Security News
The Dark Side of Open Source
At Node Congress, Socket CEO Feross Aboukhadijeh uncovers the darker aspects of open source, where applications that rely heavily on third-party dependencies can be exploited in supply chain attacks.
event-emitter
Advanced tools
Readme
$ npm install event-emitter
To port it to Browser or any other (non CJS) environment, use your favorite CJS bundler. No favorite yet? Try: Browserify, Webmake or Webpack
var ee = require('event-emitter');
var MyClass = function () { /* .. */ };
ee(MyClass.prototype); // All instances of MyClass will expose event-emitter interface
var emitter = new MyClass(), listener;
emitter.on('test', listener = function (args) {
// … react to 'test' event
});
emitter.once('test', function (args) {
// … react to first 'test' event (invoked only once!)
});
emitter.emit('test', arg1, arg2/*…args*/); // Two above listeners invoked
emitter.emit('test', arg1, arg2/*…args*/); // Only first listener invoked
emitter.off('test', listener); // Removed first listener
emitter.emit('test', arg1, arg2/*…args*/); // No listeners invoked
Removes all listeners from given event emitter object
Whether object has some listeners attached to the object.
When name
is provided, it checks listeners for specific event name
var emitter = ee();
var hasListeners = require('event-emitter/has-listeners');
var listener = function () {};
hasListeners(emitter); // false
emitter.on('foo', listener);
hasListeners(emitter); // true
hasListeners(emitter, 'foo'); // true
hasListeners(emitter, 'bar'); // false
emitter.off('foo', listener);
hasListeners(emitter, 'foo'); // false
Pipes all events from source emitter onto target emitter (all events from source emitter will be emitted also on target emitter, but not other way).
Returns pipe object which exposes pipe.close
function. Invoke it to close configured pipe.
It works internally by redefinition of emit
method, if in your interface this method is referenced differently, provide its name (or symbol) with third argument.
Unifies event handling for two objects. Events emitted on emitter1 would be also emitted on emitter2, and other way back.
Non reversible.
var eeUnify = require('event-emitter/unify');
var emitter1 = ee(), listener1, listener3;
var emitter2 = ee(), listener2, listener4;
emitter1.on('test', listener1 = function () { });
emitter2.on('test', listener2 = function () { });
emitter1.emit('test'); // Invoked listener1
emitter2.emit('test'); // Invoked listener2
var unify = eeUnify(emitter1, emitter2);
emitter1.emit('test'); // Invoked listener1 and listener2
emitter2.emit('test'); // Invoked listener1 and listener2
emitter1.on('test', listener3 = function () { });
emitter2.on('test', listener4 = function () { });
emitter1.emit('test'); // Invoked listener1, listener2, listener3 and listener4
emitter2.emit('test'); // Invoked listener1, listener2, listener3 and listener4
$ npm test
FAQs
Environment agnostic event emitter
The npm package event-emitter receives a total of 6,379,241 weekly downloads. As such, event-emitter popularity was classified as popular.
We found that event-emitter demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 1 open source maintainer collaborating on the project.
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Security News
At Node Congress, Socket CEO Feross Aboukhadijeh uncovers the darker aspects of open source, where applications that rely heavily on third-party dependencies can be exploited in supply chain attacks.
Research
Security News
The Socket Research team found this npm package includes code for collecting sensitive developer information, including your operating system username, Git username, and Git email.
Security News
OpenJS is warning of social engineering takeovers targeting open source projects after receiving a credible attempt on the foundation.