Talk:JController and its subclass usage overview

2011-08-28T23:01:25Z

Cjjoe: Created page with "This article needs some serious grammatical revision, it's like someone just dumped this into Google Translate."

This article needs some serious grammatical revision, it's like someone just dumped this into Google Translate.

Archived:Developing a MVC Component/Using the database

2011-08-24T05:41:04Z

Cjjoe: /* Display the chosen message */

This tutorial is for {{JVer|1.6}}

== Articles in this series ==
{{Chunk:Developing a Model-View-Controller (MVC) Component for Joomla!1.6 - Contents}}

== 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.

== Using the database ==
Components usually manage their contents using the database. During the install/uninstall/update phase of a component, you can execute SQL queries through the use of SQL text files.

With your favorite file manager and editor put two files ''admin/sql/install.mysql.utf8.sql'' and ''admin/sql/updates/mysql/0.0.6.sql'' containing:


''admin/sql/install.mysql.utf8.sql'' and ''admin/sql/updates/mysql/0.0.6.sql''
<source lang="sql">
DROP TABLE IF EXISTS `#__helloworld`;

CREATE TABLE `#__helloworld` (
`id` int(11) NOT NULL auto_increment,
`greeting` varchar(25) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=0 DEFAULT CHARSET=utf8;

INSERT INTO `#__helloworld` (`greeting`) VALUES
('Hello World!'),
('Good bye World!');
</source>


This is the install file. It will be executed if you put an appropriate order in the ''helloworld.xml'' file


''helloworld.xml''
<source lang="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>0.0.6</version>

<description>Description of the Hello World component ...</description>

<install> 
<sql>
<file driver="mysql" charset="utf8">sql/install.mysql.utf8.sql</file>
</sql>
</install>
<uninstall> 
<sql>
<file driver="mysql" charset="utf8">sql/uninstall.mysql.utf8.sql</file>
</sql>
</uninstall>
<update> 
<schemas>
<schemapath type="mysql">sql/updates/mysql</schemapath>
</schemas>
</update>



<files folder="site">
<filename>index.html</filename>
<filename>helloworld.php</filename>
<filename>controller.php</filename>
<folder>views</folder>
<folder>models</folder>
</files>

<administration>

<menu>Hello World!</menu>


<files folder="admin">

<filename>index.html</filename>
<filename>helloworld.php</filename>

<folder>sql</folder>

<folder>tables</folder>

<folder>models</folder>
</files>
</administration>

</extension>
</source>


Do the same for the uninstall file:

With your favorite file manager and editor put a file ''admin/sql/uninstall.mysql.utf8.sql'' containing:


''admin/sql/uninstall.mysql.utf8.sql''
<source lang="sql">
DROP TABLE IF EXISTS `#__helloworld`;
</source>


== Adding a new field type ==
For the moment, we have used a [[Developing_a_Model-View-Controller_%28MVC%29_Component_for_Joomla!1.6_-_Part_03|hard coded field type for messages]]. We need to use our database for choosing the message.

Modify the ''site/views/helloworld/tmpl/default.xml'' file and put these lines


''site/views/helloworld/tmpl/default.xml''
<source lang="xml">
<?xml version="1.0" encoding="utf-8"?>
<metadata>
<layout title="COM_HELLOWORLD_HELLOWORLD_VIEW_DEFAULT_TITLE">
<message>COM_HELLOWORLD_HELLOWORLD_VIEW_DEFAULT_DESC</message>
</layout>
<fields
name="request"
addfieldpath="/administrator/components/com_helloworld/models/fields"
>
<fieldset name="request">
<field
name="id"
type="helloworld"
label="COM_HELLOWORLD_HELLOWORLD_FIELD_GREETING_LABEL"
description="COM_HELLOWORLD_HELLOWORLD_FIELD_GREETING_DESC"
/>
</fieldset>
</fields>
</metadata>
</source>


It introduces a new field type and tells Joomla to look for the field definition in the ''/administrator/components/com_helloworld/models/fields'' folder.

