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. Here, we go over the various fields on a template object, and what they do.

Fields

Backend
This sets the backend that the template will use.
Recipients
Here, you can select one or multiple kinds of recipients. If none are selected, the template won’t be used.
Subject
You can use template variables here but be careful not to make it too long. [1]
Content
Here’s where the body of your message goes. You can use template variables here and there is a toolbar at the top of the text books that has a few tools for convenience. Of particular note is the check mark button (✓) that shows a preview. Use this to check your template.
Attachments
You can add zero-multiple attachments here. What’s available here depends on what’s set up in the code (see attachments) [2]
From address
Normally optional since backends have a way to specify a site-wide default from address if they need one at all. You can use template variables here. [3]
Bulk
When this is on, only one message will be sent per template to all recipients and the recipients parameter will not be available. When it is turned off, a separate message will be made for each recipient, and you can use the recipients parameter.
Enabled
Turning this off will case the template to be ignored.

Example Content

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 {{ recipient.name }},</p>

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

Note that the exact variables available will depend on which model the notification is attached to. This example assumes bulk is turned off.

Variables

Several variables are provided to you in the template context.

object
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.
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.
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.

Most of the time, it’s recommended to just try and use a field on the object 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 escaping 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.
[1]The subject field only shows if the backend supports it, i.e. it has USE_SUBJECT set to True.
[2]The attachments field only shows if the backend supports it, i.e. it has USE_ATTACHMENTS set to True.
[3]The from address field only shows if the backend supports it, i.e. it has USE_FROM_SUBJECT set to True.