express/lib/request.js
2011-12-30 15:04:41 -08:00

384 lines
8.1 KiB
JavaScript

/*!
* Express - request
* Copyright(c) 2010 TJ Holowaychuk <tj@vision-media.ca>
* MIT Licensed
*/
/**
* Module dependencies.
*/
var http = require('http')
, utils = require('./utils')
, connect = require('connect')
, parse = require('url').parse
, mime = require('mime');
/**
* Request prototype.
*/
var req = exports = module.exports = {
__proto__: http.IncomingMessage.prototype
};
/**
* Return request header or optional default.
*
* The `Referrer` header field is special-cased,
* both `Referrer` and `Referer` will yield are
* interchangeable.
*
* Examples:
*
* req.header('Content-Type');
* // => "text/plain"
*
* req.header('content-type');
* // => "text/plain"
*
* req.header('Accept');
* // => undefined
*
* req.header('Accept', 'text/html');
* // => "text/html"
*
* @param {String} name
* @param {String} defaultValue
* @return {String}
* @api public
*/
req.header = function(name, defaultValue){
switch (name = name.toLowerCase()) {
case 'referer':
case 'referrer':
return this.headers.referrer
|| this.headers.referer
|| defaultValue;
default:
return this.headers[name] || defaultValue;
}
};
/**
* Get `field`'s `param` value, defaulting to ''.
*
* Examples:
*
* req.get('content-disposition', 'filename');
* // => "something.png"
*
* req.get('content-disposition', 'rawr');
* // => ""
*
* @param {String} field
* @param {String} param
* @return {String}
* @api public
*/
req.get = function(field, param){
// TODO: rename... add tests, make .get() .header()
var val = this.header(field);
if (!val) return '';
var regexp = new RegExp(param + ' *= *(?:"([^"]+)"|([^;]+))', 'i');
if (!regexp.exec(val)) return '';
return RegExp.$1 || RegExp.$2;
};
/**
* Check if the given `type` is acceptable,
* otherwise you should respond with 406 "Not Acceptable".
*
* Examples:
*
* // Accept: text/html
* req.accepts('html');
* // => true
*
* // Accept: text/*; application/json
* req.accepts('html');
* req.accepts('text/html');
* req.accepts('text/plain');
* req.accepts('application/json');
* // => true
*
* req.accepts('image/png');
* req.accepts('png');
* // => false
*
* @param {String} type
* @return {Boolean}
* @api public
*/
req.accepts = function(type){
return utils.accepts(type, this.header('Accept'));
};
/**
* Check if the given `charset` is acceptable,
* otherwise you should respond with 406 "Not Acceptable".
*
* @param {String} charset
* @return {Boolean}
* @api public
*/
req.acceptsCharset = function(charset){
var accepted = this.acceptedCharsets;
return accepted.length
? ~accepted.indexOf(charset)
: true;
};
/**
* Check if the given `lang` is acceptable,
* otherwise you should respond with 406 "Not Acceptable".
*
* @param {String} lang
* @return {Boolean}
* @api public
*/
req.acceptsLanguage = function(lang){
var accepted = this.acceptedLanguages;
return accepted.length
? ~accepted.indexOf(lang)
: true;
};
/**
* Return an array of Accepted media types
* ordered from highest quality to lowest.
*
* Examples:
*
* [ { value: 'application/json',
* quality: 1,
* type: 'application',
* subtype: 'json' },
* { value: 'text/html',
* quality: 0.5,
* type: 'text',
* subtype: 'html' } ]
*
* @return {Array}
* @api public
*/
req.__defineGetter__('accepted', function(){
var accept = this.header('Accept');
return accept
? utils.parseAccept(accept)
: [];
});
/**
* Return an array of Accepted languages
* ordered from highest quality to lowest.
*
* Examples:
*
* Accept-Language: en;q=.5, en-us
* ['en-us', 'en']
*
* @return {Array}
* @api public
*/
req.__defineGetter__('acceptedLanguages', function(){
var accept = this.header('Accept-Language');
return accept
? utils
.parseQuality(accept)
.map(function(obj){
return obj.value;
})
: [];
});
/**
* Return an array of Accepted charsets
* ordered from highest quality to lowest.
