Add new product type for grouped product

Question

I have created a new product type and if I create a grouped product it currently will not let me select any products of my new type under associated products. I enabled SQL logging and I see this query:

SELECT 
    `e` . *,
    `links`.`link_id`,
    `link_attribute_position_int`.`value` AS `position`,
    `link_attribute_qty_decimal`.`value` AS `qty`
FROM
    `catalog_product_entity` AS `e`
        LEFT JOIN
    `catalog_product_link` AS `links` ON links.linked_product_id = e.entity_id
        AND links.link_type_id = 3
        AND links.product_id = '4'
        LEFT JOIN
    `catalog_product_link_attribute_int` AS `link_attribute_position_int` ON link_attribute_position_int.link_id = links.link_id
        AND link_attribute_position_int.product_link_attribute_id = '2'
        LEFT JOIN
    `catalog_product_link_attribute_decimal` AS `link_attribute_qty_decimal` ON link_attribute_qty_decimal.link_id = links.link_id
        AND link_attribute_qty_decimal.product_link_attribute_id = '3'
WHERE
    (((`e`.`required_options` != '1') OR (`e`.`required_options` IS NULL)))
    AND (((`e`.`type_id` = 'simple') OR (`e`.`type_id` = 'virtual') OR (`e`.`type_id` = 'downloadable')))
    AND (`e`.`entity_id` != '4')
ORDER BY `e`.`entity_id` DESC
LIMIT 20

I know this is the query getting the products I can select for the grid, but I can't figure out where the code is that builds the WHERE clause. Here is the stack trace for the query:

#1 Magento_Db_Adapter_Pdo_Mysql[Varien_Db_Adapter_Pdo_Mysql]#000000004a3d0c9b00007f76c0d70388#->_debugStat(2, 'SELECT `e`.*, `l...', array(), &Varien_Db_Statement_Pdo_Mysql#000000004
#2 Magento_Db_Adapter_Pdo_Mysql[Varien_Db_Adapter_Pdo_Mysql]#000000004a3d0c9b00007f76c0d70388#->query('SELECT `e`.*, `l...', array()) called at [lib/Zend/Db/Adapter/Abstract.php:734]
#3 Magento_Db_Adapter_Pdo_Mysql[Zend_Db_Adapter_Abstract]#000000004a3d0c9b00007f76c0d70388#->fetchAll('SELECT `e`.*, `l...', array()) called at [lib/Varien/Data/Collection/Db.php:734]
#4 Mage_Catalog_Model_Resource_Product_Link_Product_Collection[Varien_Data_Collection_Db]#000000004a3d0ea500007f76c0d70388#->_fetchAll('SELECT `e`.*, `l...') called at [app/code/core/Mage/E
#5 Mage_Catalog_Model_Resource_Product_Link_Product_Collection[Mage_Eav_Model_Entity_Collection_Abstract]#000000004a3d0ea500007f76c0d70388#->_loadEntities(false, false) called at [app/code/
#6 Mage_Catalog_Model_Resource_Product_Link_Product_Collection[Mage_Eav_Model_Entity_Collection_Abstract]#000000004a3d0ea500007f76c0d70388#->load() called at [app/code/core/Mage/Adminhtml/B
#7 Mage_Adminhtml_Block_Catalog_Product_Edit_Tab_Super_Group[Mage_Adminhtml_Block_Widget_Grid]#000000004a3d0ebe00007f76c0d70388#->_prepareCollection() called at [app/code/core/Mage/Adminhtm
#8 Mage_Adminhtml_Block_Catalog_Product_Edit_Tab_Super_Group#000000004a3d0ebe00007f76c0d70388#->_prepareCollection() called at [app/code/core/Mage/Adminhtml/Block/Widget/Grid.php:626]
#9 Mage_Adminhtml_Block_Catalog_Product_Edit_Tab_Super_Group[Mage_Adminhtml_Block_Widget_Grid]#000000004a3d0ebe00007f76c0d70388#->_prepareGrid() called at [app/code/core/Mage/Adminhtml/Bloc
#10 Mage_Adminhtml_Block_Catalog_Product_Edit_Tab_Super_Group[Mage_Adminhtml_Block_Widget_Grid]#000000004a3d0ebe00007f76c0d70388#->_beforeToHtml() called at [var/Mage_Core_Block
#11 Mage_Adminhtml_Block_Catalog_Product_Edit_Tab_Super_Group[Mage_Core_Block_Abstract]#000000004a3d0ebe00007f76c0d70388#->toHtml() called at [app/code/core/Mage
#12 Mage_Core_Block_Text_List#000000004a3d0ef700007f76c0d70388#->_toHtml() called at [var/Mage_Core_Block_Abstract.php:921]
#13 Mage_Core_Block_Text_List[Mage_Core_Block_Abstract]#000000004a3d0ef700007f76c0d70388#->toHtml() called at [app/code/core/Mage/Core/Model/Layout.php:555]
#14 Mage_Core_Model_Layout#000000004a3d0cf300007f76c0d70388#->getOutput() called at [app/code/core/Mage/Core/Controller/Varien/Action.php:390]
#15 Mage_Adminhtml_Catalog_ProductController[Mage_Core_Controller_Varien_Action]#000000004a3d0ce600007f76c0d70388#->renderLayout() called at [app/code/core/Mage/Adminhtml/controllers/Catalo
#16 Mage_Adminhtml_Catalog_ProductController#000000004a3d0ce600007f76c0d70388#->superGroupGridOnlyAction() called at [app/code/core/Mage/Core/Controller/Varien/Action.php:418]
#17 Mage_Adminhtml_Catalog_ProductController[Mage_Core_Controller_Varien_Action]#000000004a3d0ce600007f76c0d70388#->dispatch('superGroupGridOn...') called at [app/code/core/Mage/Core/Contro
#18 Mage_Core_Controller_Varien_Router_Admin[Mage_Core_Controller_Varien_Router_Standard]#000000004a3d0cac00007f76c0d70388#->match(&Mage_Core_Controller_Request_Http#000000004a3d0cc600007f7
#19 Mage_Core_Controller_Varien_Front#000000004a3d0c5400007f76c0d70388#->dispatch() called at [app/code/core/Mage/Core/Model/App.php:354]
#20 Mage_Core_Model_App#000000004a3d0cd800007f76c0d70388#->run(array('scope_code' => '', 'scope_type' => 'store', 'options' => array())) called at [app/Mage.php:684]
#21 Mage::run('', 'store') called at [index.php:87]

Answer 1

I finally found it. It's set in the config.xml, of course. Its in Mage_Adminhtml_Block_Catalog_Product_Edit_Tab_Super_Group::_prepareCollection(). The second line gets all the nodes:

Mage::getConfig()->getNode('global/catalog/product/type/grouped/allow_product_types')->children();

Then, after getting all the node names, its added to the query with a simple ->addAttributeToFilter('type_id', $allowProductTypes); call.