Google's App Engine allows you to make
use of Google accounts to help in user authorization. Often, you'll want to
keep your own 'wrapper' accounts to keep additional information about
your users. This lesson discusses how to do that. Consider a site that:
handlers: For
the login:required pages, the system will take care of checking if the
user is signed in. If he is not, it will send him to sign in using Google's sign-in dialogue. Google also
takes care of sending the user back to the page that was being accessed
after sign in.- url: / script: social_controller.py - url: /.* script: social_controller.py login: required We define our wrapper 'Person' class in the following way: class Person(db.Model): The
important part is the 'user' property, which refers to a Google user
account object. If the persons in our system have an associated user,
we can always find the current user's additional information (in this
case just first and last)first=db.StringProperty() last=db.StringProperty() user = db.UserProperty() index.html is the only one where login is NOT required. When any visitor goes there, he can either click login to get to Google's login page, or enter a first and last name and click register: ** index.html ** <html> Here's the controller code that renders the above HTML template:<body> Already a member? <a href={{login_url}} >Sign in</a> <h2>Not a member? Register here:</h2> <form action="/on_register" method="get"> <div>first:<input type="text" name="first"></div> <div>last:<input type="text" name="last"></div> <div><input type="submit" value="Register"></div> </form> </body> </html> class MainPage(webapp.RequestHandler): def get(self): # this page is not login required, so a visitor could register user = users.get_current_user() if user: # if we are indeed logged in self.redirect('/home') login_url=users.create_login_url(self.request.uri) # if not logged in, we'll put up a link to login as well as registration template_values={'login_url':login_url} # render the page using the template engine path = os.path.join(os.path.dirname(__file__),'index.html') self.response.out.write(template.render(path,template_values)) Notice that we first to see if the user is already logged in. If they are, they're redirected to the home page. If not, we setup the login_url template value and render the page. login_url uses the Google User class method 'create_login_url'. You just give it a URL which is where the login dialog should send the user once he logs in. class RegisterHandler(webapp.RequestHandler): on_register requires login because of how the app.yaml is setup. Thus, prior to this controller code being reached, the user will be asked to login to Google (or create an account). Then the code above is invoked.def get(self): # the yaml file requires login, so when we get here, we're logged in user = users.get_current_user() #if not user: #self.redirect(users.create_login_url(self.request.uri)) # call google sign in page # see if this google user is already in our system pquery = db.GqlQuery("SELECT * FROM Person where user= :1",user) person = pquery.get() if person: # dude has already registered message='you were already registered' else: person = Person() person.first=self.request.get('first') person.last=self.request.get('last') person.user=user person.put() message='welcome' logouturl = users.create_logout_url('/') template_values={'person':person,'message':message,'logouturl':logouturl} # render the page using the template engine path = os.path.join(os.path.dirname(__file__),'home.html') self.response.out.write(template.render(path,template_values)) This code creates a new Person, sets the first and last fields, and puts it to the database. It also sets up a logout_url template value so we can put a link on the resulting page that is rendered (home.html) home.html just shows the user his first and last name as well as his Google nickname: *** home.html*** <html> <body> {% if message %} {{message}} {% endif %} <h2>Profile Info</h2> {{ person.first}} {{ person.last}} {{ person.user.nickname}} <br/> <a href={{logout_url}}>logout</a> </body> </html> Here's documentation for the Google App Engine User API |
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Handling Users |