I am trying to upload images using google-app-engine with Python. i tried the example from https://developers.google.com/appengine/docs/python/images/usingimages " Can anyone explain me how can i upload images using using google-app-engine? Thank you!
Logs:
File "C:\\Program Files\\Google\\google_appengine\\google\\appengine\\api\\datastore_types.py", line 382, in __ init __ raise datastore_errors.BadKeyError('Invalid string key %s.' % encoded)
BadKeyError: Invalid string key
The Code:
import cgi
import datetime
import urllib
import webapp2
from google.appengine.ext import db
from google.appengine.api import images
from google.appengine.api import users
class Greeting(db.Model):
"""Models a Guestbook entry with an author, content, avatar, and date."""
author = db.StringProperty()
content = db.StringProperty(multiline=True)
avatar = db.BlobProperty()
date = db.DateTimeProperty(auto_now_add=True)
def guestbook_key(guestbook_name=None):
"""Constructs a Datastore key for a Guestbook entity with guestbook_name."""
return db.Key.from_path('Guestbook', guestbook_name or 'default_guestbook')
class MainPage(webapp2.RequestHandler):
def get(self):
self.response.out.write('<html><body>')
guestbook_name=self.request.get('guestbook_name')
greetings = db.GqlQuery('SELECT * '
'FROM Greeting '
'WHERE ANCESTOR IS :1 '
'ORDER BY date DESC LIMIT 10',
guestbook_key(guestbook_name))
for greeting in greetings:
if greeting.author:
self.response.out.write(
'<b>%s</b> wrote:' % greeting.author)
else:
self.response.out.write('An anonymous person wrote:')
self.response.out.write('<div><img src="img?img_id=%s"></img>' %
greeting.key())
self.response.out.write('<blockquote>%s</blockquote></div>' %
cgi.escape(greeting.content))
self.response.out.write("""
<form action="/sign?%s" enctype="multipart/form-data" method="post">
<div><textarea name="content" rows="3" cols="60"></textarea></div>
<div><label>Avatar:</label></div>
<div><input type="file" name="img"/></div>
<div><input type="submit" value="Sign Guestbook"></div>
</form>
<hr>
<form>Guestbook name: <input value="%s" name="guestbook_name">
<input type="submit" value="switch"></form>
</body>
</html>""" % (urllib.urlencode({'guestbook_name': guestbook_name}),
cgi.escape(guestbook_name)))
class Image(webapp2.RequestHandler):
def get(self):
greeting = db.get(self.request.get('img_id'))
if greeting.avatar:
self.response.headers['Content-Type'] = 'image/png'
self.response.out.write(greeting.avatar)
else:
self.response.out.write('No image')
class Guestbook(webapp2.RequestHandler):
def post(self):
guestbook_name = self.request.get('guestbook_name')
greeting = Greeting(parent=guestbook_key(guestbook_name))
if users.get_current_user():
greeting.author = users.get_current_user().nickname()
greeting.content = self.request.get('content')
avatar = images.resize(self.request.get('img'), 32, 32)
greeting.avatar = db.Blob(avatar)
greeting.put()
self.redirect('/?' + urllib.urlencode(
{'guestbook_name': guestbook_name}))
app = webapp2.WSGIApplication([('/', MainPage),
('/img', Image),
('/sign', Guestbook)],
debug=True)
You are using Jinja-like params but you are not populating any template, instead you are formatting a string with python:
self.response.out.write("""
<form action="/sign?%s" enctype="multipart/form-data" method="post">
<div><textarea name="content" rows="3" cols="60"></textarea></div>
<div><label>Avatar:</label></div>
<div><input type="file" name="img"/></div>
<div><input type="submit" value="Sign Guestbook"></div>
</form>
<hr>
<form>Guestbook name: <input value="%s" name="guestbook_name">
<input type="submit" value="switch"></form>
</body>
</html>""" % (urllib.urlencode({'guestbook_name': guestbook_name}),
cgi.escape(guestbook_name)))
Note that you say urrlib.urlenconde({'guestbook_name': guestbook_name})
where python is just needing a string: guestbook_name
. Also, given that you are using the same value for all placeholders you can use instead
"...<input value="%(guestbook)s" name..." % {'guestbook': cgi.escape(guestbook_name)})
or
"...<input value="{0}" name... ...</html>".format(cgi.escape(guestbook_name))
Hope it helps.
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