Question

I’ve a $_POST that sends an array. And i’ve a prevoious array with contains a key that could contain or not one of the values from teh $_POST.

For Example:

$_post: Array ( [0] => 13 [1] => 10 [2] => 52) 
Previous: Array ( [0] => Array ( [collection_id] => 13 [artwork_id] => 21 ) 
                  [1] => Array ( [collection_id] => 11 [artwork_id] => 21 ) ) 

So i need to check if the $_POST itms already exists on the previuos array ([collection_id] key) and extract the new ones (in this case [1] => 10 [2] => 52) to ve added to the database and also get those which has changed that need to be removed from the database (replaced) by the new values.

This my current code but not working well…

            $new_nodes = array();

            $i = 0;
            foreach($old_nodes as $node){
                foreach ($collections as $collection) {
                    $new = array('collection_id' => $collection, 'artwork_id' => $artwork['id']);
                    if(array_diff($node, $new)){
                        if($collection > 0){
                            array_push($new_nodes, $new);
                        }
                    }
                    else{
                        unset($old_nodes[$i]);
                    }
                }
                $i++;
            }


            foreach($new_nodes as $node){
                for ($i = 0; $i <= count($new_nodes); $i++) {
                    if(isset($new_nodes[$i])){
                        if(!array_diff($node, $new_nodes[$i])){
                            unset($new_nodes[$i]);
                        }
                    }
                }
            }

NOTE: old_nodes is “Previous” and $collections is “$_POST”

Answer 1

Try something like this:

$old_nodes = array();
$new_nodes = array();
$del_nodes = array();

foreach ($collections as $collection) {
    array_push($old_nodes, $collection['collection_id']);
}

$new_nodes = array_diff($collections, $old_nodes);

$del_nodes = array_diff($old_nodes, $collections);