|
||||||
Example of dependency injection
|
Example of dependency injection
|
||||||
-------------------------------
|
-------------------------------
|
||||||
|
|
||||||
Brief example below demonstrates usage of *Dependency Injector* for creating
|
Let's go through next example:
|
||||||
several IoC containers for some example application:
|
|
||||||
|
.. image:: https://raw.githubusercontent.com/wiki/ets-labs/python-dependency-injector/img/engines_cars/diagram.png
|
||||||
|
:width: 100%
|
||||||
|
:align: center
|
||||||
|
|
||||||
|
Listing of ``example.engines`` module:
|
||||||
|
|
||||||
|
.. code-block:: python
|
||||||
|
|
||||||
|
"""Dependency injection example, engines module."""
|
||||||
|
|
||||||
|
|
||||||
|
class Engine(object):
|
||||||
|
"""Example engine base class.
|
||||||
|
|
||||||
|
Engine is a heart of every car. Engine is a very common term and could be
|
||||||
|
implemented in very different ways.
|
||||||
|
"""
|
||||||
|
|
||||||
|
|
||||||
|
class GasolineEngine(Engine):
|
||||||
|
"""Gasoline engine."""
|
||||||
|
|
||||||
|
|
||||||
|
class DieselEngine(Engine):
|
||||||
|
"""Diesel engine."""
|
||||||
|
|
||||||
|
|
||||||
|
class ElectroEngine(Engine):
|
||||||
|
"""Electro engine."""
|
||||||
|
|
||||||
|
Listing of ``example.cars`` module:
|
||||||
|
|
||||||
|
.. code-block:: python
|
||||||
|
|
||||||
|
"""Dependency injection example, cars module."""
|
||||||
|
|
||||||
|
|
||||||
|
class Car(object):
|
||||||
|
"""Example car."""
|
||||||
|
|
||||||
|
def __init__(self, engine):
|
||||||
|
"""Initializer."""
|
||||||
|
self._engine = engine # Engine is injected
|
||||||
|
|
||||||
|
Next example demonstrates creation of several cars with different engines:
|
||||||
|
|
||||||
|
.. code-block:: python
|
||||||
|
|
||||||
|
"""Dependency injection example, Cars & Engines."""
|
||||||
|
|
||||||
|
import example.cars
|
||||||
|
import example.engines
|
||||||
|
|
||||||
|
|
||||||
|
if __name__ == '__main__':
|
||||||
|
gasoline_car = example.cars.Car(example.engines.GasolineEngine())
|
||||||
|
diesel_car = example.cars.Car(example.engines.DieselEngine())
|
||||||
|
electro_car = example.cars.Car(example.engines.ElectroEngine())
|
||||||
|
|
||||||
|
While previous example demonstrates advantages of dependency injection, there
|
||||||
|
is a disadvantage demonstration as well - creation of car requires additional
|
||||||
|
code for specification of dependencies. Nevertheless, this disadvantage could
|
||||||
|
be easily avoided by using a dependency injection framework for creation of
|
||||||
|
inversion of control container (IoC container).
|
||||||
|
|
||||||
|
Example of creation of several inversion of control containers (IoC containers)
|
||||||
|
using *Dependency Injector*:
|
||||||
|
|
||||||
|
.. code-block:: python
|
||||||
|
|
||||||
|
"""Dependency injection example, Cars & Engines IoC containers."""
|
||||||
|
|
||||||
|
import example.cars
|
||||||
|
import example.engines
|
||||||
|
|
||||||
|
import dependency_injector.containers as containers
|
||||||
|
import dependency_injector.providers as providers
|
||||||
|
|
||||||
|
|
||||||
|
class Engines(containers.DeclarativeContainer):
|
||||||
|
"""IoC container of engine providers."""
|
||||||
|
|
||||||
|
gasoline = providers.Factory(example.engines.GasolineEngine)
|
||||||
|
|
||||||
|
diesel = providers.Factory(example.engines.DieselEngine)
|
||||||
|
|
||||||
|
electro = providers.Factory(example.engines.ElectroEngine)
|
||||||
|
|
||||||
|
|
||||||
|
class Cars(containers.DeclarativeContainer):
|
||||||
|
"""IoC container of car providers."""
|
||||||
|
|
||||||
|
gasoline = providers.Factory(example.cars.Car,
|
||||||
|
engine=Engines.gasoline)
|
||||||
|
|
||||||
|
diesel = providers.Factory(example.cars.Car,
|
||||||
|
engine=Engines.diesel)
|
||||||
|
|
||||||
|
electro = providers.Factory(example.cars.Car,
|
||||||
|
engine=Engines.electro)
|
||||||
|
|
||||||
|
|
||||||
|
if __name__ == '__main__':
|
||||||
|
gasoline_car = Cars.gasoline()
|
||||||
|
diesel_car = Cars.diesel()
|
||||||
|
electro_car = Cars.electro()
|
||||||
|
|
||||||
|
Dependency injection in action
|
||||||
|
------------------------------
|
||||||
|
|
||||||
|
Brief example below is a simplified version of inversion of control
|
||||||
|
containters from one of the real-life applications. This example demonstrates
|
||||||
|
usage of *Dependency Injector* inversion of control containers & providers
|
||||||
|
for specifying all application components and their dependencies beetween
|
||||||
|
each other in one module. Besides other listed above advantages, it gives a
|
||||||
|
great opportunity to control & manage application's structure in one place.
|
||||||
|
|
||||||
.. code-block:: python
|
.. code-block:: python
|
||||||
|
|
||||||
|
|
Loading…
Reference in New Issue
Block a user