Magento – Associating Simple Products with Required Options to a Grouped Product

(Magento 1.4)
A conceptually obvious task of associating simple products with required options to a grouped product proved to be more of a challenge than expected. By default, Magento doesn’t allow this relationship; however, with some simple core overrides, it is possible with the following steps:

1. Create two basic local modules with the following structures:

app/code/local/{module}/Catalog

• Block/Adminhtml/Product/Edit/Tab/Super/Group.php
• Model/Product/Type/Grouped.php
• etc/config.xml

app/code/local/{module}/CatalogInventory

• Model/Mysql4/Indexer/Stock/Grouped.php
• etc/config.xml

2. Edit Group.php by extending Mage_Adminhtml_Block_Catalog_Product_Edit_Tab_Super_Group and only overriding the method _prepareCollection(). In the core file, Magento specifies a required option filter; simply remove this and you’re left with:

protected function _prepareCollection()
    {
        $allowProductTypes = array();
        foreach (Mage::getConfig()->getNode('global/catalog/product/type/grouped/allow_product_types')->children() as $type) {
            $allowProductTypes[] = $type->getName();
        }

        $collection = Mage::getModel('catalog/product_link')->useGroupedLinks()
            ->getProductCollection()
            ->setProduct($this->_getProduct())
            ->addAttributeToSelect('*')
            ->addAttributeToFilter('type_id', $allowProductTypes);

        $this->setCollection($collection);
        return Mage_Adminhtml_Block_Widget_Grid::_prepareCollection();
    }

3. Edit Grouped.php by extending Mage_Catalog_Model_Product_Type_Grouped and overriding its getAssociatedProducts() method. Remove the required option filter, and you’re left with:

public function getAssociatedProducts($product = null)
	{
		if (!$this->getProduct($product)->hasData($this->_keyAssociatedProducts)) {
			$associatedProducts = array();

			if (!Mage::app()->getStore()->isAdmin()) {
				$this->setSaleableStatus($product);
			}

			$collection = $this->getAssociatedProductCollection($product)
			->addAttributeToSelect('*')
			->setPositionOrder()
			->addStoreFilter($this->getStoreFilter($product))
			->addAttributeToFilter('status', array('in' => $this->getStatusFilters($product)));

			foreach ($collection as $product) {
				$associatedProducts[] = $product;
			}

			$this->getProduct($product)->setData($this->_keyAssociatedProducts, $associatedProducts);
		}
		return $this->getProduct($product)->getData($this->_keyAssociatedProducts);
	}

4. The last update for the /Catalog sub-module is to create the config.xml file. This file should look like this:

<?xml version="1.0"?>
<config>
	<modules>
		<{Module}_Catalog>
			<version>0.1.0</version>
		</{Module}_Catalog>
	</modules>
	<global>
		<blocks>
            <adminhtml>
                <rewrite>               <catalog_product_edit_tab_super_group>{Module}_Catalog_Block_Adminhtml_Product_Edit_Tab_Super_Group</catalog_product_edit_tab_super_group>
                </rewrite>
            </adminhtml>
        </blocks>
		<models>
			<catalog>
				<rewrite>				<product_type_grouped>{Module}_Catalog_Model_Product_Type_Grouped</product_type_grouped>
				</rewrite>
			</catalog>
		</models>
	</global>
</config>

5. Now edit Grouped.php under the CatalogInventory sub-module. Extend Mage_CatalogInventory_Model_Mysql4_Indexer_Stock_Grouped and override its _getStockStatusSelect(…) method. Remove the required option clause from the sql query, and you’re code should look as such:

