foreach until find some value - php

Question

I have a code that get categories from database but I don't know how to get all subcategories(parents).
This my php code :
function get_the_category($allCats,$filter_id = null) {
$re_struct_cat = array();
$filter_id = 10;
$ids = array();
$xx = array();
foreach($allCats as $cat_key=>$cat_val) {
$re_struct_cat[$cat_val["id"]] = array(
"title" => $cat_val["cat_title"],
"parent" => $cat_val["cat_parent"],
);
$ids = array_merge($ids,array($cat_val["id"]));
}
foreach($ids as $k=>$v) {
if($re_struct_cat[$v]["parent"]) {
$xx[] = $re_struct_cat[$re_struct_cat[$v]["parent"]];
}
}
return $xx;
//return $re_struct_cat;
//print_r($re_struct_cat);
}
What I want exactly
I have table with 3 columns [id,title,parent]
ID TITLE PARENT
1 Science 0
2 Math 1
3 Algebra 2
4 Analyse 2
5 Functions 4
So if variable filter_id = 10 I got cat_parent = 4
So I want to take that value and looking for it in array and if find another cat_parent do the same thing until find 0 or null value

Answer 1

It is not the most optimal solution, but you can use iterators.
Firstly, create the custom iterator, that can handle categories:
class AdjacencyListIterator extends RecursiveArrayIterator
{
private $adjacencyList;
public function __construct(
array $adjacencyList,
array $array = null,
$flags = 0
) {
$this->adjacencyList = $adjacencyList;
$array = !is_null($array)
? $array
: array_filter($adjacencyList, function ($node) {
return is_null($node['parent']);
});
parent::__construct($array, $flags);
}
private $children;
public function hasChildren()
{
$children = array_filter($this->adjacencyList, function ($node) {
return $node['parent'] === $this->current()['id'];
});
if (!empty($children)) {
$this->children = $children;
return true;
}
return false;
}
public function getChildren()
{
return new static($this->adjacencyList, $this->children);
}
}
It is taken from my another answer.
Then you can simply loop over this iterator until you find the needed id:
$id = 5;
$categories = [];
$result = null;
foreach ($iterator as $node) {
$depth = $iterator->getDepth();
$categories[$depth] = $node['categoryname'];
if ($node['id'] === $id) {
$result = array_slice($categories, 0, $depth + 1);
break;
}
}
Here is the demo.