1. module eventemitter3
   1. boolean eventemitter3.prefixed
   2. function eventemitter3 ()
   3. function eventemitter3.EventEmitter ()
   4. object eventemitter3.EventEmitter.prototype
2. module eventemitter3.EventEmitter
   1. boolean eventemitter3.EventEmitter.prefixed
   2. function eventemitter3.EventEmitter ()
3. module eventemitter3.EventEmitter.prototype
   1. function eventemitter3.EventEmitter.prototype.addListener (event, fn, context)
   2. function eventemitter3.EventEmitter.prototype.emit (event, a1, a2, a3, a4, a5)
   3. function eventemitter3.EventEmitter.prototype.eventNames ()
   4. function eventemitter3.EventEmitter.prototype.listeners (event, exists)
   5. function eventemitter3.EventEmitter.prototype.off (event, fn, context, once)
   6. function eventemitter3.EventEmitter.prototype.on (event, fn, context)
   7. function eventemitter3.EventEmitter.prototype.once (event, fn, context)
   8. function eventemitter3.EventEmitter.prototype.removeAllListeners (event)
   9. function eventemitter3.EventEmitter.prototype.removeListener (event, fn, context, once)
   10. function eventemitter3.EventEmitter.prototype.setMaxListeners ()

module eventemitter3

function eventemitter3 ()

• description and source-code

  function EventEmitter() {
    this._events = new Events();
    this._eventsCount = 0;
  }

• example usage

  n/a

function eventemitter3.EventEmitter ()

• description and source-code

  function EventEmitter() {
    this._events = new Events();
    this._eventsCount = 0;
  }

• example usage

  n/a

module eventemitter3.EventEmitter

function eventemitter3.EventEmitter ()

• description and source-code

  function EventEmitter() {
    this._events = new Events();
    this._eventsCount = 0;
  }

• example usage

  n/a

module eventemitter3.EventEmitter.prototype

function eventemitter3.EventEmitter.prototype.addListener (event, fn, context)

• description and source-code

  function on(event, fn, context) {
    var listener = new EE(fn, context || this)
      , evt = prefix ? prefix + event : event;
  
    if (!this._events[evt]) this._events[evt] = listener, this._eventsCount++;
    else if (!this._events[evt].fn) this._events[evt].push(listener);
    else this._events[evt] = [this._events[evt], listener];
  
    return this;
  }

• example usage

  n/a

function eventemitter3.EventEmitter.prototype.emit (event, a1, a2, a3, a4, a5)

• description and source-code

  function emit(event, a1, a2, a3, a4, a5) {
    var evt = prefix ? prefix + event : event;
  
    if (!this._events[evt]) return false;
  
    var listeners = this._events[evt]
      , len = arguments.length
      , args
      , i;
  
    if (listeners.fn) {
      if (listeners.once) this.removeListener(event, listeners.fn, undefined, true);
  
      switch (len) {
        case 1: return listeners.fn.call(listeners.context), true;
        case 2: return listeners.fn.call(listeners.context, a1), true;
        case 3: return listeners.fn.call(listeners.context, a1, a2), true;
        case 4: return listeners.fn.call(listeners.context, a1, a2, a3), true;
        case 5: return listeners.fn.call(listeners.context, a1, a2, a3, a4), true;
        case 6: return listeners.fn.call(listeners.context, a1, a2, a3, a4, a5), true;
      }
  
      for (i = 1, args = new Array(len -1); i < len; i++) {
        args[i - 1] = arguments[i];
      }
  
      listeners.fn.apply(listeners.context, args);
    } else {
      var length = listeners.length
        , j;
  
      for (i = 0; i < length; i++) {
        if (listeners[i].once) this.removeListener(event, listeners[i].fn, undefined, true);
  
        switch (len) {
          case 1: listeners[i].fn.call(listeners[i].context); break;
          case 2: listeners[i].fn.call(listeners[i].context, a1); break;
          case 3: listeners[i].fn.call(listeners[i].context, a1, a2); break;
          case 4: listeners[i].fn.call(listeners[i].context, a1, a2, a3); break;
          default:
            if (!args) for (j = 1, args = new Array(len -1); j < len; j++) {
              args[j - 1] = arguments[j];
            }
  
            listeners[i].fn.apply(listeners[i].context, args);
        }
      }
    }
  
    return true;
  }

• example usage

  n/a

function eventemitter3.EventEmitter.prototype.eventNames ()

• description and source-code

  function eventNames() {
    var names = []
      , events
      , name;
  
    if (this._eventsCount === 0) return names;
  
    for (name in (events = this._events)) {
      if (has.call(events, name)) names.push(prefix ? name.slice(1) : name);
    }
  
    if (Object.getOwnPropertySymbols) {
      return names.concat(Object.getOwnPropertySymbols(events));
    }
  
    return names;
  }

• example usage

  n/a

function eventemitter3.EventEmitter.prototype.listeners (event, exists)

• description and source-code

  function listeners(event, exists) {
    var evt = prefix ? prefix + event : event
      , available = this._events[evt];
  
    if (exists) return !!available;
    if (!available) return [];
    if (available.fn) return [available.fn];
  
    for (var i = 0, l = available.length, ee = new Array(l); i < l; i++) {
      ee[i] = available[i].fn;
    }
  
    return ee;
  }

• example usage

  ...
  - Domain support has been removed.
  - We do not `throw` an error when you emit an `error` event and nobody is
    listening.
  - The `newListener` event is removed as the use-cases for this functionality are
    really just edge cases.
  - No `setMaxListeners` and its pointless memory leak warnings. If you want to
    add `end` listeners you should be able to do that without modules complaining.
  - No `listenerCount` method. Use `EE.listeners(event).length` instead.
  - Support for custom context for events so there is no need to use `fn.bind`.
  - The `listeners` method can do existence checking instead of returning only
    arrays.
  - The `removeListener` method removes all matching listeners, not only the
    first.
  
