JavaScript Cache Buster Example

cachebuster.js

/**
 * Generates a random hex string
 */
function s4() {
    return Math.floor((1 + Math.random()) * 0x10000)
        .toString(16)
        .substring(1);
}

/**
 * Append `?cb=` to each download of a `.pdf` file
 */
$('a').each(function () {
    var href = $(this).attr('href');
    
    if (href.indexOf(".pdf") > 0 && href.indexOf("?") === -1)
        $(this).attr('href', href + "?cb=" + s4() + "" + s4());
});