@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

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)

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