Collapses a multidimensional array into a simpler array that has the key as the nested dot notation along with it's value.

example.php

<?php 
/**
 * Link to original answer http://stackoverflow.com/a/10424516/461712 by http://stackoverflow.com/users/249538/goat
 */
 
class ArrUtils {
  
  /**
	 * @param $array
	 * @return array
	 */
	protected function getArrayKeysDotNotation($array)
	{
		$arrayIterator = new RecursiveIteratorIterator(new RecursiveArrayIterator($array));
		$result = array();
		foreach ($arrayIterator as $leafValue) {
			$keys = array();
			foreach (range(0, $arrayIterator->getDepth()) as $depth) {
				$keys[] = $key = $arrayIterator->getSubIterator($depth)->key();
			}
			$result[ join('.', $keys) ] = $leafValue;
		}

		return $result;
	}
}