Django Notification

Many sites need to notify users when certain events have occurred and to allow configurable options as to how those notifications are to be received.

The project aims to provide a Django app for this sort of functionality. This includes:

• submission of notification messages by other apps
• notification messages on signing in
• notification messages via email (configurable by user)
• notification messages via feed

Configuration

• Add 'notification' to your INSTALLED_APPS setting
• If you'd like automatic reporting when a model is saved, add the setting AUTO_NOTIFY, of the form ((path.to.model, path.to.callback), ...) where each entry is a tuple of models and the functions that should be called when an instance of that model is saved. Here you can pass send directly or a function you define that calls send to actually create the notices.

After you follow the aforementioned steps, read the next section for the next steps on usage.

Usage

Integrating notification support into your app is a simple three-step process.

• create your notice types
• create your notice templates
• send notifications

Creating Notice Types

You need to call create_notice_type(label, display, description) once to create the notice types for your application in the database. label is just the internal shortname that will be used for the type, display is what the user will see as the name of the notification type and description is a short description.

For example:

notification.create_notice_type("friends_invite",
    "Invitation Received", "you have received an invitation")

One good way to automatically do this notice type creation is in a management.py file for your app, attached to the syncdb signal. Here is an example:

from django.conf import settings
from django.utils.translation import ugettext_noop as _

if "notification" in settings.INSTALLED_APPS:
    from notification import models as notification

    def create_notice_types(app, created_models, verbosity, **kwargs):
        notification.create_notice_type("friends_invite",
            _("Invitation Received"), _("you have received an invitation"))
        notification.create_notice_type("friends_accept",
            _("Acceptance Received"), _("an invitation you sent has been accepted"))

    signals.post_syncdb.connect(create_notice_types, sender=notification)
else:
    print "Skipping creation of NoticeTypes as notification app not found"

Notice that the code is wrapped in a conditional clause so if django-notification is not installed, your app will proceed anyway.

Note that the display and description arguments are marked for translation by using ugettext_noop. That will enable you to use Django's makemessages management command and use django-notification's i18n capabilities.

Notification templates

There are four different templates that can to be written for the actual content of the notices:

• short.txt is a very short, text-only version of the notice (suitable for things like email subjects)
• full.txt is a longer, text-only version of the notice (suitable for things like email bodies)
• notice.html is a short, html version of the notice, displayed in a user's notice list on the website
• full.html is a long, html version of the notice (not currently used for anything)

Each of these should be put in a directory on the template path called notification/<notice_type_label>/<template_name>.

If any of these are missing, a default would be used. In practice, notice.html and full.txt should be provided at a minimum.

For example, notification/friends_invite/notice.html might contain:

{% spaceless %}
{% load i18n %}
{% url invitations as invitation_page %}
{% url profile_detail username=invitation.from_user.username as user_url %}
{% endspaceless %}
{% blocktrans with invitation.from_user as invitation_from_user %}
<a href="{{ user_url }}">{{ invitation_from_user }}</a> has requested to
add you as a friend (see <a href="{{ invitation_page }}">invitations</a>)
{% endblocktrans %}

and notification/friends_full.txt might contain:

{% spaceless %}
{% load i18n %}
{% url invitations as invitation_page %}
{% endspaceless %}
{% blocktrans with invitation.from_user as invitation_from_user %}
{{ invitation_from_user }} has requested to add you as a friend.
You can accept their invitation at:

http://{{ current_site }}{{ invitation_page }}
{% endblocktrans %}

The context variables are provided when sending the notification.

Sending Notifications

There are two different ways of sending out notifications. We have support for blocking and non-blocking methods of sending notifications. The most simple way to send out a notification, for example:

notification.send([to_user], "friends_invite", {"from_user": from_user})

One thing to note is that send is a proxy around either send_now or queue. They all have the same signature:

send(users, label, extra_context, on_site)

The parameters are:

• users is an iterable of User objects to send the notification to.
• label is the label you used in the previous step to identify the notice type.
• extra_content is a dictionary to add custom context entries to the template used to render to notification. This is optional.
• on_site is a boolean flag to determine whether an Notice object is created in the database.

send_now vs. queue vs. send

Lets first break down what each does.

send_now

This is a blocking call that will check each user for elgibility of the notice and actually peform the send.

queue

This is a non-blocking call that will queue the call to send_now to be executed at a later time. To later execute the call you need to use the emit_notices management command.

send

A proxy around send_now and queue. It gets its behavior from a global setting named NOTIFICATION_QUEUE_ALL. By default it is False. This setting is meant to help control whether you want to queue any call to send.

send also accepts now and queue keyword arguments. By default each option is set to False to honor the global setting which is False. This enables you to override on a per call basis whether it should call send_now or queue.

Displaying notifications

The urls for this app include notification_context_notices and notification_notices that correspond to views to show context and site-wide notifications, respectively; both of these return notice_types (the list of notice types, so you can use them as javascript filters or something) and notices, which is a paginator with the notifications for the current logged in user. An example template using these objects to display the notifications for a user would be:

{%load i18n humanize%}
<ul id="notices">
    {%for notice in notices.object_list%}
    <li class="notice {%if notice.is_unseen%}unseen{%endif%} {{notice.notice_type.label}}">
        <div>
            {#the notices already come as html#}
            <p>{{notice|safe}}</p>
            <span>{{notice.added|naturalday}}</span>
        </div>
    </li>
    {%endfor%}
 </ul>
<div class="pagination">
    <span class="step-links">
        {% if notices.has_previous %}
            <a href="?page={{ notices.previous_page_number }}">{% trans "previous"%}</a>
        {% endif %}

        <span class="current">
        {%if notices.paginator.num_pages%}
            {%blocktrans with notices.number as n and notices.paginator.num_pages as N%}
                Page {{ n }} of {{ N }}.
            {%endblocktrans%}
        {%endif%}
        </span>

        {% if notices.has_next %}
            <a href="?page={{ notices.next_page_number }}">{%trans "next"%}</a>
        {% endif %}
    </span>
</div>

Optional notification support

In case you want to use django-notification in your reusable app, you can wrap the import of django-notification in a conditional clause that tests if it's installed before sending a notice. As a result your app or project still functions without notification.

For example:

from django.conf import settings

if "notification" in settings.INSTALLED_APPS:
    from notification import models as notification
else:
    notification = None

and then, later:

if notification:
    notification.send([to_user], "friends_invite", {
        "from_user": from_user
    })