Archived:Developing a MVC Component/Adding a view to the site part

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Under Construction

Indroduction

This tutorial is part of the Developing a Model-View-Controller (MVC) Component for Joomla!1.6 tutorial. You are encouraged to read the precedent parts of the tutorial before reading this one.

In the Joomla!1.6 framework, third party components authors divide their code in three main parts:

• models They are responsible for managing the data
• controllers They perform tasks, set and get states of the models and ask the views to display
• views They display the content according to the type (error, feed, html, json, raw, xml) and the layout chosen by the controllers

Setting the controller

In the core code of Joomla, there is a class able to manage controllers: JController. This class has to be extended to be used it in our component. In the file site/helloworld.php (entry point of our Hello World component), put these lines

site/helloworld.php

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

The getInstance static method of the JController class will create a controller. In the code above, it will create a controller named HelloWorldController using the controller.php file

With your favorite files manager and editor, create a site/controller.php file containing site/controller.php

<?php
// No direct access to this file
defined('_JEXEC') or die('Restricted access');
// import Joomla controller library
jimport('joomla.application.component.controller');
// inherit the JController class
class HelloWorldController extends JController
{
}

When no task is given in the variables request, the default task will be executed. It's the display task by default. The JController class has such a task. In our example, it will display a view named HelloWorld.

Setting the view

With your favorite files manager and editor, create a file site/views/helloworld/view.html.php able to display the default view and containing

site/views/helloworld/view.html.php

<?php
// No direct access to this file
defined('_JEXEC') or die('Restricted access');
// import Joomla view library
jimport('joomla.application.component.view');
class HelloWorldViewHelloWorld extends JView {
	protected $msg=null;
	// Overwriting JView display method
	function display($tpl = null) {
		// Assigning data to the view
		$this->msg = 'Hello World';
		parent::display($tpl);
	}
}

The display method of the Jview class is called by the display task of the JController class. In our case, this method will display data using the tmpl/default.php file. With your favorite files manager and editor, create a file site/views/helloworld/tmpl/default.php able to display the default view and containing

site/views/helloworld/tmpl/default.php

<?php
// No direct access to this file
defined('_JEXEC') or die('Restricted access');
?>
<h1><?php echo $this->msg; ?></h1>

You can test this basic component by putting index.php?option=com_helloworld in your browser address (don't forget to prefix this address by your Joomla!1.6 installation path).

Packaging the component

Create a compressed file of your code directory or directly download the archive and install it using the extension manager of Joomla!1.6. You can test this basic component by putting index.php?option=com_helloworld in your browser address.

Content of your code directory

• helloworld.xml
• site/index.html
• site/helloworld.php
• site/views/index.html
• site/views/helloworld/index.html
• site/views/helloworld/view.html.php
• site/views/helloworld/tmpl/index.html
• site/views/helloworld/tmpl/default.php
• admin/index.html
• admin/helloworld.php

Create a compressed file of this directory or directly download the archive and install it using the extension manager of Joomla!1.6. You can test this basic component by putting index.php?option=com_helloworld or administrator/index.php?option=com_helloworld in your browser address. You can also noticed that the Hello World! component is visible in the administrator site of your Joomla!1.6 installation under the Components menu.

helloworld.xml

<?xml version="1.0" encoding="utf-8"?>
<extension type="component" version="1.6.0" method="upgrade">
	<name>Hello World!</name>
	<creationDate>November 2009</creationDate>
	<author>John Doe</author>
	<authorEmail>john.doe@example.org</authorEmail>
	<authorUrl>http://www.example.org</authorUrl>
	<copyright>Copyright Info</copyright>
	<license>License Info</license>
	<version>0.0.2</version>
	<description>Description of the Hello World component ...</description>

	<files folder="site">
		<filename>index.html</filename>
		<filename>helloworld.php</filename>
		<!-- The controller is included in the package -->
		<filename>controller.php</filename>
		<!-- The entire views folder is included in the package -->
		<folder>views</folder>
	</files>

	<administration>
		<menu>Hello World!</menu>
		<files folder="admin">
			<filename>index.html</filename>
			<filename>helloworld.php</filename>
		</files>		
	</administration>
</extension>

Contributors

• Christophe Demko