jquery free document.ready alternative

docReady.js

// https://stackoverflow.com/questions/9899372/pure-javascript-equivalent-of-jquerys-ready-how-to-call-a-function-when-t/9899701#9899701

function docReady(fn) {
    // see if DOM is already available
    if (document.readyState === "complete" || document.readyState === "interactive") {
        // call on next available tick
        setTimeout(fn, 1);
    } else {
        document.addEventListener("DOMContentLoaded", fn);
    }
}   

docReady(function() {
    // DOM is loaded and ready for manipulation here
});