JS: escape XML

encodeHTML.js

//credits zzzzBov http://stackoverflow.com/questions/7918868/how-to-escape-xml-entities-in-javascript
if (!String.prototype.encodeHTML) {
  String.prototype.encodeHTML = function () {
    return this.replace(/&/g, '&')
               .replace(/</g, '&lt;')
               .replace(/>/g, '&gt;')
               .replace(/"/g, '&quot;')
               .replace(/'/g, '&apos;');
  };
}

if (!String.prototype.decodeHTML) {
  String.prototype.decodeHTML = function () {
    return this.replace(/&apos;/g, "'")
               .replace(/&quot;/g, '"')
               .replace(/&gt;/g, '>')
               .replace(/&lt;/g, '<')
               .replace(/&amp;/g, '&');
  };
}