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