protected function _prepareColumns()
{
$this->addColumn('period', array('header' => Mage::helper('sales')->__('Period'), 'index' => 'period', 'width' => 100, 'sortable' => false, 'period_type' => $this->getPeriodType(), 'renderer' => 'adminhtml/report_sales_grid_column_renderer_date', 'totals_label' => Mage::helper('adminhtml')->__('Total'), 'html_decorators' => array('nobr')));
$this->addColumn('product_name', array('header' => Mage::helper('sales')->__('Product Name'), 'index' => 'product_name', 'type' => 'string', 'sortable' => false));
if ($this->getFilterData()->getStoreIds()) {
$this->setStoreIds(explode(',', $this->getFilterData()->getStoreIds()));
}
$currencyCode = $this->getCurrentCurrencyCode();
$this->addColumn('product_price', array('header' => Mage::helper('sales')->__('Price'), 'type' => 'currency', 'currency_code' => $currencyCode, 'index' => 'product_price', 'sortable' => false));
$this->addColumn('vendor_name', array('header' => Mage::helper('sales')->__('Vendor'), 'index' => 'vendor_name', 'type' => 'string', 'sortable' => false));
$this->addColumn('qty_ordered', array('header' => Mage::helper('sales')->__('Quantity Ordered'), 'index' => 'qty_ordered', 'type' => 'number', 'total' => 'sum', 'sortable' => false));
$this->addExportType('*/*/exportBestsellersCsv', Mage::helper('adminhtml')->__('CSV'));
$this->addExportType('*/*/exportBestsellersExcel', Mage::helper('adminhtml')->__('Excel XML'));
return parent::_prepareColumns();
}
