Event emitter for Relaks
npm install relaks-event-emitterRelaks Event Emitter is the base class of data sources used by Relaks applications. It's designed for promised-based asynchronous code. It provides a notable feature allowing event listeners to postpone the default action associated with an event.
* addEventListener
* removeEventListener
* triggerEvent
* waitForEvent
``typescript`
function addEventListener(name: string, handler: function, beginning?:boolean): void
Add an event listener. If beginning is true, then handler will receive the event prior to handlers added previously. Otherwise it's placed at the end of the queue.
`typescript`
function removeEventListener(name: string, handler: function): void
Remove an event listener.
`typescript`
async function waitForEvent(type: string): Event
Return a promise that is fulfilled when an event of the specified type occurs.
`typescript`
function triggerEvent(evt: object): boolean
Send an event object to any listeners interested in the event. A method used by the event emitter itself. The return value indicates whether there were any listeners.
* preventDefault
* postponeDefault
* stopImmediatePropagation
* waitForDecision
`typescript`
function preventDefault(void): void
Indicate that the default action should not be performed.
`typescript`
function postponeDefault(proceed: Promise): void
`typescript`
function postponeDefault(callback: AsyncFunction): void
Request that the default action to be postponed. The method accepts either a promise or a callback function that returns a promise. An event emitter would wait for this promise to be fulfilled before perform the default action. If the promise's fulfillment value is false (and not merely "falsy"), that'd be the equivalent of calling preventDefault() and stopImmediatePropagation()--i.e. the default action will not occur.
When there are multiple listeners, a call to this method will keep other listeners from receiving the event until the promise given is fulfilled.
`typescript`
function stopImmediatePropagation(void): void
Keep listeners further down the chain from receiving this event.
`typescript`
async function waitForDecision(void): void
A method used by the event emitter itself. If a promise is given to postponeDefault()` within an event handler, this method will wait for its fulfillment. The method returns immediately otherwise.