python-dependency-injector/README.rst

Objects
=======

Dependency management tool for Python projects

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| *PyPi*                                | .. image:: https://pypip.in/version/Objects/badge.svg             |
|                                       |    :target: https://pypi.python.org/pypi/Objects/                 |
|                                       |    :alt: Latest Version                                           |
|                                       | .. image:: https://pypip.in/download/Objects/badge.svg            |
|                                       |    :target: https://pypi.python.org/pypi/Objects/                 |
|                                       |    :alt: Downloads                                                |
|                                       | .. image:: https://pypip.in/license/Objects/badge.svg             |
|                                       |    :target: https://pypi.python.org/pypi/Objects/                 |
|                                       |    :alt: License                                                  |
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| *Python versions and implementations* | .. image:: https://pypip.in/py_versions/Objects/badge.svg         |
|                                       |    :target: https://pypi.python.org/pypi/Objects/                 |
|                                       |    :alt: Supported Python versions                                |
|                                       | .. image:: https://pypip.in/implementation/Objects/badge.svg      |
|                                       |    :target: https://pypi.python.org/pypi/Objects/                 |
|                                       |    :alt: Supported Python implementations                         |
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| *Builds and test 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                                          |
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Introduction
------------

Python ecosystem consists of a big amount of various classes, functions and
objects 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 amount of objects and their dependencies
also increased extremely fast and became hard to maintain.

*Objects* is designed to be developer's friendly tool for managing 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 Singleton
    from objects.providers import NewInstance

    from objects.injections import KwArg
    from objects.injections import Attribute
    from objects.injections 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 = NewInstance(ObjectA,
                               KwArg('db', database))
        """:type: (objects.Provider) -> ObjectA"""

        object_b = NewInstance(ObjectB,
                               KwArg('a', object_a),
                               KwArg('db', database))
        """:type: (objects.Provider) -> ObjectB"""


    # Catalog static provides.
    a1, a2 = Catalog.object_a(), Catalog.object_a()
    b1, b2 = Catalog.object_b(), Catalog.object_b()

    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))
    @inject(KwArg('b', Catalog.object_b))
    @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/