/app/code/core/Mage/Adminhtml/Block/Tag/Tag/Grid.php

<?php
/**
 * Magento
 *
 * NOTICE OF LICENSE
 *
 * This source file is subject to the Open Software License (OSL 3.0)
 * that is bundled with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://opensource.org/licenses/osl-3.0.php
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@magentocommerce.com so we can send you a copy immediately.
 *
 * DISCLAIMER
 *
 * Do not edit or add to this file if you wish to upgrade Magento to newer
 * versions in the future. If you wish to customize Magento for your
 * needs please refer to http://www.magentocommerce.com for more information.
 *
 * @category    Mage
 * @package     Mage_Adminhtml
 * @copyright   Copyright (c) 2009 Irubin Consulting Inc. DBA Varien (http://www.varien.com)
 * @license     http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
 */

/**
 * Adminhtml all tags grid
 *
 * @category   Mage
 * @package    Mage_Adminhtml
 * @author     Magento Core Team <core@magentocommerce.com>
 */
class Mage_Adminhtml_Block_Tag_Tag_Grid extends Mage_Adminhtml_Block_Widget_Grid
{
    /**
     * Constructor
     *
     * @return void
     */
    public function __construct()
    {
        parent::__construct();
        $this->setId('tag_tag_grid')
             ->setDefaultSort('name')
             ->setDefaultDir('ASC')
             ->setUseAjax(true)
             ->setSaveParametersInSession(true);
    }

    protected function _addColumnFilterToCollection($column)
    {
        if($column->getIndex()=='stores') {
            $this->getCollection()->addStoreFilter($column->getFilter()->getCondition(), false);
        } else {
            parent::_addColumnFilterToCollection($column);
        }
        return $this;
    }

    protected function _prepareCollection()
    {
        $collection = Mage::getResourceModel('tag/tag_collection')
            ->addSummary(Mage::app()->getStore()->getId())
            ->addStoresVisibility();
        $this->setCollection($collection);
        return parent::_prepareCollection();
    }

    protected function _prepareColumns()
    {
        $this->addColumn('name', array(
            'header'    => Mage::helper('tag')->__('Tag'),
            'index'     => 'name',
        ));

        $this->addColumn('total_used', array(
            'header'    => Mage::helper('tag')->__('Uses'),
            'width'     => 140,
            'align'     => 'right',
            'index'     => 'uses',
            'type'      => 'number',
        ));

        $this->addColumn('products', array(
            'header'    => Mage::helper('tag')->__('Products'),
            'width'     => 140,
            'align'     => 'right',
            'index'     => 'products',
            'type'      => 'number',
        ));

        $this->addColumn('customers', array(
            'header'    => Mage::helper('tag')->__('Customers'),
            'width'     => 140,
            'align'     => 'right',
            'index'     => 'customers',
            'type'      => 'number',
        ));

        $this->addColumn('popularity', array(
            'header'    => Mage::helper('tag')->__('Popularity'),
            'width'     => 140,
            'align'     => 'right',
            'index'     => 'popularity',
            'type'      => 'number',
        ));

        $this->addColumn('status', array(
            'header'    => Mage::helper('tag')->__('Status'),
            'width'     => 90,
            'index'     => 'status',
            'type'      => 'options',
            'options'   => $this->helper('tag/data')->getStatusesArray(),
        ));

        if (!Mage::app()->isSingleStoreMode()) {
            $this->addColumn('visible_in', array(
                'header'                => Mage::helper('tag')->__('Visible In'),
                'type'                  => 'store',
                'skipAllStoresLabel'    => true,
                'index'                 => 'stores',
                'sortable'              => false,
                'store_view'            => true
            ));
        }

        return parent::_prepareColumns();
    }

    protected function _prepareMassaction()
    {
        $this->setMassactionIdField('tag_id');
        $this->getMassactionBlock()->setFormFieldName('tag');

        $this->getMassactionBlock()->addItem('delete', array(
             'label'    => Mage::helper('tag')->__('Delete'),
             'url'      => $this->getUrl('*/*/massDelete'),
             'confirm'  => Mage::helper('tag')->__('Are you sure?')
        ));

        $statuses = $this->helper('tag/data')->getStatusesOptionsArray();

        array_unshift($statuses, array('label'=>'', 'value'=>''));

        $this->getMassactionBlock()->addItem('status', array(
             'label'=> Mage::helper('tag')->__('Change status'),
             'url'  => $this->getUrl('*/*/massStatus', array('_current'=>true)),
             'additional' => array(
                    'visibility' => array(
                         'name'     => 'status',
                         'type'     => 'select',
                         'class'    => 'required-entry',
                         'label'    => Mage::helper('tag')->__('Status'),
                         'values'   => $statuses
                     )
             )
        ));

        return $this;
    }

    /*
     * Retrieves Grid Url
     *
     * @return string
     */
    public function getGridUrl()
    {
        return $this->getUrl('*/tag/ajaxGrid', array('_current' => true));
    }

    /**
     * Retrives row click URL
     *
     * @param  mixed $row
     * @return string
     */
    public function getRowUrl($row)
    {
        return $this->getUrl('*/*/edit', array('tag_id' => $row->getId()));
    }
}