Developing a Model-View-Controller (MVC) Component for Joomla!1.6 – Part 08

http://docs.joomla.org/

Introduction

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.

Joomla!1.6 manages languages for components in four different situations:

  • displaying a component in the public site
  • managing a component in the backend
  • managing menus in the backend
  • installing a component (new in 1.6)

Joomla!1.6 uses two different location folder for languages:

  • one in administrator/language or language
  • one in the component folder (administrator/component/*component*/language or component/*component*/language)

It depends how the component is installed.

Adding language translation in the public site

With your favorite file manager and editor, put a file site/language/en-GB/en-GB.com_helloworld.ini. This file will contain translation for the public part. For the moment, this file is empty

site/language/en-GB/en-GB.com_helloworld.ini

   

For the moment, there are no translations strings in this file.

Adding language translation when managing the component

With your favorite file manager and editor, put a file admin/language/en-GB/en-GB.com_helloworld.ini. This file will contain translation for the backend part.

admin/language/en-GB/en-GB.com_helloworld.ini

COM_HELLOWORLD_HELLOWORLD_FIELD_GREETING_DESC="This message will be displayed"  COM_HELLOWORLD_HELLOWORLD_FIELD_GREETING_LABEL="Message"  COM_HELLOWORLD_HELLOWORLD_HEADING_GREETING="Greeting"  COM_HELLOWORLD_HELLOWORLD_HEADING_ID="Id"  

Adding language translation when managing the menus in the backend

With your favorite file manager and editor, put a file admin/language/en-GB/en-GB.com_helloworld.sys.ini. This file will contain translation for the backend part.

admin/language/en-GB/en-GB.com_helloworld.sys.ini

COM_HELLOWORLD="Hello World!"  COM_HELLOWORLD_DESCRIPTION="This is the Hello World description"  COM_HELLOWORLD_HELLOWORLD_VIEW_DEFAULT_TITLE="Hello World"  COM_HELLOWORLD_HELLOWORLD_VIEW_DEFAULT_DESC="This view displays a selected message"  COM_HELLOWORLD_MENU="Hello World!"  

Adding translation when installing the component

With your favorite file manager and editor, put a file language/en-GB/en-GB.ini. This file will contain translation for the install.

language/en-GB/en-GB.ini

COM_HELLOWORLD="Hello World!"  COM_HELLOWORLD_DESCRIPTION="This is the Hello World description"  

The COM_HELLOWORLD_DESCRIPTION can be used in the helloworld.xml file

Packaging the component

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 add a menu item of this component using the menu manager in the backend.

helloworld.xml

<?xml version="1.0" encoding="utf-8"?>  <extension type="component" version="1.6.0" method="upgrade">     	<name>COM_HELLOWORLD</name>  	<!-- The following elements are optional and free of formatting conttraints -->  	<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>  	<!--  The version string is recorded in the components table -->  	<version>0.0.8</version>  	<!-- The description is optional and defaults to the name -->  	<description>COM_HELLOWORLD_DESCRIPTION</description>     	<install> <!-- Runs on install -->  		<sql>  			<file driver="mysql" charset="utf8">sql/install.mysql.utf8.sql</file>  		</sql>  	</install>  	<uninstall> <!-- Runs on uninstall -->  		<sql>  			<file driver="mysql" charset="utf8">sql/uninstall.mysql.utf8.sql</file>  		</sql>  	</uninstall>  	<update> <!-- Runs on update; New in 1.6 -->  		<schemas>  			<schemapath type="mysql">sql/updates/mysql</schemapath>  		</schemas>  	</update>     	<!-- Site Main File Copy Section -->  	<!-- Note the folder attribute: This attribute describes the folder  		to copy FROM in the package to install therefore files copied  		in this section are copied from /site/ in the package -->  	<files folder="site">  		<filename>index.html</filename>  		<filename>helloworld.php</filename>  		<filename>controller.php</filename>  		<folder>views</folder>  		<folder>models</folder>  		<folder>language</folder>  	</files>     	<administration>  		<!-- Administration Menu Section -->  		<menu>COM_HELLOWORLD_MENU</menu>  		<!-- Administration Main File Copy Section -->  		<!-- Note the folder attribute: This attribute describes the folder  			to copy FROM in the package to install therefore files copied  			in this section are copied from /admin/ in the package -->  		<files folder="admin">  			<!-- Admin Main File Copy Section -->  			<filename>index.html</filename>  			<filename>helloworld.php</filename>  			<filename>controller.php</filename>  			<!-- SQL files section -->  			<folder>sql</folder>  			<!-- tables files section -->  			<folder>tables</folder>  			<!-- models files section -->  			<folder>models</folder>  			<!-- views files section -->  			<folder>views</folder>  		</files>  		<languages folder="admin">  			<language tag="en-GB">language/en-GB/en-GB.com_helloworld.ini</language>  			<language tag="en-GB">language/en-GB/en-GB.com_helloworld.sys.ini</language>  		</languages>  	</administration>     </extension>  

In this helloworld.xml file, languages are installed in:

  • administrator/language for the admin part (look at the xml languages tag)
  • components/com_helloworld/language for the site part (there are no xml languages tag in the site part of the xml description file, but the language folder is included)

Developing a Model-View-Controller (MVC) Component for Joomla!1.6 – Part 02

http://docs.joomla.org

Introduction

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.

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

In the core code of Joomla, there is a class able to manage controllers: JController. This class has to be extended to be used 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');     /**   * Hello World Component Controller   */  class HelloWorldController extends JController  {  }  

When no task is given in the request variables, 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 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');     /**   * HTML View class for the HelloWorld Component   */  class HelloWorldViewHelloWorld extends JView  {  	// 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 with 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>  

This template file will be included by the JView class. Therefore, here, $this refers to the HelloWorldViewHelloWorld class.

Packaging the component

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>  	<!-- The following elements are optional and free of formatting conttraints -->  	<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>  	<!--  The version string is recorded in the components table -->  	<version>0.0.2</version>  	<!-- The description is optional and defaults to the name -->  	<description>Description of the Hello World component ...</description>     	<update> <!-- Runs on update; New in 1.6 -->  		<schemas>  			<schemapath type="mysql">sql/updates/mysql</schemapath>  		</schemas>  	</update>     	<!-- Site Main File Copy Section -->  	<!-- Note the folder attribute: This attribute describes the folder  		to copy FROM in the package to install therefore files copied  		in this section are copied from /site/ in the package -->  	<files folder="site">  		<filename>index.html</filename>  		<filename>helloworld.php</filename>  		<filename>controller.php</filename>  		<folder>views</folder>  	</files>     	<administration>  		<!-- Administration Menu Section -->  		<menu>Hello World!</menu>  		<!-- Administration Main File Copy Section -->  		<!-- Note the folder attribute: This attribute describes the folder  			to copy FROM in the package to install therefore files copied  			in this section are copied from /admin/ in the package -->  		<files folder="admin">  			<!-- Admin Main File Copy Section -->  			<filename>index.html</filename>  			<filename>helloworld.php</filename>  			<!-- SQL files section -->  			<folder>sql</folder>  		</files>  	</administration>     </extension>  

Result: You will see by default the message contained in the variable $this->msg in the view.html.php file.