PHP recursive search and replace array elements

Question

Hi all,

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.

I've been bashing my head against a wall with this one for hours. Please help!

Cheers, Gaz.

Answer 1

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

Answer 2

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 3

PHP 5.3 gets an array_replace_recursive method.

I just hope you'll be able to use it ;)

http://www.php.net/manual/fr/function.array-replace-recursive.php

Answer 4

here's a recursive solution

function makeObject($array){
   $data = false;
   foreach($array as $key=>$value){
      if(is_array($value)){
        $value = makeObject($value);
      }
      $data -> {$key} = $value;
   }
   return $data;
}

thanks for getting me there!