Django Persistent Messages

A Django app for unified and persistent user messages/notifications, built on top of Django's messages framework (django.contrib.messages).

Persistent Messages is a messages storage backend that provides support for messages that are supposed to be persistent, that is, they outlast a browser session and will be stored in the database. These messages can be displayed as you will to the user, you can let the user mark them as read, remove them or even reply them. For some of these actions there are views you can import in your project urls.py.

• Support persistent and nonpersistent messages for authenticated users. Persistent messages are stored in the database.
• For anonymous users, messages are stored using the cookie/session-based approach. There is no support for persistent messages for anonymous users.
• There is a unified API for displaying messages to both types of users, that is, you can use the same code you'd be using with Django's messaging framework in order to add and display messages, but there is additional functionality available if the user is authenticated.

Installation

This document assumes that you are familiar with Python and Django.

1. Clone this git repository (no PyPI package for this fork). master branch is the lastest stable branch:

    $ git clone git://github.com/maraujop/django-persistent-messages.git
   

2. Make sure persistent_messages is in your PYTHONPATH.

3. Add persistent_messages to your INSTALLED_APPS setting.

    INSTALLED_APPS = (
        ...
        'persistent_messages',
    )
   

4. Make sure Django's MessageMiddleware is in your MIDDLEWARE_CLASSES setting (which is the case by default):

    MIDDLEWARE_CLASSES = (
        ...
        'django.contrib.messages.middleware.MessageMiddleware',
    )
   

5. Optional Add the persistent_messages URLs to your URL conf. For instance, in order to make messages available under http://domain.com/messages/, add the following line to urls.py.

    urlpatterns = patterns('',
        (r'^messages/', include('persistent_messages.urls')),
        ...
    )
   

6. In your settings, set the message storage backend to persistent_messages.storage.PersistentMessageStorage:

    MESSAGE_STORAGE = 'persistent_messages.storage.PersistentMessageStorage'
   

7. Set up the database tables using

    $ manage.py syncdb
   

8. If you want to use the bundled templates, add the templates directory to your TEMPLATE_DIRS setting:

    TEMPLATE_DIRS = (
        ...
        'path/to/persistent_messages/templates')
    )
   

Using messages in views and templates

Message levels

Django's messages framework provides a number of message levels for various purposes such as success messages, warnings etc.

import persistent_messages
# persistent message levels:
persistent_messages.INFO 
persistent_messages.SUCCESS 
persistent_messages.WARNING
persistent_messages.ERROR

This app provides constants with the same names, the difference being that messages with these levels are going to be persistent:

from django.contrib import messages
# temporary message levels:
messages.INFO 
messages.SUCCESS 
messages.WARNING
messages.ERROR

Note: Let's stress the importance of this. If you use persistent_messages constants the message will be stored in the database and kept there till somebody explicitly deletes it. If you use contrib.messages constants, you get the same behavior as if you were using a non persistent storage, messages are stored in the database ensuring reception but they are removed right after being accessed.

Adding a message

Since the app is implemented as a storage backend for Django's messages framework, you can still use the regular Django API to add a message:

from django.contrib import messages
messages.add_message(request, messages.INFO, 'Hello world.')

This is compatible and equivalent to using the API provided by persistent_messages:

import persistent_messages
from django.contrib import messages
persistent_messages.add_message(request, messages.INFO, 'Hello world.')

In order to add a persistent message (one that is stored permanently in the Database), use persistent_messages levels listed above:

messages.add_message(request, persistent_messages.WARNING, 'This message is stored in persistent_messages table till removed.')

or the equivalent:

persistent_messages.add_message(request, persistent_messages.WARNING, 'This message is stored in persistent_messages table till removed')

Note that this is only possible for logged-in users, so you are probably going to have make sure that the current user is not anonymous using request.user.is_authenticated(). Adding a persistent message for anonymous users raises a NotImplementedError.

