Currently translated at 70.9% (554 of 781)

Build full set of updates and push them to backend just once

Currently translated at 70.9% (554 of 781)

Using class attribute seems more readable than self.get_file_format().

Currently translated at 70.7% (552 of 781)

As response handling has changed in Django 1.5, current approach no
longer works. In future we should use StreamingHttpResponse class, but
as this is available only since Django 1.5, it should be done once we're
ready to drop 1.4 support.

Since Django 1.5 CommandError is raised further instead of changing it
to SystemExist as was the case before.