how to integrate third-party JavaScript libraries in userscripts

Question

For this userscript I'm writing, I need to use a third-party JavaScript library which has 3 JavaScript files. Since @require doesn't work on Chrome, how can I add multiple external JavaScript libraries to a userscript? I'm considering all the possibilities before choosing one.

I know you can add jQuery using this method. I have personally used that. Is it possible to add other libraries using this work-around as well?

Answer 1

Try adding following function in your userscript,

/**
 * Dynamically loading javascript files.
 *
 * @param filename url of the file
 * @param callback callback function, called when file is downloaded and ready
 */
function loadjscssfile(filename, callback) {
    var fileref = document.createElement('script')
    fileref.setAttribute("type", "text/javascript")
    fileref.setAttribute("src", filename)
    if (fileref.readyState) {
        fileref.onreadystatechange = function() { /*IE*/
            if (fileref.readyState == "loaded" || fileref.readyState == "complete") {
                fileref.onreadystatechange = null;
                callback();
            }
        }
    } else {
        fileref.onload = function() {  /*Other browsers*/
            callback();
        }
    }

    // Try to find the head, otherwise default to the documentElement
    if (typeof fileref != "undefined")
        (document.getElementsByTagName("head")[0] || document.documentElement).appendChild(fileref)
}

As the files are loaded asynchronously, and order of the loading of files is not guaranteed, than for multiple external files, call this function in a chined function e.g.

loadjscssfile("http://code.jquery.com/jquery-1.6.3.min.js", function() {
    loadjscssfile("http://www.abc.org./script/otherFile.js", function() {
       // call your function that depends on the external libriries here.
     });
});

Chain as many exeternal files as you need, the order of loading files will be properly preserved. Hope this helps, all best