I wanted a way to quickly review my K2 attachments, so I created and installed the necessary files as shown in the attached images.

<b>1) administrator/components/com_k2/controllers/attachments.php</b>

<?php
/*
// "K2" Component by JoomlaWorks for Joomla! 1.5.x - Version 2.0
// Copyright (c) 2006 - 2009 JoomlaWorks Ltd. All rights reserved.
// Released under the GNU/GPL license: http://www.gnu.org/copyleft/gpl.html
// More info at http://www.joomlaworks.gr and http://k2.joomlaworks.gr
// Designed and developed by the JoomlaWorks team
// *** Last update: August 6th, 2009 ***
//
// Created by E.W. Madison 08/28/2009
//
*/

/* no direct access */
defined('_JEXEC') or die ('Restricted access');

jimport('joomla.application.component.controller');

class K2ControllerAttachments extends JController
{

	function display() {
		JRequest::setVar('view', 'attachments');
		parent::display();
	}

	function remove() {
		JRequest::checkToken() or jexit('Invalid Token');
		$model = & $this->getModel('attachments');
		$model->remove();
	}

}

<b>2) administrator/components/com_k2/models/attachments.php
</b>
<?php

/*
// "K2" Component by JoomlaWorks for Joomla! 1.5.x - Version 2.0
// Copyright (c) 2006 - 2009 JoomlaWorks Ltd. All rights reserved.
// Released under the GNU/GPL license: http://www.gnu.org/copyleft/gpl.html
// More info at http://www.joomlaworks.gr and http://k2.joomlaworks.gr
// Designed and developed by the JoomlaWorks team
// *** Last update: August 6th, 2009 ***
//
// Created by E.W. Madison 08/28/2009
//
*/

/* no direct access */

defined('_JEXEC') or die ('Restricted access');

jimport('joomla.application.component.model');

JTable::addIncludePath(JPATH_COMPONENT.DS.'tables');

class K2ModelAttachments extends JModel
{
	function getData() {
	
		global $mainframe;
		$option = JRequest::getCmd('option');
		$view = JRequest::getCmd('view');
		$db = & JFactory::getDBO();
		$limit = $mainframe->getUserStateFromRequest('global.list.limit', 'limit', $mainframe->getCfg('list_limit'), 'int');
		$limitstart = $mainframe->getUserStateFromRequest($option.$view.'.limitstart', 'limitstart', 0, 'int');
		$filter_order = $mainframe->getUserStateFromRequest($option.$view.'filter_order', 'filter_order', 'id', 'cmd');
		$filter_order_Dir = $mainframe->getUserStateFromRequest($option.$view.'filter_order_Dir', 'filter_order_Dir', 'DESC', 'word');
//		$filter_state = $mainframe->getUserStateFromRequest($option.$view.'filter_state', 'filter_state', -1, 'int');
		$search = $mainframe->getUserStateFromRequest($option.$view.'search', 'search', '', 'string');
		$search = JString::strtolower($search);
	
		$query = "SELECT * FROM #__k2_attachments WHERE id>0";

		if ($search) {
			$query .= " AND LOWER( filename ) LIKE ".$db->Quote('%'.$search.'%');
		}
	
		if (!$filter_order) {
			$filter_order = "filename";
		}
	
		$query .= " ORDER BY {$filter_order} {$filter_order_Dir}";
		$db->setQuery($query, $limitstart, $limit);
		$rows = $db->loadObjectList();
		return $rows;
	}

	function getTotal() {
	
		global $mainframe;
		$option = JRequest::getCmd('option');
		$view = JRequest::getCmd('view');
		$db = & JFactory::getDBO();
		$limit = $mainframe->getUserStateFromRequest('global.list.limit', 'limit', $mainframe->getCfg('list_limit'), 'int');
		$limitstart = $mainframe->getUserStateFromRequest($option.'.limitstart', 'limitstart', 0, 'int');
		$filter_state = $mainframe->getUserStateFromRequest($option.$view.'filter_state', 'filter_state', 1, 'int');
		$search = $mainframe->getUserStateFromRequest($option.$view.'search', 'search', '', 'string');
		$search = JString::strtolower($search);
	
