@allansli/barcode-febraban-core

Draw the barcode on a Brazilian boleto. That barcode is ITF (Interleaved 2 of 5), the symbology Febraban uses for the código de barras. @allansli/barcode-febraban-core is the vanilla JavaScript encoder: it turns an even-length digit string into the character sequence that BarcodeInterleaved2of5.ttf renders as the bars.

Pass digits you already have (the 44-digit código de barras is the usual input). This package does not parse a boleto, does not convert a 47-digit linha digitável into 44 digits, and does not compute the módulo-11 DAC.

The framework packages call this function:

• @allansli/angular-barcode-febraban — AngularJS 1.x
• @allansli/react-barcode-febraban — React
• @allansli/vue-barcode-febraban — Vue 3
• @allansli/ng-barcode-febraban — Angular 15+

Install

npm install @allansli/barcode-febraban-core

Minimal example

import { generateBarcodeSequence } from "@allansli/barcode-febraban-core";

const sequence = generateBarcodeSequence("1234567890");
console.log(sequence); // "(<RÆÜè)"

Put sequence in an element with class barcodei2of5 after loading assets/css/barcode.css. Host BarcodeInterleaved2of5.ttf yourself; npm does not ship the font.

When to use

• You need an ITF (Interleaved 2 of 5) barcode for a Brazilian boleto (Febraban código de barras).
• The input is a string of digits with even length. A 44-digit código de barras qualifies.
• You want vanilla JS (ESM, CommonJS, or a browser script) and will render with BarcodeInterleaved2of5.ttf.

When not to use

• EAN, UPC, Code 128, QR, or any symbology other than ITF.
• You have a 47-digit linha digitável and need it converted. Odd length returns "". There is no 47→44 conversion.
• You need the DAC (módulo 11) computed or checked.
• You need a canvas or SVG barcode that does not use this font.
• You want a component: use the React, Vue, Angular, or AngularJS package instead of calling this from a template by hand.

| Expectation | This package | |---|---| | 44-digit código de barras | Encodes (even length, digits only) | | 47-digit linha digitável | Returns "" — there is no conversion | | DAC (módulo 11) | Not computed or checked | | Odd length | Returns "" (no leading-zero pad) | | Non-digits / non-strings | Returns "" (does not throw) |

Other entry points

The minimal example is ESM (Vite, Webpack, Rollup). CommonJS and a browser script use the same function.

CommonJS (Node.js, older bundlers)

const { generateBarcodeSequence } = require("@allansli/barcode-febraban-core");

const sequence = generateBarcodeSequence("1234567890");

Browser (script tag)

<script src="node_modules/@allansli/barcode-febraban-core/src/generate-barcode-sequence.js"></script>
<script>
  var sequence = barcodeFebrabanCore.generateBarcodeSequence("1234567890");
</script>

The UMD entry src/index.js also works in Node/AMD. In a browser it expects the encoder script above (or a bundle that concatenates both).

API

generateBarcodeSequence(barcode)

Parameters

| Name | Type | Description | |---|---|---| | barcode | string | Digits only, even length |

Returns string — Font-encoded sequence wrapped in parentheses, or "" for invalid input (including null, numbers, odd length, and 47-digit linha digitável).

Encoding (for this font, not a generic ITF bit pattern):

• Pairs 00–49 → charCode = pair + 48
• Pairs 50–99 → charCode = pair + 142
• Result wrapped in ( ) for the font’s start/stop bars

generateBarcodeSequence("1234567890");
// pairs: 12, 34, 56, 78, 90 → "(<RÆÜè)"

generateBarcodeSequence("0".repeat(47)); // linha digitável length
// ""

CSS & Font

Published npm packages include the CSS only. They do not include BarcodeInterleaved2of5.ttf (no redistributable license; see NOTICE).

The CSS still references the historical relative path:

@font-face {
  font-family: "BarcodeInterleaved2of5";
  src: url("../fonts/BarcodeInterleaved2of5.ttf") format("truetype");
}

Host a copy of that file (from this git tree for local demos, or a font you are licensed to use) at fonts/BarcodeInterleaved2of5.ttf next to css/, or override @font-face in your app.

<link rel="stylesheet" href="node_modules/@allansli/barcode-febraban-core/assets/css/barcode.css" />

Or in a bundler:

import "@allansli/barcode-febraban-core/assets/css/barcode.css";

<div class="barcodei2of5"><!-- sequence goes here --></div>

GitHub Pages demos load the TTF from packages/core/assets/fonts/ in this repo.

License

MIT © Allan Martins de Paula (source code). The TrueType font in git is not covered by MIT and is not published to npm; see NOTICE.