README.md

Barcode editor

Demo

Tested only in Chrome desktop!

Summary

• Enter up to 19 digits
• Calculate checksum
• Generate fluid barcode from digits & checksum
• Change colors of barcode

Stack used

Default Vue app created with vue-cli. Added custom reset and color styles (src/assets/styles/) for fast prototyping.

Completed in 3 days total

1. read task and think
2. coding (~6 hours)
3. deploy & readme

---

Tech. highlights

Checksum calculation

Alternative approach: we also can use loops - less readable but more performant for some cases

checksum() {
  if (!this.code) return null;

  const evenSum = this.digitsArray
    .filter((v, i) => i % 2 !== 0)
    .reduce((a, b) => a + b, 0);
  const oddSum = this.digitsArray
    .filter((v, i) => i % 2 === 0)
    .reduce((a, b) => a + b, 0);

  const remainder = (evenSum + oddSum * 3) % 10;
  return remainder === 0 ? 0 : 10 - remainder;
}

Bars' sizing

Bars are made with div blocks sized in percent units. Another possible approaches:

• SVG: ~same performance, harder implementation, research needed.
• Canvas: no comments, not in this case.

Universal sizing algorithm still isn't obvious for me, so optimal decision in terms 'get this job done' was to check if Digit belongs to specific range with given characteristics.

 barStyle(d) {
   let width;
   let height;

   // Assign width
   if (d < 4) {
     width = 4;
   } else if (d < 8) {
     width = 10;
   } else {
     width = 17;
   }
   
   // Assign height
   if ([0, 4, 8].includes(d)) {
     height = 4;
   } else if ([1, 5, 9].includes(d)) {
     height = 8;
   } else if ([2, 6].includes(d)) {
     height = 12;
   } else {
     height = 16;
   }

   return {
     height: `${height * 5}%`,
     width: `${width}%`,
   };
 }

Some possible enhancements

• use Vuex as data storage for more complex interactions;
• move Barcode out from its background for better reusabilty;
• use more global styles or css/ui-frameworks;
• mobile views / cross browser testing
• moreover: maybe start with Nuxt.js, not just Vue;
• some interface ideas:
  • we will need sidebar/toolbar with more menus/tools;
  • maybe make Barcode container resizable (smth like vue-draggable-resizable plugin)

---

Project setup

npm install

Compiles and hot-reloads for development

npm run serve

Compiles and minifies for production

npm run build

Run your tests

npm run test

Lints and fixes files

npm run lint

Run your unit tests

npm run test:unit

Customize configuration

See Configuration Reference.