Create and Manage Templates

This guide walks you through the complete workflow of creating, configuring, and managing notification templates in Collate.

Creating a Custom Template

Use the steps below to create a new notification template.

Navigate to Settings > Notifications > Notification Templates
Click Create Template button.
A form will appear with fields for defining your template.

Alternative Path: Creating Templates While Creating a Notification

Notification templates can also be created directly during the creation of a new notification subscription:

Navigate to Settings > Notifications > Alerts.
Click Add Alert.
In the notification creation form, a Create Template option will be available.
You may:
- Create a new custom template on the spot, or
- Select an existing template.
If no template is created or selected, the system default template will be applied.
Once the notification is saved, the created template is automatically linked and will be used for that notification.

Filling in Template Details

Name (Required)

A unique identifier for the template used internally. Example: high-priority-alerts, test-failure-notification, schema-change-alerts

Use lowercase with hyphens for clarity
Keep it concise and descriptive

Description (Optional)

Document when and why this template should be used. Example: Send notifications when critical test cases fail. Used with real-time test subscriptions.

Subject (Required)

The email subject line or notification title. Constraints: Maximum 255 characters Example:

[{{publisherName}}] - {{camelCaseToTitle event.entityType}} Updated: {{entity.fullyQualifiedName}}

This renders to: [Data Alerts] - Table Updated: database.schema.customers The subject uses the same placeholders and helpers as the body. It is plain text, so don’t add HTML tags. To keep a & in a name from showing as &, use triple braces: {{{entity.name}}}.

Keep subjects concise (under 100 characters) as they appear in email clients where space is limited.

Body (Required)

The main template content in HTML with Handlebars. Constraints: Maximum 65,536 characters Example:

<strong>{{event.userName}}</strong> updated <strong>{{camelCaseToTitle event.entityType}}</strong>:
<a href="{{buildEntityUrl event.entityType entity}}">{{entity.fullyQualifiedName}}</a>

{{#with (groupEventChanges event.changeDescription) as |changes|}}
{{#if changes.updates}}
<h3>Updated Fields:</h3>
<ul>
  {{#each (limit changes.updates 10)}}
  <li>{{name}}</li>
  {{/each}}
</ul>
{{/if}}
{{/with}}

Save the Template

Review all fields for accuracy
Click Save button.
The template is now available for use in event subscriptions

Modifying Templates

Editing User Templates

User templates (those you created) can be fully edited:

Navigate to Settings > Notifications > Templates
Find the template in the list
Click the Edit button
Modify any fields (Name, Display Name, Description, Subject, Body)
Click Save

Changes take effect immediately for any subscriptions using the template.

Editing System Templates

System templates (pre-built by Collate) can be partially edited:

You can modify: Subject and Body
You cannot modify: Name and Display Name
System templates track if you’ve customized them

Important: If you don’t customize a system template, it automatically updates when Collate releases improvements. Once you customize it, you’re responsible for maintaining it.

Linking Templates to Event Subscriptions

Templates become useful when connected to event subscriptions. Here’s how to use them:

Step 1: Navigate to Subscriptions

Go to Settings > Notifications > Subscriptions
Create a new subscription or edit an existing one

Step 2: Select a Template

In the subscription form, find the Notification Template dropdown
Choose from:
- System Templates - Pre-built templates for common entity types
- User Templates - Custom templates you’ve created
- (blank) - Use default formatting per channel

Step 3: Configure Other Settings

Complete the rest of the subscription setup:

Event Type - Which changes trigger the notification
Destinations - Where to send notifications (email, Slack, Teams, etc.)
Filters - Optional conditions for when to send

Step 4: Save the Subscription

Your template is now active and will be used for all notifications from this subscription.

