Notification Templates

Notification templates use django’s build-in templating system. This gives us more than enough power to craft the kind of message we want, without making things too onerous.

Example

The way a template looks shouldn’t be too foreign to you if you’re already used to django; but just in case you’re wondering, here’s an example:

<p>Hi {{ contact.name }},</p>

<p>{{ content.poster.name }} has posted a comment on your blog titled
{{ content.article.title }}.</p>

Note that the exact variables available will depend on which model the notification is attached to.

Variables

Several variables are provided to you in the template context.

content
This refers to whatever model the notification is attached to. It is visible as the content-type field of the notification when you’re editing it in the admin. Most of the time, you’re probably going to be wanting to use this.
contact
The Contact object that the message is being sent to. This object has 3 attributes: name, protocol, and address.
recipient
The type of this depends on which channel is selected as the recipient of a notification, and what kind of objects that channel returns. In practice, it will probably be some sort of user/user-profile object. When site contacts are the recipient, the value is a SiteContact object.
actor
This is only available if actor_type is specified for the notification. It refers to whoever or whatever is causing action associated with the notification.
target
This is only available if target_model is specified for the notification. It refers to whoever or whatever the action associated with the notification is affecting.

Most of the time, it’s recommended to just try and use a field on the content variable instead of target or actor. Sometimes, though, this is just not possible, and you want to be able to differentiate between the two at runtime, so that’s why they exist.

Miscellaneous Notes

Escaping

Django’s template engine has been primarily designed for outputting HTML. The only place in which this really matters is when it comes to excaping content. Plain text and HTML content work fine, however, with other formats like Markdown we need to wrap all the template variables with a custom variable escaping object that escapes everything on the fly. This has a few consequences.

  1. Most variables will be wrapped in this class. While the class mostly mimics the behavior of the underlying object, any template filter using isinstance will fail.
  2. In order to maintain compatibility with template filters, we don’t try to escape any of the basic numeric or date/time objects. For the most part this is okay, but it is theoretically possible to end up with a weird result.
  3. The result of template filters is typically not escaped correctly.

Subjects

Templates have a subject field which is sometimes used, depending on the backend. Any backend which supports a subject, has the attribute USE_SUBJECT set to True. Setting a subject on a template who’s backend doesn’t use it has no effect.