Blog - Using Observables to make our app work with barcode scanners

imperative-third-shot.js

const ENTER_KEY_CODE = 13
const MAX_INTERVAL_BETWEEN_EVENTS_IN_MS = 50
let keyCodesBuffer = []
let cleanBufferTimeout

document.addEventListener("keypress", (event) => {
  const keyCode = event.keyCode
  
  stopCleanBufferTimeout()
  if(keyCode === ENTER_KEY_CODE) {
    fillInputWithKeyCodesBuffer()
    cleanBuffer()
  } else {
    addToBuffer(keyCode)
    cleanBufferAfter(MAX_INTERVAL_BETWEEN_EVENTS_IN_MS)
  }
})

function fillInputWithKeyCodesBuffer() {
  // …
}

function cleanBuffer() {
  keyCodesBuffer = []
}

function addToBuffer(keyCode) {
  keyCodesBuffer.push(keyCode)
}

function cleanBufferAfter(timeout) {
  cleanBufferTimeout = setTimeout(cleanBuffer, timeout)
}

function stopCleanBufferTimeout() {
  clearTimeout(cleanBufferTimeout) 
}