Dynamically duplicating an array key in php for function recursion?

Im working on creating a modular CMS system in codeigniter and Im having trouble figuring out how to, and whether I can, dynamically add array keys within a function, based on the current depth of the array. For instance, I have data that looks like the following --

[header] => Array ( 
  [blocks] => Array ( 
    [utilitynav] => Array ( 
      [name] => utilitynav [module] => admin [helper] => [model] => [data] => 
    ) 
    [topnav] => Array ( 
      [name] => topnav [module] => admin [helper] => topnav [model] => Db_Sitepages [data] => 
    ) 
    [subhead] => Array ( 
      [name] => subhead [module] => admin [helper] => [model] => [data] => [hasChildren] => 1 
        [blocks] => Array ( 
          [testchild] => Array ( [name] => testchild [module] => admin [helper] => [model] => [data] => [parent] => subhead 
        ) 
      ) 
    ) 
  ) 
)

-- Basically, Blocks have children which are wrapped within the parent block. Im trying to figure out an effective way to manage the levels as right now I am using a separate function to output the children blocks, and if I wanted to be able to go 3 levels deep, I would have to create yet another function. So I am trying to do it recursively, by dynamically adding an array key to my for each statement each time the function reiterates.

For example, this is the function I am using to output the blocks --

  function outputChildBlocks($view_name)
  {

    if(isset($this->view_data[$view_name]['blocks']))
    {
      $html='<div class="blockWrapper">';

        foreach($this->view_data[$view_name]['blocks'] as $block)
        {
            $html.= '<div class="block '.$block['name'].'">';
            $module = $block['module'];
            $name = $block['name'];
            $data['block'] = $block;

            if($block['helper'] != null)
            {
              $this->load->helper($module.'/'.$block['helper']);
            }
            if($block['model'] != null)
            {
              $data['model'] = new $block['model']();
            }

            $html .= $this->load->view($module.'/blocks/'.$name, $data, true);
              if(isset($block['hasChildren']))
              {
                $html .= $this->outputChildChildBlocks($view_name, $name);
              }
            $html.= '</div>';
        }
      $html .= '</div>';
      return $html;
    }
  }

As you can see, at the bottom I am checking if parent has children, and if it does, I call a completely seperate function to output the child blocks (outputChildChildBlocks) -- So, instead, I would like to have the function recognize the depth of the current location, and when it gets to the if statement at bottom, if it does have children, run itself again, add a counter for each level, and then instead of

foreach($this->view_data[$view_name]['blocks'] as $block)

have it go

foreach($this->view_data[$view_name]['blocks'][$name]['blocks'] as $block)

for the 2nd level, then go

foreach($this->view_data[$view_name]['blocks'][$name]['blocks'][$name]['blocks'] as $block)

for the 3rd level, so on and so forth.

Anyways I am not sure how to dynamically add the ['blocks'] key on to the array, for every iteration of the function that has been run for that main block... (obviously I have a [footer] and a [content] block and what not as well with their own sets of blocks)

Anyways sorry if I over explained or complicated the question I have a tendency to do that but I am trying to be as clear as possible and I will be eternally indebted to you if you can show me the best way of making this function recursive!