mirror of
https://github.com/ets-labs/python-dependency-injector.git
synced 2024-11-22 09:36:48 +03:00
179 lines
7.1 KiB
ReStructuredText
179 lines
7.1 KiB
ReStructuredText
Objects
|
|
=======
|
|
|
|
Dependency injection framework for Python projects.
|
|
|
|
+---------------------------------------+-------------------------------------------------------------------+
|
|
| *PyPi* | .. image:: https://img.shields.io/pypi/v/Objects.svg |
|
|
| | :target: https://pypi.python.org/pypi/Objects/ |
|
|
| | :alt: Latest Version |
|
|
| | .. image:: https://img.shields.io/pypi/dm/Objects.svg |
|
|
| | :target: https://pypi.python.org/pypi/Objects/ |
|
|
| | :alt: Downloads |
|
|
| | .. image:: https://img.shields.io/pypi/l/Objects.svg |
|
|
| | :target: https://pypi.python.org/pypi/Objects/ |
|
|
| | :alt: License |
|
|
+---------------------------------------+-------------------------------------------------------------------+
|
|
| *Python versions and implementations* | .. image:: https://img.shields.io/pypi/pyversions/Objects.svg |
|
|
| | :target: https://pypi.python.org/pypi/Objects/ |
|
|
| | :alt: Supported Python versions |
|
|
| | .. image:: https://img.shields.io/pypi/implementation/Objects.svg |
|
|
| | :target: https://pypi.python.org/pypi/Objects/ |
|
|
| | :alt: Supported Python implementations |
|
|
+---------------------------------------+-------------------------------------------------------------------+
|
|
| *Builds and tests coverage* | .. image:: https://travis-ci.org/rmk135/objects.svg?branch=master |
|
|
| | :target: https://travis-ci.org/rmk135/objects |
|
|
| | :alt: Build Status |
|
|
| | .. image:: https://coveralls.io/repos/rmk135/objects/badge.svg |
|
|
| | :target: https://coveralls.io/r/rmk135/objects |
|
|
| | :alt: Coverage Status |
|
|
+---------------------------------------+-------------------------------------------------------------------+
|
|
|
|
Introduction
|
|
------------
|
|
|
|
Python ecosystem consists of a big amount of various libraries that contain
|
|
different classes and functions that could be used for applications
|
|
development. Each of them has its own role.
|
|
|
|
Modern Python applications are mostly the composition of well-known open
|
|
source systems / frameworks / libraries and some turnkey functionality.
|
|
|
|
When application goes bigger, its complexity and SLOC_ are also increased.
|
|
Being driven by SOLID_ (for example), developers often start to split
|
|
application's sources into not so big classes, functions and modules. It
|
|
always helps, but there is another problem on the horizon.
|
|
|
|
It sounds like "I have so many classes and functions! They are great, now I can
|
|
understand each of them, but it is so hard to see the whole picture! How are
|
|
they linked with each other? What dependencies does this class have?". And
|
|
this is a key question: "What dependencies do certain class / function have?".
|
|
To resolve this issues developers have to go inside with IoC_ principles and
|
|
implementation patterns.
|
|
|
|
One of such IoC_ implementation patterns is called `dependency injection`_.
|
|
|
|
*Objects* is a dependency injection framework for Python projects.
|
|
|
|
It was designed to be developer's friendly tool for managing any kind of
|
|
Python objects and their dependencies in formal, pretty way.
|
|
|
|
Main idea of *Objects* is to keep dependencies under control.
|
|
|
|
Installation
|
|
------------
|
|
|
|
*Objects* library is available on PyPi_::
|
|
|
|
pip install objects
|
|
|
|
Documentation
|
|
-------------
|
|
|
|
*Objects* documentation is hosted on ReadTheDocs:
|
|
|
|
- `Stable version`_
|
|
- `Latest version`_
|
|
|
|
Examples
|
|
--------
|
|
|
|
.. code-block:: python
|
|
|
|
"""Concept example of `Objects`."""
|
|
|
|
from objects.catalog import AbstractCatalog
|
|
|
|
from objects.providers import Factory
|
|
from objects.providers import Singleton
|
|
|
|
from objects.injections import KwArg
|
|
from objects.injections import Attribute
|
|
from objects.decorators import inject
|
|
|
|
import sqlite3
|
|
|
|
|
|
class ObjectA(object):
|
|
|
|
"""Example class ObjectA, that has dependency on database."""
|
|
|
|
def __init__(self, db):
|
|
"""Initializer."""
|
|
self.db = db
|
|
|
|
|
|
class ObjectB(object):
|
|
|
|
"""Example class ObjectB, that has dependencies on ObjectA and database."""
|
|
|
|
def __init__(self, a, db):
|
|
"""Initializer."""
|
|
self.a = a
|
|
self.db = db
|
|
|
|
|
|
class Catalog(AbstractCatalog):
|
|
|
|
"""Catalog of objects providers."""
|
|
|
|
database = Singleton(sqlite3.Connection,
|
|
KwArg('database', ':memory:'),
|
|
Attribute('row_factory', sqlite3.Row))
|
|
""":type: (objects.Provider) -> sqlite3.Connection"""
|
|
|
|
object_a_factory = Factory(ObjectA,
|
|
KwArg('db', database))
|
|
""":type: (objects.Provider) -> ObjectA"""
|
|
|
|
object_b_factory = Factory(ObjectB,
|
|
KwArg('a', object_a_factory),
|
|
KwArg('db', database))
|
|
""":type: (objects.Provider) -> ObjectB"""
|
|
|
|
|
|
# Catalog static provides.
|
|
a1, a2 = Catalog.object_a_factory(), Catalog.object_a_factory()
|
|
b1, b2 = Catalog.object_b_factory(), Catalog.object_b_factory()
|
|
|
|
assert a1 is not a2
|
|
assert b1 is not b2
|
|
assert a1.db is a2.db is b1.db is b2.db is Catalog.database()
|
|
|
|
|
|
# Example of inline injections.
|
|
@inject(KwArg('a', Catalog.object_a_factory))
|
|
@inject(KwArg('b', Catalog.object_b_factory))
|
|
@inject(KwArg('database', Catalog.database))
|
|
def example(a, b, database):
|
|
assert a.db is b.db is database is Catalog.database()
|
|
|
|
|
|
example()
|
|
|
|
|
|
You can get more *Objects* examples in ``/examples`` directory on
|
|
GitHub:
|
|
|
|
https://github.com/rmk135/objects
|
|
|
|
|
|
Feedback
|
|
--------
|
|
|
|
Feel free to post questions, bugs, feature requests, proposals etc. on
|
|
*Objects* GitHub Issues:
|
|
|
|
https://github.com/rmk135/objects/issues
|
|
|
|
Your feedback is quite important!
|
|
|
|
|
|
.. _PyPi: https://pypi.python.org/pypi/Objects
|
|
.. _Stable version: http://objects.readthedocs.org/en/stable/
|
|
.. _Latest version: http://objects.readthedocs.org/en/latest/
|
|
.. _SLOC: http://en.wikipedia.org/wiki/Source_lines_of_code
|
|
.. _SOLID: http://en.wikipedia.org/wiki/SOLID_%28object-oriented_design%29
|
|
.. _IoC: http://en.wikipedia.org/wiki/Inversion_of_control
|
|
.. _dependency injection: http://en.wikipedia.org/wiki/Dependency_injection
|