https://soporte.unae.edu.ec/static/js/sysend.js?v=1.7.0

1/**@license
2 *  sysend.js - send messages between browser windows/tabs
3 *  Copyright (C) 2014 Jakub Jankiewicz <https://jcubic.pl>
4 *
5 *  This program is free software: you can redistribute it and/or modify
6 *  it under the terms of the GNU General Public License as published by
7 *  the Free Software Foundation, either version 3 of the License, or
8 *  (at your option) any later version.
9 *
10 *  This program is distributed in the hope that it will be useful,
11 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 *  GNU General Public License for more details.
14 *
15 *  You should have received a copy of the GNU General Public License
16 *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
17 *
18 *  The idea for this implementation came from this StackOverflow question:
19 *  https://stackoverflow.com/q/24182409/387194
20 */
21var sysend = (function() {
22    // we use prefix so `foo' event don't collide with `foo' locaStorage value
23    var uniq_prefix = '___sysend___';
24    // we use id because storage event is not executed if message was not
25    // changed, and we want it if user send same object twice (before it will
26    // be removed)
27    var id = 0;
28    function get(key) {
29        return localStorage.getItem(uniq_prefix + key);
30    }
31    function set(key, value) {
32        localStorage.setItem(uniq_prefix + key, value);
33    }
34    function remove(key) {
35        localStorage.removeItem(uniq_prefix + key);
36    }
37    function to_json(input) {
38        var obj = [id++];
39        // undefined in array get stringified as null
40        if (typeof input != 'undefined') {
41            obj.push(input);
42        }
43        return JSON.stringify(obj);
44    }
45    function from_json(json) {
46        return JSON.parse(json);
47    }
48    // object with user events as keys and values arrays of callback functions
49    var callbacks = {};
50    window.addEventListener('storage', function(e) {
51        // get user key
52        var key = e.key.replace(new RegExp('^' + uniq_prefix), '');
53        if (callbacks[key]) {
54            var obj = JSON.parse(get(key));
55            if (obj) {
56                // don't call on remove
57                callbacks[key].forEach(function(fn) {
58                    fn(obj[1], key);
59                });
60            }
61        }
62    }, false);
63    var timer;
64    return {
65        broadcast: function(event, message) {
66            set(event, to_json(message));
67            clearTimeout(timer);
68            //clean up localstorage
69            timer = setTimeout(function() {
70                remove(event);
71            }, 1000);
72        },
73        on: function(event, fn) {
74            if (!callbacks[event]) {
75                callbacks[event] = [];
76            }
77            callbacks[event].push(fn);
78        },
79        off: function(event, fn) {
80            if (callbacks[event]) {
81                if (fn) {
82                    for (var i=callbacks[event].length; i--;) {
83                        if (callbacks[event][i] == fn) {
84                            callbacks[event].splice(i, 1);
85                        }
86                    }
87                } else {
88                    for (var i=callbacks[event].length; i--;) {
89                        callbacks[event].splice(i, 1);
90                    }
91                }
92            }
93        }
94    };
95})();