Silverstripe - show products from parent category and subcategory - silverstripe

Question

I have problem when i try to loop all products from parent category and its sub-catgories.
I create two extra page types:
ProductCategory
Product
In SiteTree (pages) i create structure:
|-Pages
|- Dental equipment (productCategory)
|----- Sub category (productCategory)
|----- Sub sub category (productCategory)
|----- Sub sub sub category (productCategory)
|----- Product 1 (product type)
|----- Product 2 (product type)
|----- Product 3 (product type)
|----- Product 4 (product type)
Now in ProductCategory_Controller i create method to loop all products that not working.
public function Products()
{
$products = Product::get()->filter([
'ParentID' => $this->ID
]);
return $products;
}
My question is how to get all products thats belongs to all parenet and sub-categories?

Answer 1

If you're trying to get the products for the current category page and all parent category pages, then the example code below might point you in the right direction.
If I misunderstood your question, please comment and I'll update my answer.
<?php
namespace {
class ProductCategoryPageController extends PageController
{
public function ProductsInCurrentPageTree()
{
$currentPage = $this->data();
$parentPage = $currentPage->getParent();
if (!$parentPage) {
// No parent page, return the current page products
return ProductPage::get()->filter('ParentID', $currentPage->ID);
}
$pageTreeIds = [
$currentPage->ID,
$parentPage->ID,
];
while ($parentPage = $parentPage->getParent()) {
// Any conditions to break out of the loop, for instance, if your category/product pages does not start from the root level
if (!$parentPage instanceof ProductCategoryPage) {
break;
}
$pageTreeIds[] = $parentPage->ID;
}
return ProductPage::get()->filterAny(['ParentID' => $pageTreeIds]);
}
}
}

Answer 2

Recursively call the same function for child category pages, but when no children, then add products to an array list. Untested code, but should be clear enough:
class ProductCategoryPageController extends PageController {
public function ProductsRecursive($iParentID,$productList) {
$productCategoryPages = ProductCategoryPage::get()->filter(['ParentID' => $iParentID]);
if ($productCategoryPages) {
//assuming product category pages only have children and no products themselves
foreach ($productCategoryPages as $productCategoryPage)
$productList = $this->ProductsRecursive($productCategoryPage->ID,$productList);
}
else {
//assuming you only are collecting product pages that have no children
foreach (ProductPage::get()->filter(['ParentID' => $iParentID]) as $productPage)
$productList->push($productPage);
}
return $productList;
}
public function Products() {
return $this->ProductsRecursive($this->ID, ArrayList::create());
}
}