ndef/lib/ndef-text.js

Library to create and parse NDEF messages.

var util = require('./ndef-util');

// decode text bytes from ndef record payload
// @returns a string
function decode(data) {

    var languageCodeLength = (data[0] & 0x3F), // 6 LSBs
        languageCode = data.slice(1, 1 + languageCodeLength),
        utf16 = (data[0] & 0x80) !== 0; // assuming UTF-16BE

    // TODO need to deal with UTF in the future
    // console.log("lang " + languageCode + (utf16 ? " utf16" : " utf8"));

    return util.bytesToString(data.slice(languageCodeLength + 1));
}

// encode text payload
// @returns an array of bytes
function encode(text, lang, encoding) {

    // ISO/IANA language code, but we're not enforcing
    if (!lang) { lang = 'en'; }

    var encoded = util.stringToBytes(lang + text);
    encoded.unshift(lang.length);

    return encoded;
}

module.exports = {
    encodePayload: encode,
    decodePayload: decode
}