pass extra content-type values to file upload handlers

[Waldemar Kornewald]

Currently, file upload handlers can only get the actual content type and charset, but App Engine's Blobstore file service passes a few extra vales to the content type which are needed to get the uploaded file's identifier ("blob-key"). Here's a sample snippet of an HTTP upload request's POST data:

--===============0880245784==
Content-Type: message/external-body; blob-key="WEexn9L82wky30ADBOWqYA=="; access-type="X-AppEngine-BlobKey"
MIME-Version: 1.0
Content-Disposition: form-data; name="file"; filename="django-nonrel.diff"

Content-Type: application/octet-stream
MIME-Version: 1.0
Content-Length: 8522
content-type: application/octet-stream
content-disposition: form-data; name="file"; filename="django-nonrel.diff"
X-AppEngine-Upload-Creation: 2010-06-08 15:34:32.685000


--===============0880245784==--

The attached patch changes the file upload handling code such that it passes a dictionary with all extra content type arguments to the upload handler. With this I was able to successfully upload files to a model's FileField via a ModelForm.

[Adam Nelson]

It seems like you could use this definition:

def new_file(self, field_name, file_name, content_type, content_length, 
	            charset=None, content_type_extra={}):

Then you wouldn't have to check if content_type_extra is None.

[Waldemar Kornewald]

Maybe it's fine with a .copy(), but then that's an unnecessary copy. Normally, I don't pass mutable objects as default arguments because that can lead to hidden, hard to track bugs, so I've just settled on always using None. Is this a show-stopper? :)

[Adam Nelson]

Good point, we should add that to the style guide:

​http://www.network-theory.co.uk/docs/pytut/DefaultArgumentValues.html

Nevertheless, this ticket needs to be approved by a committer first.

[Waldemar Kornewald]

Still no response from a committer? :(
Is something missing?

[Waldemar Kornewald]

What does it take to get this committed into trunk? This change is absolutely necessary for App Engine's Blobstore and it's a really harmless change.

[Łukasz Rekucki]

Probably a simple test case and some docs for people that need this. I see no obvious reason not to do this.

[Waldemar Kornewald]

patch (with unit tests and docs)

[Waldemar Kornewald]

Done. I've added a simple test case and docs. Do you need anything else before it can be committed?

[patchhammer]

content_type_extra.diff fails to apply cleanly on to trunk

[Waldemar Kornewald]

patch against trunk

[Waldemar Kornewald]

I've updated the patch.

[Jacob]

Milestone 1.4 deleted

[grant.callaghan@…]

+1. I would really like to see this patch applied

[mvschaik]

Updated patch to apply to current master

[Benjamin Kagia]

line 34 and 35 of the patch are made redundant by the previous line:

content_type_extra = meta_data.get('content-type', (0, {}))[1]

content_type_extra is then guaranteed not to be None.

[Benjamin Kagia]

@mvschaik are you still working on this? You may want to take a look at this ​my branch

[Tim Graham]

Edited version of kagia's branch: ​https://github.com/django/django/pull/1301

[Tim Graham <timograham@…>]

In b0953dc91385fb2823294a76d3c99e01c7b7e4ee:

Fixed #13721 -- Added UploadedFile.content_type_extra.

Thanks Waldemar Kornewald and mvschaik for work on the patch.

[Tim Graham <timograham@…>]

In d3e33fff12266b51ab1488f7094855aef6061e9e:

Made content_type_extra optional for TemporaryUploadedFile and MemoryUploadedFile.

This provides better backwards compatibility for those constructing these
objects manually.

Refs #13721.

[Gabe]

Hi guys!

I'm using Django 1.5 with Python 2.7 running in Google App Engine. I got into this project recently, the former programmers didn't use the webapp framework, but now I have to be able to make file upload possible with large files (GAE doesn't allow more than 1 MB). I tried to make blobstore work, but I couldn't, then I started looking into this stuff and found this patch. Is it possible to make this patch work with GAE?

Thanks in advance!

Gabe

[Tim Graham]

Hi Gabe, this ticket trackers isn't a support channel. Please see ​https://docs.djangoproject.com/en/stable/faq/help/ for ways to get help. Thanks!