mongo-scheduler

Persistent event scheduler using mongodb as storage

Provide the scheduler with some storage and timing info and it will emit events with the corresponding document at the right time

Installation

npm install mongo-scheduler

Usage

Initialization

var Scheduler = require('mongo-scheduer')
var scheduler = new Scheduler(connection, options)

Arguments

• connectionString - mongodb connections string (i.e.: "mongodb://localhost:27017/scheduler-db") or a mongoose connection object
• options - Options object

Valid Options

• pollInterval - Frequency in ms that the scheduler should poll the db. Default: 60000 (1 minute)
• doNotFire - If set to true, this instance will only schedule events, not fire them. Default: false

schedule()

Schedules an event.

var event = {name: 'breakfast' collection: 'meals', after: new Date(), data: 'Fry'}
scheduler.schedule(event)

Arguments

• event - Event details
• [callback]

Event Fields

• name - Name of event that should be fired
• [cron] - A cron string representing a frequency this should fire on
• [collection] - Info about the documents this event corresponds to
• [id] - Value of the _id field of the document this event corresponds to
• [after] - Time that the event should be triggered at, if left blank it will trigger the next time the scheduler polls
• [query] - a MongoDB query expression to select records that this event should be triggered for
• [data] <Object|Primitive> - Extra data to attach to the event

on

Event handler.

scheduler.on('breakfast', function(meal, event) {
  console.log(event.data + " the " + meal.ingredients)
  // Assuming the document {ingredients: "Bacon and Eggs"} is in the meals collection
  // prints "Fry the Bacon and Eggs"
})

Arguments

• eventName - Name of event
• handler - handler

Error handling

If the scheduler encounters an error it will emit an 'error' event. In this case the handler, will receive two arguments: the Error object, and the event doc (if applicable).

License

MIT License