Recursively search objects

Question

I want to recursively search and replace elements in an array.

The array is tree based so looks like

Object
   Children
      Object type A
      Object type B
Object
   Children
      Object type A
Object

etc.

I want to be able to replace certain items with other items, so for example, I want to replace all entries in the array (at whatever depth level) of type A with an array of type B. But here's the catch: The newly replaced objects may also have children of type A that need to be replaced.

So far I've got

foreach ($nodes as &$node) {
    // Replace node?
    if ($node['type'] == 'RefObject') {
        $n = $this->site->get_node_where('id', $node['node_ref']);
        // Replace node
        $node = $this->site->get_node_where('object_id', $n['object_id']);
        // Get children
        $node['children'] = $this->site->get_descendants($node['lft'], $node['rgt']);
    }
}
return $nodes;

Which will replace the first level of RefObjects, but will not search the subsequently added children.

Answer 1

Put your code into a function and call it again. Pseudocode:

function checkArray($array) {
    ...
    if (is_array($node)) {  // or whatever other criterium
        checkArray($node);  // same function
    }
}

The basics of recursion are to call the same code again...

Answer 2

you need to add this code into a function and call the function on the child nodes.

something like this (note the parseNodes function is called again inside the function):

function parseNodes($node) {

   foreach($nodes as &$node) {
    // Replace node?
    if($node['type'] == 'RefObject') {
        $n = $this->site->get_node_where('id', $node['node_ref']);
        // Replace node
        $node = $this->site->get_node_where('object_id', $n['object_id']);
        // Get children
        $node['children'] = parseNodes($this->site->get_descendants($node['lft'], $node['rgt']));
    }
   }
   return $nodes;
 }

Josh