Desarrollo de un Componente MVC/Usar la facilidad filtro de idioma

<?php
/**
 * @package     Joomla.Administrator
 * @subpackage  com_helloworld
 *
 * @copyright   Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE.txt
 */
// No direct access to this file
defined('_JEXEC') or die('Restricted access');

/**
 * HelloWorldList Model
 *
 * @since  0.0.1
 */
class HelloWorldModelHelloWorlds extends JModelList
{
	/**
	 * Constructor.
	 *
	 * @param   array  $config  An optional associative array of configuration settings.
	 *
	 * @see     JController
	 * @since   1.6
	 */
	public function __construct($config = array())
	{
		if (empty($config['filter_fields']))
		{
			$config['filter_fields'] = array(
				'id',
				'greeting',
				'author',
				'created',
				'language',
				'published'
			);
		}

		parent::__construct($config);
	}

	/**
	 * Method to build an SQL query to load the list data.
	 *
	 * @return      string  An SQL query
	 */
	protected function getListQuery()
	{
		// Initialize variables.
		$db    = JFactory::getDbo();
		$query = $db->getQuery(true);

		// Create the base select statement.
		$query->select('a.id as id, a.greeting as greeting, a.published as published, a.created as created, 
			  a.image as imageInfo, a.latitude as latitude, a.longitude as longitude, a.alias as alias, a.language as language')
			  ->from($db->quoteName('#__helloworld', 'a'));

		// Join over the categories.
		$query->select($db->quoteName('c.title', 'category_title'))
			->join('LEFT', $db->quoteName('#__categories', 'c') . ' ON c.id = a.catid');
        
		// Join with users table to get the username of the author
		$query->select($db->quoteName('u.username', 'author'))
			->join('LEFT', $db->quoteName('#__users', 'u') . ' ON u.id = a.created_by');

		// Join with languages table to get the language title and image to display
		// Put these into fields called language_title and language_image so that 
		// we can use the little com_content layout to display the map symbol
		$query->select($db->quoteName('l.title', 'language_title') . "," .$db->quoteName('l.image', 'language_image'))
			->join('LEFT', $db->quoteName('#__languages', 'l') . ' ON l.lang_code = a.language');

		// Filter: like / search
		$search = $this->getState('filter.search');

		if (!empty($search))
		{
			$like = $db->quote('%' . $search . '%');
			$query->where('greeting LIKE ' . $like);
		}

		// Filter by published state
		$published = $this->getState('filter.published');

		if (is_numeric($published))
		{
			$query->where('a.published = ' . (int) $published);
		}
		elseif ($published === '')
		{
			$query->where('(a.published IN (0, 1))');
		}

		// Filter by language, if the user has set that in the filter field
		$language = $this->getState('filter.language');
		if ($language)
		{
			$query->where('a.language = ' . $db->quote($language));
		}

		// Add the list ordering clause.
		$orderCol	= $this->state->get('list.ordering', 'greeting');
		$orderDirn 	= $this->state->get('list.direction', 'asc');

		$query->order($db->escape($orderCol) . ' ' . $db->escape($orderDirn));

		return $query;
	}
}

<?php
/**
 * @package     Joomla.Administrator
 * @subpackage  com_helloworld
 *
 * @copyright   Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE.txt
 */

// No direct access to this file
defined('_JEXEC') or die('Restricted Access');

use Joomla\Registry\Registry;

JHtml::_('formbehavior.chosen', 'select');

