Multipart POST request Google Glass

问题

I am trying to add an attachment to my timeline with the multipart encoding. I've been doing something like the following:

req = urllib2.Request(url,data={body}, header={header})
resp = urllib2.urlopen(req).read()

And it has been working fine for application/json. However, I'm not sure how to format the body for multipart. I've also used some libraries: requests and poster and they both return 401 for some reason.

How can I make a multipart request either with a libary(preferably a plug-in to urllib2) or with urllib2 itself (like the block of code above)?

EDIT: I also would like this to be able to support the mirror-api "video/vnd.google-glass.stream-url" from https://developers.google.com/glass/timeline

For the request using poster library here is the code:

register_openers()
datagen, headers = multipart_encode({'image1':open('555.jpg', 'rb')})

Here it is using requets:

headers = {'Authorization' : 'Bearer %s' % access_token}
files = {'file': open('555.jpg', 'rb')}
r = requests.post(timeline_url,files=files, headers=headers)

Returns 401 -> header

Thank you

回答1:

There is a working Curl example of a multipart request that uses the streaming video url feature here:

Previous Streaming Video Answer with Curl example

It does exactly what you are trying to do, but with Curl. You just need to adapt that to your technology stack.

The 401 you are receiving is going to prevent you even if you use the right syntax. A 401 response indicates you do not have authorization to modify the timeline. Make sure you can insert a simple hello world text only card first. Once you get past the 401 error and get into parsing errors and format issues the link above should be everything you need.

One last note, you don't need urllib2, the Mirror API team dropped a gem of a feature in our lap and we don't need to be bothered with getting the binary of the video, check that example linked above I only provided a URL in the multipart payload, no need to stream the binary data! Google does all the magic in XE6 and above for us.

Thanks Team Glass!

I think you will find this is simpler than you think. Try out the curl example and watch out for incompatible video types, when you get that far, if you don't use a compatible type it will appear not to work in Glass, make sure your video is encoded in a Glass friendly format.

Good luck!

回答2:

How to add an attachment to a timeline with multipart encoding:

The easiest way to add attachments with multipart encoding to a timeline is to use the Google APIs Client Library for Python. With this library, you can simple use the following example code provided in the Mirror API timeline insert documentation (click the Python tab under Examples).

from apiclient.discovery import build
service = build('mirror', 'v1')

def insert_timeline_item(service, text, content_type=None, attachment=None,
                         notification_level=None):
  timeline_item = {'text': text}
  media_body = None
  if notification_level:
    timeline_item['notification'] = {'level': notification_level}
  if content_type and attachment:
    media_body = MediaIoBaseUpload(
        io.BytesIO(attachment), mimetype=content_type, resumable=True)
  try:
    return service.timeline().insert(
        body=timeline_item, media_body=media_body).execute()
  except errors.HttpError, error:
    print 'An error occurred: %s' % error

You cannot actually use requests or poster to automatically encode your data, because these libraries encode things in multipart/form-data whereas Mirror API wants things in multipart/related.

How to debug your current error code:

Your code gives a 401, which is an authorization error. This means you are probably failing to include your access token with your requests. To include an access token, set the Authorization field to Bearer: YOUR_ACCESS_TOKEN in your request (documentation here).

If you do not know how to get an access token, the Glass developer docs has a page here explaining how to obtain an access token. Make sure that your authorization process requested the following scope for multipart-upload, otherwise you will get a 403 error. https://www.googleapis.com/auth/glass.timeline

回答3:

This is how I did it and how the python client library does it.

from email.mime.multipart import MIMEMultipart
from email.mime.nonmultipart import MIMENonMultipart
from email.mime.image import MIMEImage

mime_root = MIMEMultipart('related', '===============xxxxxxxxxxxxx==')
headers= {'Content-Type': 'multipart/related; '
          'boundary="%s"' % mime_root.get_boundary(),
          'Authorization':'Bearer %s' % access_token}
setattr(mime_root, '_write_headers', lambda self: None)
#Create the metadata part of the MIME
mime_text = MIMENonMultipart(*['application','json'])
mime_text.set_payload("{'text':'waddup doe!'}")
print "Attaching the json"
mime_root.attach(mime_text)

if method == 'Image':
    #DO Image
    file_upload = open('555.jpg', 'rb')
    mime_image = MIMENonMultipart(*['image', 'jpeg'])
    #add the required header
    mime_image['Content-Transfer-Encoding'] = 'binary'
    #read the file as binary
    mime_image.set_payload(file_upload.read())
    print "attaching the jpeg"
    mime_root.attach(mime_image)

elif method == 'Video':
    mime_video = MIMENonMultipart(*['video', 'vnd.google-glass.stream-url'])
    #add the payload
    mime_video.set_payload('https://dl.dropboxusercontent.com/u/6562706/sweetie-wobbly-cat-720p.mp4')
    mime_root.attach(mime_video)

Mark Scheel I used your video for testing purposes :) Thank you.

来源：https://stackoverflow.com/questions/17536127/multipart-post-request-google-glass

标签

python

django

google-mirror-api