How to remove attribute from Product Collection

Question

I have created an observer that manipulates the advanced search result of Magento. For this, I've used the controller_action_layout_render_before_catalogsearch_advanced_result observer.

I'm using an "dummy" attribute called "brand". This attribute doesn't accually contain something, but is just there so that the user can input a value in the normal magento forms.

Now my problem is that I can not seem to remove this dummy attribute. I've tried removeAttributeFromFilter() (and removeFieldFromFilter()) but it does not seem to disappear.

I cannot just reset the WHERE statement, because all other attributes do need to function like normal.

The observer:

class Jeroen_SearchFilter_Model_Observers_Searchresults
{
      function manipulateSQL( $event ){
         if(!Mage::app()->getRequest()->getOriginalPathInfo() == "/catalogsearch/advanced/result/";){ 
            //double check if this we're really using advanced search
            return;
         }

         $block = Mage::app()->getLayout()->getBlock('search_result_list');

         if($block){
             $collection = $block->getLoadedProductCollection();
             $searchFilterTable = Mage::getSingleton('core/resource')->getTableName('searchFilter/searchtable');
             $collection->getSelect()->join(array("searchfilter" => $searchFilterTable), "e.entity_id = searchfilter.product_id" );
             $collection->getSelect()->where("searchfilter.brandAttributeId = 'mybrand'");
             $collection->removeAttributeFromFilter("brand");
             $block->setLoadedProductCollection($collection);
         }
      }

}

Does anyone know how to remove the brand attribute from the collection?

Answer 1

No, you have to construct a new query. Once you hit the DB with a query with conditions, you can't just remove a condition and have new data, you have to construct a new query.

Afaik standard Magento does not have any methods to explicitely remove filters (besides clear(), which resets all filters and unloads the collection).

Check here for more information

Answer 2

To my knowledge the only way is to edit the where part and remove the part where the condition is set on the attribute you want to remove:

$where = $collection->getSelect()->getPart(Zend_Db_Select::WHERE);
foreach ($where as $key => $condition)
{
    // You may have to adapt this condition depending on the situation
    if (strpos("brand",$condition) !== false)
    {
        unset($where[$key]);
    }
}
$collection->getSelect()->setPart(Zend_Db_Select::WHERE, $where);