$listOrder     = $this->escape($this->state->get('list.ordering'));
$listDirn      = $this->escape($this->state->get('list.direction'));
?>
<form action="index.php?option=com_helloworld&view=helloworlds" method="post" id="adminForm" name="adminForm">
	<div id="j-sidebar-container" class="span2">
		<?php echo JHtmlSidebar::render(); ?>
	</div>
	<div id="j-main-container" class="span10">
        <div class="row-fluid">
            <div class="span6">
                <?php echo JText::_('COM_HELLOWORLD_HELLOWORLDS_FILTER'); ?>
                <?php
                    echo JLayoutHelper::render(
                        'joomla.searchtools.default',
                        array('view' => $this)
                    );
                ?>
            </div>
        </div>
        <table class="table table-striped table-hover">
            <thead>
            <tr>
                <th width="1%"><?php echo JText::_('COM_HELLOWORLD_NUM'); ?></th>
                <th width="2%">
                    <?php echo JHtml::_('grid.checkall'); ?>
                </th>
                <th width="15%">
                    <?php echo JHtml::_('searchtools.sort', 'COM_HELLOWORLD_HELLOWORLDS_NAME', 'greeting', $listDirn, $listOrder); ?>
                </th>
                <th width="15%">
                    <?php echo JText::_('COM_HELLOWORLD_HELLOWORLDS_POSITION'); ?>
                </th>
                <th width="15%">
                    <?php echo JText::_('COM_HELLOWORLD_HELLOWORLDS_IMAGE'); ?>
                </th>
                <th width="15%">
                    <?php echo JHtml::_('searchtools.sort', 'COM_HELLOWORLD_AUTHOR', 'author', $listDirn, $listOrder); ?>
                </th>
                <th width="15%">
                    <?php echo JHtml::_('searchtools.sort', 'COM_HELLOWORLD_LANGUAGE', 'language', $listDirn, $listOrder); ?>
                </th>
                <th width="15%">
                    <?php echo JHtml::_('searchtools.sort', 'COM_HELLOWORLD_CREATED_DATE', 'created', $listDirn, $listOrder); ?>
                </th>
                <th width="5%">
                    <?php echo JHtml::_('searchtools.sort', 'COM_HELLOWORLD_PUBLISHED', 'published', $listDirn, $listOrder); ?>
                </th>
                <th width="2%">
                    <?php echo JHtml::_('searchtools.sort', 'COM_HELLOWORLD_ID', 'id', $listDirn, $listOrder); ?>
                </th>
            </tr>
            </thead>
            <tfoot>
                <tr>
                    <td colspan="5">
                        <?php echo $this->pagination->getListFooter(); ?>
                    </td>
                </tr>
            </tfoot>
            <tbody>
                <?php if (!empty($this->items)) : ?>
                    <?php foreach ($this->items as $i => $row) :
                        $link = JRoute::_('index.php?option=com_helloworld&task=helloworld.edit&id=' . $row->id);
                        $row->image = new Registry;
                        $row->image->loadString($row->imageInfo);
                    ?>
                        <tr>
                            <td><?php echo $this->pagination->getRowOffset($i); ?></td>
                            <td>
                                <?php echo JHtml::_('grid.id', $i, $row->id); ?>
                            </td>
                            <td>
                                <a href="<?php echo $link; ?>" title="<?php echo JText::_('COM_HELLOWORLD_EDIT_HELLOWORLD'); ?>">
                                    <?php echo $row->greeting; ?>
                                </a>
                                <span class="small break-word">
                                	<?php echo JText::sprintf('JGLOBAL_LIST_ALIAS', $this->escape($row->alias)); ?>
                                </span>
                                <div class="small">
                                    <?php echo JText::_('JCATEGORY') . ': ' . $this->escape($row->category_title); ?>
                                </div>
                            </td>
                            <td align="center">
                                <?php echo "[" . $row->latitude . ", " . $row->longitude . "]"; ?>
                            </td>
                            <td align="center">
                                <?php
                                    $caption = $row->image->get('caption') ? : '' ;
                                    $src = JURI::root() . ($row->image->get('image') ? : '' );
                                    $html = '<p class="hasTooltip" style="display: inline-block" data-html="true" data-toggle="tooltip" data-placement="right" title="<img width=\'100px\' height=\'100px\' src=\'%s\'>">%s</p>';
                                    echo sprintf($html, $src, $caption);  ?>
                            </td>
                            <td align="center">
                                <?php echo $row->author; ?>
                            </td>
                            <td align="center">
                                <?php echo JLayoutHelper::render('joomla.content.language', $row); ?>
                            </td>
                            <td align="center">
                                <?php echo substr($row->created, 0, 10); ?>
                            </td>
                            <td align="center">
                                <?php echo JHtml::_('jgrid.published', $row->published, $i, 'helloworlds.', true, 'cb'); ?>
                            </td>
                            <td align="center">
                                <?php echo $row->id; ?>
                            </td>
                        </tr>
                    <?php endforeach; ?>
                <?php endif; ?>
            </tbody>
        </table>
        <input type="hidden" name="task" value=""/>
        <input type="hidden" name="boxchecked" value="0"/>
        <?php echo JHtml::_('form.token'); ?>
    </div>
</form>