Show Failed Rows in a Data Quality Alert

Test case alerts use the default Entity Updated Notification template. There is no separate data quality template. The default template already shows the failed row count and a table of failed rows, so if your alert uses it, steps 1 to 3 below are all you need. Step 4 is only for alerts that use a custom template. To show failed rows in an alert:

In the test settings, turn on Compute Row Count. The failed row count and sample aren’t available when this option is off. The Compare 2 tables for differences test is the exception: it collects a sample whenever it fails.
Check that the test type collects a sample. Only these tests do:
- Column Values To Be Between
- Column Values To Be In Set
- Column Values To Be Not In Set
- Column Values To Be Not Null
- Column Values To Be Unique
- Column Values To Match Regex Pattern
- Column Values To Not Match Regex
- Column Value Lengths To Be Between
- Custom SQL Query
- Compare 2 tables for differences
Other tests don’t produce a table.
Under Settings > Preferences > Profiler Configuration, check that Enable Storing of Sample Data is on. It’s on by default. When it’s off, no sample is collected.
If your alert uses a custom template, add the snippet below to the template body.
Run a test that fails.
In the resulting notification, confirm that the failed row count and sample table appear.

The snippet below shows the failed row count and a table of up to 10 columns and 3 failed rows, with the tested column in bold:

{{#with (groupEventChanges event.changeDescription) as |changes|}}
{{#if (and (eq event.entityType 'testCase') (hasFieldInChanges changes 'testCaseResult'))}}
{{#if entity.testCaseResult.failedRows}}Failed rows: {{entity.testCaseResult.failedRows}} ({{math entity.testCaseResult.failedRowsPercentage 'round' 2}}%){{/if}}
{{#with (parseEntityLink entity.entityLink) as |link|}}{{{renderTableSample entity.failedRowsSample link.arrayField 10 3}}}{{/with}}
{{/if}}
{{/with}}

Copy all six lines. The first two make the block appear only when a new test result arrives, and the last two close them. The sample only appears when the test fails. Collate masks columns tagged PII.Sensitive in the sample. If the table has the PII.Sensitive tag, Collate masks every column. A test notification uses generated data without a failed result or failed-row sample, so the test case section stays empty. To view this section, run a test that fails and inspect the actual notification. The editor suggestions that appear after you enter {{ list the basic Handlebars blocks (if, each, with, unless), the custom helpers with an example of each, and the event, entity, baseUrl, publisherName, and emailingEntity placeholders. For more information, see the Custom Helpers Reference.

Reacting to a Data Contract Status Change

A data contract has an approval status in entity.entityStatus. The values are Draft, In Review, Approved, Archived, Deprecated, Rejected, and Unprocessed. When the status changes, the change event records it under the field name entityStatus. To show a message only when the status changed, group the changes and check for that field:

{{#with (groupEventChanges event.changeDescription) as |changes|}}
  {{#if (hasFieldInChanges changes "entityStatus")}}
    <p>The status of <strong>{{entity.name}}</strong> changed to <strong>{{entity.entityStatus}}</strong>.</p>
  {{/if}}
{{/with}}

{{#if entity.owners}}
  <p>Owners:
  {{#each entity.owners}}{{name}}{{#unless @last}}, {{/unless}}{{/each}}
  </p>
{{/if}}

Use {{buildEntityUrl event.entityType entity}} to link to the contract.

A change to entityStatus appears only on update events. A create event has no list of changes, and soft-delete and restore events list only the deleted field.

A template changes only what the notification shows. It can’t stop the alert from firing. A data contract alert can’t currently filter on the approval status (entityStatus). The only status filter for data contracts, Get Data Contract Status Updates, checks the validation result (such as Failed or Aborted), not the approval status. An alert on data contracts therefore sends a notification for every matching contract change, not only for status changes.

Template Validation and Testing

Validating Templates

Before you save a template, click Validate in the template editor. Validation checks the Handlebars syntax. It doesn’t check whether a placeholder exists, so a misspelled placeholder passes validation and renders as empty text.

Sending Test Notifications

Send a test from the alert form, not from the template editor:

Open or create an alert, and select a source.
Add at least one external destination, such as Email, Slack, MS Teams, or Google Chat.
Under Notification Template, select a saved template or Create Custom Template. Test Template isn’t available for System Default Template.
Click Test Template.
Check your destinations to verify formatting and content.

The test uses generated sample data, not a real event.

