Like var_dump, but it prints out the whole expression "path" to the given string.

find_deep_needle.php

<?php
/**
 * Like var_dump, but it prints out the whole expression "path" to the given string. 
 * 
 * @param mixed $haystack
 *  The object or array with many levels of nested arrays or objects containing your needle
 * @param str $php_exp
 *  The php expression for the initial $haystack param
 * @return str
 *  No return value. Prints output to stdout (assumed to be a browser).
 */
function find_deep_needle($haystack, $php_exp = '$node') {
  if (gettype($haystack) == 'object') {
    $props = get_object_vars($haystack);
    foreach($props as $prop => $value) {
      switch(gettype($value)) {
        case 'string':
          print "<br>$php_exp->$prop = " . htmlentities($value);
          break;
        case 'object':
        case 'array':
          _find_deep_needle($value, $needle, "$php_exp->$prop");
          break;
      }
    }
  } elseif (gettype($haystack) == 'array') {
    foreach($haystack as $prop => $value) {
      switch(gettype($value)) {
        case 'string':
          print "<br>$php_exp&#x005B;'$prop'&#x005D; = " . htmlentities($value);
          break;
        case 'object':
        case 'array':
          _find_deep_needle($value, $needle, "$php_exp&#x005B;'$prop'&#x005D;");
          break;
      }
    }
  }
}