Scan Detector

Detect barcode scanner and keyboard input events separately in your web or electronJS application with ease.

install

$ npm i scan-detector --save

Quick usage

const ScanDetector = require("scan-detector");

let detector = ScanDetector();

detector.attach();

document.addEventListener("scanner", (e) => {
  // handle scan code
});

document.addEventListener("keyboard", (e) => {
  // handle keyboard input
});

detector.detach();

Options

let sd = ScanDetector({ element: document, minCodeLength: 4 });

| Option | Type | Default | Description | | --------------- | ------------------------- | -------- | ----------------------------------------------- | | element | html element | document | html element to attach and listen for inputs | | prefix | array (char codes) | [] | these characters will be discarded | | suffix | array (char codes) | [9, 13] | possible end characters, will be discarded | | avgCharTime | number (ms) | 30 | average time between each scanner keydown event | | minCodeLength | number | 6 | min length of scanned code | | customEncoder | function(number keyCode) | null | will be called on each keydown event | | onScanFinish | function(string scanCode) | null | will be called when scan is finished | | preventDefault | bool | false | prevent default keydown behavior | | stopPropagation | bool | false | stops event propagation | | debugMode | bool | false | logs each keydown event in console |

Methods

setOptions(options):

seta detector options.

getOptions():

returns detector options.

attach():

attach detector to the element, it will listen to keydown event in the element.

detach():

detach detector from element.

Example

const ScanDetector = require("scan-detector");

let input = document.getElementById("text_input");

let detector = ScanDetector({
  element: document,
  avgCharTime: 30,
  minCodeLength: 6,
  customEncoder: (event) => {
    return event.key;
  },
  onScanFinish: (code) => {
    return [...code.matchAll(/Alt([0-9]{3})/g)].reduce((t, v) => {
      return (t += String.fromCharCode(+v[1]));
    }, "");
  },
});

detector.attach();

document.addEventListener("scanner", (e) => {
  input.value = e.detail;
});

document.addEventListener("keyboard", (e) => {
  console.log(e);
});