@kpi4me/golden-layout
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A multi-screen javascript Layout manager https://golden-layout.com
257 lines (208 loc) • 6 kB
JavaScript
/**
* socket.io
* Copyright(c) 2011 LearnBoost <dev@learnboost.com>
* MIT Licensed
*/
(function (exports, io, global) {
/**
* There is a way to hide the loading indicator in Firefox. If you create and
* remove a iframe it will stop showing the current loading indicator.
* Unfortunately we can't feature detect that and UA sniffing is evil.
*
* @api private
*/
var indicator = global.document && "MozAppearance" in
global.document.documentElement.style;
/**
* Expose constructor.
*/
exports['jsonp-polling'] = JSONPPolling;
/**
* The JSONP transport creates an persistent connection by dynamically
* inserting a script tag in the page. This script tag will receive the
* information of the Socket.IO server. When new information is received
* it creates a new script tag for the new data stream.
*
* @constructor
* @extends {io.Transport.xhr-polling}
* @api public
*/
function JSONPPolling (socket) {
io.Transport['xhr-polling'].apply(this, arguments);
this.index = io.j.length;
var self = this;
io.j.push(function (msg) {
self._(msg);
});
};
/**
* Inherits from XHR polling transport.
*/
io.util.inherit(JSONPPolling, io.Transport['xhr-polling']);
/**
* Transport name
*
* @api public
*/
JSONPPolling.prototype.name = 'jsonp-polling';
/**
* Posts a encoded message to the Socket.IO server using an iframe.
* The iframe is used because script tags can create POST based requests.
* The iframe is positioned outside of the view so the user does not
* notice it's existence.
*
* @param {String} data A encoded message.
* @api private
*/
JSONPPolling.prototype.post = function (data) {
var self = this
, query = io.util.query(
this.socket.options.query
, 't='+ (+new Date) + '&i=' + this.index
);
if (!this.form) {
var form = document.createElement('form')
, area = document.createElement('textarea')
, id = this.iframeId = 'socketio_iframe_' + this.index
, iframe;
form.className = 'socketio';
form.style.position = 'absolute';
form.style.top = '0px';
form.style.left = '0px';
form.style.display = 'none';
form.target = id;
form.method = 'POST';
form.setAttribute('accept-charset', 'utf-8');
area.name = 'd';
form.appendChild(area);
document.body.appendChild(form);
this.form = form;
this.area = area;
}
this.form.action = this.prepareUrl() + query;
function complete () {
initIframe();
self.socket.setBuffer(false);
};
function initIframe () {
if (self.iframe) {
self.form.removeChild(self.iframe);
}
try {
// ie6 dynamic iframes with target="" support (thanks Chris Lambacher)
iframe = document.createElement('<iframe name="'+ self.iframeId +'">');
} catch (e) {
iframe = document.createElement('iframe');
iframe.name = self.iframeId;
}
iframe.id = self.iframeId;
self.form.appendChild(iframe);
self.iframe = iframe;
};
initIframe();
// we temporarily stringify until we figure out how to prevent
// browsers from turning `\n` into `\r\n` in form inputs
this.area.value = io.JSON.stringify(data);
try {
this.form.submit();
} catch(e) {}
if (this.iframe.attachEvent) {
iframe.onreadystatechange = function () {
if (self.iframe.readyState == 'complete') {
complete();
}
};
} else {
this.iframe.onload = complete;
}
this.socket.setBuffer(true);
};
/**
* Creates a new JSONP poll that can be used to listen
* for messages from the Socket.IO server.
*
* @api private
*/
JSONPPolling.prototype.get = function () {
var self = this
, script = document.createElement('script')
, query = io.util.query(
this.socket.options.query
, 't='+ (+new Date) + '&i=' + this.index
);
if (this.script) {
this.script.parentNode.removeChild(this.script);
this.script = null;
}
script.async = true;
script.src = this.prepareUrl() + query;
script.onerror = function () {
self.onClose();
};
var insertAt = document.getElementsByTagName('script')[0];
insertAt.parentNode.insertBefore(script, insertAt);
this.script = script;
if (indicator) {
setTimeout(function () {
var iframe = document.createElement('iframe');
document.body.appendChild(iframe);
document.body.removeChild(iframe);
}, 100);
}
};
/**
* Callback function for the incoming message stream from the Socket.IO server.
*
* @param {String} data The message
* @api private
*/
JSONPPolling.prototype._ = function (msg) {
this.onData(msg);
if (this.isOpen) {
this.get();
}
return this;
};
/**
* The indicator hack only works after onload
*
* @param {Socket} socket The socket instance that needs a transport
* @param {Function} fn The callback
* @api private
*/
JSONPPolling.prototype.ready = function (socket, fn) {
var self = this;
if (!indicator) return fn.call(this);
io.util.load(function () {
fn.call(self);
});
};
/**
* Checks if browser supports this transport.
*
* @return {Boolean}
* @api public
*/
JSONPPolling.check = function () {
return 'document' in global;
};
/**
* Check if cross domain requests are supported
*
* @returns {Boolean}
* @api public
*/
JSONPPolling.xdomainCheck = function () {
return true;
};
/**
* Add the transport to your public io.transports array.
*
* @api private
*/
io.transports.push('jsonp-polling');
})(
'undefined' != typeof io ? io.Transport : module.exports
, 'undefined' != typeof io ? io : module.parent.exports
, this
);