javascriptnode.jsparsingtagstlv

EMVCo TLV string parser library for Javascript

I want to parse a TLV string and get the value when I give the tag value.

Sample:

000201021642333310011114235204546757034445802IN5910My Company6005Vegas6304bb02

Based on TLV rules Tag 52 will give value 5467, 57 will be 333.

Solution 
  • var str = '000201021642333310011114235204546757034445802IN5910My Company6005Vegas6304bb02';
var headerLength = 6; // assuming header length is always 6
var header = str.substring(0, 6);

var tags = [];

// start after header
var i = 6;
while (i < str.length) {
    var tag = str.substring(i, i + 2);
    i += 2;
    var valueLength = Number(str.substring(i, i + 2));
    i += 2;
    var value = str.substring(i, i + valueLength);
    i += valueLength;
    tags.push({tag: tag, value: value});
}