<?php
/**
 * @package     Joomla.Administrator
 * @subpackage  com_helloworld
 *
 * @copyright   Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE.txt
 */

// No direct access to this file
defined('_JEXEC') or die('Restricted access');

/**
 * HelloWorld View
 * This is the site view presenting the user with the ability to add a new Helloworld record
 * 
 */
class HelloWorldViewForm extends JViewLegacy
{

	protected $form = null;
	protected $canDo;

	/**
	 * Display the Hello World view
	 *
	 * @param   string  $tpl  The name of the layout file to parse.
	 *
	 * @return  void
	 */
	public function display($tpl = null)
	{
		// Get the form to display
		$this->form = $this->get('Form');
		// Get the javascript script file for client-side validation
		$this->script = $this->get('Script'); 

		// Propose current language as default
		if (JLanguageMultilang::isEnabled())
		{
			$lang = JFactory::getLanguage()->getTag();
			$this->form->setFieldAttribute('language', 'default', $lang);
		}

		// Check that the user has permissions to create a new helloworld record
		$this->canDo = JHelperContent::getActions('com_helloworld');
		if (!($this->canDo->get('core.create'))) 
		{
			$app = JFactory::getApplication(); 
			$app->enqueueMessage(JText::_('JERROR_ALERTNOAUTHOR'), 'error');
			$app->setHeader('status', 403, true);
			return;
		}
        
		// Check for errors.
		if (count($errors = $this->get('Errors')))
		{
			throw new Exception(implode("\n", $errors), 500);
		}

		// Call the parent display to display the layout file
		parent::display($tpl);

		// Set properties of the html document
		$this->setDocument();
	}

	/**
	 * Method to set up the html document properties
	 *
	 * @return void
	 */
	protected function setDocument() 
	{
		$document = JFactory::getDocument();
		$document->setTitle(JText::_('COM_HELLOWORLD_HELLOWORLD_CREATING'));
		$document->addScript(JURI::root() . $this->script);
		$document->addScript(JURI::root() . "/administrator/components/com_helloworld"
		                                  . "/views/helloworld/submitbutton.js");
		JText::script('COM_HELLOWORLD_HELLOWORLD_ERROR_UNACCEPTABLE');
	}
}

<?php
/**
 * @package     Joomla.Administrator
 * @subpackage  com_helloworld
 *
 * @copyright   Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE.txt
 */

// No direct access to this file
defined('_JEXEC') or die('Restricted access');

JLoader::register('HelloworldHelperRoute', JPATH_ROOT . '/components/com_helloworld/helpers/route.php');

/**
 * HelloWorld Model
 *
 * @since  0.0.1
 */
class HelloWorldModelHelloWorld extends JModelItem
{
	/**
	 * @var object item
	 */
	protected $item;

	/**
	 * Method to auto-populate the model state.
	 *
	 * This method should only be called once per instantiation and is designed
	 * to be called on the first call to the getState() method unless the model
	 * configuration flag to ignore the request is set.
	 *
	 * Note. Calling getState in this method will result in recursion.
	 *
	 * @return	void
	 * @since	2.5
	 */
	protected function populateState()
	{
		// Get the message id
		$jinput = JFactory::getApplication()->input;
		$id     = $jinput->get('id', 1, 'INT');
		$this->setState('message.id', $id);

		// Load the parameters.
		$this->setState('params', JFactory::getApplication()->getParams());
		parent::populateState();
	}

