/*!
|
* media-typer
|
* Copyright(c) 2014-2017 Douglas Christopher Wilson
|
* MIT Licensed
|
*/
|
|
'use strict'
|
|
/**
|
* 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 / "!" / "#" /
|
* "$" / "&" / "-" / "^" / "_"
|
* restricted-name-chars =/ "." ; Characters before first dot always
|
* ; specify a facet name
|
* restricted-name-chars =/ "+" ; Characters after last plus always
|
* ; specify a structured syntax suffix
|
* ALPHA = %x41-5A / %x61-7A ; A-Z / a-z
|
* DIGIT = %x30-39 ; 0-9
|
*/
|
var SUBTYPE_NAME_REGEXP = /^[A-Za-z0-9][A-Za-z0-9!#$&^_.-]{0,126}$/
|
var TYPE_NAME_REGEXP = /^[A-Za-z0-9][A-Za-z0-9!#$&^_-]{0,126}$/
|
var TYPE_REGEXP = /^ *([A-Za-z0-9][A-Za-z0-9!#$&^_-]{0,126})\/([A-Za-z0-9][A-Za-z0-9!#$&^_.+-]{0,126}) *$/
|
|
/**
|
* Module exports.
|
*/
|
|
exports.format = format
|
exports.parse = parse
|
exports.test = test
|
|
/**
|
* Format object to media type.
|
*
|
* @param {object} obj
|
* @return {string}
|
* @public
|
*/
|
|
function format (obj) {
|
if (!obj || typeof obj !== 'object') {
|
throw new TypeError('argument obj is required')
|
}
|
|
var subtype = obj.subtype
|
var suffix = obj.suffix
|
var type = obj.type
|
|
if (!type || !TYPE_NAME_REGEXP.test(type)) {
|
throw new TypeError('invalid type')
|
}
|
|
if (!subtype || !SUBTYPE_NAME_REGEXP.test(subtype)) {
|
throw new TypeError('invalid subtype')
|
}
|
|
// format as type/subtype
|
var string = type + '/' + subtype
|
|
// append +suffix
|
if (suffix) {
|
if (!TYPE_NAME_REGEXP.test(suffix)) {
|
throw new TypeError('invalid suffix')
|
}
|
|
string += '+' + suffix
|
}
|
|
return string
|
}
|
|
/**
|
* Test media type.
|
*
|
* @param {string} string
|
* @return {object}
|
* @public
|
*/
|
|
function test (string) {
|
if (!string) {
|
throw new TypeError('argument string is required')
|
}
|
|
if (typeof string !== 'string') {
|
throw new TypeError('argument string is required to be a string')
|
}
|
|
return TYPE_REGEXP.test(string.toLowerCase())
|
}
|
|
/**
|
* Parse media type to object.
|
*
|
* @param {string} string
|
* @return {object}
|
* @public
|
*/
|
|
function parse (string) {
|
if (!string) {
|
throw new TypeError('argument string is required')
|
}
|
|
if (typeof string !== 'string') {
|
throw new TypeError('argument string is required to be a string')
|
}
|
|
var match = TYPE_REGEXP.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)
|
}
|
|
return new MediaType(type, subtype, suffix)
|
}
|
|
/**
|
* Class for MediaType object.
|
* @public
|
*/
|
|
function MediaType (type, subtype, suffix) {
|
this.type = type
|
this.subtype = subtype
|
this.suffix = suffix
|
}
|
