wallet-core/node_modules/encoding/lib/encoding.js
2016-10-10 03:43:44 +02:00

114 lines
3.1 KiB
JavaScript

'use strict';
var iconvLite = require('iconv-lite');
// Load Iconv from an external file to be able to disable Iconv for webpack
// Add /\/iconv-loader$/ to webpack.IgnorePlugin to ignore it
var Iconv = require('./iconv-loader');
// Expose to the world
module.exports.convert = convert;
/**
* Convert encoding of an UTF-8 string or a buffer
*
* @param {String|Buffer} str String to be converted
* @param {String} to Encoding to be converted to
* @param {String} [from='UTF-8'] Encoding to be converted from
* @param {Boolean} useLite If set to ture, force to use iconvLite
* @return {Buffer} Encoded string
*/
function convert(str, to, from, useLite) {
from = checkEncoding(from || 'UTF-8');
to = checkEncoding(to || 'UTF-8');
str = str || '';
var result;
if (from !== 'UTF-8' && typeof str === 'string') {
str = new Buffer(str, 'binary');
}
if (from === to) {
if (typeof str === 'string') {
result = new Buffer(str);
} else {
result = str;
}
} else if (Iconv && !useLite) {
try {
result = convertIconv(str, to, from);
} catch (E) {
console.error(E);
try {
result = convertIconvLite(str, to, from);
} catch (E) {
console.error(E);
result = str;
}
}
} else {
try {
result = convertIconvLite(str, to, from);
} catch (E) {
console.error(E);
result = str;
}
}
if (typeof result === 'string') {
result = new Buffer(result, 'utf-8');
}
return result;
}
/**
* Convert encoding of a string with node-iconv (if available)
*
* @param {String|Buffer} str String to be converted
* @param {String} to Encoding to be converted to
* @param {String} [from='UTF-8'] Encoding to be converted from
* @return {Buffer} Encoded string
*/
function convertIconv(str, to, from) {
var response, iconv;
iconv = new Iconv(from, to + '//TRANSLIT//IGNORE');
response = iconv.convert(str);
return response.slice(0, response.length);
}
/**
* Convert encoding of astring with iconv-lite
*
* @param {String|Buffer} str String to be converted
* @param {String} to Encoding to be converted to
* @param {String} [from='UTF-8'] Encoding to be converted from
* @return {Buffer} Encoded string
*/
function convertIconvLite(str, to, from) {
if (to === 'UTF-8') {
return iconvLite.decode(str, from);
} else if (from === 'UTF-8') {
return iconvLite.encode(str, to);
} else {
return iconvLite.encode(iconvLite.decode(str, from), to);
}
}
/**
* Converts charset name if needed
*
* @param {String} name Character set
* @return {String} Character set name
*/
function checkEncoding(name) {
return (name || '').toString().trim().
replace(/^latin[\-_]?(\d+)$/i, 'ISO-8859-$1').
replace(/^win(?:dows)?[\-_]?(\d+)$/i, 'WINDOWS-$1').
replace(/^utf[\-_]?(\d+)$/i, 'UTF-$1').
replace(/^ks_c_5601\-1987$/i, 'CP949').
replace(/^us[\-_]?ascii$/i, 'ASCII').
toUpperCase();
}