PHP - Remove empty menus - php

Question

Good afternoon guys, I'm having a hard time finding the solution to this simple problem, I hope someone can help me.
I have a recursive array automatically generated by the source code, I use this array as the system's menu tree, however, it goes through a permission system, and some submenus are excluded, leaving certain menus empty, follow the example in JSON:
{
"1": {
"id": 1,
"idFather": null,
"nome": "test 1",
"sub": {
"4": {
"id": 4,
"idFather": 1,
"nome": "test 1.1",
"sub": {}
},
"5": {
"id": 5,
"idFather": 1,
"nome": "test 1.2",
"sub": {
"7": {
"id": 7,
"idFather": 5,
"nome": "test 1.3.1",
"sub": {}
},
"8": {
"id": 8,
"idFather": 5,
"nome": "test 1.3.2",
"sub": {}
}
}
},
"6": {
"id": 6,
"idFather": 1,
"nome": "test 1.3"
}
}
},
"2": {
"id": 2,
"idFather": null,
"nome": "test 2"
},
"3": {
"id": 3,
"idFather": null,
"nome": "test 3",
"sub": {
"10": {
"id": 10,
"idFather": 3,
"nome": "test 3.2"
}
}
}
}
Within key 1 I have key 4 with no other items, and I have key 5 with two keys (7 and 8), however, these 2 keys also do not contain items, so I need to remove keys 4, 7, 8 and consequently, key 5 too, as it will be empty at the end of the removals!
Note that key 6 inside key 1, key 10 inside key 3 and key 2 do not contain the "sub" element, so it must not be removed!
I am Brazilian, so my English may be a little rusty.

Answer 1

A simple recursive function will handle this.
Check each entry at the current level.
If it has a sub menu, call the function on the sub menu. If not, move on.
If the sub menu is now empty, remove it
The implementation looks like this:
$jsonString = "{...}"; // Your data listed above, omitted here for clarity
$menus = json_decode($jsonString);
// Pass a menu into the function.
// PHP passes objects by reference, so we're operating directly
// on the original object, hence no need for a return value.
function clearMenu(object $menu):void {
foreach($menu as $id=>$entry) {
if (isset($entry->sub)) { // If we have a submenu, handle it
clearMenu($entry->sub);
if (empty((array)$entry->sub)) { // Cast object to array to test for emptiness
unset($menu->$id); // Unset the item in the menu using the key. Unsetting the item directly doesn't work
}
}
}
}
clearMenu($menus);
$newMenus = json_encode($menus, JSON_PRETTY_PRINT);
echo "<pre>$newMenus</pre>";
Output:
{
"1": {
"id": 1,
"idFather": null,
"nome": "test 1",
"sub": {
"6": {
"id": 6,
"idFather": 1,
"nome": "test 1.3"
}
}
},
"2": {
"id": 2,
"idFather": null,
"nome": "test 2"
},
"3": {
"id": 3,
"idFather": null,
"nome": "test 3",
"sub": {
"10": {
"id": 10,
"idFather": 3,
"nome": "test 3.2"
}
}
}
}