Just a stupid question because I am trying to understand this code.
For example, if BaseRequestHandler is called, each function below is called one by one in order? dispatch -> jinja2 -> session -> auth.....
# -*- coding: utf-8 -*-
import logging
import secrets
import webapp2
from webapp2_extras import auth, sessions, jinja2
from jinja2.runtime import TemplateNotFound
from simpleauth import SimpleAuthHandler
class BaseRequestHandler(webapp2.RequestHandler):
def dispatch(self):
# Get a session store for this request.
self.session_store = sessions.get_store(request=self.request)
try:
# Dispatch the request.
webapp2.RequestHandler.dispatch(self)
finally:
# Save all sessions.
self.session_store.save_sessions(self.response)
@webapp2.cached_property
def jinja2(self):
"""Returns a Jinja2 renderer cached in the app registry"""
return jinja2.get_jinja2(app=self.app)
@webapp2.cached_property
def session(self):
"""Returns a session using the default cookie key"""
return self.session_store.get_session()
@webapp2.cached_property
def auth(self):
return auth.get_auth()
@webapp2.cached_property
def current_user(self):
"""Returns currently logged in user"""
user_dict = self.auth.get_user_by_session()
return self.auth.store.user_model.get_by_id(user_dict['user_id'])
@webapp2.cached_property
def logged_in(self):
"""Returns true if a user is currently logged in, false otherwise"""
return self.auth.get_user_by_session() is not None
def render(self, template_name, template_vars={}):
# Preset values for the template
values = {
'url_for': self.uri_for,
'logged_in': self.logged_in,
'flashes': self.session.get_flashes()
}
# Add manually supplied template values
values.update(template_vars)
# read the template or 404.html
try:
self.response.write(self.jinja2.render_template(template_name, **values))
except TemplateNotFound:
self.abort(404)
def head(self, *args):
"""Head is used by Twitter. If not there the tweet button shows 0"""
pass
class RootHandler(BaseRequestHandler):
def get(self):
"""Handles default langing page"""
self.render('home.html')
class ProfileHandler(BaseRequestHandler):
def get(self):
"""Handles GET /profile"""
if self.logged_in:
self.render('profile.html', {
'user': self.current_user,
'session': self.auth.get_user_by_session()
})
else:
self.redirect('/')
class AuthHandler(BaseRequestHandler, SimpleAuthHandler):
"""Authentication handler for OAuth 2.0, 1.0(a) and OpenID."""
# Enable optional OAuth 2.0 CSRF guard
OAUTH2_CSRF_STATE = True
USER_ATTRS = {
'facebook' : {
'id' : lambda id: ('avatar_url',
'http://graph.facebook.com/{0}/picture?type=large'.format(id)),
'name' : 'name',
'link' : 'link'
},
'google' : {
'picture': 'avatar_url',
'name' : 'name',
'link' : 'link'
},
'windows_live': {
'avatar_url': 'avatar_url',
'name' : 'name',
'link' : 'link'
},
'twitter' : {
'profile_image_url': 'avatar_url',
'screen_name' : 'name',
'link' : 'link'
},
'linkedin' : {
'picture-url' : 'avatar_url',
'first-name' : 'name',
'public-profile-url': 'link'
},
'openid' : {
'id' : lambda id: ('avatar_url', '/img/missing-avatar.png'),
'nickname': 'name',
'email' : 'link'
}
}
def _on_signin(self, data, auth_info, provider):
"""Callback whenever a new or existing user is logging in.
data is a user info dictionary.
auth_info contains access token or oauth token and secret.
"""
auth_id = '%s:%s' % (provider, data['id'])
logging.info('Looking for a user with id %s', auth_id)
user = self.auth.store.user_model.get_by_auth_id(auth_id)
_attrs = self._to_user_model_attrs(data, self.USER_ATTRS[provider])
if user:
logging.info('Found existing user to log in')
# Existing users might've changed their profile data so we update our
# local model anyway. This might result in quite inefficient usage
# of the Datastore, but we do this anyway for demo purposes.
#
# In a real app you could compare _attrs with user's properties fetched
# from the datastore and update local user in case something's changed.
user.populate(**_attrs)
user.put()
self.auth.set_session(
self.auth.store.user_to_dict(user))
else:
# check whether there's a user currently logged in
# then, create a new user if nobody's signed in,
# otherwise add this auth_id to currently logged in user.
if self.logged_in:
logging.info('Updating currently logged in user')
u = self.current_user
u.populate(**_attrs)
# The following will also do u.put(). Though, in a real app
# you might want to check the result, which is
# (boolean, info) tuple where boolean == True indicates success
# See webapp2_extras.appengine.auth.models.User for details.
u.add_auth_id(auth_id)
else:
logging.info('Creating a brand new user')
ok, user = self.auth.store.user_model.create_user(auth_id, **_attrs)
if ok:
self.auth.set_session(self.auth.store.user_to_dict(user))
# Remember auth data during redirect, just for this demo. You wouldn't
# normally do this.
self.session.add_flash(data, 'data - from _on_signin(...)')
self.session.add_flash(auth_info, 'auth_info - from _on_signin(...)')
# Go to the profile page
self.redirect('/profile')
def logout(self):
self.auth.unset_session()
self.redirect('/')
def handle_exception(self, exception, debug):
logging.error(exception)
self.render('error.html', {'exception': exception})
def _callback_uri_for(self, provider):
return self.uri_for('auth_callback', provider=provider, _full=True)
def _get_consumer_info_for(self, provider):
"""Returns a tuple (key, secret) for auth init requests."""
return secrets.AUTH_CONFIG[provider]
def _to_user_model_attrs(self, data, attrs_map):
"""Get the needed information from the provider dataset."""
user_attrs = {}
for k, v in attrs_map.iteritems():
attr = (v, data.get(k)) if isinstance(v, str) else v(data.get(k))
user_attrs.setdefault(*attr)
return user_attrs
Another question is that this code is used in webapp2 framework. Can I use this code in django or kay framework?
For 1st part of your question, short answer no.
BaseRequestHandler is a class not function, so can't really call it. The functions dispatch, jinja etc are methods of this class. They need to be called explicitly using the object of BaseRequestHandler. example
base_obj = BaseRequestHandler() #create instance base_obj.dispatch() #call dispatch method
This is just illustration to call methods, there might be some syntactic issues with respect to webapp2.