Getting Started

1. Initialization

Ensure mongodash is initialized with a global uri or mongoClient.

import mongodash from 'mongodash';

await mongodash.init({
    uri: 'mongodb://localhost:27017/my-app'
});

2. Define a Task

Use the reactiveTask function to register a task. You define what to watch and how to process it.

import { reactiveTask } from 'mongodash';

// Define a task that sends an email when a User is created or updated
// multiple tasks can listen to the same collection!
await reactiveTask({
    task: 'send-welcome-email', // Unique Job ID
    collection: 'users',        // Collection to watch
    
    // Optional: Only trigger if specific fields change
    watchProjection: { status: 1, email: 1 },
    
    // Optional: Filter documents (Standard Query or Aggregation Expression)
    filter: { status: 'active' },

    // The logic to execute
    handler: async (context) => {
        // Fetch the document (verifies filter & optimistic locking)
        const userDoc = await context.getDocument();
        
        console.log(`Processing user: ${userDoc._id}`);
        await sendEmail(userDoc.email, 'Welcome!');
    }
});

For a full list of options, see Configuration.

3. Start the System

After registering all tasks, start the scheduler. This will assume leadership (if possible) and start processing.

import { startReactiveTasks } from 'mongodash';

await startReactiveTasks();