Modifying vs. Duplicating Templates

When to Modify

Modify a template when you want to update all existing subscriptions using it:

Impact: All active subscriptions using this template immediately get new formatting
Use when: Improving a template everyone already uses

When to Duplicate

Create a new template based on an existing one when:

You want a variation for a specific use case
You want to test changes before affecting production subscriptions
Different teams need different formatting

How to duplicate: You can’t automatically duplicate, but you can:

Copy the template content
Create a new template
Paste the content as a starting point
Modify as needed

Deleting Templates

Delete User Templates

You can safely delete user templates you created:

Go to Settings > Notifications > Templates
Find your template
Click the Delete button
Confirm the deletion

Note: If the template is actively used in subscriptions, consider what will happen to those subscriptions when you delete it.

System Templates

System templates cannot be deleted (they’re read-only by default). If you’ve customized a system template and want to revert to the original, click Restore. After restoring, the template will once again stay synchronized with the Collate-provided system default (unless you modify it manually).

Troubleshooting Template Issues

Template Won’t Save

Common causes:

Body exceeds 65,536 characters - simplify the content
Subject exceeds 255 characters - shorten the subject
Invalid Handlebars syntax - check brackets are balanced
Required fields are empty - fill in Name, Display Name, Subject, and Body

Notifications Not Using Template

Check:

Is the template selected in the subscription settings?
Is the subscription active?
For system templates, do the subscription’s event type and entity type match your template name?

Template Shows Wrong Data

Check:

Are you using the correct property names? See Template Context Reference
Is the data available for this entity type?
Are you using conditionals for optional fields?

Next Steps

Learn about available data → Template Context Reference
Master Handlebars → Handlebars Templating Guide
Get help with issues → Troubleshooting Guide

Overview

Data Quality & Observability

Create and Manage Templates

Create and Manage Templates

Creating a Custom Template

Alternative Path: Creating Templates While Creating a Notification

Filling in Template Details

Name (Required)

Description (Optional)

Subject (Required)

Body (Required)

Save the Template

Modifying Templates

Editing User Templates

Editing System Templates

Linking Templates to Event Subscriptions

Step 1: Navigate to Subscriptions

Step 2: Select a Template

Step 3: Configure Other Settings

Step 4: Save the Subscription

Show Failed Rows in a Data Quality Alert

Reacting to a Data Contract Status Change

Template Validation and Testing

Validating Templates

Sending Test Notifications

Modifying vs. Duplicating Templates

When to Modify

When to Duplicate

Deleting Templates

Delete User Templates

System Templates

Troubleshooting Template Issues

Template Won’t Save

Notifications Not Using Template

Template Shows Wrong Data

Next Steps

​Create and Manage Templates

​Creating a Custom Template

​Alternative Path: Creating Templates While Creating a Notification

​Filling in Template Details

Name (Required)

Description (Optional)

Subject (Required)

Body (Required)

​Save the Template

​Modifying Templates

​Editing User Templates

​Editing System Templates

​Linking Templates to Event Subscriptions

​Step 1: Navigate to Subscriptions

​Step 2: Select a Template

​Step 3: Configure Other Settings

​Step 4: Save the Subscription

​Show Failed Rows in a Data Quality Alert

​Reacting to a Data Contract Status Change

​Template Validation and Testing

​Validating Templates

​Sending Test Notifications

​Modifying vs. Duplicating Templates

​When to Modify

​When to Duplicate

​Deleting Templates

​Delete User Templates

​System Templates

​Troubleshooting Template Issues

​Template Won’t Save

​Notifications Not Using Template

​Template Shows Wrong Data

​Next Steps

Create and Manage Templates

Creating a Custom Template

Alternative Path: Creating Templates While Creating a Notification

Filling in Template Details

Save the Template

Modifying Templates

Editing User Templates

Editing System Templates

Linking Templates to Event Subscriptions

Step 1: Navigate to Subscriptions

Step 2: Select a Template

Step 3: Configure Other Settings

Step 4: Save the Subscription

Show Failed Rows in a Data Quality Alert

Reacting to a Data Contract Status Change

Template Validation and Testing

Validating Templates

Sending Test Notifications

Modifying vs. Duplicating Templates

When to Modify

When to Duplicate

Deleting Templates

Delete User Templates

System Templates

Troubleshooting Template Issues

Template Won’t Save

Notifications Not Using Template

Template Shows Wrong Data

Next Steps