tutorial/example of multipart/form-data

[Andrew Smolik]

Hi,

I'm new to django-rest-framework and I'm having a hard time figuring out how to upload a file via the api. I've done a lot of searching on google but there are no examples. Is it possible to create a multipart/form-data example and post it to github? It would be greatly appreciated.

Thanks,

Andrew

[Tom Christie]

Hi Andrew,

  What language is your client written in?

As a starter for trying out how multipart file upload works, use this simple view,

and throw some requests at it using curl and/or python requests.

    @api_view(['POST'])

    def upload_api_view(request):

        return Response({'data': request.DATA, 'files': request.FILES)

Using requests: http://docs.python-requests.org/en/latest/user/quickstart/#post-a-multipart-encoded-file

Curl: https://httpkit.com/resources/HTTP-from-the-Command-Line/#post-html-multipart

Play around with that and make sure it all makes sense.

There's no FileField/ImageField support yet, so you'll need to write the view to handle the upload yourself.

Django's file upload docs are here: https://docs.djangoproject.com/en/dev/topics/http/file-uploads/?from=olddocs

Cheers,

  Tom

[Andrew Smolik]

Hi Tom,

Thank you for the information! I've been posting to the view below and I get a 200 but the file never uploads (I don't see it in the db or filesystem). If you have time, can you provide a more detail example? It would be greatly appreciated.

Thanks,

Andrew

[Tom Christie]

The request.FILES property behaves just the same as it does with standard Django.

Cribbing some stuff from the docs: https://docs.djangoproject.com/en/dev/topics/http/file-uploads/

You can deal with the uploaded file manually, eg...

@api_view(['POST'])

    def upload_file(request):

        handle_uploaded_file(request.FILES['file'])

        return Response('uploaded')

    def handle_uploaded_file(f):

        with open('some/file/name.txt', 'wb+') as destination:

            for chunk in f.chunks():

                destination.write(chunk)

Use the UploadedFile to set the value of a FileField on a model, eg...

    @api_view(['POST'])

    def upload_file(request):

        instance = MyModelWithFileField(file_field=request.FILES['file'])

            instance.save()

            return Response('uploaded')

And, since Marko has just added support for FileFields and ImageFields (version 2.1.3), you can now also use the standard create and update generic views, or use a ModelSerializer for a model which includes a FileField or ImageField.

I would love to update the docs with some more complete examples at some point.  If you get what you want working and would consider contributing, please consider making a pull request to the documentation addressing whatever bits you think would be helpful to newcomers.

Cheers,

  t.

[Andrew Smolik]

Hi,

Thanks for your help. I was able to get it working. I created a tutorial/example of the multipart/form-data with django-rest-framwork (https://github.com/ansother/multipart-form-data_django_rest_framework_tutorial). If you would like, in late december I can probably add it to the django-rest-framework website (this is my first time contributing to an open source project). 

Also, I think it would be helpful if you could add search to the django-rest-framework. It would make navigating the site much easier. 

Thanks again,

Andrew

[greenhand]

I am new to python and DRF and thank you very much for the tutorial.

Unfortunately, I encounter an error when posting to api/upload_serializers/

The error message is:

 

TypeError at /api/upload_serializers/
object.__new__(cStringIO.StringO) is not safe, use cStringIO.StringO.__new__()
Request Method: POST
Request URL: api/upload_serializers/
Django Version: 1.4.2
Exception Type: TypeError
Exception Value: object.__new__(cStringIO.StringO) is not safe, use cStringIO.StringO.__new__()
 
Exception Location: /usr/lib/python2.7/copy_reg.py in __newobj__, line 93
Python Executable: /usr/bin/python
Python Version: 2.7.1

 

Does I miss something?

 

As for another question, what is the difference between these two APIs (/api/upload_form/ and /api/upload_serializers/)?

