CodeIgniter create n-level deep navigation

Question

I'd like some help please. I have created dynamic a menu navbar that displays the menu items accoridning to the order that I've set them. I'm using this nestedsortable plugin, to order my menu items, but currently my menu has only 2 levels, so basicly it goes like this: ``` Item1 Item2 > Subitem2.1 > Subitem2.2 Item3 etc etc. ``` What I'd like to do is make it with n-levels, so basicly something like this: ``` Item1 Item2 > Subitem2.1 >> Subitem2.1.1 > Subitem2.2 Item3 etc etc. ``` and each item can go n-level deep. The problem is that if I set a new order to my menu items that is more than 2 levels deep I get an error and the order is not stored in the database. How can I fix this please ??? The database structure is this: ``` table: Menu id (pk) menu_item parent_id // it is the id of the parent menu item order ``` Here are my main (model) functions: ``` // save the order of the menu items public function save_order($items){ if (count($items)>0) { foreach ($items as $order => $item)…

Accepted Answer

Considering the database output, it seems the items are stored in the database correctly. And the problem belongs to the `get_menu()` method and its algorithm to create the output.

In order to create a n-level deep menu, you should iterate through the items recursively.

Here we go:

```
function prepareList(array $items, $pid = 0)
{
    $output = array();

# loop through the items
    foreach ($items as $item) {

# Whether the parent_id of the item matches the current $pid
        if ((int) $item['parent_id'] == $pid) {

# Call the function recursively, use the item's id as the parent's id
            # The function returns the list of children or an empty array()
            if ($children = prepareList($items, $item['id'])) {

# Store all children of the current item
                $item['children'] = $children;
            }

# Fill the output
            $output[] = $item;
        }
    }

return $output;
}
```

You could use the above logic as a helper function (in CodeIgniter) or a private method within your Controller class.

Then call that function/method inside `get_menu()` method as follows:

```
public function get_menu()
{
    $this->db->select('id, menu_item, parent_id');
    $this->db->order_by('parent_id, order');
    $menu_items = $this->db->get('menu')->result_array();

return prepareList($menu_items);
}
```

Note: I used the `prepareList()` as a helper (global) function. If you decide to use that as a private method, you should replace the function name by `$this->prepareList()` everywhere (even inside the function itself).

Here is the Online Demo.

CodeIgniter create n-level deep navigation

Solution

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