With your favorite file manager and editor put a file ''admin/models/fields/helloworld.php'' file containing:


''admin/models/fields/helloworld.php''
<source lang="php">
<?php
// No direct access to this file
defined('_JEXEC') or die;

// import the list field type
jimport('joomla.form.helper');
JFormHelper::loadFieldClass('list');

/**
* HelloWorld Form Field class for the HelloWorld component
*/
class JFormFieldHelloWorld extends JFormFieldList
{
/**
* The field type.
*
* @var string
*/
protected $type = 'HelloWorld';

/**
* Method to get a list of options for a list input.
*
* @return array An array of JHtml options.
*/
protected function getOptions()
{
$db = JFactory::getDBO();
$query = $db->getQuery(true);
$query->select('id,greeting');
$query->from('#__helloworld');
$db->setQuery((string)$query);
$messages = $db->loadObjectList();
$options = array();
if ($messages)
{
foreach($messages as $message)
{
$options[] = JHtml::_('select.option', $message->id, $message->greeting);
}
}
$options = array_merge(parent::getOptions(), $options);
return $options;
}
}
</source>


The new field type displays a drop-down list of messages to choose from. You can see the result of this change in the menu manager section for the helloworld item.

== Display the chosen message ==
When a menu item of this component is created/updated, Joomla stores the identifier of the message. The ''HelloWorldModelHelloWorld'' model has now to compute the message according to this identifier and the data stored in the database.

Modify the ''site/models/helloworld.php'' file:


''site/models/helloworld.php''
<source lang="php">
<?php
// No direct access to this file
defined('_JEXEC') or die('Restricted access');

// import Joomla modelitem library
jimport('joomla.application.component.modelitem');

/**
* HelloWorld Model
*/
class HelloWorldModelHelloWorld extends JModelItem
{
/**
* @var string msg
*/
protected $msg;

/**
* Returns a reference to the a Table object, always creating it.
*
* @param type The table type to instantiate
* @param string A prefix for the table class name. Optional.
* @param array Configuration array for model. Optional.
* @return JTable A database object
* @since 1.6
*/
public function getTable($type = 'HelloWorld', $prefix = 'HelloWorldTable', $config = array())
{
return JTable::getInstance($type, $prefix, $config);
}
/**
* Get the message
* @return string The message to be displayed to the user
*/
public function getMsg()
{
if (!isset($this->msg))
{
$id = JRequest::getInt('id', 1);
// Get a TableHelloWorld instance
$table = $this->getTable();

// Load the message
$table->load($id);

// Assign the message
$this->msg = $table->greeting;
}
return $this->msg;
}
}
</source>


The model now asks the ''TableHelloWorld'' to get the message. This table class has to be defined in ''admin/tables/helloworld.php'' file


''admin/tables/helloworld.php''
<source lang="php">
<?php
// No direct access
defined('_JEXEC') or die('Restricted access');

// import Joomla table library
jimport('joomla.database.table');

/**
* Hello Table class
*/
class HelloWorldTableHelloWorld extends JTable
{
/**
* Constructor
*
* @param object Database connector object
*/
function __construct(&$db)
{
parent::__construct('#__helloworld', 'id', $db);
}
}
</source>


You shouldn't see any differences, but if you access the database you should see a table named ''jos_helloworld'' with two columns: id and greeting. And two entries: ''Hello World!'' and ''Good bye World''

