Silverstripe - show products from parent category and subcategory

Question

I have problem when i try to loop all products from parent category and its sub-catgories.

I create two extra page types:

1. ProductCategory
2. 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());
    }
}