FileSystemStorage.save should support any file-like objects

[Vlastimil Zíma]

I propose generic support of FileSystemStorage.save(), so content argument can be any object with read([size]) method.

I see no reason why FileSystemStorage does not support regular file-like objects. IT is common practise to support any file-like objects in python libraries, where file-like object is an argument.

Blocker of this is content.chunks() call which itself is nothing else then generator over file.read(chunk_size). Storage itself could easily call content.read(chunk_size) directly which grants support to various file-like objects.

Calls like this are just weird:

storage.save(target, File(open(filename)))

The File objects is here only because it has chunks() method required by FileSystemStorage.save() call.

I have seen #8204 but I do not require anything so specific. It is just painful, when you want to use storage for anything else than file from query or form.

[Claude Paroz]

In #15644, we added support for file-like objects to the File wrapper. Do you think it is still too much to call storage.save(target, File(<file-like-object>))?

[Vlastimil Zíma]

Replying to claudep:

In #15644, we added support for file-like objects to the File wrapper. Do you think it is still too much to call storage.save(target, File(<file-like-object>))?

Yes. It is seems fairly excessive - you make File object from file object - only to provide chunks() method. Also this is not a solution for other file-like objects, e.g. StringIO.

[Claude Paroz]

Wrapping StringIO in a File object should work. Report it as a separate ticket if you can show that it does not.

Maybe the simplest fix would be to wrap content in a File object if it has no chunks method. This would preserve compatibility in the case someone passes a custom content instance (which might implement chunks in a non-standard way).

[Marcin Biernat]

​https://github.com/django/django/pull/775

[Honza Král <Honza.Kral@…>]

In 129d2e8f85b1e80f10ec967b72ba0af9b239019f:

Merge pull request #775 from HiddenData/ticket-18899

Fixed #18899 -- FileSystemStorage.save should support any file-like objects

[Tim Graham <timograham@…>]

In 3f16e4df:

Fixed #27145 -- Updated Storage.save() docs for refs #18899.

[Tim Graham <timograham@…>]

In f79dce16:

[1.10.x] Fixed #27145 -- Updated Storage.save() docs for refs #18899.

Backport of 3f16e4df494dc9143d110b886c8e8608f9d2b584 from master