protected function _getStockStatusSelect($entityIds = null, $usePrimaryTable = false)
    {
        $adapter  = $this->_getWriteAdapter();
        $idxTable = $usePrimaryTable ? $this->getMainTable() : $this->getIdxTable();
        $select   = $adapter->select()
            ->from(array('e' => $this->getTable('catalog/product')), array('entity_id'));
        $this->_addWebsiteJoinToSelect($select, true);
        $this->_addProductWebsiteJoinToSelect($select, 'cw.website_id', 'e.entity_id');
        $select->columns('cw.website_id')
            ->join(
                array('cis' => $this->getTable('cataloginventory/stock')),
                '',
                array('stock_id'))
            ->joinLeft(
                array('cisi' => $this->getTable('cataloginventory/stock_item')),
                'cisi.stock_id = cis.stock_id AND cisi.product_id = e.entity_id',
                array())
            ->joinLeft(
                array('l' => $this->getTable('catalog/product_link')),
                'e.entity_id = l.product_id AND l.link_type_id=' . Mage_Catalog_Model_Product_Link::LINK_TYPE_GROUPED,
                array())
            ->joinLeft(
                array('le' => $this->getTable('catalog/product')),
                'le.entity_id = l.linked_product_id',
                array())
            ->joinLeft(
                array('i' => $idxTable),
                'i.product_id = l.linked_product_id AND cw.website_id = i.website_id AND cis.stock_id = i.stock_id',
                array())
            ->columns(array('qty' => new Zend_Db_Expr('0')))
            ->where('cw.website_id != 0')
            ->where('e.type_id = ?', $this->getTypeId())
            ->group(array('e.entity_id', 'cw.website_id', 'cis.stock_id'));

        // add limitation of status
        $psExpr = $this->_addAttributeToSelect($select, 'status', 'e.entity_id', 'cs.store_id');
        $psCond = $adapter->quoteInto($psExpr . '=?', Mage_Catalog_Model_Product_Status::STATUS_ENABLED);

        if ($this->_isManageStock()) {
            $statusExpr = new Zend_Db_Expr('IF(cisi.use_config_manage_stock = 0 AND cisi.manage_stock = 0,'
                . ' 1, cisi.is_in_stock)');
        } else {
            $statusExpr = new Zend_Db_Expr('IF(cisi.use_config_manage_stock = 0 AND cisi.manage_stock = 1,'
                . 'cisi.is_in_stock, 1)');
        }

        $stockStatusExpr = new Zend_Db_Expr("LEAST(MAX(IF({$psCond}, i.stock_status, 0))"
            . ", {$statusExpr})");

        $select->columns(array(
            'status' => $stockStatusExpr
        ));

        if (!is_null($entityIds)) {
            $select->where('e.entity_id IN(?)', $entityIds);
        }

        return $select;
    }

6. Edit config.xml under CatalogInventory, which should look as such:

<?xml version="1.0"?>
<config>
	<modules>
		<{Module}_CatalogInventory>
			<version>0.1.0</version>
		</{Module}_CatalogInventory>
	</modules>
	<global>
		<models>
			<cataloginventory_mysql4>
				<rewrite>
					<indexer_stock_grouped>{Module}_CatalogInventory_Model_Mysql4_Indexer_Stock_Grouped</indexer_stock_grouped>
				</rewrite>
			</cataloginventory_mysql4>
		</models>
	</global>
</config>

7. As with any module, you’ll want to define it within your app/etc/modules/{Module}_App.xml file. Simple add:

                 <{Module}_Catalog>
			<active>true</active>
			<codePool>local</codePool>
		</{Module}_Catalog>
		<{Module}_CatalogInventory>
			<active>true</active>
			<codePool>local</codePool>
		</{Module}_CatalogInventory>

That’s all there is to it. Now, from the admin section, you can associate simple products that have required options to a grouped product. Also, with the CatalogInventory modifications, the stock_status will be set appropriately, and the product will be visible from the catalog search and catalog landings pages.

I didn’t dive into the meanings of my changes, but if you’ve done any Magento core overrides in the past, it should be self explanatory.

To see an example, check out http://www.motionsavers.com/catalogsearch/result/?q=Cotterman . As of this posting, each Cotterman ladder is a grouped product with numerous simple product associations, each of which contains required options. Hope this saves someone time…