ChildNode.append() polyfill

ChildNode.append() polyfill

/**
 * ChildNode.append() polyfill
 * https://gomakethings.com/adding-an-element-to-the-end-of-a-set-of-elements-with-vanilla-javascript/
 * @author Chris Ferdinandi
 * @license MIT
 */
          (function (elem) {

            // Check if element is a node
            // https://github.com/Financial-Times/polyfill-service
            var isNode = function (object) {
        
                // DOM, Level2
                if (typeof Node === 'function') {
                    return object instanceof Node;
                }
        
                // Older browsers, check if it looks like a Node instance)
                return object &&
                    typeof object === "object" &&
                    object.nodeName &&
                    object.nodeType >= 1 &&
                    object.nodeType <= 12;
        
            };
        
            // Add append() method to prototype
            for (var i = 0; i < elem.length; i++) {
                if (!window[elem[i]] || 'append' in window[elem[i]].prototype) continue;
                window[elem[i]].prototype.append = function () {
                    var argArr = Array.prototype.slice.call(arguments);
                    var docFrag = document.createDocumentFragment();
        
                    for (var n = 0; n < argArr.length; n++) {
                        docFrag.appendChild(isNode(argArr[n]) ? argArr[n] : document.createTextNode(String(argArr[n])));
                    }
        
                    this.appendChild(docFrag);
                };
            }
        
        })(['Element', 'CharacterData', 'DocumentType']);