Contributions
=============

All contributions and third party integrations live inside
``django_pgschemas.contrib``.

If you want to implement an integration with other Django packages, please
submit a pull request containing:

* The code for your integration.
* The tests for your integration.
* The docs for your integration in this section of the documentation.

We're striving to maintain/increase our code coverage, but please, make sure your
integration is properly tested. Proper tests will always beat meaningless 100%
coverage.

Caching
-------

In order to generate tenant aware cache keys, we provide
``django_pgschemas.contrib.cache.make_key`` which can be used as
``KEY_FUNCTION``:

.. code-block:: python

    CACHES = {
        "default": {
            # ...
            "KEY_FUNCTION": "django_pgschemas.contrib.cache.make_key",
        }
    }


Tenant aware file system storage
--------------------------------

We provide a tenant aware file system storage at
``django_pgschemas.contrib.files.TenantFileSystemStorage``. It subclasses
``django.core.files.storage.FileSystemStorage`` and behaves like it in every
aspect, except that it prepends a tenant identifier to the path and URL of all
files.

By default, the tenant identifier is the schema name of the current tenant. In
order to override this behavior, it is possible to provide a different
identifier. The storage will consider these options when looking for an
identifier:

* A method called ``schema_pathname`` in the current tenant. This method must
  accept no arguments and return an identifier.
* A function specified in a setting called ``PGSCHEMAS_PATHNAME_FUNCTION``. This
  function must accept a schema descriptor and return an identifier.
* Finally, the identifier will default to the schema name of the current tenant.

In the case of the URL returned from the storage, if the storage detects that
the current schema has been routed via subfolder, it won't prepend the schema
identifier, because it considers that the path is properly disambiguated as is.
This means that instead of something like::

    /tenant1/static/tenant1/path/to/file.txt

It will generate::

    /tenant1/static/path/to/file.txt

This storage class is a convenient way of storing media files in a folder
structure organized at the top by tenants, as well as providing a perceived
tenant centric organization in the URLs that are generated. However, this
storage class does NOT provide any form of security, such as controlling that
from one tenant, files from another tenant are not accessible. Such security
requirements have other implications that fall out of the scope of this basic
utility.

.. tip::

    In a project that requires airtight security, you might want to use and
    customize `django-private-storage`_.

.. _django-private-storage: https://github.com/edoburu/django-private-storage

Channels (websockets)
---------------------

We provide a tenant aware protocol router for using with ``channels``. You can
use it as follows:

.. code-block:: python

    # routing.py

    from django_pgschemas.contrib.channels2 import TenantProtocolRouter

    application = TenantProtocolRouter()

    # settings.py

    ASGI_APPLICATION = "routing.application"

It requires that you also route the websockets requests, at least for the
dynamic tenants. If you don't route websocket requests for static tenants, the
dynamic route will be used:

.. code-block:: python

    TENANTS = {
        # ...
        "default": {
            # ...
            "URLCONF": "tenant_app.urls",
            "WS_URLCONF": "tenant_app.ws_urls",
        }
    }

You still need to name your channel groups appropriately, taking the
current tenant into account if you want to keep your groups tenant-specific.
You will get the current tenant in ``scope["tenant"]``.

For Channels 3 to use with Django 3+, you can use
``django_pgschemas.contrib.channels3``.

.. attention::

    This module is NOT included in the test battery of the package.
    Please, create a `GitHub issue`_ for any errors you may find.

.. _GitHub issue: https://github.com/lorinkoz/django-pgschemas/issues