	/**
	 * Method to get a table object, load it if necessary.
	 *
	 * @param   string  $type    The table name. Optional.
	 * @param   string  $prefix  The class prefix. Optional.
	 * @param   array   $config  Configuration array for model. Optional.
	 *
	 * @return  JTable  A JTable object
	 *
	 * @since   1.6
	 */
	public function getTable($type = 'HelloWorld', $prefix = 'HelloWorldTable', $config = array())
	{
		return JTable::getInstance($type, $prefix, $config);
	}

	/**
	 * Get the message
	 * @return object The message to be displayed to the user
	 */
	public function getItem()
	{
		if (!isset($this->item)) 
		{
			$id    = $this->getState('message.id');
			$db    = JFactory::getDbo();
			$query = $db->getQuery(true);
			$query->select('h.greeting, h.params, h.image as image, c.title as category, h.latitude as latitude, h.longitude as longitude')
				  ->from('#__helloworld as h')
				  ->leftJoin('#__categories as c ON h.catid=c.id')
				  ->where('h.id=' . (int)$id);

			if (JLanguageMultilang::isEnabled())
			{
				$lang = JFactory::getLanguage()->getTag();
				$query->where('h.language IN ("*","' . $lang . '")');
			}

			$db->setQuery((string)$query);
		
			if ($this->item = $db->loadObject()) 
			{
				// Load the JSON string
				$params = new JRegistry;
				$params->loadString($this->item->params, 'JSON');
				$this->item->params = $params;

				// Merge global params with item params
				$params = clone $this->getState('params');
				$params->merge($this->item->params);
				$this->item->params = $params;

				// Convert the JSON-encoded image info into an array
				$image = new JRegistry;
				$image->loadString($this->item->image, 'JSON');
				$this->item->imageDetails = $image;
			}
			else
			{
				throw new Exception('Helloworld id not found', 404);
			}
		}
		return $this->item;
	}

	public function getMapParams()
	{
		if ($this->item) 
		{
			$url = HelloworldHelperRoute::getAjaxURL();
			$this->mapParams = array(
				'latitude' => $this->item->latitude,
				'longitude' => $this->item->longitude,
				'zoom' => 10,
				'greeting' => $this->item->greeting,
				'ajaxurl' => $url
			);
			return $this->mapParams; 
		}
		else
		{
			throw new Exception('No helloworld details available for map', 500);
		}
	}

	public function getMapSearchResults($mapbounds)
	{
		try 
		{
			$db    = JFactory::getDbo();
			$query = $db->getQuery(true);
			$query->select('h.id, h.alias, h.catid, h.greeting, h.latitude, h.longitude')
			   ->from('#__helloworld as h')
			   ->where('h.latitude > ' . $mapbounds['minlat'] . 
				' AND h.latitude < ' . $mapbounds['maxlat'] .
				' AND h.longitude > ' . $mapbounds['minlng'] .
				' AND h.longitude < ' . $mapbounds['maxlng']);

			if (JLanguageMultilang::isEnabled())
			{
				$lang = JFactory::getLanguage()->getTag();
				$query->where('h.language IN ("*","' . $lang . '")');
			}

			$db->setQuery($query);
			$results = $db->loadObjectList(); 
		}
		catch (Exception $e)
		{
			$msg = $e->getMessage();
			JFactory::getApplication()->enqueueMessage($msg, 'error'); 
			$results = null;
		}

		if (JLanguageMultilang::isEnabled())
		{
			$query_lang = "&lang={$lang}";
		}
		else
		{
			$query_lang = "";
		}

		for ($i = 0; $i < count($results); $i++) 
		{
			$results[$i]->url = JRoute::_('index.php?option=com_helloworld&view=helloworld&id=' . $results[$i]->id . 
				":" . $results[$i]->alias . '&catid=' . $results[$i]->catid . $query_lang);
		}

		return $results; 
	}
}

<?php
/*
 * View file for the view which displays a list of helloworld messages in a given category
 */
 
defined('_JEXEC') or die;

class HelloworldViewCategory extends JViewLegacy
{
	public function display($tpl = null)
	{
		$this->categoryName = $this->get("CategoryName");

