Triggers

Execute a function in response to a change in the database.

To create an executable, decorate a function with the @trigger decorator within a class that extends the base SquidService class.

The following example shows a trigger that is executed on a change to the users database collection in the built-in database:

Backend code

import { SquidService, trigger, TriggerRequest } from '@squidcloud/backend';

export class ExampleService extends SquidService {
  @trigger('userChange', 'users')
  async handleUserChange(request: TriggerRequest): Promise<void> {
    // TODO - add your business logic here
  }
}

If the function is triggered by a database other than the built-in database, then the integration ID must be specified as the third parameter in the @trigger decorator. For example:

Backend code

@trigger('userChange', 'users', 'HrDatabase') // id, collection, integration

The trigger takes the following parameters:

Name	Type	Description
id	string	The id of the trigger. Should be unique.
collectionName	string	The name of the collection to trigger on.
integrationId?	string	The id of the connector to trigger on. If not provided, the built_in_db is used.

The trigger request provides the following information on the change:

{
  squidDocId: SquidDocId; // the primary key for the document
  mutationType: MutationType; // the type of operation performed
  docBefore?: T; // the document's previous state
  docAfter?: T; // the document's updated state
}

For more information, view the API documentation for the trigger decorator.