将父树对象/数组转换为平面数组

Question

I'm having a difficult time finding information on this. There is plenty of information about taking a flat array and creating a parent tree, but no way to reverse it, especially when you are not sure how deep it goes. This is what I have:

array(
"id"=> "4",
"name"=> "online",
"safe_name"=> "online",
"drive_id"=> "1",
"parent_id"=> "3",
"created_at"=> "2015-06-24 14:06:10",
"updated_at"=> "2015-06-24 14:06:10",
"type"=> "folder",
"parents"=> array(
    "id"=>"3",
    "name"=>"dam12",
    "safe_name"=>"dam12",
    "drive_id"=>"1",
    "parent_id"=>2,
    "created_at"=>"2015-06-24 14:06:10",
    "updated_at"=>"2015-06-24 14:06:10",
    "type"=>"folder",
    "parents"=> array(
        "id"=> "2",
        "name"=> "Course Materials",
        "safe_name"=> "coure_materials",
        "drive_id"=> "1",
        "parent_id"=> NULL,
        "created_at"=> "2015-06-24 14:06:10",
        "updated_at"=> "2015-06-24 14:06:10",
        "type"=> "folder",
        "parents"=>array()
    )
)

)

What I am trying to get is:

array(
    array(
        "id"=> "2",
        "name"=> "Course Materials",
        "safe_name"=> "coure_materials",
        "drive_id"=> "1",
        "parent_id"=> NULL,
        "created_at"=> "2015-06-24 14:06:10",
        "updated_at"=> "2015-06-24 14:06:10",
        "type"=> "folder"
    ),
    array(
        "id"=>"3",
        "name"=>"dam12",
        "safe_name"=>"dam12",
        "drive_id"=>"1",
        "parent_id"=>2,
        "created_at"=>"2015-06-24 14:06:10",
        "updated_at"=>"2015-06-24 14:06:10",
        "type"=>"folder"
    ),
    array(
        "id"=> "4",
        "name"=> "online",
        "safe_name"=> "online",
        "drive_id"=> "1",
        "parent_id"=> "3",
        "created_at"=> "2015-06-24 14:06:10",
        "updated_at"=> "2015-06-24 14:06:10",
        "type"=> "folder",
    )
)

I'm trying to achieve something more of a path. What are my options? What is the best way to achieve this?

SOLUTION Andrew gave me a close solution, I needed to do some tweaking as I was only getting the last item in the tree. here is my code, everything else is explained in Andrew's explanation.

if(is_array($parents)){
        foreach ($parents as $key => $parent) {
            if(isset($parent->parents)){
                if(is_array($parent->parents)){
                    $this->formatParents($parent->parents);
                }
                array_push($this->flat_parents, $parent);
            }else{
                array_push($this->flat_parents, $parent);
            }
        } 
    }

Answer 1

It will recursively gather all the values from an array of undetermined depth.

$test = array(
    "id"=> "4",
    "name"=> "online",
    "safe_name"=> "online",
    "drive_id"=> "1",
    "parent_id"=> "3",
    "created_at"=> "2015-06-24 14:06:10",
    "updated_at"=> "2015-06-24 14:06:10",
    "type"=> "folder",
    "parents"=> array(
        "id"=>"3",
        "name"=>"dam12",
        "safe_name"=>"dam12",
        "drive_id"=>"1",
        "parent_id"=>2,
        "created_at"=>"2015-06-24 14:06:10",
        "updated_at"=>"2015-06-24 14:06:10",
        "type"=>"folder",
        "parents"=> array(
            "id"=> "2",
            "name"=> "Course Materials",
            "safe_name"=> "coure_materials",
            "drive_id"=> "1",
            "parent_id"=> NULL,
            "created_at"=> "2015-06-24 14:06:10",
            "updated_at"=> "2015-06-24 14:06:10",
            "type"=> "folder",
            "parents"=>array()
        )
    )
);

class ItEasierWithAClass
{
    private $array_needed = array();

    public function getValues($array)
    {
        foreach($array as $key => $value)
        {
            if(is_array($value))
            {
                $this->getValues($value);
            }
            else
            {
                $this->array_needed[$array['id']][$key] = $value;
            }
        }
    }

    public function getArray()
    {
        return $this->array_needed;
    }
}


$test1 = new ItEasierWithAClass;

$test1->getValues($test);
echo '<pre>';
print_r($test1->getArray());

Output:

Array
(
    [4] => Array
        (
            [id] => 4
            [name] => online
            [safe_name] => online
            [drive_id] => 1
            [parent_id] => 3
            [created_at] => 2015-06-24 14:06:10
            [updated_at] => 2015-06-24 14:06:10
            [type] => folder
        )

    [3] => Array
        (
            [id] => 3
            [name] => dam12
            [safe_name] => dam12
            [drive_id] => 1
            [parent_id] => 2
            [created_at] => 2015-06-24 14:06:10
            [updated_at] => 2015-06-24 14:06:10
            [type] => folder
        )

    [2] => Array
        (
            [id] => 2
            [name] => Course Materials
            [safe_name] => coure_materials
            [drive_id] => 1
            [parent_id] => 
            [created_at] => 2015-06-24 14:06:10
            [updated_at] => 2015-06-24 14:06:10
            [type] => folder
        )

)

It's not the prettiest thing in the world, but it gets the job done.