Magento Admin grid problem

Question

I have a magento admin grid module and when I am inside the grid on the admin menu it shows me the header and the add item button but it throws this error

Fatal error: Call to undefined method NAMESPACE_Garantiaextendida_Model_Mysql4_Garantiaextendida_Collection::setPageSize() in G:\xampp\htdocs\webpage\app\code\core\Mage\Adminhtml\Block\Widget\Grid.php on line 553

This is my mysql4 model collection

   <?php 

class Felisiakluciano_Garantiaextendida_Model_Mysql4_Garantiaextendida_Collection extends  Mage_Core_Model_Mysql4_Collection_Abstract
{
    protected function _construct()
    {
        $this->_init('garantiaextendida/garantiaextendida');
    }   
}

Can somebody help me? Please its more than urgent. Thanks and Good Bye.

Answer 1

Check if NAMESPACE_Garantiaextendida_Model_Mysql4_Garantiaextendida_Collection is extending the right core Magento abstract collection class that it is supposed to.

Answer 2

The collection you are calling is the cause. That is why you are having an error when calling setPageSize(). This can be caused by several things, here are a few to check: not declared model in config.xml, error in files inside Model, error when calling the collection with an incorrect name.

You can get a fully functional admin/backend extension from here and try to reuse it as a base.