/*!
* media-typer
* Copyright(c) 2014 Douglas Christopher Wilson
* MIT Licensed
*/
/**
* RegExp to match *( ";" parameter ) in RFC 2616 sec 3.7
*
* parameter = token "=" ( token | quoted-string )
* token = 1*<any CHAR except CTLs or separators>
* separators = "(" | ")" | "<" | ">" | "@"
* | "," | ";" | ":" | "\" | <">
* | "/" | "[" | "]" | "?" | "="
* | "{" | "}" | SP | HT
* quoted-string = ( <"> *(qdtext | quoted-pair ) <"> )
* qdtext = <any TEXT except <">>
* quoted-pair = "\" CHAR
* CHAR = <any US-ASCII character (octets 0 - 127)>
* TEXT = <any OCTET except CTLs, but including LWS>
* LWS = [CRLF] 1*( SP | HT )
* CRLF = CR LF
* CR = <US-ASCII CR, carriage return (13)>
* LF = <US-ASCII LF, linefeed (10)>
* SP = <US-ASCII SP, space (32)>
* SHT = <US-ASCII HT, horizontal-tab (9)>
* CTL = <any US-ASCII control character (octets 0 - 31) and DEL (127)>
* OCTET = <any 8-bit sequence of data>
*/
var paramRegExp = /; *([!#$%&'\*\+\-\.0-9A-Z\^_`a-z\|~]+) *= *("(?:[ !\u0023-\u005b\u005d-\u007e\u0080-\u00ff]|\\[\u0020-\u007e])*"|[!#$%&'\*\+\-\.0-9A-Z\^_`a-z\|~]+) */g;
var textRegExp = /^[\u0020-\u007e\u0080-\u00ff]+$/
var tokenRegExp = /^[!#$%&'\*\+\-\.0-9A-Z\^_`a-z\|~]+$/
/**
* RegExp to match quoted-pair in RFC 2616
*
* quoted-pair = "\" CHAR
* CHAR = <any US-ASCII character (octets 0 - 127)>
*/
var qescRegExp = /\\([\u0000-\u007f])/g;
/**
* RegExp to match chars that must be quoted-pair in RFC 2616
*/
var quoteRegExp = /([\\"])/g;
/**
* RegExp to match type in RFC 6838
*
* type-name = restricted-name
* subtype-name = restricted-name
* restricted-name = restricted-name-first *126restricted-name-chars
* restricted-name-first = ALPHA / DIGIT
* restricted-name-chars = ALPHA / DIGIT / "!" / "#" /
* "$" / "&" / "-" / "^" / "_"
* restricted-name-chars =/ "." ; Characters before first dot always
* ; specify a facet name
* restricted-name-chars =/ "+" ; Characters after last plus always
* ; specify a structured syntax suffix
* ALPHA = %x41-5A / %x61-7A ; A-Z / a-z
* DIGIT = %x30-39 ; 0-9
*/
var subtypeNameRegExp = /^[A-Za-z0-9][A-Za-z0-9!#$&^_.-]{0,126}$/
var typeNameRegExp = /^[A-Za-z0-9][A-Za-z0-9!#$&^_-]{0,126}$/
var typeRegExp = /^ *([A-Za-z0-9][A-Za-z0-9!#$&^_-]{0,126})\/([A-Za-z0-9][A-Za-z0-9!#$&^_.+-]{0,126}) *$/;
/**
* Module exports.
*/
exports.format = format
exports.parse = parse
/**
* Format object to media type.
*
* @param {object} obj
* @return {string}
* @api public
*/
function format(obj) {
if (!obj || typeof obj !== 'object') {
throw new TypeError('argument obj is required')
}
var parameters = obj.parameters
var subtype = obj.subtype
var suffix = obj.suffix
var type = obj.type
if (!type || !typeNameRegExp.test(type)) {
throw new TypeError('invalid type')
}
if (!subtype || !subtypeNameRegExp.test(subtype)) {
throw new TypeError('invalid subtype')
}
// format as type/subtype
var string = type + '/' + subtype
// append +suffix
if (suffix) {
if (!typeNameRegExp.test(suffix)) {
throw new TypeError('invalid suffix')
}
string += '+' + suffix
}
// append parameters
if (parameters && typeof parameters === 'object') {
var param
var params = Object.keys(parameters).sort()
for (var i = 0; i < params.length; i++) {
param = params[i]
if (!tokenRegExp.test(param)) {
throw new TypeError('invalid parameter name')
}
string += '; ' + param + '=' + qstring(parameters[param])
}
}
return string
}
/**
* Parse media type to object.
*
* @param {string|object} string
* @return {Object}
* @api public
*/
function parse(string) {
if (!string) {
throw new TypeError('argument string is required')
}
// support req/res-like objects as argument
if (typeof string === 'object') {
string = getcontenttype(string)
}
if (typeof string !== 'string') {
throw new TypeError('argument string is required to be a string')
}
var index = string.indexOf(';')
var type = index !== -1
? string.substr(0, index)
: string
var key
var match
var obj = splitType(type)
var params = {}
var value
paramRegExp.lastIndex = index
while (match = paramRegExp.exec(string)) {
if (match.index !== index) {
throw new TypeError('invalid parameter format')
}
index += match[0].length
key = match[1].toLowerCase()
value = match[2]
if (value[0] === '"') {
// remove quotes and escapes
value = value
.substr(1, value.length - 2)
.replace(qescRegExp, '$1')
}
params[key] = value
}
if (index !== -1 && index !== string.length) {
throw new TypeError('invalid parameter format')
}
obj.parameters = params
return obj
}
/**
* Get content-type from req/res objects.
*
* @param {object}
* @return {Object}
* @api private
*/
function getcontenttype(obj) {
if (typeof obj.getHeader === 'function') {
// res-like
return obj.getHeader('content-type')
}
if (typeof obj.headers === 'object') {
// req-like
return obj.headers && obj.headers['content-type']
}
}
/**
* Quote a string if necessary.
*
* @param {string} val
* @return {string}
* @api private
*/
function qstring(val) {
var str = String(val)
// no need to quote tokens
if (tokenRegExp.test(str)) {
return str
}
if (str.length > 0 && !textRegExp.test(str)) {
throw new TypeError('invalid parameter value')
}
return '"' + str.replace(quoteRegExp, '\\$1') + '"'
}
/**
* Simply "type/subtype+siffx" into parts.
*
* @param {string} string
* @return {Object}
* @api private
*/
function splitType(string) {
var match = typeRegExp.exec(string.toLowerCase())
if (!match) {
throw new TypeError('invalid media type')
}
var type = match[1]
var subtype = match[2]
var suffix
// suffix after last +
var index = subtype.lastIndexOf('+')
if (index !== -1) {
suffix = subtype.substr(index + 1)
subtype = subtype.substr(0, index)
}
var obj = {
type: type,
subtype: subtype,
suffix: suffix
}
return obj
}