== Packaging the component ==

Content of your code directory
* ''[[#helloworld.xml|helloworld.xml]]''
* ''[[Developing_a_Model-View-Controller_(MVC)_Component_for_Joomla!1.6_-_Part_01#index.html|site/index.html]]''
* ''[[Developing_a_Model-View-Controller_(MVC)_Component_for_Joomla!1.6_-_Part_02#site/helloworld.php|site/helloworld.php]]''
* ''[[Developing_a_Model-View-Controller_(MVC)_Component_for_Joomla!1.6_-_Part_02#site/controller.php|site/controller.php]]''
* ''[[Developing_a_Model-View-Controller_(MVC)_Component_for_Joomla!1.6_-_Part_01#index.html|site/views/index.html]]''
* ''[[Developing_a_Model-View-Controller_(MVC)_Component_for_Joomla!1.6_-_Part_01#index.html|site/views/helloworld/index.html]]''
* ''[[Developing_a_Model-View-Controller_(MVC)_Component_for_Joomla!1.6_-_Part_04#site/views/helloworld/view.html.php|site/views/helloworld/view.html.php]]''
* ''[[Developing_a_Model-View-Controller_(MVC)_Component_for_Joomla!1.6_-_Part_01#index.html|site/views/helloworld/tmpl/index.html]]''
* ''[[#site/views/helloworld/tmpl/default.xml|site/views/helloworld/tmpl/default.xml]]''
* ''[[Developing_a_Model-View-Controller_(MVC)_Component_for_Joomla!1.6_-_Part_02#site/views/helloworld/tmpl/default.php|site/views/helloworld/tmpl/default.php]]''
* ''[[Developing_a_Model-View-Controller_(MVC)_Component_for_Joomla!1.6_-_Part_01#index.html|site/models/index.html]]''
* ''[[#site/models/helloworld.php|site/models/helloworld.php]]''
* ''[[Developing_a_Model-View-Controller_(MVC)_Component_for_Joomla!1.6_-_Part_01#index.html|admin/index.html]]''
* ''[[Developing_a_Model-View-Controller_(MVC)_Component_for_Joomla!1.6_-_Part_01#admin/helloworld.php|admin/helloworld.php]]''
* ''[[Developing_a_Model-View-Controller_(MVC)_Component_for_Joomla!1.6_-_Part_01#index.html|admin/sql/index.html]]''
* ''[[#admin/sql/install.mysql.utf8.sql|admin/sql/install.mysql.utf8.sql]]''
* ''[[#admin/sql/uninstall.mysql.utf8.sql|admin/sql/uninstall.mysql.utf8.sql]]''
* ''[[Developing_a_Model-View-Controller_(MVC)_Component_for_Joomla!1.6_-_Part_01#index.html|admin/sql/updates/index.html]]''
* ''[[Developing_a_Model-View-Controller_(MVC)_Component_for_Joomla!1.6_-_Part_01#index.html|admin/sql/updates/mysql/index.html]]''
* ''[[Developing_a_Model-View-Controller_(MVC)_Component_for_Joomla!1.6_-_Part_01#admin/sql/updates/mysql/0.0.1.sql|admin/sql/updates/mysql/0.0.1.sql]]''
* ''[[#admin/sql/install.mysql.utf8.sql|admin/sql/updates/mysql/0.0.6.sql]]''
* ''[[Developing_a_Model-View-Controller_(MVC)_Component_for_Joomla!1.6_-_Part_01#index.html|admin/models/index.html]]''
* ''[[Developing_a_Model-View-Controller_(MVC)_Component_for_Joomla!1.6_-_Part_01#index.html|admin/models/fields/index.html]]''
* ''[[#admin/models/fields/helloworld.php|admin/models/fields/helloworld.php]]''
* ''[[Developing_a_Model-View-Controller_(MVC)_Component_for_Joomla!1.6_-_Part_01#index.html|admin/tables/index.html]]''
* ''[[#admin/tables/helloworld.php|admin/tables/helloworld.php]]''

Create a compressed file of this directory or directly download the [http://joomlacode.org/gf/download/frsrelease/11394/58405/com_helloworld-1.6-part06.zip 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.

== Zips ==
Download the zip file for this Part:
[http://www.leyar.com/joomlaorg/part06.zip]

== Navigate ==

[[Developing a Model-View-Controller (MVC) Component for Joomla!1.6 - Part 05|Prev: Adding a variable request in the menu type]]
[[Developing a Model-View-Controller (MVC) Component for Joomla!1.6 - Part 07|Next: Basic backend]]

== Contributors ==
*[[User:cdemko|Christophe Demko]]
*[[User:oaksu|Ozgur Aksu]]

[[Category:Development]]
[[category:Joomla! 1.6]]
[[category:Manual]]

''Italic text''

Joomla! Documentation - User contributions [en]

Talk:JController and its subclass usage overview

Archived:Developing a MVC Component/Using the database