		$query = "SELECT COUNT(*) FROM #__k2_attachments WHERE id>0";
		
		if ($filter_state > -1) {
			$query .= " AND published={$filter_state}";
		}
		
		if ($search) {
			$query .= " AND LOWER( filename ) LIKE ".$db->Quote('%'.$search.'%');
		}
		
		$db->setQuery($query);
		$total = $db->loadresult();
		return $total;
	}


	function remove() {
	
		global $mainframe;
		$db = & JFactory::getDBO();
		$cid = JRequest::getVar('cid');
		$row = & JTable::getInstance('K2Attachment', 'Table');
		foreach ($cid as $id) {
			$row->load($id);
			$row->delete($id);
		}
		$cache = & JFactory::getCache('com_k2');
		$cache->clean();
		$mainframe->redirect('index.php?option=com_k2&view=attachments', JText::_('Delete Completed'));
	}
	

}

<b>3) administrator/components/com_k2/views/attachments/tmpl/default.php</b>

<?php
/*
// "K2" Component by JoomlaWorks for Joomla! 1.5.x - Version 2.0
// Copyright (c) 2006 - 2009 JoomlaWorks Ltd. All rights reserved.
// Released under the GNU/GPL license: http://www.gnu.org/copyleft/gpl.html
// More info at http://www.joomlaworks.gr and http://k2.joomlaworks.gr
// Designed and developed by the JoomlaWorks team
// *** Last update: August 6th, 2009 ***
//
// Created by E.W. Madison 08/28/2009
//
*/

/* no direct access */
defined('_JEXEC') or die ('Restricted access');

?>
<script type="text/javascript">
	window.addEvent('domready', function(){
		$$('#toolbar-Link a').addEvent('click', function(e){
			var answer = confirm('<?php echo JText::_('This will permanently delete all attachments. Are you sure?', true); ?>')
			if (!answer){
				new Event(e).stop();
			}
		})
	});
</script>
<form action="index.php" method="post" name="adminForm">
  <table width="100%">
    <tr>
      <td align="left"><?php echo JText::_('Filter:'); ?>
        <input type="text" name="search" id="search" value="<?php echo $this->lists['search'] ?>" class="text_area" onchange="document.adminForm.submit();" title="<?php echo JText::_('Filter by Attachment'); ?>"/>
        <button onclick="this.form.submit();"><?php echo JText::_('Go'); ?></button>
</td>
    </tr>
  </table>
  <table class="adminlist">
    <thead>
      <tr>
        <th width="20"> # </th>
        <th width="20"> <input type="checkbox" name="toggle" value="" onclick="checkAll(<?php echo count( $this->rows ); ?>);" /></th>
        <th class="title"> <?php echo JHTML::_('grid.sort',   JText::_('Item ID'), 'itemID', @$this->lists['order_Dir'], @$this->lists['order'] ); ?> </th>
        <th> <?php echo JHTML::_('grid.sort',   JText::_('FileName'), 'filename', @$this->lists['order_Dir'], @$this->lists['order'] ); ?> </th>
        <th> <?php echo JHTML::_('grid.sort',   JText::_('Title'), 'title', @$this->lists['order_Dir'], @$this->lists['order'] ); ?> </th>
        <th> <?php echo JHTML::_('grid.sort',   JText::_('Title Attribute'), 'titleAttribute', @$this->lists['order_Dir'], @$this->lists['order'] ); ?> </th>
        <th> <?php echo JHTML::_('grid.sort', JText::_('Hits'), 'hits', @$this->lists['order_Dir'], @$this->lists['order'] ); ?> </th>
        <th> <?php echo JHTML::_('grid.sort', JText::_('ID'), 'id', @$this->lists['order_Dir'], @$this->lists['order'] ); ?> </th>
      </tr>
    </thead>
    <tbody>
  <?php
  $k = 0; $i = 0;
	foreach ($this->rows as $row) :
		$row->checked_out=0;
		$checked 	= JHTML::_('grid.checkedout', $row, $i );
		?>
      <tr class="<?php echo "row$k"; ?>">
        <td width="20" align="center"><?php echo $i+1; ?></td>
        <td width="20" align="center"><?php echo $checked; ?></td>
        <td><a href="<?php echo $row->link; ?>"><?php echo $row->itemID;?></a></td>
        <td><?php echo $row->filename;?></td>
        <td><?php echo $row->title;?></td>
        <td><?php echo $row->titleAttribute;?></td>
        <td><?php echo $row->hits;?></td>
        <td align="center"><?php echo $row->id; ?></td>
      </tr>
      <?php $k = 1 - $k; $i++; endforeach; ?>
    </tbody>
    <tfoot>
      <tr>
        <td colspan="10"><?php echo $this->page->getListFooter(); ?></td>
      </tr>
    </tfoot>
  </table>
  <input type="hidden" name="option" value="<?php echo $option;?>" />
  <input type="hidden" name="view" value="attachments" />
  <input type="hidden" name="task" value="" />
  <input type="hidden" name="filter_order" value="<?php echo $this->lists['order']; ?>" />
  <input type="hidden" name="filter_order_Dir" value="<?php echo $this->lists['order_Dir']; ?>" />
  <input type="hidden" name="boxchecked" value="0" />
  <?php echo JHTML::_( 'form.token' );?>
</form>

