mirror of https://github.com/espruino/BangleApps
92 lines
2.7 KiB
JavaScript
92 lines
2.7 KiB
JavaScript
// Encoding documentation:
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// https://en.wikipedia.org/wiki/International_Article_Number_(EAN)#Binary_encoding_of_data_digits_into_EAN-13_barcode
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/*
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* JS source adapted from https://github.com/lindell/JsBarcode
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2016 Johan Lindell (johan@lindell.me)
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to
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* deal in the Software without restriction, including without limitation the
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* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
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* sell copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*/
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const EAN = require("cards.EAN.js");
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const EAN13_STRUCTURE = [
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'LLLLLL', 'LLGLGG', 'LLGGLG', 'LLGGGL', 'LGLLGG',
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'LGGLLG', 'LGGGLL', 'LGLGLG', 'LGLGGL', 'LGGLGL'
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];
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// Calculate the checksum digit
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// https://en.wikipedia.org/wiki/International_Article_Number_(EAN)#Calculation_of_checksum_digit
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const checksum = (number) => {
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const res = number
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.substr(0, 12)
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.split('')
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.map((n) => +n)
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.reduce((sum, a, idx) => (
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idx % 2 ? sum + a * 3 : sum + a
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), 0);
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return (10 - (res % 10)) % 10;
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};
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class EAN13 extends EAN {
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constructor(data, options) {
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// Add checksum if it does not exist
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if (/^[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]$/.test(data)) {
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data += checksum(data);
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}
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super(data, options);
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// Adds a last character to the end of the barcode
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this.lastChar = options.lastChar;
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}
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valid() {
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return (
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/^[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]$/.test(this.data) &&
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+this.data[12] === checksum(this.data)
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);
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}
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leftText() {
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return super.leftText(1, 6);
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}
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leftEncode() {
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const data = this.data.substr(1, 6);
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const structure = EAN13_STRUCTURE[this.data[0]];
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return super.leftEncode(data, structure);
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}
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rightText() {
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return super.rightText(7, 6);
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}
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rightEncode() {
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const data = this.data.substr(7, 6);
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return super.rightEncode(data, 'RRRRRR');
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}
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}
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module.exports = EAN13; |