J2.5:Developing a MVC Component/Adding backend actions

<?php
// No direct access to this file
defined('_JEXEC') or die('Restricted access');
// import Joomla view library
jimport('joomla.application.component.view');
/**
 * HelloWorldList View
 */
class HelloWorldViewHelloWorlds extends JView
{
 
        /**
         * HelloWorldList 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);
        }
 
        /**
         * Setting the toolbar
         */
        protected function addToolBar() 
        {
                JToolBarHelper::title(JText::_('COM_HELLOWORLD_MANAGER_HELLOWORLDS'));
                JToolBarHelper::deleteListX('', 'helloworlds.delete');
                JToolBarHelper::editListX('helloworld.edit');
                JToolBarHelper::addNewX('helloworld.add');
        }
}

<?php
// No direct access to this file
defined('_JEXEC') or die('Restricted access');
// import Joomla controller library
jimport('joomla.application.component.controller');
 
class HelloWorldControllerHelloWorlds extends JControllerAdmin
{
 
        /**
         * Proxy for getModel.
         * @since       1.6
         */
        public function getModel($name = 'HelloWorld', $prefix = 'HelloWorldModel') 
        {
                $model = parent::getModel($name, $prefix, array('ignore_request' => true));
                return $model;
        }
}

<?php
// No direct access to this file
defined('_JEXEC') or die('Restricted access');
// import Joomla controller library
jimport('joomla.application.component.controller');
/**
 * HelloWorld Controller
 */
class HelloWorldControllerHelloWorld extends JControllerForm
{
}

<?php
// No direct access to this file
defined('_JEXEC') or die('Restricted access');
// import Joomla view library
jimport('joomla.application.component.view');
/**
 * HelloWorld View
 */
class HelloWorldViewHelloWorld extends JView
{
 
        /**
         * display method of Hello view
         * @return void
         */
        public function display($tpl = null) 
        {
                // get the Data
                $form = $this->get('Form');
                $item = $this->get('Item');
 
                // Check for errors.
                if (count($errors = $this->get('Errors'))) 
                {
                        JError::raiseError(500, implode("<br />", $errors));
                        return false;
                }
 
                // Assign the Data
                $this->form = $form;
                $this->item = $item;
                // Set the toolbar
                $this->addToolBar();
                // Display the template
                parent::display($tpl);
        }
 
        /**
         * Setting the toolbar
         */
        protected function addToolBar() 
        {
                JRequest::setVar('hidemainmenu', true);
                $isNew          = ($this->item->id == 0);
 
                JToolBarHelper::title($isNew ? JText::_('COM_HELLOWORLD_MANAGER_BANNER_NEW') : JText::_('COM_HELLOWORLD_MANAGER_BANNER_EDIT'));
                JToolBarHelper::save('helloworld.save');
                JToolBarHelper::cancel('helloworld.cancel', $isNew ? 'JTOOLBAR_CANCEL' : 'JTOOLBAR_CLOSE');
        }
}

<?php
// No direct access
defined('_JEXEC') or die('Restricted access');
JHTML::_('behavior.tooltip');
?>
<form action="<?php echo JRoute::_('index.php?option=com_helloworld&layout=edit&id='.(int) $this->item->id); ?>" method="post" name="adminForm" id="helloworld-form">
        <fieldset class="adminform">
                <legend><?php echo JText::_( 'com_helloworld_HelloWorld_Details' ); ?></legend>
                <?php foreach($this->form->getFieldset() as $field): ?>
                        <?php if (!$field->hidden): ?>
                                <?php echo $field->label; ?>
                        <?php endif; ?>
                        <?php echo $field->input; ?>
                <?php endforeach; ?>
        </fieldset>
        <input type="hidden" name="task" value="" />
        <?php echo JHtml::_('form.token'); ?>
</form>

<?php
defined('_JEXEC') or die('Restricted access');
// import Joomla modelform library
jimport('joomla.application.component.modeladmin');
 
/**
 * HelloWorld Model
 */
class HelloWorldModelHelloWorld extends JModelAdmin
{
 
        public function getTable($type = 'HelloWorld', $prefix = 'HelloWorldTable', $config = array())
        {
                return JTable::getInstance($type, $prefix, $config);
        }
 
        public function getForm($data = array(), $loadData = true)
        {
                // Get the form.
                $form = $this->loadForm('com_helloworld.helloworld', 'helloworld', array('control' => 'jform', 'load_data' => $loadData));
                if (empty($form)) {
                        return false;
                }
 
                return $form;
        }
 
        protected function loadFormData()
        {
                // Check the session for previously entered form data.
                $data = JFactory::getApplication()->getUserState('com_helloworld.edit.helloworld.data', array());
 
                if (empty($data)) {
                        $data = $this->getItem();
                }
 
                return $data;
        }
}