koa-lite/lib/response.js
2013-11-13 18:41:40 -08:00

428 lines
8 KiB
JavaScript

/**
* Module dependencies.
*/
var debug = require('debug')('koa:response');
var Negotiator = require('negotiator');
var statuses = require('./status');
var Cookies = require('cookies');
var qs = require('querystring');
var Stream = require('stream');
var fresh = require('fresh');
var http = require('http');
var path = require('path');
var mime = require('mime');
var basename = path.basename;
var extname = path.extname;
var url = require('url');
var parse = url.parse;
var stringify = url.format;
/**
* Prototype.
*/
module.exports = {
/**
* Return the request socket.
*
* @return {Connection}
* @api public
*/
get socket() {
// TODO: TLS
return this.ctx.req.socket;
},
/**
* Return response header.
*
* @return {Object}
* @api public
*/
get header() {
// TODO: wtf
return this.res._headers || {};
},
/**
* Return response status string.
*
* @return {String}
* @api public
*/
get statusString() {
return http.STATUS_CODES[this.status];
},
/**
* Get response status code.
*
* @return {Number}
* @api public
*/
get status() {
return this.res.statusCode;
},
/**
* Set response status code.
*
* @param {Number|String} val
* @api public
*/
set status(val) {
if ('string' == typeof val) {
var n = statuses[val.toLowerCase()];
if (!n) throw new Error(statusError(val));
val = n;
}
this.res.statusCode = val;
var noContent = 304 == this.status || 204 == this.status;
if (noContent && this.body) this.body = null;
},
/**
* Get response body.
*
* @return {Mixed}
* @api public
*/
get body() {
return this._body;
},
/**
* Set response body.
*
* @param {String|Buffer|Object|Stream} val
* @api public
*/
set body(val) {
this._body = val;
// no content
if (null == val) {
var s = this.status;
this.status = 304 == s ? 304 : 204;
this.res.removeHeader('Content-Type');
this.res.removeHeader('Content-Length');
this.res.removeHeader('Transfer-Encoding');
return;
}
// set the content-type only if not yet set
var setType = !this.header['content-type'];
// string
if ('string' == typeof val) {
if (setType) this.type = ~val.indexOf('<') ? 'html' : 'text';
this.length = Buffer.byteLength(val);
return;
}
// buffer
if (Buffer.isBuffer(val)) {
if (setType) this.type = 'bin';
this.length = val.length;
return;
}
// stream
if (val instanceof Stream) {
if (setType) this.type = 'bin';
return;
}
// json
this.type = 'json';
},
/**
* Set Content-Length field to `n`.
*
* @param {Number} n
* @api public
*/
set length(n) {
this.set('Content-Length', n);
},
/**
* Return parsed response Content-Length when present.
*
* @return {Number}
* @api public
*/
get length() {
var len = this.header['content-length'];
var body = this.body;
if (null == len) {
if (!body) return;
if ('string' == typeof body) return Buffer.byteLength(body);
return body.length;
}
return ~~len;
},
/**
* Check if a header has been written to the socket.
*
* @return {Boolean}
* @api public
*/
get headerSent() {
return this.res.headersSent;
},
/**
* Vary on `field`.
*
* @param {String} field
* @api public
*/
vary: function(field){
this.append('Vary', field);
},
/**
* Perform a 302 redirect to `url`.
*
* The string "back" is special-cased
* to provide Referrer support, when Referrer
* is not present `alt` or "/" is used.
*
* Examples:
*
* this.redirect('back');
* this.redirect('back', '/index.html');
* this.redirect('/login');
* this.redirect('http://google.com');
*
* @param {String} url
* @param {String} alt
* @api public
*/
redirect: function(url, alt){
if ('back' == url) url = this.ctx.get('Referrer') || alt || '/';
this.set('Location', url);
if (!~[300, 301, 302, 303, 305, 307].indexOf(this.status)) this.status = 302;
// html
if (this.ctx.accepts('html')) {
url = escape(url);
this.type = 'text/html; charset=utf-8';
this.body = 'Redirecting to <a href="' + url + '">' + url + '</a>.';
return;
}
// text
this.body = 'Redirecting to ' + url + '.';
},
/**
* Set Content-Disposition header to "attachment" with optional `filename`.
*
* @param {String} filename
* @api public
*/
attachment: function(filename){
if (filename) this.type = extname(filename);
this.set('Content-Disposition', filename
? 'attachment; filename="' + basename(filename) + '"'
: 'attachment');
},
/**
* Set Content-Type response header with `type` through `mime.lookup()`
* when it does not contain "/", or set the Content-Type to `type` otherwise.
*
* Examples:
*
* this.type = '.html';
* this.type = 'html';
* this.type = 'json';
* this.type = 'application/json';
* this.type = 'png';
*
* @param {String} type
* @api public
*/
set type(type){
if (!~type.indexOf('/')) {
type = mime.lookup(type);
var cs = mime.charsets.lookup(type);
if (cs) type += '; charset=' + cs.toLowerCase();
}
this.set('Content-Type', type);
},
/**
* Return the request mime type void of
* parameters such as "charset".
*
* @return {String}
* @api public
*/
get type() {
var type = this.get('Content-Type');
if (!type) return;
return type.split(';')[0];
},
/**
* Return response header.
*
* Examples:
*
* this.get('Content-Type');
* // => "text/plain"
*
* this.get('content-type');
* // => "text/plain"
*
* @param {String} name
* @return {String}
* @api public
*/
get: function(name){
return this.header[name.toLowerCase()];
},
/**
* Set header `field` to `val`, or pass
* an object of header fields.
*
* Examples:
*
* this.set('Foo', ['bar', 'baz']);
* this.set('Accept', 'application/json');
* this.set({ Accept: 'text/plain', 'X-API-Key': 'tobi' });
*
* @param {String|Object|Array} field
* @param {String} val
* @api public
*/
set: function(field, val){
if (2 == arguments.length) {
if (Array.isArray(val)) val = val.map(String);
else val = String(val);
this.res.setHeader(field, val);
} else {
for (var key in field) {
this.set(key, field[key]);
}
}
},
/**
* Append `val` to header `field`.
*
* @param {String} field
* @param {String} val
* @api public
*/
append: function(field, val){
field = field.toLowerCase();
var header = this.header;
var list = header[field];
// not set
if (!list) return this.set(field, val);
// append
list = list.split(/ *, */);
if (!~list.indexOf(val)) list.push(val);
this.set(field, list.join(', '));
},
/**
* Inspect implementation.
*
* TODO: add tests
*
* @return {Object}
* @api public
*/
inspect: function(){
var o = this.toJSON();
o.body = this.body;
o.statusString = this.statusString;
return o;
},
/**
* Return JSON representation.
*
* @return {Object}
* @api public
*/
toJSON: function(){
return {
status: this.status,
header: this.header
}
}
};
/**
* Return status error message.
*
* @param {String} val
* @return {String}
* @api private
*/
function statusError(val) {
var s = 'invalid status string "' + val + '", try:\n\n';
Object.keys(statuses).forEach(function(name){
var n = statuses[name];
s += ' - ' + n + ' "' + name + '"\n';
});
return s;
}
/**
* Escape special characters in the given string of html.
*
* @param {String} html
* @return {String}
* @api private
*/
function escape(html) {
return String(html)
.replace(/&/g, '&amp;')
.replace(/"/g, '&quot;')
.replace(/</g, '&lt;')
.replace(/>/g, '&gt;');
}