django-notify 1.0.2

A Django application which provides temporary notifications.

A Django application which provides temporary notifications.

Notification messages persist until a request retrieves them.

Installation

Add the middleware to your MIDDLEWARE_CLASSES setting (the default temporary storage relies on Django’s contrib.sessions application, so place this after SessionMiddleware):

'django_notify.middleware.NotificationsMiddleware',

To make it easy to access notifications in templates, add the context processor into your TEMPLATE_CONTEXT_PROCESSORS setting:

'django_notify.context_processors.notifications',

Usage

Adding a temporary notification message

The middleware adds an instance of a temporary storage class called notifications to your request. To add a notification, call:

request.notifications.add('Hello world.')

You can optionally provide a string containing tags (which is usually represented as HTML classes for the message):

request.notifications.add('Your rating is over 9000!', 'error')

Displaying temporary notifications

In your template (rendered with RequestContext or with request.notifications passed as notifications in its context) using something like:

{% if notifications %}
<ul class="notifications">
        {% for message in notifications %}
        <li{% if message.tags %} class="{{ message.tags }}"{% endif %}>{{ message }}</li>
        {% endfor %}
</ul>
{% endif %}

The notifications are marked to be cleared when the storage instance is iterated (cleared when the response is processed). To avoid the notifications being cleared, you can set request.notifications.used = False after iterating.

Temporary Storage Backends

Django notify can use different backends to store temporary messages. To change which backend is being used, add a NOTIFICATIONS_STORAGE to your settings, referencing to the module and class of the storage class. For example:

NOTIFICATIONS_STORAGE = 'cookie.CookieStorage'

Django Notify first looks for the module inside of django_notify.storage, and if not found, tries to import the full given module directly.

Three temporary storage classes are included in Django Notify:

'session.SessionStorage'

This class stores all messages inside of the request’s session. It requires Django’s contrib.session application.

'cookie.CookieStorage'

This class stores the notification data in a cookie (signed with a secret hash to prevent manipulation) to persist notifications across requests. Old messages are dropped if the cookie data size would exceed 4096 bytes.

'fallback.FallbackStorage'

This is the default temporary storage class.

This class uses CookieStorage for all notification messages, falling back to using SessionStorage for the messages which could not fit in a single cookie.

Since it is uses SessionStorage, it also requires Django’s contrib.session application.

To write your own, subclass the BaseStorage class in django_notify.storage.base and write _get and _store methods.