Flatten multidimensional array to 3 levels preserving the first level keys

Question

I have a nested multidimensional array like this:

$array = [
    1 => [
        [
            ['catName' => 'Villes', 'catUrl' => 'villes', 'parent' => 151],
            [
                ['catName' => 'Administratif', 'catUrl' => 'territoire', 'parent' => 37],
                [
                    ['catName' => 'Gegraphie', 'catUrl' => 'geographie', 'parent' => 0]
                ]
            ]
        ]
    ]
];

I would like to flatten it to a simpler structure, like this:

array (
  1 => 
  array (
    0 => 
    array (
      'catName' => 'Villes',
      'catUrl' => 'villes',
      'parent' => 151,
    ),
    1 => 
    array (
      'catName' => 'Administratif',
      'catUrl' => 'territoire',
      'parent' => 37,
    ),
    2 => 
    array (
      'catName' => 'Gegraphie',
      'catUrl' => 'geographie',
      'parent' => 0,
    ),
  ),
)

I suppose it would work with some recursive function, but my skills in there are not my best. How can I accomplish this?

Answer 1

It's not pretty, but it works:

$deeparray = array();  // the really nested array goes here
$flattened = array();

function flatten($item,$key)
{
  global $flattened;
  if ( $key == 'catName' || $key == 'catUrl' || $key == 'parent' )
  {
    if ( sizeof( $flattened) == 0 )
    {  $flattened[] = array( $key=>$item );  }
    else
    {
      $last = array_pop($flattened);
      if ( array_key_exists($key,$last) )
      {
        $flattened[] = $last;
        $flattened[] = array( $key=>$item );
      }
      else
      {
        $last[ $key ] = $item;
        $flattened[] = $last;
      }
    }
  }
}



array_walk_recursive($deeparray,'flatten',$flattened);

$flattened = array($flattened);