<b>4) administrator/components/com_k2/views/attachments/view.html.php</b>

<?php

/*
// "K2" Component by JoomlaWorks for Joomla! 1.5.x - Version 2.0
// Copyright (c) 2006 - 2009 JoomlaWorks Ltd. All rights reserved.
// Released under the GNU/GPL license: http://www.gnu.org/copyleft/gpl.html
// More info at http://www.joomlaworks.gr and http://k2.joomlaworks.gr
// Designed and developed by the JoomlaWorks team
// *** Last update: August 6th, 2009 ***
//
// Created by E.W. Madison 08/28/2009
//
*/

/* no direct access */

defined('_JEXEC') or die ('Restricted access');

jimport('joomla.application.component.view');

class K2ViewAttachments extends JView
{

	function display($tpl = null)
	{
	
		global $mainframe;
		$user = & JFactory::getUser();
		$option = JRequest::getCmd('option');
		$view = JRequest::getCmd('view');
		$limit = $mainframe->getUserStateFromRequest('global.list.limit', 'limit', $mainframe->getCfg('list_limit'), 'int');
		$limitstart = $mainframe->getUserStateFromRequest($option.$view.'.limitstart', 'limitstart', 0, 'int');
		$filter_order = $mainframe->getUserStateFromRequest($option.$view.'filter_order', 'filter_order', 'id', 'cmd');
		$filter_order_Dir = $mainframe->getUserStateFromRequest($option.$view.'filter_order_Dir', 'filter_order_Dir', 'DESC', 'word');
//		$filter_state = $mainframe->getUserStateFromRequest($option.$view.'filter_state', 'filter_state', -1, 'int');
		$search = $mainframe->getUserStateFromRequest($option.$view.'search', 'search', '', 'string');
		$search = JString::strtolower($search);
		$model = & $this->getModel();
	
		$attachments = $model->getData();
		
		for ($i=0; $i<sizeof($attachments); $i++){
		
		$attachments[$i]->link = JRoute::_('index.php?option=com_k2&view=item&cid='.$attachments[$i]->itemID);
		
		}
		
		$this->assignRef('rows', $attachments);
		$total = $model->getTotal();
	
		jimport('joomla.html.pagination');
		$pageNav = new JPagination($total, $limitstart, $limit);
		$this->assignRef('page', $pageNav);
	
		$lists = array ();
		$lists['search'] = $search;
		$lists['order_Dir'] = $filter_order_Dir;
		$lists['order'] = $filter_order;
	
		$this->assignRef('lists', $lists);
	
		JToolBarHelper::title(JText::_('Attachments'));
		
