在 Google App Engine 上使用文本数据库 (text_db) 和 AuthSub 从电子表格中读取数据时遇到问题。按照《使用 AuthSub 和文本数据库进行数据获取》和《使用 App Engine 读取电子表格》两篇文章中的说明进行操作后，将这两篇文章中的代码合并到同一个文件中，但在本地运行时出现错误。错误信息是：“DownloadError: ApplicationError: 2 nonnumeric port: ''”。
2. 解决方案
要解决此问题，需要在运行客户端对象之前调用 gdata.alt.appengine.run_on_appengine() 以注册客户端。此外，还需要修改 auth_url 行，将范围 URL 传递给 GenerateAuthSubURL() 方法，而不是将其作为单独的参数传递。
以下是修改后的代码：
import wsgiref.handlers
import cgi
from google.appengine.ext import webapp
from google.appengine.api import users
import atom.url
import gdata.service
import gdata.alt.appengine
import gdata.spreadsheet.text_db
import settings
class Fetcher(webapp.RequestHandler):
def get(self):
# Write our pages title
self.response.out.write("""<html><head><title>
Google Data Feed Fetcher: read Google Data API Atom feeds</title>""")
self.response.out.write('</head><body>')
next_url = atom.url.Url('http', settings.HOST_NAME, path='/step4')
# Allow the user to sign in or sign out
if users.get_current_user():
self.response.out.write('<a href="%s">Sign Out</a><br>' % (
users.create_logout_url(str(next_url))))
else:
self.response.out.write('<a href="%s">Sign In</a><br>' % (
users.create_login_url(str(next_url))))
# Initialize a client to talk to Google Data API services.
client = gdata.spreadsheet.text_db.DatabaseClient()
auth_url = client._GetDocsClient().GenerateAuthSubURL(
next_url,
('http://spreadsheets.google.com/feeds/', 'http://docs.google.com/feeds/documents/'), secure=False, session=True)
# Register the client with the App Engine SDK.
gdata.alt.appengine.run_on_appengine(client)
gdata.alt.appengine.run_on_appengine(client._GetDocsClient())
gdata.alt.appengine.run_on_appengine(client._GetSpreadsheetsClient())
feed_url = self.request.get('feed_url')
session_token = None
# Find the AuthSub token and upgrade it to a session token.
auth_token = gdata.auth.extract_auth_sub_token_from_url(self.request.uri)
if auth_token:
# Upgrade the single-use AuthSub token to a multi-use session token.
client._GetDocsClient().SetAuthSubToken(auth_token)
session_token = client._GetDocsClient().UpgradeToSessionToken(auth_token) #If I don't pass this argument I get a NonAuthSubToken
client._GetSpreadsheetsClient().SetAuthSubToken(client._GetDocsClient().GetAuthSubToken())
# session_token = client.upgrade_to_session_token(auth_token)
if session_token and users.get_current_user():
# If there is a current user, store the token in the datastore and
# associate it with the current user. Since we told the client to
# run_on_appengine, the add_token call will automatically store the
# session token if there is a current_user.
client.token_store.add_token(session_token)
elif session_token:
# Since there is no current user, we will put the session token
# in a property of the client. We will not store the token in the
# datastore, since we wouldn't know which user it belongs to.
# Since a new client object is created with each get call, we don't
# need to worry about the anonymous token being used by other users.
client.current_token = session_token
self.response.out.write('<div id="main">')
self.fetch_feed(client, feed_url)
self.response.out.write('</div>')
self.response.out.write(
'<div id="sidebar"><div id="scopes"><h4>Request a token</h4><ul>')
self.response.out.write('<li><a href="%s">Google Documents</a></li>' % (auth_url))
self.response.out.write('</ul></div><br/><div id="tokens">')
def fetch_feed(self, client, feed_url):
# Attempt to fetch the feed.
if not feed_url:
self.response.out.write(
'No feed_url was specified for the app to fetch.<br/>')
example_url = atom.url.Url('http', settings.HOST_NAME, path='/step4',
params={'feed_url':
'http://docs.google.com/feeds/documents/private/full'}
).to_string()
self.response.out.write('Here's an example query which will show the'
' XML for the feed listing your Google Documents <a '
'href="%s">%s</a>' % (example_url, example_url))
return
try:
response = client.Get(feed_url, converter=str)
self.response.out.write(cgi.escape(response))
except gdata.service.RequestError, request_error:
# If fetching fails, then tell the user that they need to login to
# authorize this app by logging in at the following URL.
if request_error[0]['status'] == 401:
# Get the URL of the current page so that our AuthSub request will
# send the user back to here.
next = atom.url.Url('http', settings.HOST_NAME, path='/step4',
params={'feed_url': feed_url})
# If there is a current user, we can request a session token, otherwise
# we should ask for a single use token.
auth_sub_url = client.GenerateAuthSubURL(next, feed_url,
secure=False, session=True)
self.response.out.write('<a href="%s">' % (auth_sub_url))
self.response.out.write(
'Click here to authorize this application to view the feed</a>')
else:
self.response.out.write(
'Something went wrong, here is the error object: %s ' % (
str(request_error[0])))
def main():
application = webapp.WSGIApplication([('/.*', Fetcher),], debug=True)
wsgiref.handlers.CGIHandler().run(application)
if __name__ == '__main__':
main()
注意：在修改后的代码中，auth_url 行已更改为：
auth_url = client._GetDocsClient().GenerateAuthSubURL(
next_url,
('http://spreadsheets.google.com/feeds/', 'http://docs.google.com/feeds/documents/'), secure=False, session=True)
并且添加了以下代码来注册客户端：
gdata.alt.appengine.run_on_appengine(client)
gdata.alt.appengine.run_on_appengine(client._GetDocsClient())
gdata.alt.appengine.run_on_appengine(client._GetSpreadsheetsClient())