		$this->items = $this->get('Items');
		$this->pagination = $this->get('Pagination');
		$this->state = $this->get('State');
		$this->filterForm    	= $this->get('FilterForm');
		$this->activeFilters 	= $this->get('ActiveFilters');

		$this->subcategories = $this->get('Subcategories');

		parent::display($tpl);
	}
}

<?php
/**
 * Model for displaying the helloworld messages in a given category
 */

defined('_JEXEC') or die;

class HelloworldModelCategory extends JModelList
{
	public function __construct($config = array())
	{
		if (empty($config['filter_fields']))
		{
			$config['filter_fields'] = array(
				'id',
				'greeting',
				'alias',
			);
		}

		parent::__construct($config);
	}
    
	protected function populateState($ordering = null, $direction = null)
	{
		parent::populateState($ordering, $direction);
        
		$app = JFactory::getApplication('site');
		$catid = $app->input->getInt('id');

		$this->setState('category.id', $catid);
	}
    
	protected function getListQuery()
	{
		$db    = JFactory::getDbo();
		$query = $db->getQuery(true);

		$catid = $this->getState('category.id'); 
		$query->select('id, greeting, alias, catid')
			->from($db->quoteName('#__helloworld'))
			->where('catid = ' . $catid);

		if (JLanguageMultilang::isEnabled())
		{
			$lang = JFactory::getLanguage()->getTag();
			$query->where('language IN ("*","' . $lang . '")');
		}

		$orderCol	= $this->state->get('list.ordering', 'greeting');
		$orderDirn 	= $this->state->get('list.direction', 'asc');

		$query->order($db->escape($orderCol) . ' ' . $db->escape($orderDirn));

		return $query;	
	}

	public function getCategoryName()
	{
		$catid = $this->getState('category.id'); 
		$categories = JCategories::getInstance('Helloworld', array());
		$categoryNode = $categories->get($catid);   
		return $categoryNode->title; 
	}
    
	public function getSubcategories()
	{
		$catid = $this->getState('category.id'); 
		$categories = JCategories::getInstance('Helloworld', array());
		$categoryNode = $categories->get($catid);
		$subcats = $categoryNode->getChildren(); 
        
		$lang = JFactory::getLanguage()->getTag();
		if (JLanguageMultilang::isEnabled() && $lang)
		{
			$query_lang = "&lang={$lang}";
		}
		else
		{
			$query_lang = '';
		}
        
		foreach ($subcats as $subcat)
		{
			$subcat->url = JRoute::_("index.php?view=category&id=" . $subcat->id . $query_lang);
		}
		return $subcats;
	}
}

<?php
/**
 * Class definition for HelloworldCategories
 */

defined('_JEXEC') or die;

class HelloworldCategories extends JCategories
{

	public function __construct($options = array())
	{
		$options['table'] = '#__helloworld';
		$options['extension'] = 'com_helloworld';

		parent::__construct($options);
	}
}

<?php
/**
 * Layout file for displaying helloworld messages belonging to a given category
 */

defined('_JEXEC') or die;

JHtml::_('formbehavior.chosen', 'select');

