def init_app(self, app, configstore):
        """Initialize the extension for the given application and store.

        Parse the configuration values stored in the database obtained from
        the ``WAFFLE_CONFS`` value of the configuration.

        Arguments:
            app: Flask application instance
            configstore (WaffleStore): database store.

        """
        if not hasattr(app, 'extensions'):
            app.extensions = {}

        self.state = _WaffleState(app, configstore)
        app.extensions['waffleconf'] = self.state