J2.5:Developing a MVC Component/Adding decorations to the backend

<?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');
        }
        /**
         * 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 to this file
defined('_JEXEC') or die('Restricted access');
 
// import Joomla view library
jimport('joomla.application.component.view');
 
/**
 * HelloWorld View
 */
class HelloWorldViewHelloWorld extends JView
{
        /**
         * View form
         *
         * @var         form
         */
        protected $form = null;
 
        /**
         * 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);
 
                // Set the document
                $this->setDocument();
        }
 
        /**
         * Setting the toolbar
         */
        protected function addToolBar() 
        {
                JRequest::setVar('hidemainmenu', true);
                $isNew = ($this->item->id == 0);
                JToolBarHelper::title($isNew ? JText::_('COM_HELLOWORLD_MANAGER_HELLOWORLD_NEW') : JText::_('COM_HELLOWORLD_MANAGER_HELLOWORLD_EDIT'), 'helloworld');
                JToolBarHelper::save('helloworld.save');
                JToolBarHelper::cancel('helloworld.cancel', $isNew ? 'JTOOLBAR_CANCEL' : 'JTOOLBAR_CLOSE');
        }
        /**
         * Method to set up the document properties
         *
         * @return void
         */
        protected function setDocument() 
        {
                $isNew = ($this->item->id < 1);
                $document = JFactory::getDocument();
                $document->setTitle($isNew ? JText::_('COM_HELLOWORLD_HELLOWORLD_CREATING') : JText::_('COM_HELLOWORLD_HELLOWORLD_EDITING'));
        }
}

<?php
// No direct access to this file
defined('_JEXEC') or die('Restricted access');
// Set some global property
$document = JFactory::getDocument();
$document->addStyleDeclaration('.icon-48-helloworld {background-image: url(../media/com_helloworld/images/tux-48x48.png);}');
// import joomla controller library
jimport('joomla.application.component.controller');
// Get an instance of the controller prefixed by HelloWorld
$controller = JController::getInstance('HelloWorld');
// Perform the Request task
$controller->execute(JRequest::getCmd('task'));
// Redirect if set by the controller
$controller->redirect();