You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
118 lines
2.1 KiB
JavaScript
118 lines
2.1 KiB
JavaScript
/*!
|
|
* vary
|
|
* Copyright(c) 2014-2015 Douglas Christopher Wilson
|
|
* MIT Licensed
|
|
*/
|
|
|
|
'use strict';
|
|
|
|
/**
|
|
* Module exports.
|
|
*/
|
|
|
|
module.exports = vary;
|
|
module.exports.append = append;
|
|
|
|
/**
|
|
* Variables.
|
|
*/
|
|
|
|
var separators = /[\(\)<>@,;:\\"\/\[\]\?=\{\}\u0020\u0009]/;
|
|
|
|
/**
|
|
* Append a field to a vary header.
|
|
*
|
|
* @param {String} header
|
|
* @param {String|Array} field
|
|
* @return {String}
|
|
* @api public
|
|
*/
|
|
|
|
function append(header, field) {
|
|
if (typeof header !== 'string') {
|
|
throw new TypeError('header argument is required');
|
|
}
|
|
|
|
if (!field) {
|
|
throw new TypeError('field argument is required');
|
|
}
|
|
|
|
// get fields array
|
|
var fields = !Array.isArray(field)
|
|
? parse(String(field))
|
|
: field;
|
|
|
|
// assert on invalid fields
|
|
for (var i = 0; i < fields.length; i++) {
|
|
if (separators.test(fields[i])) {
|
|
throw new TypeError('field argument contains an invalid header');
|
|
}
|
|
}
|
|
|
|
// existing, unspecified vary
|
|
if (header === '*') {
|
|
return header;
|
|
}
|
|
|
|
// enumerate current values
|
|
var val = header;
|
|
var vals = parse(header.toLowerCase());
|
|
|
|
// unspecified vary
|
|
if (fields.indexOf('*') !== -1 || vals.indexOf('*') !== -1) {
|
|
return '*';
|
|
}
|
|
|
|
for (var i = 0; i < fields.length; i++) {
|
|
var fld = fields[i].toLowerCase();
|
|
|
|
// append value (case-preserving)
|
|
if (vals.indexOf(fld) === -1) {
|
|
vals.push(fld);
|
|
val = val
|
|
? val + ', ' + fields[i]
|
|
: fields[i];
|
|
}
|
|
}
|
|
|
|
return val;
|
|
}
|
|
|
|
/**
|
|
* Parse a vary header into an array.
|
|
*
|
|
* @param {String} header
|
|
* @return {Array}
|
|
* @api private
|
|
*/
|
|
|
|
function parse(header) {
|
|
return header.trim().split(/ *, */);
|
|
}
|
|
|
|
/**
|
|
* Mark that a request is varied on a header field.
|
|
*
|
|
* @param {Object} res
|
|
* @param {String|Array} field
|
|
* @api public
|
|
*/
|
|
|
|
function vary(res, field) {
|
|
if (!res || !res.getHeader || !res.setHeader) {
|
|
// quack quack
|
|
throw new TypeError('res argument is required');
|
|
}
|
|
|
|
// get existing header
|
|
var val = res.getHeader('Vary') || ''
|
|
var header = Array.isArray(val)
|
|
? val.join(', ')
|
|
: String(val);
|
|
|
|
// set new header
|
|
if ((val = append(header, field))) {
|
|
res.setHeader('Vary', val);
|
|
}
|
|
}
|