Templates

A template words the message for an event. The Templates page lists them and has an editor with a live preview. The template language itself is described in Templates and Expressions and templates.

The template list: each template's name, its title and its body.

The template list: each template's name, its title and its body.

The list

Column	What it shows
Name	The name you chose. It is what the route editor lists.
Title	The template for the message title.
Body	The template for the message body, or “the event’s own body” when it is empty.
Actions	Edit and Delete.

The search box looks in the name, title and body. Headings sort the list; it starts sorted by name. With no templates the page says “No templates yet, so every message uses the event’s own title and body.”

Creating a template

1. Press New template. The editor opens under the list with a starting title of [{{ severity }}] {{ title }} and a body of {{ body }}.

2. Give it a Name, up to 100 characters.

3. Write the Title and the Body. Values go between double braces. Leave either empty to keep the event’s own title or body; a template needs at least one of the two.

4. Check the Preview beside the form. It updates shortly after you stop typing.

5. Press Create template.

Under the form, What a template can use opens a short reference:

Name	Meaning
title, body	The text the event was sent with.
topic, severity, status	For example orders.failed, error, firing.
labels.<key>	One label, as in labels.env.
payload.<field>	A field of the JSON payload, as in payload.order.id.
count, events	How many events the message covers, and the list of them.
| cut(n)	Shortens text to n characters.
| default(...)	Used when the value is missing.
| tojson	Writes a value as JSON.

For example: [{{ labels.env | default('dev') }}] {{ title | cut(80) }}.

The server checks a template when you save it. A template with neither a title nor a body is refused, and so is one that does not parse; the reason is shown above the buttons.

The preview

The preview shows the message as its reader would get it: the title, and the body under it.

Control	What it does
With the event	Chooses the event to word. The menu lists the 20 newest events and starts on The newest event. On an instance with no events at all the choice reads A sample event: a built-in failed payment on the topic orders.payment.failed.
As sent to	Chooses a connection. The preview then also shows The request this connection sends: method, URL, headers and body, with secrets masked. With No connection only the wording is shown.
Destination	Appears for connections whose channel takes a destination, labelled with what that channel calls it. Leave it empty to use the connection’s own.

When the template fails on the chosen event, the preview shows the error in red, followed by “Until this is fixed, the event’s own title and body are sent:” and that default wording. The same happens at delivery: a template that fails does not stop the message.

The preview words one event. To see what a template does with a real route, including noise control, use the tester on Routes.

Using a template

A template does nothing until a route’s target uses it. In the route editor, under Send to, choose it in the Wording column of a target. Escalation steps have the same menu. See Routes and the tester.

Editing and deleting

Edit opens the template in the same editor; Save template stores it. The change applies to messages composed from then on.

Delete asks for confirmation. The server refuses while a route’s target or one of its escalation steps uses the template, and names the routes: “this template is used by: … Change those routes first.” Change those targets back to The event’s own wording, or to another template, then delete.