Inspecting object in javascript

An interesting problem is to inspect unknown objects in javascript. Found a good example of how to do it here. Just to rehash in case the site move:

function inspect(obj, maxLevels, level)
{
 var str = '', type, msg;

   // Start Input Validations
   // Don't touch, we start iterating at level zero
   if(level == null)  level = 0;

   // At least you want to show the first level
   if(maxLevels == null) maxLevels = 1;
   if(maxLevels < 1)    
       return '<font color="red">Error: Levels number must be > 0</font>';

   // We start with a non null object
   if(obj == null)
   return '<font color="red">Error: Object <b>NULL</b></font>';
   // End Input Validations

   // Each Iteration must be indented
   str += '<ul>';

   // Start iterations for all objects in obj
   for(property in obj)
   {
     try
     {
         // Show "property" and "type property"
         type =  typeof(obj[property]);
         str += '<li>(' + type + ') ' + property +
                ( (obj[property]==null)?(': <b>null</b>'):('')) + '</li>';

         // We keep iterating if this property is an Object, non null
         // and we are inside the required number of levels
         if((type == 'object') && (obj[property] != null) && (level+1 < maxLevels))
         str += inspect(obj[property], maxLevels, level+1);
     }
     catch(err)
     {
       // Is there some properties in obj we can't access? Print it red.
       if(typeof(err) == 'string') msg = err;
       else if(err.message)        msg = err.message;
       else if(err.description)    msg = err.description;
       else                        msg = 'Unknown';

       str += '<li><font color="red">(Error) ' + property + ': ' + msg +'</font></li>';
     }
   }

     // Close indent
     str += '</ul>';

   return str;
}

Javascript ninja on Cakephp

Fuh.. Cakephp by default uses the script.aculo.us library for ajax which uses the prototype javascript library. To get you're ninja on prototype you can refer directly to the docs. Good stuff..