*
* Examples:
*
* Accept-Charset: iso-8859-5;q=.2, unicode-1-1;q=0.8
* ['unicode-1-1', 'iso-8859-5']
*
* @return {Array}
* @api public
*/
req.__defineGetter__('acceptedCharsets', function(){
var accept = this.header('Accept-Charset');
return accept
? utils
.parseQuality(accept)
.map(function(obj){
return obj.value;
})
: [];
});
/**
* Return the value of param `name` when present or `defaultValue`.
*
* - Checks body params, ex: id=12, {"id":12}
* - Checks route placeholders, ex: _/user/:id_
* - Checks query string params, ex: ?id=12
*
* To utilize request bodies, `req.body`
* should be an object. This can be done by using
* the `connect.bodyParser()` middleware.
*
* @param {String} name
* @param {Mixed} defaultValue
* @return {String}
* @api public
*/
req.param = function(name, defaultValue){
// req.body
if (this.body && undefined !== this.body[name]) return this.body[name];
// route params
if (this.params
&& this.params.hasOwnProperty(name)
&& undefined !== this.params[name]) {
return this.params[name];
}
// query-string
if (undefined !== this.query[name]) return this.query[name];
return defaultValue;
};
/**
* Check if the incoming request contains the "Content-Type"
* header field, and it contains the give mime `type`.
*
* Examples:
*
* // With Content-Type: text/html; charset=utf-8
* req.is('html');
* req.is('text/html');
* // => true
*
* // When Content-Type is application/json
* req.is('json');
* req.is('application/json');
* // => true
*
* req.is('html');
* // => false
*
* Ad-hoc callbacks can also be registered with Express, to perform
* assertions again the request, for example if we need an expressive
* way to check if our incoming request is an image, we can register "an image"
* callback:
*
* app.is('an image', function(req){
* return 0 == req.headers['content-type'].indexOf('image');
* });
*
* app.is('an attachment', function(req){
* return 0 == req.headers['content-disposition'].indexOf('attachment');
* });
*
* Now within our route callbacks, we can use to to assert content types
* such as "image/jpeg", "image/png", etc.
*
* app.post('/image/upload', function(req, res, next){
* if (req.is('an image')) {
* // do something
* } else {
* next();
* }
* });
*
* @param {String} type
* @return {Boolean}
* @api public
*/
req.is = function(type){
var fn = this.app.is(type);
if (fn) return fn(this);
var ct = this.headers['content-type'];
if (!ct) return false;
ct = ct.split(';')[0];
if (!~type.indexOf('/')) type = mime.lookup(type);
if (~type.indexOf('*')) {
type = type.split('/');
ct = ct.split('/');
if ('*' == type[0] && type[1] == ct[1]) return true;
if ('*' == type[1] && type[0] == ct[0]) return true;
return false;
}
return !! ~ct.indexOf(type);
};
/**
* Short-hand for `req.connection.encrypted`.
*
* @return {Boolean}
* @api public
*/
req.__defineGetter__('secure', function(){
return this.connection.encrypted;
});
/**
* Short-hand for `require('url').parse(req.url).pathname`.
*
* @return {String}
* @api public
*/
req.__defineGetter__('path', function(){
return parse(this.url).pathname;
});
/**
* Check if the request is fresh, aka
* Last-Modified and/or the ETag
* still match.
*
* @return {Boolean}
* @api public
*/
req.__defineGetter__('fresh', function(){
return ! this.stale;
});
/**
* Check if the request is stale, aka
* Last-Modified and/or the ETag for the
* resource has changed.
*
* @return {Boolean}
* @api public
*/
req.__defineGetter__('stale', function(){
return connect.utils.modified(this, this.res);
});
/**
* Check if the request was an _XMLHttpRequest_.
*
* @return {Boolean}
* @api public
*/
req.__defineGetter__('xhr', function(){
return 'xmlhttprequest' == this.header('X-Requested-With', '').toLowerCase();
});