如何在JavaScript中验证EAN/GTIN条形码
如何在JavaScript中检查字符串是否为有效的EAN/GTIN条形码?
我需要检查EAN8、EAN12、EAN13、EAN14、EAN18以及GTIN12、GTIN13、GTIN14。
解决方案
编辑我还创建了一个npm模块,可以在github上找到。
我创建了一个小库,支持EAN8、EAN12、EAN13、EAN14、EAN18、GTIN12、GTIN13和GTIN14。
它可以在node.js和所有现代浏览器中运行。
barcoder.js:
/*!
* Barcoder
* Copyright (c) 2013 mifitto GmbH <dominik@mifitto.com>
* MIT Licensed
*/
(function() {
'use strict';
/**
* Library version.
*/
var version = '1.1.0';
/**
* Supported formats
*/
var minValidLength = 6;
var maxValidLength = 18;
var usualValidChars = /^d+$/;
var formats = {
'ean8' : { validChars : /^d+$/, validLength : 8 },
'ean12' : { validChars : /^d+$/, validLength : 12 },
'ean13' : { validChars : /^d+$/, validLength : 13 },
'ean14' : { validChars : /^d+$/, validLength : 14 },
'ean18' : { validChars : /^d+$/, validLength : 18 },
'gtin12' : { validChars : /^d+$/, validLength : 12 },
'gtin13' : { validChars : /^d+$/, validLength : 13 },
'gtin14' : { validChars : /^d+$/, validLength : 14 }
};
/**
* Validates the checksum (Modulo 10)
* GTIN implementation factor 3
*
* @param {String} value The barcode to validate
* @return {Boolean}
* @api private
*/
var validateGtin = function( value ) {
var barcode = value.substring( 0, value.length - 1 );
var checksum = parseInt( value.substring( value.length - 1 ), 10 );
var calcSum = 0;
var calcChecksum = 0;
barcode.split('').map(function( number, index ) {
number = parseInt( number, 10 );
if ( value.length % 2 === 0 ) {
index += 1;
}
if ( index % 2 === 0 ) {
calcSum += number;
}
else {
calcSum += number * 3;
}
});
calcSum %= 10;
calcChecksum = (calcSum === 0) ? 0 : (10 - calcSum);
if ( calcChecksum !== checksum ) {
return false;
}
return true;
};
/**
* Barcoder class
*
* @param {string} format See formats
* @param {Object} options Valid option `enableZeroPadding`, defaults to `true`
* @api public
*/
var Barcoder = function ( format, options ) {
if ( format && !formats[format] ) throw new Error( '"format" invalid' );
this.format = (format) ? formats[format] : 'autoSelect';
this.options = (options) ? options : { enableZeroPadding : true };
if ( !this.options.enableZeroPadding ) {
this.options.enableZeroPadding = true;
}
};
/**
* Validates a barcode
*
* @param {string} barcode EAN/GTIN barcode
* @return {Boolean}
* @api public
*/
Barcoder.prototype.validate = function( barcode ) {
var self = this;
if ( self.format === 'autoSelect' ) {
if ( barcode.length < minValidLength || barcode.length > maxValidLength ) {
return false;
}
var isValidGtin = validateGtin( barcode );
var paddedBarcode = barcode;
var successfullyPadded = false;
if ( !isValidGtin ) {
var possiblyMissingZeros = maxValidLength - barcode.length;
while( possiblyMissingZeros-- ) {
paddedBarcode = '0' + paddedBarcode;
if ( validateGtin( paddedBarcode ) ) {
isValidGtin = true;
successfullyPadded = true;
break;
}
}
}
return {
possibleType: (barcode.length > 8) ? 'GTIN' + barcode.length : 'EAN8 / padded GTIN',
isValid: isValidGtin
};
}
var validChars = self.format.validChars;
var validLength = self.format.validLength;
var enableZeroPadding = self.options.enableZeroPadding;
if ( validChars.exec( barcode ) === null ) {
return false;
}
if ( enableZeroPadding && barcode.length < validLength ) {
var missingZeros = validLength - barcode.length;
while( missingZeros-- ) {
barcode = '0' + barcode;
}
}
else if ( !enableZeroPadding && barcode.length != validLength ) {
return false;
}
else if ( barcode.length > validLength ) {
return false;
}
return validateGtin( barcode );
};
/**
* Export
*/
if ( 'undefined' !== typeof module && module.exports ) {
module.exports = Barcoder;
exports.version = version;
}
if ( 'undefined' === typeof ender ) {
this['Barcoder'] = Barcoder;
}
if ( 'function' === typeof define && define.amd ) {
define('Barcoder', [], function () {
return Barcoder;
});
}
}).call( this );
安装:
$ npm install barcoder
用法:
var Barcoder = require('barcoder');
var ean1 = '0016T20054453';
var ean2 = '9330071314999';
var validator = new Barcoder('ean13');
console.log( '%s ean1 is valid: %s', ean1, validator.validate( ean1 ) );
console.log( '%s ean2 is valid: %s', ean1, validator.validate( ean2 ) );
// or /w automatic type selection
validator = new Barcoder();
var validation1 = validator.validate( ean1 );
var validation2 = validator.validate( ean2 );
console.log( '%s is valid: %s and has guessed type: %s', ean1, validation1.isValid, validation1.possibleType );
console.log( '%s is valid: %s and has guessed type: %s', ean2, validation2.isValid, validation2.possibleType );
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