Upload files in Google App Engine

Solution 1:

In fact, this question is answered in the App Egnine documentation. See an example on Uploading User Images.

HTML code, inside <form></form>:

<input type="file" name="img"/>

Python code:

class Guestbook(webapp.RequestHandler):
  def post(self):
    greeting = Greeting()
    if users.get_current_user():
      greeting.author = users.get_current_user()
    greeting.content = self.request.get("content")
    avatar = self.request.get("img")
    greeting.avatar = db.Blob(avatar)
    greeting.put()
    self.redirect('/')

Solution 2:

Here is a complete, working file. I pulled the original from the Google site and modified it to make it slightly more real world.

A few things to notice:

This code uses the BlobStore API
The purpose of this line in the ServeHandler class is to "fix" the key so that it gets rid of any name mangling that may have occurred in the browser (I didn't observe any in Chrome)
```
blob_key = str(urllib.unquote(blob_key))
```
The "save_as" clause at the end of this is important. It will make sure that the file name does not get mangled when it is sent to your browser. Get rid of it to observe what happens.
```
self.send_blob(blobstore.BlobInfo.get(blob_key), save_as=True)
```

Good Luck!

import os
import urllib

from google.appengine.ext import blobstore
from google.appengine.ext import webapp
from google.appengine.ext.webapp import blobstore_handlers
from google.appengine.ext.webapp import template
from google.appengine.ext.webapp.util import run_wsgi_app

class MainHandler(webapp.RequestHandler):
    def get(self):
        upload_url = blobstore.create_upload_url('/upload')
        self.response.out.write('<html><body>')
        self.response.out.write('<form action="%s" method="POST" enctype="multipart/form-data">' % upload_url)
        self.response.out.write("""Upload File: <input type="file" name="file"><br> <input type="submit" name="submit" value="Submit"> </form></body></html>""")

        for b in blobstore.BlobInfo.all():
            self.response.out.write('<li><a href="/serve/%s' % str(b.key()) + '">' + str(b.filename) + '</a>')

class UploadHandler(blobstore_handlers.BlobstoreUploadHandler):
    def post(self):
        upload_files = self.get_uploads('file')
        blob_info = upload_files[0]
        self.redirect('/')

class ServeHandler(blobstore_handlers.BlobstoreDownloadHandler):
    def get(self, blob_key):
        blob_key = str(urllib.unquote(blob_key))
        if not blobstore.get(blob_key):
            self.error(404)
        else:
            self.send_blob(blobstore.BlobInfo.get(blob_key), save_as=True)

def main():
    application = webapp.WSGIApplication(
          [('/', MainHandler),
           ('/upload', UploadHandler),
           ('/serve/([^/]+)?', ServeHandler),
          ], debug=True)
    run_wsgi_app(application)

if __name__ == '__main__':
  main()

Upload files in Google App Engine

Solution 1:

Solution 2:

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