Extended API

Persistent Messages has an extended API that will let you do some extra nice things. This is the prototype of add_message in contrib messages:

def add_message(request, level, message, extra_tags='', fail_silently=False):

This is the prototype of add_message in Persistent Messages.

def add_message(request, level, message, extra_tags='', fail_silently=False, subject='', user=None, email=False, from_user=None, parent_msg=None, expires=None, close_timeout=None):

Subject and email notifications

Using persistent_messages.add_message, you can also add a subject line to the message. You can also set if you want an email notification to be sent. The following message will be stored as a message in the database and also sent to the email address associated with the current user:

persistent_messages.add_message(request, persistent_messages.INFO, 'Message body', subject='Please read me', email=True)

Note! Email notifications at the moment are too simple, I don't recommend using them, I'm not.

Send messages to different users

You can also pass this function a User object if the message is supposed to be sent to a user other than the one who is currently authenticated. User Sally will see this message the next time she logs in:

from django.contrib.auth.models import User
sally = User.objects.get(username='Sally')
persistent_messages.add_message(request, persistent_messages.SUCCESS, 'Hi Sally, here is a message to you.', subject='Success message', user=sally)

You can also set a from_user, which lets you use Persistent Messages as messaging system between users.

You can make messages expire

You need to pass a date and time to expires argument. Once the message has expired, it will not be included in the returned QuerySet. At the moment there is no view or method to clear expired messages from database.

Displaying messages

Messages can be displayed as described in the Django manual. However, you are probably going to want to include links tags for closing each message (i.e. marking it as read). In your template, use something like:

{% if messages %}
<ul class="messages">
    {% for message in messages %}
    <li{% if message.tags %} class="{{ message.tags }}"{% endif %}>
        {% if message.subject %}<strong>{{ message.subject }}</strong><br />{% endif %}
        {{ message.message }}<br />
        {% if message.is_persistent %}<a href="{% url message_mark_read message.pk %}">close</a>{% endif %}
    </li>
    {% endfor %}
</ul>
{% endif %}

You can also use the bundled templates instead. The following line replaces the code above. It allows the user to remove messages and mark them as read using Ajax requests, provided your HTML page includes JQuery:

{% include "persistent_messages/message/includes/messages.jquery.html" %}

Storage extra methods

In Django request._messages is set to the default storage you configured in your settings. Persistent Messages storage has some extra methods that Django built-in storages don't have that can be very useful:

• get_persistent: Get read and unread persistent messages
• get_persistent_unread: Get unread persistent messages
• get_nonpersistent: Gets nonpersistent messages
• count_unread: Counts persistent and nonpersistent unread messages
• count_persistent_unread: Counts persistent unread messages
• count_nonpersistent: Counts nonpersistent messages

Let's see some examples of what this means.

Display only nonpersistent messages

This is reduced version of a template that would let you iterate over nonpersistent messages:

{% if messages.get_nonpersistent %}
    {% for message in messages.get_nonpersistent %}
        [...]
    {% endfor %}
{% endif %}

Display number of unread messages

Imagine you've created an inbox for your users using Persistent Messages and you want to show them in the menu how many unread messages they have, if they have them:

<ul id="menu">
    <li><a href="">inbox {% if messages.count_persistent_unread > 0 %}({{ messages.count_persistent_unread }}){% endif %}</a></li>
</ul>

URLs and Persistent Messages Views

As said before you can import Persistent Messages URLs in your project's URL conf. This are the named urls you get:

• {% url message_detail message_id %} This renders template persistent_messages/message/detail.html with specific message in the context as message.
• {% url message_mark_read message_id %} Marks specific message as read
• {% url message_mark_all_read %} Marks all messages of the currently logged in user as read
• {% url message_delete message_id %} Deletes specific message
• {% url message_delete_all %} Deletes all the messages of the currently logged in user

There is plenty of room for improvement in these views and urls.

RANDOM NOTES

philomat is the author of this application. I maintain my own fork of the project, as the author didn't look to be very interested in maintaining it, as you can see in this pull request.

• This application is in need of a testing suite, currently testing checks the sadly famous "2+2=4"