encodeWord: function(data, mimeWordEncoding, maxLength) {
mimeWordEncoding = (mimeWordEncoding || 'Q').toString().toUpperCase().trim().charAt(0);
maxLength = maxLength || 0;
var encodedStr,
toCharset = 'UTF-8',
i, len, parts;
if (maxLength && maxLength > 7 + toCharset.length) {
maxLength -= (7 + toCharset.length);
}
if (mimeWordEncoding === 'Q') {
// https://tools.ietf.org/html/rfc2047#section-5 rule (3)
encodedStr = libqp.encode(data).replace(/[^a-z0-9!*+\-\/=]/ig, function(chr) {
var ord = chr.charCodeAt(0).toString(16).toUpperCase();
if (chr === ' ') {
return '_';
} else {
return '=' + (ord.length === 1 ? '0' + ord : ord);
}
});
} else if (mimeWordEncoding === 'B') {
encodedStr = typeof data === 'string' ? data : libbase64.encode(data);
maxLength = Math.max(3, (maxLength - maxLength % 4) / 4 * 3);
}
if (maxLength && encodedStr.length > maxLength) {
if (mimeWordEncoding === 'Q') {
encodedStr = splitMimeEncodedString(encodedStr, maxLength).join('?= =?' + toCharset + '?' + mimeWordEncoding + '?');
} else {
// RFC2047 6.3 (2) states that encoded-word must include an integral number of characters, so no chopping unicode sequences
parts = [];
for (i = 0, len = encodedStr.length; i < len; i += maxLength) {
parts.push(libbase64.encode(encodedStr.substr(i, maxLength)));
}
if (parts.length > 1) {
encodedStr = parts.join('?= =?' + toCharset + '?' + mimeWordEncoding + '?');
} else {
encodedStr = parts.join('');
}
}
} else if (mimeWordEncoding === 'B') {
encodedStr = libbase64.encode(data);
}
return '=?' + toCharset + '?' + mimeWordEncoding + '?' + encodedStr + (encodedStr.substr(-2) === '?=' ? '' : '?=');
},
encodeWord: function (data, mimeWordEncoding, maxLength) {
mimeWordEncoding = (mimeWordEncoding || 'Q').toString().toUpperCase().trim().charAt(0);
maxLength = maxLength || 0;
var encodedStr,
toCharset = 'UTF-8',
i, len, parts, lpart, chr;
if (maxLength && maxLength > 7 + toCharset.length) {
maxLength -= (7 + toCharset.length);
}
if (mimeWordEncoding === 'Q') {
// https://tools.ietf.org/html/rfc2047#section-5 rule (3)
encodedStr = libqp.encode(data).replace(/[^a-z0-9!*+\-\/=]/ig, function (chr) {
var ord = chr.charCodeAt(0).toString(16).toUpperCase();
if (chr === ' ') {
return '_';
} else {
return '=' + (ord.length === 1 ? '0' + ord : ord);
}
});
} else if (mimeWordEncoding === 'B') {
encodedStr = typeof data === 'string' ? data : libbase64.encode(data);
maxLength = maxLength ? Math.max(3, (maxLength - maxLength % 4) / 4 * 3) : 0;
}
if (maxLength && (mimeWordEncoding !== 'B' ? encodedStr : libbase64.encode(data)).length > maxLength) {
if (mimeWordEncoding === 'Q') {
encodedStr = splitMimeEncodedString(encodedStr, maxLength).join('?= =?' + toCharset + '?' + mimeWordEncoding + '?');
} else {
// RFC2047 6.3 (2) states that encoded-word must include an integral number of characters, so no chopping unicode sequences
parts = [];
lpart = '';
for (i = 0, len = encodedStr.length; i < len; i++) {
chr = encodedStr.charAt(i);
// check if we can add this character to the existing string
// without breaking byte length limit
if (Buffer.byteLength(lpart + chr) <= maxLength || i === 0) {
lpart += chr;
} else {
// we hit the length limit, so push the existing string and start over
parts.push(libbase64.encode(lpart));
lpart = chr;
}
}
if (lpart) {
parts.push(libbase64.encode(lpart));
}
if (parts.length > 1) {
encodedStr = parts.join('?= =?' + toCharset + '?' + mimeWordEncoding + '?');
} else {
encodedStr = parts.join('');
}
}
} else if (mimeWordEncoding === 'B') {
encodedStr = libbase64.encode(data);
}
return '=?' + toCharset + '?' + mimeWordEncoding + '?' + encodedStr + (encodedStr.substr(-2) === '?=' ? '' : '?=');
},