Dom methods

dom.js

// executes a callback for a dom element and all it's children

function walk(node, callback) {
  callback(node);
  node.childNodes.forEach(function(child) {
    walk(child, callback);
  });
}

// same functionality as the built-in one

function getElementsByTagName(tagName) {
  var matches = [];

  walk(document.body, function(node) {
    if (node.nodeName.toLowerCase() === tagName) {
      matches.push(node);
    }
  });

  return matches;
}