Add a new event listener
@param {events} event - The name of the event listener to add an event for
@param {function} callback - The callback to invoke when the event is called
492503
function addListener(event, callback) {
    checkEventValid(event);

    if (listeners[event]) {
        listeners[event].push(callback);
    } else {
        listeners[event] = [callback];
    }
}
236970
function on(dom, eventType, callback) {
  if (document.addEventListener) {
    dom.addEventListener(eventType, callback);
  } else {
    dom.attachEvent('on' + eventType, callback);
  }
}
335376
function triggerListeners(listeners, event, args)
  {
    if (listeners && event in listeners)
    {
      var eventListeners = listeners[ event ];
      var triggerGroup = ++triggerId;
      var next, node = eventListeners.next;

      while (node !== eventListeners)
      {
        next = node.next;
        node.trigger( triggerGroup, args, false );
        node = next;
      }

      node = eventListeners.next;

      while (node !== eventListeners)
      {
        next = node.next;
        node.trigger( triggerGroup, args, true );
        node = next;
      }
    }
  }
804147
public static function listen(string $event, callable $callback) {
		if (!isset(self::$events[$event])) {
			self::$events[$event] = [];
		}
		self::$events[$event][] = $callback;
	}
883579
def add_event(self, event):
        
        self._events.append(event)
        self._events_by_name[event.get_name] = event
525758
function _addEvent(object, type, callback) {
        if (object.addEventListener) {
            object.addEventListener(type, callback, false);
            return;
        }

        object.attachEvent('on' + type, callback);
    }
482449
function(object, events, callback) {
      var listeners = this._listeners || (this._listeners = {});
      var id = object._listenerId || (object._listenerId = _.uniqueId('l'));
      listeners[id] = object;
      object.on(events, callback || this, this);
      return this;
    }
651520
def _trigger_event(self, event):
    

    if event is None or event not in self.__listeners:
      raise ValueError('invalid event type: {0!r}'.format(event))

    # Check the event has not already been triggered, then mark
    # the event as triggered.
    if event in self.__event_set:
      raise RuntimeError('event already triggered: {0!r}'.format(event))
    self.__event_set.add(event)
    listeners = self.__listeners[event] + self.__listeners[None]

    # Remove one-off listeners.
    self.__listeners[event][:] = (l for l in self.__listeners[event] if not l.once)
    self.__listeners[None][:] = (l for l in self.__listeners[None] if not l.once)

    for listener in listeners:
      # XXX: What to do on exceptions? Catch and make sure all listeners
      # run through? What to do with the exception(s) then?
      listener.callback(self, event)
918863
function createEventEmitterCallback(event, emitter) {
    return function (ex) {
        if (ex) {
            emitter.emit('error', ex);
        } else {
            var args = Array.prototype.slice.call(arguments);
            args[0] = event;
            emitter.emit.apply(emitter, args);
            if (event == 'end') {
                emitter.removeAllListeners();
            }
        }
    };
}
1355559
public function on($event, $callback) {
		if (!is_callable($callback)) {
			throw new ListenException(var_export($callback, true) . " is not callback");
		}
		$this->callback[$event] = $callback;
	}
343467
function () {

        var i = this.c.length, j, c;
        while( i-- ){
            c = this.c[i];
            if( c !== undefined ){
                if( c.events !== undefined ){
                    j = c.events.length;
                    while( j-- ) c.addEventListener( c.events[j], this, false );
                }
            }
        }

    }
279715
public function addListener($name, callable $callback) {
        if(!array_key_exists($name, $this->registered_events)) {
            $this->registered_events[$name] = [];
        }

        $this->registered_events[$name][] = $callback;
    }
238895
function listenersHelp (element, events, handler, method) {
  let list = events.split(' ')
  for (let i = 0, len = list.length; i < len; i++) {
    let item = list[i]
    if (method === false) {
      element.removeEventListener(item, handler)
    } else {
      element.addEventListener(item, handler, false)
    }
  }
}
734674
def add_event(self, func: Callable, event: str) -> None:
        
        self._events[event].add(func)
1188662
function registerEventListener(eventList, callback) {
        for (var x = 0; x < eventList.length; x++) {
            if (POINTER_MOVE.indexOf(eventList[x]) === -1) {
                me.input.pointerEventTarget.addEventListener(eventList[x], callback, { passive: (api.preventDefault === false) });
            }
        }
    }
1273251
function(target, event, callback, traditional) {
			if(_.type(target) === 'string' || _.type(target) === 'array') {
				var elements = _.type(target) === 'string'? $$(target) : target;
				
				elements.forEach(function(element) {
					_.event.bind(element, event, callback, traditional);
				});
			}
			else if(_.type(event) === 'string') {
				if(traditional) {
					target['on' + event] = callback;
				}
				else {
					target.addEventListener(event, callback, false);
				}
			}
			else if(_.type(event) === 'array') {
				for (var i=0; i<event.length; i++) {
					_.event.bind(target, event[i], callback, arguments[2]);
				}
			}
			else {
				for (var name in event) {
					_.event.bind(target, name, event[name], arguments[2]);
				}
			}
		}
737991
function addEvent(elem, event, fn) {
  if (elem.addEventListener) {
    elem.addEventListener(event, fn, false);
    return fn;
  } else {
    let fn2 = function() {
      // set the this pointer same as addEventListener when fn is called
      return(fn.call(elem, window.event));
    };
    elem.attachEvent("on" + event, fn2);
    return fn2;
  }
}