Node.js Event Emitters HTTP Analytics through an Event Emitter
Example
In the HTTP server code (e.g. server.js):
const EventEmitter = require('events')
const serverEvents = new EventEmitter()
// Set up an HTTP server
const http = require('http')
const httpServer = http.createServer((request, response) => {
// Handler the request...
// Then emit an event about what happened
serverEvents.emit('request', request.method, request.url)
});
// Expose the event emitter
module.exports = serverEvents
In supervisor code (e.g. supervisor.js):
const server = require('./server.js')
// Since the server exported an event emitter, we can listen to it for changes:
server.on('request', (method, url) => {
console.log(`Got a request: ${method} ${url}`)
})
Whenever the server gets a request, it will emit an event called request which the supervisor is listening for, and then the supervisor can react to the event.
