event-schema

Validates event payloads by attaching a JSON schema to each event topic.

Example

const EventSchema = require('event-schema')
const es = new EventSchema()

// define a topic and what the event payload must look like
es.define('topicX', {
    type: 'object',
    properties: {
        name: {
            type: 'string',
            minLength: 1
        },
        age: {
            type: 'integer',
            minimum: 0
        }
    }
})

// subscribe a handler to the event
es.on('topicX', function (payload) {
    console.log(payload)
})

// emit an event to the topic
es.emit('topicX', {
    name: 'Bob',
    age: 20
})

Create EventSchema instance

Each event-schema instance manages its own topics, handlers, and emitted events.

const EventSchema = require('event-schema')
const es = new EventSchema()

Define a JSON Schema to use for a Specific Topic

es.define('topicX', {
    type: 'string',
    minLength: 1
})

Subscribe to an Event Topic

es.on('topicX', function (payload) {
    // add code to handle the event payload here
})

Unsubscribe from an Event Topic

function handler (payload) {
    // add code to handle the event payload here
}

// add an event handler first
es.on('topicX', handler)

// remove the handler
es.off('topicX', handler)

Subscribe to a Single Event on a Topic

es.once('topicX', function handler (payload) {
    // this code will only run for the first event on this topic
})