$listOrder     = $this->escape($this->state->get('list.ordering'));
$listDirn      = $this->escape($this->state->get('list.direction'));
$lang = JFactory::getLanguage()->getTag();
if (JLanguageMultilang::isEnabled() && $lang)
{
    $query_lang = "&lang={$lang}";
}
else
{
    $query_lang = "";
}
?>
<form action="#" method="post" id="adminForm" name="adminForm">
<h1><?php echo $this->categoryName; ?></h1>
<div id="j-main-container" class="span10">
    <div class="row-fluid">
        <div class="span10">
            <?php
                echo JLayoutHelper::render(
                    'joomla.searchtools.default',
                    array('view' => $this, 'searchButton' => false)
                );
            ?>
        </div>
    </div>
<table class="table table-striped table-hover">
    <thead>
    <tr>
        <th width="5%"><?php echo JText::_('JGLOBAL_NUM'); ?></th>
        <th width="20%">
            <?php echo JHtml::_('searchtools.sort', 'COM_HELLOWORLD_HELLOWORLD_GREETING_LABEL', 'greeting', $listDirn, $listOrder); ?>
        </th>
        <th width="20%">
            <?php echo JHtml::_('searchtools.sort', 'COM_HELLOWORLD_HELLOWORLD_ALIAS_LABEL', 'alias', $listDirn, $listOrder); ?>
        </th>
        <th width="20%">
            <?php echo JText::_('COM_HELLOWORLD_HELLOWORLD_FIELD_URL_LABEL'); ?>
        </th>
        <th width="5%">
            <?php echo JHtml::_('searchtools.sort', 'JGLOBAL_FIELD_ID_LABEL', 'id', $listDirn, $listOrder); ?>
        </th>
    </tr>
    </thead>
    <tfoot>
        <tr>
            <td colspan="5">
                <?php echo $this->pagination->getListFooter(); ?>
            </td>
        </tr>
    </tfoot>
    <tbody>
        <?php if (!empty($this->items)) : ?>
            <?php foreach ($this->items as $i => $row) : 
                $url = JRoute::_('index.php?option=com_helloworld&view=helloworld&id=' . $row->id . ':' . $row->alias . '&catid=' . $row->catid . $query_lang);
                ?>
                <tr>
                    <td align="center"><?php echo $this->pagination->getRowOffset($i); ?></td>
                    <td align="center"><?php echo $row->greeting; ?></td>
                    <td align="center"><?php echo $row->alias; ?></td>
                    <td align="center"><a href="<?php echo $url; ?>"><?php echo $url; ?></a></td>
                    <td align="center"><?php echo $row->id; ?></td>
                </tr>
            <?php endforeach; ?>
        <?php endif; ?>
    </tbody>
</table>
<h1><?php echo JText::_('COM_HELLOWORLD_HEADER_SUBCATEGORIES'); ?></h1>
<?php foreach ($this->subcategories as $subcategory) : ?>
    <h3><a href="<?php echo $subcategory->url; ?>"> <?php echo $subcategory->title; ?> </a></h3>
    <p><?php echo $subcategory->description; ?></p>
<?php endforeach; ?>
</div>
</form>

<?php

defined('_JEXEC') or die;

/**
 * Helloworld Component Helper file for generating the URL Routes
 *
 */
class HelloworldHelperRoute
{
	/**
	 * When the Helloworld message is displayed then there is also shown a map with a Search Here button.
	 * This function generates the URL which the Ajax call will use to perform the search. 
	 * 
	 */
	public static function getAjaxURL()
	{
		if (!JLanguageMultilang::isEnabled())
		{
			return null;
		}
        
		$lang = JFactory::getLanguage()->getTag();
		$app  = JFactory::getApplication();
		$sitemenu= $app->getMenu();
		$thismenuitem = $sitemenu->getActive();

		// if we haven't got an active menuitem, or we're currently on a menuitem 
		// with view=category or note = "Ajax", then just stay on it
		if (!$thismenuitem || strpos($thismenuitem->link, "view=category") !== false || $thismenuitem->note == "Ajax")
		{
			return null;
		}

		// look for a menuitem with the right language, and a note field of "Ajax"
		$menuitem = $sitemenu->getItems(array('language','note'), array($lang, "Ajax"));
		if ($menuitem)
		{
			$itemid = $menuitem[0]->id; 
			$url = JRoute::_("index.php?Itemid=$itemid&view=helloworld&format=json");
			return $url;
		}
		else
		{
			return null;
		}
	}
}

<?php

defined('_JEXEC') or die;

class HelloworldRouter implements JComponentRouterInterface
{

	public function build(&$query)
	{
		$segments = array();

		if (!JLanguageMultilang::isEnabled() || !isset($query['view']))
		{
			return $segments;
		}

		$lang = JFactory::getLanguage()->getTag();
		$app  = JFactory::getApplication();
        
