/* global attachEvent */
/**
* Module requirements.
*/
var XMLHttpRequest = require('xmlhttprequest-ssl');
var Polling = require('./polling');
var Emitter = require('component-emitter');
var inherit = require('component-inherit');
var debug = require('debug')('engine.io-client:polling-xhr');
/**
* Module exports.
*/
module.exports = XHR;
module.exports.Request = Request;
/**
* Empty function
*/
function empty () {}
/**
* XHR Polling constructor.
*
* @param {Object} opts
* @api public
*/
function XHR (opts) {
Polling.call(this, opts);
this.requestTimeout = opts.requestTimeout;
this.extraHeaders = opts.extraHeaders;
if (typeof location !== 'undefined') {
var isSSL = 'https:' === location.protocol;
var port = location.port;
// some user agents have empty `location.port`
if (!port) {
port = isSSL ? 443 : 80;
}
this.xd = (typeof location !== 'undefined' && opts.hostname !== location.hostname) ||
port !== opts.port;
this.xs = opts.secure !== isSSL;
}
}
/**
* Inherits from Polling.
*/
inherit(XHR, Polling);
/**
* XHR supports binary
*/
XHR.prototype.supportsBinary = true;
/**
* Creates a request.
*
* @param {String} method
* @api private
*/
XHR.prototype.request = function (opts) {
opts = opts || {};
opts.uri = this.uri();
opts.xd = this.xd;
opts.xs = this.xs;
opts.agent = this.agent || false;
opts.supportsBinary = this.supportsBinary;
opts.enablesXDR = this.enablesXDR;
opts.withCredentials = this.withCredentials;
// SSL options for Node.js client
opts.pfx = this.pfx;
opts.key = this.key;
opts.passphrase = this.passphrase;
opts.cert = this.cert;
opts.ca = this.ca;
opts.ciphers = this.ciphers;
opts.rejectUnauthorized = this.rejectUnauthorized;
opts.requestTimeout = this.requestTimeout;
// other options for Node.js client
opts.extraHeaders = this.extraHeaders;
return new Request(opts);
};
/**
* Sends data.
*
* @param {String} data to send.
* @param {Function} called upon flush.
* @api private
*/
XHR.prototype.doWrite = function (data, fn) {
var isBinary = typeof data !== 'string' && data !== undefined;
var req = this.request({ method: 'POST', data: data, isBinary: isBinary });
var self = this;
req.on('success', fn);
req.on('error', function (err) {
self.onError('xhr post error', err);
});
this.sendXhr = req;
};
/**
* Starts a poll cycle.
*
* @api private
*/
XHR.prototype.doPoll = function () {
debug('xhr poll');
var req = this.request();
var self = this;
req.on('data', function (data) {
self.onData(data);
});
req.on('error', function (err) {
self.onError('xhr poll error', err);
});
this.pollXhr = req;
};
/**
* Request constructor
*
* @param {Object} options
* @api public
*/
function Request (opts) {
this.method = opts.method || 'GET';
this.uri = opts.uri;
this.xd = !!opts.xd;
this.xs = !!opts.xs;
this.async = false !== opts.async;
this.data = undefined !== opts.data ? opts.data : null;
this.agent = opts.agent;
this.isBinary = opts.isBinary;
this.supportsBinary = opts.supportsBinary;
this.enablesXDR = opts.enablesXDR;
this.withCredentials = opts.withCredentials;
this.requestTimeout = opts.requestTimeout;
// SSL options for Node.js client
this.pfx = opts.pfx;
this.key = opts.key;
this.passphrase = opts.passphrase;
this.cert = opts.cert;
this.ca = opts.ca;
this.ciphers = opts.ciphers;
this.rejectUnauthorized = opts.rejectUnauthorized;
// other options for Node.js client
this.extraHeaders = opts.extraHeaders;
this.create();
}
/**
* Mix in `Emitter`.
*/
Emitter(Request.prototype);
/**
* Creates the XHR object and sends the request.
