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 therecipients
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.
- 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. - 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.
- 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 . |