Andrew Smolik於 2012年11月26日星期一UTC+8下午1時22分50秒寫道：

[Dwayne Ghant]

Hey Tom,

I tried to used Andrew's code that he build from you suggestions and I keep getting the error listed below: 

------------------------------------------------------------------------------------------------------------------------

Environment:

Request Method: POST

Request URL: http://127.0.0.1:8000/upload_form/

Django Version: 1.4.2

Python Version: 2.7.3

Installed Applications:

('django.contrib.auth',

 'django.contrib.contenttypes',

 'django.contrib.sessions',

 'django.contrib.sites',

 'django.contrib.messages',

 'django.contrib.staticfiles',

 'rest_framework')

Installed Middleware:

('django.middleware.common.CommonMiddleware',

 'django.contrib.sessions.middleware.SessionMiddleware',

 'django.middleware.csrf.CsrfViewMiddleware',

 'django.contrib.auth.middleware.AuthenticationMiddleware',

 'django.contrib.messages.middleware.MessageMiddleware')

Traceback:

File "C:\Python27\lib\site-packages\django\core\handlers\base.py" in get_response

  111.                         response = callback(request, *callback_args, **callback_kwargs)

File "C:\Python27\lib\site-packages\django\views\generic\base.py" in view

  48.             return self.dispatch(request, *args, **kwargs)

File "C:\Python27\lib\site-packages\django\views\decorators\csrf.py" in wrapped_view

  77.         return view_func(*args, **kwargs)

File "C:\Python27\lib\site-packages\rest_framework\views.py" in dispatch

  363.             response = self.handle_exception(exc)

File "C:\Python27\lib\site-packages\rest_framework\views.py" in dispatch

  360.             response = handler(request, *args, **kwargs)

File "C:\Python27\lib\site-packages\rest_framework\decorators.py" in handler

  30.             return func(*args, **kwargs)

File "C:\Users\dghant\Documents\workspace-eclipse-jee-juno\PESC_webservice\PESC_webservice\views.py" in upload_form

  43.         instance = Files(docfile=request.FILES['file'], title=request.DATA['title'])

File "C:\Python27\lib\site-packages\rest_framework\request.py" in FILES

  159.             self._load_data_and_files()

File "C:\Python27\lib\site-packages\rest_framework\request.py" in _load_data_and_files

  190.             self._data, self._files = self._parse()

File "C:\Python27\lib\site-packages\rest_framework\request.py" in _parse

  274.         parsed = parser.parse(stream, media_type, self.parser_context)

File "C:\Python27\lib\site-packages\rest_framework\parsers.py" in parse

  137.             tree = ET.parse(stream)

File "C:\Python27\lib\xml\etree\ElementTree.py" in parse

  1183.     tree.parse(source, parser)

File "C:\Python27\lib\xml\etree\ElementTree.py" in parse

  656.                 parser.feed(data)

File "C:\Python27\lib\xml\etree\ElementTree.py" in feed

  1643.             self._raiseerror(v)

File "C:\Python27\lib\xml\etree\ElementTree.py" in _raiseerror

  1507.         raise err

Exception Type: ParseError at /upload_form/

Exception Value: syntax error: line 1, column 0

------------------------------------------------------------------------------------------------------------------------

Any assistance would greatly be appreciated. 

[Dwayne Ghant]

Hey Andrew,

I follow you tutorial exactly the way you instructed and received the error below: 

Your help would be deeply appreciated. 

[Andrew Smolik]

make sure these python packages are installed:

Django==1.4.2

Pygments==1.5

argparse==1.2.1

djangorestframework==2.1.6

wsgiref==0.1.2

requests==0.14.2

Markdown==2.2.0

dj-database-url==0.2.0

how are you making the post?

Andrew

[IAmIT (Michel)]

Thanx Andrew, perfect example, exactly what I was looking for!
And thanx rest framework developers for the adding of the File and ImageFields to the serializer.... what a number of codelines this is saving me!

Op maandag 26 november 2012 06:22:50 UTC+1 schreef Andrew Smolik het volgende:

[Tom Christie]

Hi Andrew, I just had a chance to look at this for the first time today - great stuff, very helpful!

If you do want to contribute some docs along these lines that'd be great.

I expect the docs would include a slimmed down version of this tut, and also a link to your repo for the full thing.

Thanks!

  Tom

[Dwayne Ghant]

Thanks Andrew,

I will make sure that all these package are installed.  To answer your question, I use 'curl' for testing all my post.

[Andrew Smolik]

You should try using the requests module in the example. I didn't test with curl. 

Thanks,

Andrew

Sent from my iPhone. Please excuse any typos. 

[Andrew Smolik]

Sure. Do you have any example docs that I can model my docs off of?

Thanks,

Andrew

Sent from my iPhone. Please excuse any typos.