J2.5:Developing a MVC Component/Adding configuration

<?php
// No direct access to this file
defined('_JEXEC') or die('Restricted access');
 
// import Joomla view library
jimport('joomla.application.component.view');
 
/**
 * HelloWorlds View
 */
class HelloWorldViewHelloWorlds extends JView
{
        /**
         * HelloWorlds view display method
         * @return void
         */
        function display($tpl = null) 
        {
                // Get data from the model
                $items = $this->get('Items');
                $pagination = $this->get('Pagination');
 
                // Check for errors.
                if (count($errors = $this->get('Errors'))) 
                {
                        JError::raiseError(500, implode('<br />', $errors));
                        return false;
                }
                // Assign data to the view
                $this->items = $items;
                $this->pagination = $pagination;
 
                // Set the toolbar
                $this->addToolBar();
 
                // Display the template
                parent::display($tpl);
 
                // Set the document
                $this->setDocument();
        }
 
        /**
         * Setting the toolbar
         */
        protected function addToolBar() 
        {
                JToolBarHelper::title(JText::_('COM_HELLOWORLD_MANAGER_HELLOWORLDS'), 'helloworld');
                JToolBarHelper::deleteListX('', 'helloworlds.delete');
                JToolBarHelper::editListX('helloworld.edit');
                JToolBarHelper::addNewX('helloworld.add');
                JToolBarHelper::preferences('com_helloworld');
        }
        /**
         * Method to set up the document properties
         *
         * @return void
         */
        protected function setDocument() 
        {
                $document = JFactory::getDocument();
                $document->setTitle(JText::_('COM_HELLOWORLD_ADMINISTRATION'));
        }
}

<?php
// No direct access
defined('_JEXEC') or die('Restricted access');
 
// import Joomla table library
jimport('joomla.database.table');
 
/**
 * Hello Table class
 */
class HelloWorldTableHelloWorld extends JTable
{
        /**
         * Constructor
         *
         * @param object Database connector object
         */
        function __construct(&$db) 
        {
                parent::__construct('#__helloworld', 'id', $db);
        }
        /**
         * Overloaded bind function
         *
         * @param       array           named array
         * @return      null|string     null is operation was satisfactory, otherwise returns an error
         * @see JTable:bind
         * @since 1.5
         */
        public function bind($array, $ignore = '') 
        {
                if (isset($array['params']) && is_array($array['params'])) 
                {
                        // Convert the params field to a string.
                        $parameter = new JRegistry;
                        $parameter->loadArray($array['params']);
                        $array['params'] = (string)$parameter;
                }
                return parent::bind($array, $ignore);
        }
 
        /**
         * Overloaded load function
         *
         * @param       int $pk primary key
         * @param       boolean $reset reset data
         * @return      boolean
         * @see JTable:load
         */
        public function load($pk = null, $reset = true) 
        {
                if (parent::load($pk, $reset)) 
                {
                        // Convert the params field to a registry.
                        $params = new JRegistry;
                        $params->loadJSON($this->params);
                        $this->params = $params;
                        return true;
                }
                else
                {
                        return false;
                }
        }
}

<?php
// No direct access
defined('_JEXEC') or die('Restricted access');
JHtml::_('behavior.tooltip');
JHtml::_('behavior.formvalidation');
$params = $this->form->getFieldsets('params');
?>
<form action="<?php echo JRoute::_('index.php?option=com_helloworld&layout=edit&id='.(int) $this->item->id); ?>" method="post" name="adminForm" id="helloworld-form" class="form-validate">
 
        <div class="width-60 fltlft">
                <fieldset class="adminform">
                        <legend><?php echo JText::_( 'COM_HELLOWORLD_HELLOWORLD_DETAILS' ); ?></legend>
                        <ul class="adminformlist">
<?php foreach($this->form->getFieldset('details') as $field): ?>
                                <li><?php echo $field->label;echo $field->input;?></li>
<?php endforeach; ?>
                        </ul>
        </div>
 
        <div class="width-40 fltrt">
                <?php echo JHtml::_('sliders.start', 'helloworld-slider'); ?>
<?php foreach ($params as $name => $fieldset): ?>
                <?php echo JHtml::_('sliders.panel', JText::_($fieldset->label), $name.'-params');?>
        <?php if (isset($fieldset->description) && trim($fieldset->description)): ?>
                <p class="tip"><?php echo $this->escape(JText::_($fieldset->description));?></p>
        <?php endif;?>
                <fieldset class="panelform" >
                        <ul class="adminformlist">
        <?php foreach ($this->form->getFieldset($name) as $field) : ?>
                                <li><?php echo $field->label; ?><?php echo $field->input; ?></li>
        <?php endforeach; ?>
                        </ul>
                </fieldset>
<?php endforeach; ?>
 
                <?php echo JHtml::_('sliders.end'); ?>
        </div>
 
        <div>
                <input type="hidden" name="task" value="helloworld.edit" />
                <?php echo JHtml::_('form.token'); ?>
        </div>
</form>

<?php
// No direct access to this file
defined('_JEXEC') or die('Restricted access');
 
// import Joomla modelitem library
jimport('joomla.application.component.modelitem');
 
/**
 * HelloWorld Model
 */
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       1.6
         */
        protected function populateState() 
        {
                $app = JFactory::getApplication();
                // Get the message id
                $id = JRequest::getInt('id');
                $this->setState('message.id', $id);
 
                // Load the parameters.
                $params = $app->getParams();
                $this->setState('params', $params);
                parent::populateState();
        }
 
        /**
         * Returns a reference to the a Table object, always creating it.
         *
         * @param       type    The table type to instantiate
         * @param       string  A prefix for the table class name. Optional.
         * @param       array   Configuration array for model. Optional.
         * @return      JTable  A database 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');
                        $this->_db->setQuery($this->_db->getQuery(true)
                                ->from('#__helloworld as h')
                                ->leftJoin('#__categories as c ON h.catid=c.id')
                                ->select('h.greeting, h.params, c.title as category')
                                ->where('h.id=' . (int)$id));
                        if (!$this->item = $this->_db->loadObject()) 
                        {
                                $this->setError($this->_db->getError());
                        }
                        else
                        {
                                // Load the JSON string
                                $params = new JRegistry;
                                $params->loadJSON($this->item->params);
                                $this->item->params = $params;
 
                                // Merge global params with item params
                                $params = clone $this->getState('params');
                                $params->merge($this->item->params);
                                $this->item->params = $params;
                        }
                }
                return $this->item;
        }
}

<?php
<?php
// No direct access to this file
defined('_JEXEC') or die('Restricted access');
 
// import Joomla view library
jimport('joomla.application.component.view');
 
/**
 * HTML View class for the HelloWorld Component
 */
class HelloWorldViewHelloWorld extends JView
{
        // Overwriting JView display method
        function display($tpl = null) 
        {
                // Assign data to the view
                $this->item = $this->get('Item');
 
                // Check for errors.
                if (count($errors = $this->get('Errors'))) 
                {
                        JError::raiseError(500, implode('<br />', $errors));
                        return false;
                }
                // Display the view
                parent::display($tpl);
        }
}

<?php
// No direct access to this file
defined('_JEXEC') or die('Restricted access');
?>
<h1><?php echo $this->item->greeting.(($this->item->category and $this->item->params->get('show_category')) ? (' ('.$this->item->category.')') : ''); ?></h1>