RecursiveIterator returns no object

Question

i have a recursivearray that does not return object/elements in a specific array structure:

Array im trying to use recursive is as follow:

$feedStruct = [database] => Array
    (
        [property] => Array
            (
                [0] => Array
                    (
                        [title] => Array
                            (
                            )

                        [tipology] => Array
                            (
                            )

                        [description] => Array
                            (
                            )

                        [location] => Array
                            (
                            )

                        [year] => Array
                            (
                            )

                        [price] => Array
                            (
                            )

                        [area_plot] => Array
                            (
                            )

                        [habitable_area] => Array
                            (
                            )

                        [ref] => Array
                            (
                            )

                        [video] => Array
                            (
                            )

                        [default_photo] => Array
                            (
                            )

                        [photo1] => Array
                            (
                            )

                    )

                [1] => Array
                    (
                        [title] => Array
                            (
                            )

                        [tipology] => Array
                            (
                            )

                        [description] => Array
                            (
                            )

                        [location] => Array
                            (
                            )

                        [year] => Array
                            (
                            )

                        [price] => Array
                            (
                            )

                        [area_plot] => Array
                            (
                            )

                        [habitable_area] => Array
                            (
                            )

                        [ref] => Array
                            (
                            )

                        [video] => Array
                            (
                            )

                        [default_photo] => Array
                            (
                            )

                        [photo1] => Array
                            (
                            )

                    )

            )

    )

Code as follow:

     $iterator = new RecursiveIteratorIterator(new RecursiveArrayIterator($feedStruct));
     $keys = array();
     foreach ($iterator as $key => $value) {
         // Build long key name based on parent keys
         for ($i = $iterator->getDepth() - 1; $i >= 0; $i--) {

          $val = $iterator->getSubIterator($i)->key();

          }
     }

When this run with the above array it does not iterate, with other arrays i dont have a problem, any ideas why?

Thank you

Answer 1

your $iterator = new RecursiveIteratorIterator(new RecursiveArrayIterator($feedStruct)); will be interpreted as $iterator = new RecursiveIteratorIterator(new RecursiveArrayIterator($feedStruct), RecursiveIteratorIterator::SELF_FIRST); because RecursiveIteratorIterator::LEAVES_ONLY is the default parameter out of three (ie RecursiveIteratorIterator::SELF_FIRST , RecursiveIteratorIterator::CHILD_FIRST ).

I will try explaining the parameters. Assume you have the array below

$array = array(
    0 => array(
        'city' => 'Jos',
        'places_to_visit' => array(
            'Lagos',
            'Capetown'
        )
    ),
    1 => "sd"
);
$iterator = new RecursiveIteratorIterator(new RecursiveArrayIterator($feedStruct), $mode);
$keys = array();
foreach ($iterator as $key => $value) {
// Build long key name based on parent keys
    for ($i = $iterator->getDepth() - 1; $i >= 0; $i--) {
        $val[] = $iterator->getSubIterator($i)->key();
    }
}

RecursiveIteratorIterator::LEAVES_ONLY means iterate only last values in each structure. In the case of the above array $array , if $mode = RecursiveIteratorIterator::LEAVES_ONLY ,

print_r($val); 
/* Outputs
city => Jos
0 => Lagos
1 => Capetown
1 => sd */

RecursiveIteratorIterator::CHILD_FIRST means iterate child values first before parents. In the case of the above array $array , if $mode = RecursiveIteratorIterator::CHILD_FIRST ,

print_r($val); 
/* Outputs
city => Jos
0 => Lagos
1 => Capetown
places_to_visit => Array()
0 => Array()
1 => sd */

RecursiveIteratorIterator::SELF_FIRST means iterate only parent values first in each structure. In the case of the above array $array , if $mode = RecursiveIteratorIterator::SELF_FIRST ,

print_r($val); 
/*Outputs 
0 => Array()
city => Jos
places_to_visit => Array()
0 => Lagos
1 => Capetown
1 => sd */

In your case, $iterator will return 0 as there are no leaves (final values) in your structure $feedStruct . Try RecursiveIteratorIterator::SELF_FIRST , works quite well.