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gistfile1.js

Boom.add('xstream', function(C) {
  var TICKET = 'any random string 1';
	var PING = 'any random string 2';
	var PING_BACK = 'any random string 3';

	var host = location.protocol + '//' + location.host + 
		(location.port ? ':' + location.port : '');
	var $ = jQuery;
	var win = window;
	var pool = {};
	var listener = new C.Event();
	var support = function() {
		return 'postMessage' in win ;
	}();
	var attach = function(fun) {
		if (window.addEventListener) {
			window.addEventListener('message', fun, false);
		} else {
			window.attachEvent('onmessage', fun);
		}
	};

	var checkout = function(data) {
		if (data.indexOf(TICKET) === 0) {
			return data.substring(TICKET.length);
		} 
		return false;
	};
	var checkin = function(data) {
		return TICKET + data;
	};
	var dispatchMessage = function(data, source, origin) {
		if ((data = checkout(data)) === false) {
			return;
		}
		if (data == PING) {
			xstream.sendRaw(checkin(PING_BACK), source, origin);

		} else if (data == PING_BACK) {
			win.clearTimeout(pool[origin].ping);
			pool[origin].pingfun = null;
			pool[origin].open = true;
			$.each(pool[origin].queue, function(index, arg) {
				xstream.sendRaw.apply(xstream, arg);
			});
			pool[origin].queue = [];

		} else {
			listener.trigger(origin, data, source, origin);
		}
	};

	var xstream = {
		send: function(data, target, channel) {
			channel = $.isArray(channel) ? channel : [channel];
			data = checkin(data);
			$.each(channel, function(index, chanel) {
				if (pool[chanel] && pool[chanel].open) {
					xstream.sendRaw(data, target, chanel);

				} else if (pool[chanel]) {
					pool[chanel].queue.push([data, target, chanel]);

				} else {
					pool[chanel] = {
						open: false,
						ping: null,
						queue: [[data, target, chanel]]
					}
					xstream.ping(target, chanel);
				}
			})
		},

		listen: function(channel, callback) {
			channel = $.isArray(channel) ? channel : [channel]

			$.each(channel, function(index, chanel) {
				listener.on(chanel, callback);
			});
		},

		ping: function(target, channel) {
			pool[channel].pingfun = function() {
				pool[channel].ping = win.setTimeout(pool[channel].pingfun, 1000);
				xstream.sendRaw(checkin(PING), target, channel);
			}
			pool[channel].pingfun();
		},

		sendRaw: function(data, target, channel) {
			try {
				if (support) {
					target.postMessage(data, channel);

				} else {
					// alert('[' + host + '] send to [' + channel + '] : ' + data);
					typeof win.navigator[channel] == 'function' && 
						win.navigator[channel](data, win, host);
				}

			} catch (e) {
				typeof console == 'object' && console.error && 
					console.error(e);
			}
		}
	}

	if (support) {
		attach(function(event) {
			var ev = event || window.event;
			dispatchMessage(ev.data, ev.source, ev.origin);
		})

	} else {
		navigator[host] = dispatchMessage;
	}

	return xstream;

}, {requires: ['event', 'jquery']});