January

Queue Trigger

The queue trigger enables you to listen to a queue and execute a workflow when a job is received.

import { trigger, workflow } from '@january/declarative';
workflow('ScheduleOrder', {
  tag: 'order_queue_name',
  trigger: trigger.queue({
    jobName: 'order.schedule',
  }),
  execute: async () => {
    console.log('Order scheduled');
  },
});

Installation

Queue trigger is available through "BullMQ" offical extension.

Update january.config.js file to include the following:

import { bullmq } from '@january/extensions/bullmq';

export default defineConfig({
  extensions: [
    // ... other extensions
    bullmq(),
  ],
});

How it works

The queue trigger uses the BullMQ library to process jobs from a queue. When a job is received, the workflow is executed.

How to use it?

There are few ways to define when the workflow should be triggered:

On any job
Specific job name
List of job names
On job status

Trigger On Job Status

To trigger a workflow based on job status, use the status option. The supported job statuses include completed, failed, waiting, and others as defined in BullMQ. Here's an example:

ts Copy code

Note: You cannot have both status and name unless you set local to true

import { trigger, workflow } from '@january/declarative';

workflow('MonitorOrder', {
  tag: 'order_queue_name',
  trigger: trigger.queue({
    status: 'completed',
  }),
  execute: async job => {
    console.log(`Order ${job.id} has been completed`);
  },
});

Trigger On Job Status and Name

If you need to trigger a workflow based on both job name and status, set the local property to true. This ensures that the trigger only listens to jobs matching both criteria.

Keep in mind that this listens to the worker's events behind the scenes which means Jobs with same name that is handled by different workers will not be listened to.

import { trigger, workflow } from '@january/declarative';

workflow('AlertOrderFailure', {
  tag: 'order_queue_name',
  trigger: trigger.queue({
    jobName: 'order.process',
    status: 'failed',
    local: true,
  }),
  execute: async ([job]) => {
    console.error(`Order ${job.id} failed`);
  },
});

Handling Multiple Job Names

You can provide an array of job names to the jobName property, allowing workflows to respond to multiple jobs.

import { trigger, workflow } from '@january/declarative';

workflow('ProcessOrderAndShipment', {
  tag: 'order_queue_name',
  trigger: trigger.queue({
    jobName: ['order.process', 'order.ship'],
  }),
  execute: async job => {
    console.log(`Job ${job.name} with ID ${job.id} executed`);
  },
});

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