		JToolBarHelper::deleteList(JText::_('Are you sure you want to delete selected attachments?'), 'remove', JText::_('Delete'));
		$toolbar=&JToolBar::getInstance('toolbar');

		JToolBarHelper::preferences('com_k2', '500', '600');
	
		JSubMenuHelper::addEntry(JText::_('Dashboard'), 'index.php?option=com_k2');
		JSubMenuHelper::addEntry(JText::_('Items'), 'index.php?option=com_k2&view=items');
		JSubMenuHelper::addEntry(JText::_('Categories'), 'index.php?option=com_k2&view=categories');
		JSubMenuHelper::addEntry(JText::_('Tags'), 'index.php?option=com_k2&view=tags');
		JSubMenuHelper::addEntry(JText::_('Comments'), 'index.php?option=com_k2&view=comments');
		JSubMenuHelper::addEntry(JText::_('Attachments'), 'index.php?option=com_k2&view=attachments', true);

		if ($user->gid > 23) {
			JSubMenuHelper::addEntry(JText::_('Users'), 'index.php?option=com_k2&view=users');
			JSubMenuHelper::addEntry(JText::_('User Groups'), 'index.php?option=com_k2&view=userGroups');
			JSubMenuHelper::addEntry(JText::_('Extra Fields'), 'index.php?option=com_k2&view=extraFields');
			JSubMenuHelper::addEntry(JText::_('Extra Field Groups'), 'index.php?option=com_k2&view=extraFieldsGroups');
			JSubMenuHelper::addEntry(JText::_('Information'), 'index.php?option=com_k2&view=info');
		}

		parent::display($tpl);
	}

}

<b>5) administrator/components/com_k2/views/cpanel/view.html.php</b>

Add this at line 40:
		$sumOfAttachments = $model->countAttachmentDownloads();
		$this->assignRef('sumOfAttachments',$sumOfAttachments);

And Add this at line 76:

		JSubMenuHelper::addEntry(JText::_('Attachments'), 'index.php?option=com_k2&view=attachments');

<b>6) administrator/components/com_k2/views/cpanel/tmpl/default.php</b>

Add this at line 102:

	<div style="float:left;">
    <div class="icon">
	    <a href="index.php?option=com_k2&amp;view=attachments">
		    <img alt="<?php echo JText::_('Attachments'); ?>" src="components/com_k2/images/dashboard/attachments.png" />
		    <span><?php echo JText::_('Attachments'); ?></span>
	    </a>
    </div>
  </div>

<b>7) administrator/components/com_k2/models/cpanel.php</b>

Add these functions around line 85:
	function countAttachments(){
		
		global $mainframe;
		$db = & JFactory::getDBO();
		$query = "SELECT COUNT(*) FROM #__k2_attachments";
		$db->setQuery($query);
		$result = $db->loadResult();
		return $result;
	}
	
	
	function countAttachmentDownloads(){
		
		global $mainframe;
		$db = & JFactory::getDBO();
		$query = "SELECT Sum(hits) FROM #__k2_attachments";
		$db->setQuery($query);
		$result = $db->loadResult();
		return $result;
	}


<b>8) Add the following to all of the other view.html.php files</b>

		JSubMenuHelper::addEntry(JText::_('Attachments'), 'index.php?option=com_k2&view=attachments');

I am not happy with the layout of all of these files, a Joomla construct issue. 

We should be able to create a Plugin (com_k2) and ALL of the files for com_k2 are located under com_k2, 

We should be able to create a Plugin under com_k2 (Attachments) and ALL of the files for attachments are located under it.

The CakePHP framework has gone a long way towards the deployment of this type of MVC framework.

I don't like having to copy and past a menu item into several files!

I don't like having to hack several non Attachments files located in the Controllers, Models, Views.

Shouldn't the structure be Plug-In com_k2 Controllers, Models, Views, etc. etc. etc. and not
Controllers, com_k2, etc., etc., etc. ; Models, com_k2 , etc., etc., etc.; Views, com_k2 , etc., etc., etc.?   

I'm just saying!

Wayne