79 lines
3.0 KiB
Plaintext
79 lines
3.0 KiB
Plaintext
|
.. _howto-custom-file-storage:
|
||
|
|
|
||
|
|
Writing a custom storage system
|
||
|
|
===============================
|
||
|
|
|
||
|
|
If you need to provide custom file storage -- a common example is storing files
|
||
|
|
on some remote system -- you can do so by defining a custom storage class.
|
||
|
|
You'll need to follow these steps:
|
||
|
|
|
||
|
|
#. Your custom storage system must be a subclass of
|
||
|
|
``django.core.files.storage.Storage``::
|
||
|
|
|
||
|
|
from django.core.files.storage import Storage
|
||
|
|
|
||
|
|
class MyStorage(Storage):
|
||
|
|
...
|
||
|
|
|
||
|
|
#. Django must be able to instantiate your storage system without any arguments.
|
||
|
|
This means that any settings should be taken from ``django.conf.settings``::
|
||
|
|
|
||
|
|
from django.conf import settings
|
||
|
|
from django.core.files.storage import Storage
|
||
|
|
|
||
|
|
class MyStorage(Storage):
|
||
|
|
def __init__(self, option=None):
|
||
|
|
if not option:
|
||
|
|
option = settings.CUSTOM_STORAGE_OPTIONS
|
||
|
|
...
|
||
|
|
|
||
|
|
#. Your storage class must implement the ``_open()`` and ``_save()`` methods,
|
||
|
|
along with any other methods appropriate to your storage class. See below for
|
||
|
|
more on these methods.
|
||
|
|
|
||
|
|
In addition, if your class provides local file storage, it must override
|
||
|
|
the ``path()`` method.
|
||
|
|
|
||
|
|
Your custom storage system may override any of the storage methods explained in
|
||
|
|
:ref:`ref-files-storage`. However, it's usually better to use the hooks
|
||
|
|
specifically designed for custom storage objects. These are:
|
||
|
|
|
||
|
|
``_open(name, mode='rb')``
|
||
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||
|
|
|
||
|
|
**Required**.
|
||
|
|
|
||
|
|
Called by ``Storage.open()``, this is the actual mechanism the storage class
|
||
|
|
uses to open the file. This must return a ``File`` object, though in most cases,
|
||
|
|
you'll want to return some subclass here that implements logic specific to the
|
||
|
|
backend storage system.
|
||
|
|
|
||
|
|
``_save(name, content)``
|
||
|
|
~~~~~~~~~~~~~~~~~~~~~~~~
|
||
|
|
|
||
|
|
Called by ``Storage.save()``. The ``name`` will already have gone through
|
||
|
|
``get_valid_name()`` and ``get_available_name()``, and the ``content`` will be a
|
||
|
|
``File`` object itself. No return value is expected.
|
||
|
|
|
||
|
|
``get_valid_name(name)``
|
||
|
|
------------------------
|
||
|
|
|
||
|
|
Returns a filename suitable for use with the underlying storage system. The
|
||
|
|
``name`` argument passed to this method is the original filename sent to the
|
||
|
|
server, after having any path information removed. Override this to customize
|
||
|
|
how non-standard characters are converted to safe filenames.
|
||
|
|
|
||
|
|
The code provided on ``Storage`` retains only alpha-numeric characters, periods
|
||
|
|
and underscores from the original filename, removing everything else.
|
||
|
|
|
||
|
|
``get_available_name(name)``
|
||
|
|
----------------------------
|
||
|
|
|
||
|
|
Returns a filename that is available in the storage mechanism, possibly taking
|
||
|
|
the provided filename into account. The ``name`` argument passed to this method
|
||
|
|
will have already cleaned to a filename valid for the storage system, according
|
||
|
|
to the ``get_valid_name()`` method described above.
|
||
|
|
|
||
|
|
The code provided on ``Storage`` simply appends underscores to the filename
|
||
|
|
until it finds one that's available in the destination directory.
|