How to sort grouped products without modifying core files

Question

The last answer here is exactly what I'm looking for, but I want to do it the clean way:
How to sort associated products in a grouped product

Has anybody a solution to achieve this within the grouped.phtml I rather don't want to open up an own module just for this sorting.

I tried $_associatedProducts = $this->getAssociatedProducts($_product)->addAttributeToSort('entity_id', 'ASC');but that doesn't work.

Answer 1

I tested this on 1.9 and you might put this code into a helper but if you look at the code which gets the associated products it eventually calls Mage_Catalog_Model_Product_Type_Grouped->getAssociatedProducts()

The code below sets the order by price and descending.

$_product = $this->getProduct();
$_grouped =  Mage::getModel('catalog/product_type_grouped');
$_storeFilter = $_grouped->getStoreFilter($_product);
$_status = $_grouped->getStatusFilters($_product);

/** @var Mage_Catalog_Model_Resource_Product_Link_Product_Collection $_associatedProducts */
$_associatedProducts = $_grouped
    ->getAssociatedProductCollection($_product)
     ->addAttributeToSelect('*')
     ->addFilterByRequiredOptions()
     //->setPositionOrder()
     ->addStoreFilter($_storeFilter)
     ->addAttributeToFilter('status', array('in' => $_status));

// Add custom filtering here
$_associatedProducts->setOrder('price', 'DESC');