info-receiver.js
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'use strict';
var EventEmitter = require('events').EventEmitter
, inherits = require('inherits')
, urlUtils = require('./utils/url')
, XDR = require('./transport/sender/xdr')
, XHRCors = require('./transport/sender/xhr-cors')
, XHRLocal = require('./transport/sender/xhr-local')
, XHRFake = require('./transport/sender/xhr-fake')
, InfoIframe = require('./info-iframe')
, InfoAjax = require('./info-ajax')
;
var debug = function() {};
if (process.env.NODE_ENV !== 'production') {
debug = require('debug')('sockjs-client:info-receiver');
}
function InfoReceiver(baseUrl, urlInfo) {
debug(baseUrl);
var self = this;
EventEmitter.call(this);
setTimeout(function() {
self.doXhr(baseUrl, urlInfo);
}, 0);
}
inherits(InfoReceiver, EventEmitter);
// TODO this is currently ignoring the list of available transports and the whitelist
InfoReceiver._getReceiver = function(baseUrl, url, urlInfo) {
// determine method of CORS support (if needed)
if (urlInfo.sameOrigin) {
return new InfoAjax(url, XHRLocal);
}
if (XHRCors.enabled) {
return new InfoAjax(url, XHRCors);
}
if (XDR.enabled && urlInfo.sameScheme) {
return new InfoAjax(url, XDR);
}
if (InfoIframe.enabled()) {
return new InfoIframe(baseUrl, url);
}
return new InfoAjax(url, XHRFake);
};
InfoReceiver.prototype.doXhr = function(baseUrl, urlInfo) {
var self = this
, url = urlUtils.addPath(baseUrl, '/info')
;
debug('doXhr', url);
this.xo = InfoReceiver._getReceiver(baseUrl, url, urlInfo);
this.timeoutRef = setTimeout(function() {
debug('timeout');
self._cleanup(false);
self.emit('finish');
}, InfoReceiver.timeout);
this.xo.once('finish', function(info, rtt) {
debug('finish', info, rtt);
self._cleanup(true);
self.emit('finish', info, rtt);
});
};
InfoReceiver.prototype._cleanup = function(wasClean) {
debug('_cleanup');
clearTimeout(this.timeoutRef);
this.timeoutRef = null;
if (!wasClean && this.xo) {
this.xo.close();
}
this.xo = null;
};
InfoReceiver.prototype.close = function() {
debug('close');
this.removeAllListeners();
this._cleanup(false);
};
InfoReceiver.timeout = 8000;
module.exports = InfoReceiver;