intercept-events

Intercept all events from events.EventEmitter.

With this module you can add and remove listeners, that will fire on all events (emits).

The only difference between a normal listeners and these listeners is, that the event type will be the first argument:

var util = require('util');
var EventEmitter = require('events').EventEmitter;
var interceptEvents = require('./index');

var MyClass = function() {
  EventEmitter.call(this);
};
util.inherits(MyClass, EventEmitter);

MyClass.prototype.test = function() {
  this.emit('my test', { the: 'data' });
};
var myClass = new MyClass();

myClass.on('my test', function() {
  console.log('From normal listener:');
  console.log(arguments);
});

var myListener1 = function() {
  console.log('From intercept listener 1:');
  console.log(arguments);
};

var myListener2 = function() {
  console.log('From intercept listener 2:');
  console.log(arguments);
};

interceptEvents.addListener(myListener1);
interceptEvents.addListener(myListener2);

myClass.test();

interceptEvents.removeListener(myListener2);

myClass.test();

This will output this:

From intercept listener 1:
{ '0': 'my test', '1': { the: 'data' } }
From intercept listener 2:
{ '0': 'my test', '1': { the: 'data' } }
From normal listener:
{ '0': { the: 'data' } }
From intercept listener 1:
{ '0': 'my test', '1': { the: 'data' } }
From normal listener:
{ '0': { the: 'data' } }
From intercept listener 1:
{ '0': 'exit', '1': 0 }

This is an early BETA version

As soon as the module has shown it's worth and stability on a live system, it will be marked as version >= 1.0.0.

Until then: Feel free to play around with it, learn from it.

To install

npm install intercept-events