django-user-messages adds offline messaging support to Django's messaging framework. It achieves this by allowing to save messages in the database. The user_messages.api.get_messages utility and the user_messages.context_processors.messages context processor transparently concatenate Django's messages and our own messages in a single list, therefore existing code works without any changes and without causing database writes. django-user-messages' functions have to be used explicitly. I consider this a feature, not a bug.

• Install django-user-messages using pip into your virtualenv.
• Add user_messages to INSTALLED_APPS and run migrate.
• Replace the default messages context processor with user_messages.context_processors.messages. The context processor provides both django.contrib.messages' and django-user-messages' messages.
• Use user_messages.api as you would use django.contrib.messages except that you pass the user model or ID as first parameter, not the current request.

Pretty much the same as Django's messaging framework:

from user_messages import api

api.info(user, 'Hey there')
api.warning(user, 'Stop this')
api.error(user, 'Not nice!')

# Passing the ID is also possible; the user instance does not
# have to be instantiated at all:
api.success(user.id, 'Yay!')

django-user-messages' messages supports two additional features not available in Django's messages framework:

• Messages can be delivered more than once by passing deliver_once=False. These messages have to be acknowledged explicitly. django-user-messages does not contain any code to do this.

• It is possible to attach additional data by passing a dictionary as meta:

  api.debug(user, 'Oww', meta={
      'url': 'http://example.com',
  })

For convenience, our messages have the same tags and level_tag properties as Django's messages. Meta properties are also accessible in templates:

{% if messages %}
  <ul class="messages">
  {% for message in messages %}
    <li class="{{ message.tags }}".>
      {% if message.meta.url %}<a href="{{ message.meta.url }}">{% endif %}
      {{ message }}
      {% if message.meta.url %}</a>{% endif %}
    </li>
  {% endfor %}
  </ul>
{% endif %}

django-user-messages' messages are also evaluated lazily.