How to debug Reports > Products > Products Ordered collection?

Question

I found that Magento Reports module is very tricky and confusing to debug.

Though I got that the Reports > Product > Products Ordered collection is generated from Mage/Adminhtml/controllers/Report/ProductController.php soldAction, I cannot seem to get query or data for debugging purposes when I change it's Grid's (Mage_Adminhtml_Block_Report_Product_Sold_Grid) _prepareCollection to below.

protected function _prepareCollection()
    {
        parent::_prepareCollection();

        $debugCollection = $this->getCollection()->initReport('reports/product_sold_collection');
        $size = $debugCollection->getSize();
        $debug = $debugCollection->debug();
        //or
        $debugQuery = $debugCollection->getSelect();
        //or
        $debugData = $debugCollection->getData();
        $this->getCollection()->initReport('reports/product_sold_collection');
        return $this;
    }

All functions getData(), debug() & getSelect() seem to be undefined in that module class hierarchy.

Answer 1

If you go and find the collection model in question you can always, temporarily while debugging define the _afterLoad method on the class and then do your debugging their. For example in this case if you go to the class: Mage_Reports_Model_Resource_Product_Sold_Collection and define the method:

public function _afterLoad()
{
    echo $this->getSelect();
    return parent::_afterLoad(); 
}

You will when generating a report get the query used. When you are done debugging remember to remove the code.

Hope it helps :-)