gistfile1.js

(function() {
  
  var getText, setText;
  
  if ('innerText' in document.documentElement) {
    getText = function(element, shallow) {
      return (!shallow) ? $(element).innerText : getText(element);
    }
    setText = function(element, text) {
      (element = $(element)).innerText = text;
      return element;
    }
  } else {
    getText = function(element, shallow) {
      return $(element).textNodes(shallow)
        .inject('', function(text, node) { return node.nodeValue });
    }
    setText = function(element, text) {
      element = $(element);
      var nodes = Element.textNodes(element);
      if (nodes.length) {
        nodes.shift().nodeValue = text;
        nodes._each(Element.remove);
      }
      else Element.insert(element, text);
      return element;
    }
  }
  
  Element.addMethods({
    textNodes: function(element, shallow) {  
      var results = [], node = $(element).firstChild;
      while (node) {
        if (node.nodeType === 3)
          results.push(node);
        else if (!shallow && node.hasChildNodes())
          results = results.concat(arguments.callee(node));
        node = node.nextSibling;
      }
      return results;
    },
    getText: getText,
    setText: setText
  });
  
})();