  It's a drop in replacement for existing EventEmitters, but just faster. Free
  ...

function eventemitter3.EventEmitter.prototype.off (event, fn, context, once)

• description and source-code

  function removeListener(event, fn, context, once) {
    var evt = prefix ? prefix + event : event;
  
    if (!this._events[evt]) return this;
    if (!fn) {
      if (--this._eventsCount === 0) this._events = new Events();
      else delete this._events[evt];
      return this;
    }
  
    var listeners = this._events[evt];
  
    if (listeners.fn) {
      if (
           listeners.fn === fn
        && (!once || listeners.once)
        && (!context || listeners.context === context)
      ) {
        if (--this._eventsCount === 0) this._events = new Events();
        else delete this._events[evt];
      }
    } else {
      for (var i = 0, events = [], length = listeners.length; i < length; i++) {
        if (
             listeners[i].fn !== fn
          || (once && !listeners[i].once)
          || (context && listeners[i].context !== context)
        ) {
          events.push(listeners[i]);
        }
      }
  
      //
      // Reset the array, or remove it completely if we have no more listeners.
      //
      if (events.length) this._events[evt] = events.length === 1 ? events[0] : events;
      else if (--this._eventsCount === 0) this._events = new Events();
      else delete this._events[evt];
    }
  
    return this;
  }

• example usage

  n/a

function eventemitter3.EventEmitter.prototype.on (event, fn, context)

• description and source-code

  function on(event, fn, context) {
    var listener = new EE(fn, context || this)
      , evt = prefix ? prefix + event : event;
  
    if (!this._events[evt]) this._events[evt] = listener, this._eventsCount++;
    else if (!this._events[evt].fn) this._events[evt].push(listener);
    else this._events[evt] = [this._events[evt], listener];
  
    return this;
  }

• example usage

  ...
    , context = { foo: 'bar' };
  
  function emitted() {
    console.log(this === context); // true
  }
  
  EE.once('event-name', emitted, context);
  EE.on('another-event', emitted, context);
  EE.removeListener('another-event', emitted, context);
  ```
  
  ### Existence
  
  To check if there is already a listener for a given event you can supply the
  `listeners` method with an extra boolean argument. This will transform the
  ...

function eventemitter3.EventEmitter.prototype.once (event, fn, context)

• description and source-code

  function once(event, fn, context) {
    var listener = new EE(fn, context || this, true)
      , evt = prefix ? prefix + event : event;
  
    if (!this._events[evt]) this._events[evt] = listener, this._eventsCount++;
    else if (!this._events[evt].fn) this._events[evt].push(listener);
    else this._events[evt] = [this._events[evt], listener];
  
    return this;
  }

• example usage

  ...
  var EE = new EventEmitter()
    , context = { foo: 'bar' };
  
  function emitted() {
    console.log(this === context); // true
  }
  
  EE.once('event-name', emitted, context);
  EE.on('another-event', emitted, context);
  EE.removeListener('another-event', emitted, context);
  ```
  
  ### Existence
  
  To check if there is already a listener for a given event you can supply the
  ...

function eventemitter3.EventEmitter.prototype.removeAllListeners (event)

• description and source-code

  function removeAllListeners(event) {
    var evt;
  
    if (event) {
      evt = prefix ? prefix + event : event;
      if (this._events[evt]) {
        if (--this._eventsCount === 0) this._events = new Events();
        else delete this._events[evt];
      }
    } else {
      this._events = new Events();
      this._eventsCount = 0;
    }
  
    return this;
  }

• example usage

  n/a

function eventemitter3.EventEmitter.prototype.removeListener (event, fn, context, once)

• description and source-code

  function removeListener(event, fn, context, once) {
    var evt = prefix ? prefix + event : event;
  
    if (!this._events[evt]) return this;
    if (!fn) {
      if (--this._eventsCount === 0) this._events = new Events();
      else delete this._events[evt];
      return this;
    }
  
    var listeners = this._events[evt];
  
    if (listeners.fn) {
      if (
           listeners.fn === fn
        && (!once || listeners.once)
        && (!context || listeners.context === context)
      ) {
        if (--this._eventsCount === 0) this._events = new Events();
        else delete this._events[evt];
      }
    } else {
      for (var i = 0, events = [], length = listeners.length; i < length; i++) {
        if (
             listeners[i].fn !== fn
          || (once && !listeners[i].once)
          || (context && listeners[i].context !== context)
        ) {
          events.push(listeners[i]);
        }
      }
  
      //
      // Reset the array, or remove it completely if we have no more listeners.
      //
      if (events.length) this._events[evt] = events.length === 1 ? events[0] : events;
      else if (--this._eventsCount === 0) this._events = new Events();
      else delete this._events[evt];
    }
  
    return this;
  }

• example usage

  ...
  
    var listeners = this._events[evt]
  , len = arguments.length
  , args
  , i;
  
    if (listeners.fn) {
  if (listeners.once) this.removeListener(event, listeners.fn, undefined, true);
  
  switch (len) {
    case 1: return listeners.fn.call(listeners.context), true;
    case 2: return listeners.fn.call(listeners.context, a1), true;
    case 3: return listeners.fn.call(listeners.context, a1, a2), true;
    case 4: return listeners.fn.call(listeners.context, a1, a2, a3), true;
    case 5: return listeners.fn.call(listeners.context, a1, a2, a3, a4), true;
  ...

function eventemitter3.EventEmitter.prototype.setMaxListeners ()

• description and source-code

  function setMaxListeners() {
    return this;
  }

• example usage

  n/a