		// get the menu item that this call to build() relates to
		if (!isset($query['Itemid']))
		{
			return $segments;
		}
		$sitemenu = $app->getMenu();
		$thisMenuitem = $sitemenu->getItem($query['Itemid']);

		if ($thisMenuitem->language != $lang)
		{
			return $segments;
		}
        
		if ($thisMenuitem->note == "Ajax")
		{   
			// We're on the /message menuitem. 
			// Check we've got the right parameters then set url segment = id : alias
			if ($query['view'] == "helloworld" && isset($query['id']))
			{
				// we'll support the passed id being in the form id:alias
				$segments[] = $query['id'];

				unset($query['id']);
				unset($query['catid']);
			}
		}
		else
		{
			// assume we're on the /messages menuitem
			if (($query['view'] == "category") && isset($query['id']))
			{
				// set this part of the url to be of the form /subcat1/subcat2/...
				$pathSegments = $this->getCategorySegments($query['id']);
				if ($pathSegments)
				{
					$segments = $pathSegments;
					unset($query['id']);
				}
			}
			elseif ($query['view'] == "helloworld" && isset($query['catid']) && isset($query['id']))
			{
				// set this part of the url to be of the form /subcat1/subcat2/.../hello-world 
				$pathSegments = $this->getCategorySegments($query['catid']);
				if ($pathSegments)
				{
					$segments = $pathSegments;
				}

				$segments[] = $query['id'];

				unset($query['id']);
				unset($query['catid']);
			}
		}

		unset($query['view']);
		return $segments;
	}

	/*
	 * This function take a category id and finds the path from that category to the root of the category tree
	 * The path returned from getPath() is an associative array of key = category id, value = id:alias
	 * If no valid category is found from the passed-in category id then null is returned. 
	 */
     
	private function getCategorySegments($catid)
	{
		$categories = JCategories::getInstance('Helloworld', array());
		$categoryNode = $categories->get($catid);
		if ($categoryNode)
		{
			$path = $categoryNode->getPath();

			return $path;
		}
		else
		{
			return null;
		}
	}

	public function parse(&$segments)
	{
		$vars = array();
		$nSegments = count($segments);
        
		$app  = JFactory::getApplication();
		$sitemenu = $app->getMenu();
		$activeMenuitem = $sitemenu->getActive();
		if (!$activeMenuitem)
		{
			return $vars;
		}
        
		if ($activeMenuitem->note == "Ajax")
		{
			// Expect 1 segment of the form id:alias for the helloworld record
			if ($nSegments == 1)
			{
				$vars['id'] = $segments[0];
				$vars['view'] = 'helloworld';
			}
		}
		else
		{
			// Try to match the categories in the segments, starting at the root
			$categories = JCategories::getInstance('Helloworld', array());
			$matchingCategory = $categories->get('root');
            
			// Go through the category tree, try to get a match between each segment
			// and the id:alias of one of the children
			// The last segment may be a category id:alias or a helloworld record id:alias
			for ($i=0; $i < $nSegments; $i++)
			{
				$children = $matchingCategory->getChildren();
				$matchingCategory = $this->match($children, $segments[$i]);
				if ($matchingCategory)
				{
					$catid = $matchingCategory->id;
					if ($i == $nSegments - 1)    // we're done, all segments are categories
					{
						$vars['view'] = 'category';
						$vars['id'] = $catid;
					}
				}
				else
				{
					if ($i == $nSegments - 1)   // all but last segment are categories
					{
						$vars['id'] = $segments[$i];
						$vars['view'] = 'helloworld';
					}
					else   // something went wrong - didn't get a match at this level
					{
						break;
					}
				}
			}
		}

		return $vars;
	}

	/*
	 * This function takes an array of categoryNode elements and a url segment
	 * It goes through the categoryNodes looking for the one whose id:alias matches the passed-in segment
	 *   and returns the matching categoryNode, or null if not found
	 */
	private function match($categoryNodes, $segment)
	{
		foreach ($categoryNodes as $categoryNode)
		{
			if ($segment == $categoryNode->id . ':' . $categoryNode->alias)
			{
				return $categoryNode;
			}
		}
		return null;
	}

	public function preprocess($query)
	{
		return $query;
	}
}