https://judiciarycommissionla.org/js/loadjs.js

1// loadScript: returns a promise that completes when the script loads
2window.loadScript = function (scriptPath) {
3    // check list - if already loaded we can ignore
4    if (loaded[scriptPath]) {
5        console.log(scriptPath + " already loaded");
6        // return 'empty' promise
7        return new this.Promise(function (resolve, reject) {
8            resolve();
9        });
10    }
11
12    return new Promise(function (resolve, reject) {
13        // create JS library script element
14        var script = document.createElement("script");
15        script.src = scriptPath;
16        script.type = "text/javascript";
17        console.log(scriptPath + " created");
18
19        // flag as loading/loaded
20        loaded[scriptPath] = true;
21
22        // if the script returns okay, return resolve
23        script.onload = function () {
24            console.log(scriptPath + " loaded ok");
25            resolve(scriptPath);
26        };
27
28        // if it fails, return reject
29        script.onerror = function () {
30            console.log(scriptPath + " load failed");
31            reject(scriptPath);
32        }
33
34        // scripts will load at end of body
35        document["body"].appendChild(script);
36    });
37}
38// store list of what scripts we've loaded
39loaded = [];