*
* @api private
*/
Request.prototype.create = function () {
var opts = { agent: this.agent, xdomain: this.xd, xscheme: this.xs, enablesXDR: this.enablesXDR };
// SSL options for Node.js client
opts.pfx = this.pfx;
opts.key = this.key;
opts.passphrase = this.passphrase;
opts.cert = this.cert;
opts.ca = this.ca;
opts.ciphers = this.ciphers;
opts.rejectUnauthorized = this.rejectUnauthorized;
var xhr = this.xhr = new XMLHttpRequest(opts);
var self = this;
try {
debug('xhr open %s: %s', this.method, this.uri);
xhr.open(this.method, this.uri, this.async);
try {
if (this.extraHeaders) {
xhr.setDisableHeaderCheck && xhr.setDisableHeaderCheck(true);
for (var i in this.extraHeaders) {
if (this.extraHeaders.hasOwnProperty(i)) {
xhr.setRequestHeader(i, this.extraHeaders[i]);
}
}
}
} catch (e) {}
if ('POST' === this.method) {
try {
if (this.isBinary) {
xhr.setRequestHeader('Content-type', 'application/octet-stream');
} else {
xhr.setRequestHeader('Content-type', 'text/plain;charset=UTF-8');
}
} catch (e) {}
}
try {
xhr.setRequestHeader('Accept', '*/*');
} catch (e) {}
// ie6 check
if ('withCredentials' in xhr) {
xhr.withCredentials = this.withCredentials;
}
if (this.requestTimeout) {
xhr.timeout = this.requestTimeout;
}
if (this.hasXDR()) {
xhr.onload = function () {
self.onLoad();
};
xhr.onerror = function () {
self.onError(xhr.responseText);
};
} else {
xhr.onreadystatechange = function () {
if (xhr.readyState === 2) {
try {
var contentType = xhr.getResponseHeader('Content-Type');
if (self.supportsBinary && contentType === 'application/octet-stream' || contentType === 'application/octet-stream; charset=UTF-8') {
xhr.responseType = 'arraybuffer';
}
} catch (e) {}
}
if (4 !== xhr.readyState) return;
if (200 === xhr.status || 1223 === xhr.status) {
self.onLoad();
} else {
// make sure the `error` event handler that's user-set
// does not throw in the same tick and gets caught here
setTimeout(function () {
self.onError(typeof xhr.status === 'number' ? xhr.status : 0);
}, 0);
}
};
}
debug('xhr data %s', this.data);
xhr.send(this.data);
} catch (e) {
// Need to defer since .create() is called directly fhrom the constructor
// and thus the 'error' event can only be only bound *after* this exception
// occurs. Therefore, also, we cannot throw here at all.
setTimeout(function () {
self.onError(e);
}, 0);
return;
}
if (typeof document !== 'undefined') {
this.index = Request.requestsCount++;
Request.requests[this.index] = this;
}
};
/**
* Called upon successful response.
*
* @api private
*/
Request.prototype.onSuccess = function () {
this.emit('success');
this.cleanup();
};
/**
* Called if we have data.
*
* @api private
*/
Request.prototype.onData = function (data) {
this.emit('data', data);
this.onSuccess();
};
/**
* Called upon error.
*
* @api private
*/
Request.prototype.onError = function (err) {
this.emit('error', err);
this.cleanup(true);
};
/**
* Cleans up house.
*
* @api private
*/
Request.prototype.cleanup = function (fromError) {
if ('undefined' === typeof this.xhr || null === this.xhr) {
return;
}
// xmlhttprequest
if (this.hasXDR()) {
this.xhr.onload = this.xhr.onerror = empty;
} else {
this.xhr.onreadystatechange = empty;
}
if (fromError) {
try {
this.xhr.abort();
} catch (e) {}
}
if (typeof document !== 'undefined') {
delete Request.requests[this.index];
}
this.xhr = null;
};
/**
* Called upon load.
*
* @api private
*/
Request.prototype.onLoad = function () {
var data;
try {
var contentType;
try {
contentType = this.xhr.getResponseHeader('Content-Type');
} catch (e) {}
if (contentType === 'application/octet-stream' || contentType === 'application/octet-stream; charset=UTF-8') {
data = this.xhr.response || this.xhr.responseText;
} else {
data = this.xhr.responseText;
}
} catch (e) {
this.onError(e);
}
if (null != data) {
this.onData(data);
}
};
/**
* Check if it has XDomainRequest.
*
* @api private
*/
Request.prototype.hasXDR = function () {
return typeof XDomainRequest !== 'undefined' && !this.xs && this.enablesXDR;
};
/**
* Aborts the request.
*
* @api public
*/
Request.prototype.abort = function () {
this.cleanup();
};
/**
* Aborts pending requests when unloading the window. This is needed to prevent
* memory leaks (e.g. when using IE) and to ensure that no spurious error is
* emitted.
*/
Request.requestsCount = 0;
Request.requests = {};
if (typeof document !== 'undefined') {
if (typeof attachEvent === 'function') {
attachEvent('onunload', unloadHandler);
} else if (typeof addEventListener === 'function') {
var terminationEvent = 'onpagehide' in self ? 'pagehide' : 'unload';
addEventListener(terminationEvent, unloadHandler, false);
}
}
function unloadHandler () {
for (var i in Request.requests) {
if (Request.requests.hasOwnProperty(i)) {
Request.requests[i].abort();
}
}
}