Archived

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

From Joomla! Documentation

< Archived:Developing a MVC Component

This page has been archived. This page contains information for an unsupported Joomla! version or is no longer relevant. It exists only as a historical reference, it will not be improved and its content may be incomplete and/or contain broken links.

Documentation all together tranparent small.png
Under Construction

This article or section is in the process of an expansion or major restructuring. You are welcome to assist in its construction by editing it as well. If this article or section has not been edited in several days, please remove this template.
This article was last edited by Cdemko (talk| contribs) 14 years ago. (Purge)

Indroduction[edit]

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

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

  • models They manage the data
  • controllers They perform tasks, set and get the 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[edit]

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 (it's a default behavior)

With your favorite file 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[edit]

With your favorite file 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) {
		// Assign data to the view
		$this->msg = 'Hello World';
		// Display the view
		parent::display($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 file 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[edit]

Content of your code directory

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 in your browser address.

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[edit]