Flash

Send messages to the user between pages.

When you instantiate the class, the attribute 'msg' will be set from the cookie, and the cookie will be deleted. If there is no flash cookie, 'msg' will default to None.

Using Flash

To set a flash message for the next page, simply set the 'msg' attribute.

Example psuedocode:

        if new_entity.put():
            flash = Flash()
            flash.msg = 'Your new entity has been created!'
            return redirect_to_entity_list()

Then in the template on the next page (you must pass flash to the template as a variable for this work):

        {% if flash.msg %}
            <div class="flash-msg">{{ flash.msg }}</div>
        {% endif %}