@riversun/event-emitter

Helper class for sending and receiving events.

Register a listener to receive events.
Also, when an event occurs, call the event to the Listener registered in advance using the emit method

MIT License

install

npm install @riversun/event-emitter

usage

on() method

on() method adds event listener functionｓ that receives events。

const eventEmitter = new EventEmitter();

eventEmitter.on('testEvent', data => {
    console.log(data);
});

emit() method

emit() method sends an event with the specified event name and data to all registered listener functions

eventEmitter.emit('testEvent', {testKey: 'testValue'});

only() method

only() method can limit the event listener function that receives events to only one.

 eventEmitter.only('testEvent', 'unique-listener', callbackFunc);

Only one listener is registered per "listenerName" even if called multiple times. If the same listenerName is set for listener, the old listener will be removed.

onAny() method

eventEmitter.onAny(data => {});
eventEmitter.emit('testEvent1', {testKey: 'testValue1'});
eventEmitter.emit('testEvent2', {testKey: 'testValue2'});

Set onAny to catch all events that occur.

run tests

npm test

Classes

EventListenerList: A sequential list containing event listeners(callback functions)
EventListenerMap: Map that stores listeners(callback functions) with the specific key

Functions

on(eventType, listenerFunc): Set eventType you want to receive and the listener function to be callbacked from #emit method (This eventType will never fire unless called with emit)
removeListener(eventType, listenerFunc): Remove specified event listener
only(eventType, listenerName, listenerFunc): Only one listener is registered per "listenerName" even if called multiple times. If the same listenerName is set for listener, the old listener will be removed.
pipe(eventEmitter): Set the emitter that receives the callback of this emitter. When the specified emitter is received a callback, the specified emitter also emits it to its listener.
emit(eventType, data): Emit data to listeners (callback functions) registered with the "on()" method.
getAllListeners() ⇒ Object: Returns all listeners like below. result={ testEvent: { listeners: [ [Function (anonymous)] ], childEventEmitters: [ { childEmitterIdx: 0, listeners: [Array] } ] } }
hasListenerFuncs(eventType) ⇒ boolean: Returns true if at least one ListenerFunction that receives the event specified by "eventType" is registered
clearAll(): Clear all related listeners
addOnIntercepterFunc(funcName, func): Add callback func(s) to notify when calling on() method.
removeOnIntercepterFunc(funcName): Add callback func to notify when calling on() method.
getAllOnIntercepterFuncs(): Returns callback func and func name to notify when calling on() method.

on(eventType, listenerFunc)

Set eventType you want to receive and the listener function to be callbacked from #emit method (This eventType will never fire unless called with emit)

Kind: global function

Param	Type
eventType	`string`
listenerFunc	`function`

removeListener(eventType, listenerFunc)

Remove specified event listener

Kind: global function

Param
eventType
listenerFunc

only(eventType, listenerName, listenerFunc)

Only one listener is registered per "listenerName" even if called multiple times. If the same listenerName is set for listener, the old listener will be removed.

Kind: global function

Param	Type
eventType	`string`
listenerName	`string`
listenerFunc	`function`

pipe(eventEmitter)

Set the emitter that receives the callback of this emitter. When the specified emitter is received a callback, the specified emitter also emits it to its listener.

Kind: global function

Param
eventEmitter

emit(eventType, data)

Emit data to listeners (callback functions) registered with the "on()" method.

Kind: global function

Param	Type
eventType	`string`
data	`object`

getAllListeners() ⇒ `Object`

Returns all listeners like below. result={ testEvent: { listeners: [ [Function (anonymous)] ], childEventEmitters: [ { childEmitterIdx: 0, listeners: [Array] } ] } }

Kind: global function

hasListenerFuncs(eventType) ⇒ `boolean`

Returns true if at least one ListenerFunction that receives the event specified by "eventType" is registered

Kind: global function

Param	Type
eventType	`string`

clearAll()

Clear all related listeners

Kind: global function

addOnIntercepterFunc(funcName, func)

Add callback func(s) to notify when calling on() method.

Kind: global function

Param
funcName
func

removeOnIntercepterFunc(funcName)

Add callback func to notify when calling on() method.

Kind: global function

Param
funcName

getAllOnIntercepterFuncs()

Returns callback func and func name to notify when calling on() method.

Kind: global function