webapp2_extras

webapp2_extras is a package with common utilities that work well with webapp2. It includes:

• Localization and internationalization support
• Sessions using secure cookies, memcache or datastore
• Extra route classes – to match subdomains and other conveniences
• Support for third party libraries: Jinja2 and Mako
• Support for threaded environments, so that you can use webapp2 outside of App Engine or in the upcoming App Engine Python 2.7 runtime

Some of these modules (i18n, Jinja2, Mako and Sessions) use configuration values that can be set in the WSGI application. When a config key is not set, the modules will use the default values they define.

All configuration keys are optional, except secret_key that must be set for Sessions. Here is an example that sets the secret_key configuration and tests that the session is working:

import webapp2
from webapp2_extras import sessions

class BaseHandler(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 session(self):
        # Returns a session using the default cookie key.
        return self.session_store.get_session()

class HomeHandler(BaseHandler):
    def get(self):
        test_value = self.session.get('test-value')
        if test_value:
            self.response.write('Session has this value: %r.' % test_value)
        else:
            self.session['test-value'] = 'Hello, session world!'
            self.response.write('Session is empty.')

config = {}
config['webapp2_extras.sessions'] = {
    'secret_key': 'some-secret-key',
}

app = webapp2.WSGIApplication([
    ('/', HomeHandler),
], debug=True, config=config)

def main():
    app.run()

if __name__ == '__main__':
    main()