J2.5:Developing a MVC Component/Adding a model to the site part

Only this version

Articles in this serie

• Developing a Basic Component
• Adding a view to the site part
• Adding a menu type to the backend part
• Adding a model to the site part
• Adding a variable request in the menu type
• Using the database
• Using the database

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 previous parts of the tutorial before reading this.

Adding a model

In the Joomla!1.6 framework, models ares responsible for managing the data. The first function that has to written for a model is a get function. It returns data to the caller. In our case, the caller will be the HelloWorldViewHelloWorld view. By default, the model named HelloWorldModelHelloWorld is the main model associated to this view. with your favorite file manager and editor put a site/models/helloworld.php file containing:

site/models/helloworld.php

<?php
// No direct access to this file
defined('_JEXEC') or die('Restricted access');
// import Joomla modelitem library
jimport('joomla.application.component.modelitem');
// inherit the JModelItem class
class HelloWorldModelHelloWorld extends JModelItem
{
        /**
         * @var string msg
         */
        protected $msg;
        /**
         * Get the message
         * @return string The message to be displayed to the user
         */
        public function getMsg() 
        {
                if (!isset($this->msg)) 
                {
                        $this->msg = 'Hello World!';
                }
                return $this->msg;
        }
}

The HelloWorldViewHelloWorld class asks the model for data using the get method of the JView class:

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');
// inherit the JView class
class HelloWorldViewHelloWorld extends JView {
        protected $msg=null;
        // Overwriting JView display method
        function display($tpl = null) {
                // Assign data to the view
                $this->msg = $this->get('Msg');
                // Display the view
                parent::display($tpl);
        }
}

Also modify your helloworld.xml file to indicate use of models and the new version:

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>0.0.4</version>
        <description>Description of the Hello World component ...</description>
 
        <files folder="site">
                <filename>index.html</filename>
                <filename>helloworld.php</filename>
                <filename>controller.php</filename>
                <folder>views</folder>
                <!-- Include the models folder -->
                <folder>models</folder>
        </files>
 
        <administration>
                <menu>Hello World!</menu>
                <files folder="admin">
                        <filename>index.html</filename>
                        <filename>helloworld.php</filename>
                </files>                
        </administration>
</extension>

Packaging the component

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.xml
• site/models/index.html
• site/models/helloworld.php
• 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 add a menu item of this component using the menu manager in the backend.

Contributors

• Christophe Demko