Modifiable RecursiveIteratorIterator/RecursiveArrayIterator

Example.php

 <?php                                                                                                                                                                                        
 $array = [                                                                                                                                                                                   
     [                                                                                                                                                                                        
         'name' => 'level1-1',                                                                                                                                                                
         'children' => [],                                                                                                                                                                    
     ],                                                                                                                                                                                       
     [                                                                                                                                                                                        
         'name' => 'level1-2',                                                                                                                                                                
         'children' => [                                                                                                                                                                      
             [                                                                                                                                                                                
                 'name' => 'level2-1',                                                                                                                                                        
                 'children' => [                                                                                                                                                              
                     [                                                                                                                                                                        
                         'name' => 'level3-1',                                                                                                                                                
                         'children' => [],                                                                                                                                                    
                     ],                                                                                                                                                                       
                     [                                                                                                                                                                        
                         'name' => 'level3-2',                                                                                                                                                
                         'children' => [                                                                                                                                                      
                             [                                                                                                                                                                
                                 'name' => 'level4-1',                                                                                                                                        
                                 'children' => [],                                                                                                                                            
                             ],                                                                                                                                                               
                         ],                                                                                                                                                                   
                     ],                                                                                                                                                                       
                 ],                                                                                                                                                                           
             ],                                                                                                                                                                               
         ],                                                                                                                                                                                   
     ],                                                                                                                                                                                       
     [                                                                                                                                                                                        
         'name' => 'level1-3',                                                                                                                                                                
         'children' => [                                                                                                                                                                      
             [                                                                                                                                                                                
                 'name' => 'level2-2',                                                                                                                                                        
                 'children' => [                                                                                                                                                              
                     [                                                                                                                                                                        
                         'name' => 'level3-3',                                                                                                                                                
                         'children' => [],                                                                                                                                                    
                     ],                                                                                                                                                                       
                 ],                                                                                                                                                                           
             ],                                                                                                                                                                               
         ],                                                                                                                                                                                   
     ],                                                                                                                                                                                       
 ];                     
 
  class MyRecursiveArrayIterator extends \ArrayIterator implements \RecursiveIterator                                                                                                          
 {                                                                                                                                                                                            
-    public function hasChildren()                                                                                                                                                            
|    {                                                                                                                                                                                        
|        $current = $this->current();                                                                                                                                                         
|                                                                                                                                                                                             
|        return is_array($current['children']) && count($current['children']);                                                                                                                
|    }                                                                                                                                                                                        
|                                                                                                                                                                                             
-    public function getChildren()                                                                                                                                                            
|    {                                                                                                                                                                                        
|        $current = $this->current();                                                                                                                                                         
|                                                                                                                                                                                             
|        return new self($current['children']);                                                                                                                                               
|    }                                                                                                                                                                                        
 }                                                                                                                                                                                            
                                                                                                                                                                                              
 $arrayIterator = new MyRecursiveArrayIterator($array);                                                                                                                                       
 $iterator = new \RecursiveIteratorIterator($arrayIterator, \RecursiveIteratorIterator::SELF_FIRST);                                                                                  
                                                                                                                                                                                              
 foreach ($iterator as $key => $value) {                                                                                                                                              
     $currentDepth = $iterator->getDepth();                                                                                                                                           
                                                                                                                                                                                              
     for ($subDepth = $currentDepth; $subDepth >= 0; $subDepth--) {                                                                                                                           
         $subIterator = $iterator->getSubIterator($subDepth);                                                                                                                         
                                                                                                                                                                                              
         if ($currentDepth === $subDepth) {                                                                                                                                                   
             $value['name'] = $value['name'].'MODIFIED';                                                                                                                                      
             $subIterator->offsetSet($subIterator->key(), $value);                                                                                                                            
         } else {                                                                                                                                                                             
             $element = $subIterator->offsetGet($subIterator->key());                                                                                                                         
                                                                                                                                                                                              
             $upperSubIterator = $iterator->getSubIterator(($subDepth+1));                                                                                                            
             $element['children'] = $upperSubIterator->getArrayCopy();                                                                                                                        
                                                                                                                                                                                              
             $subIterator->offsetSet($subIterator->key(), $element);                                                                                                                          
         }                                                                                                                                                                                    
     }                                                                                                                                                                                        
 }                                                                                                                                                                                            
 
var_dump($iterator->getArrayCopy());
/**
 Output
array(3) {
  [0]=>
  array(2) {
    ["name"]=>
    string(16) "level1-1MODIFIED"
    ["children"]=>
    array(0) {
    }
  }
  [1]=>
  array(2) {
    ["name"]=>
    string(16) "level1-2MODIFIED"
    ["children"]=>
    array(1) {
      [0]=>
      array(2) {
        ["name"]=>
        string(16) "level2-1MODIFIED"
        ["children"]=>
        array(2) {
          [0]=>
          array(2) {
            ["name"]=>
            string(16) "level3-1MODIFIED"
            ["children"]=>
            array(0) {
            }
          }
          [1]=>
          array(2) {
            ["name"]=>
            string(16) "level3-2MODIFIED"
            ["children"]=>
            array(1) {
              [0]=>
              array(2) {
                ["name"]=>
                string(16) "level4-1MODIFIED"
                ["children"]=>
                array(0) {
                }
              }
            }
          }
        }
      }
    }
  }
  [2]=>
  array(2) {
    ["name"]=>
    string(16) "level1-3MODIFIED"
    ["children"]=>
    array(1) {
      [0]=>
      array(2) {
        ["name"]=>
        string(16) "level2-2MODIFIED"
        ["children"]=>
        array(1) {
          [0]=>
          array(2) {
            ["name"]=>
            string(16) "level3-3MODIFIED"
            ["children"]=>
            array(0) {
            }
          }
        }
      }
    }
  }
}
*/

Example of modifiable SPL RecursiveIteratorIterator with RecursiveArrayIterator
Solves:
http://stackoverflow.com/q/17867245
http://stackoverflow.com/q/1228575