Respect product sort in Collections

Currently products in a collection are sorted alphabetically, since that's how $shopify->Product->get(['collection_id' => $collectionId]) returns them in getProductsFromCollection() and there's no way to sort the returned results.

After digging deeper I found there's also $shopify->Collection($collectionId)->Product->get() which returns a list of all products in the collection in their preferred sort order. Unfortunately those product objects don't contain the variant property and they're not filtered for inventory.

So what I did is pull the $shopify->Collection($collectionId) list to get the sort order, then sort the $products list based on that:

$products = self::$shopify->Product->get(['limit' => 250, 'published_status' => 'published', 'status' => 'active', 'collection_id' => $collectionId]);

// Patch: sort products by order in collection
$collection = self::$shopify->Collection($collectionId)->Product->get();
$sort = [];
foreach($collection as $key => $product) {
  $sort[$product['id']] = $key;
}

usort($products, function($a, $b) use ($sort) {
  return $sort[$a['id']] - $sort[$b['id']];
});

I'm hesitating to make a pull request because I'm unsure if this is the most effective way to do this and it's also untested (yet). Would welcome a discussion around this.

On a side note: I was also wondering what the fallback code in while (count($products) < $productsCount) is for, since I don't understand how these could differ?

tristantbg / kirby-shopify

Respect product sort in Collections #10