SuspiciousOperation when using S3

[andreiavram]

There's a catch when using S3 as your storage backend - saving and retrieving photos works as you would expect, but when trying to clear the cache folder (for example after rotating the photo) and maybe in some other cases, _get_SIZE_filename() is called, and that in turn returns a path based on MEDIA_ROOT - causing a SuspiciousOperation at least in Django 1.4 and above.

The code in issue is in photologue/models.py:

    def _get_SIZE_filename(self, size):
        photosize = PhotoSizeCache().sizes.get(size)
        generator = PhotologueSpec(photo=self, photosize=photosize)
        return os.path.join(settings.MEDIA_ROOT, generator.cachefile_name)

For my use case, where I needed to be able to delete cached sized versions of images, overriding the _get_SIZE_filename method with something like

    def _get_SIZE_filename(self, size):
        photosize = PhotoSizeCache().sizes.get(size)
        generator = PhotologueSpec(photo=self, photosize=photosize)
        return generator.cachefile_name

but there should be a better way of dealing with this in an storage independent kind of way.