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J3.x

Difference between revisions of "Developing an MVC Component/Using the database"

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J3.x:Developing an MVC Component
(Removing note about site/models/helloworld.php being not up to date.)
('a' to 'an' as 'M' pronounced 'em')
 
(20 intermediate revisions by 6 users not shown)
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{{:J3.1:Developing a MVC Component}}
+
<noinclude><languages /></noinclude>
 +
{{:J3.1:Developing an MVC Component/<translate><!--T:1-->
 +
en</translate>}}
 +
<translate>== Introduction == <!--T:2--></translate>
 +
<translate><!--T:3-->
 +
This tutorial is part of the [[S:MyLanguage/J3.3:Developing an MVC Component | Developing an MVC Component for Joomla! 3.3]] tutorial. You are encouraged to read the previous parts of the tutorial before reading this.</translate>
  
== Introduction ==
+
<translate>== Using the database == <!--T:4--></translate>
This tutorial is part of the [[J3.2:Developing a MVC Component | Developing a MVC Component for Joomla! 3.2]] tutorial. You are encouraged to read the previous parts of the tutorial before reading this.
+
<translate><!--T:5-->
 +
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.</translate>
  
== Using the database ==
+
<translate><!--T:6-->
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 create two files called <tt>admin/sql/install.mysql.utf8.sql</tt> and <tt>admin/sql/updates/mysql/0.0.6.sql</tt>. They should both have the same content, as follows:</translate>
 
+
With your favorite file manager and editor create two files called ''admin/sql/install.mysql.utf8.sql'' and ''admin/sql/updates/mysql/0.0.6.sql''. They should both have the same content, as follows:
+
  
 
<span id="admin/sql/install.mysql.utf8.sql">
 
<span id="admin/sql/install.mysql.utf8.sql">
''admin/sql/install.mysql.utf8.sql'' and ''admin/sql/updates/mysql/0.0.6.sql''
+
<tt>'''admin/sql/install.mysql.utf8.sql''' and '''admin/sql/updates/mysql/0.0.6.sql'''</tt>
 
<source lang="sql">
 
<source lang="sql">
 
DROP TABLE IF EXISTS `#__helloworld`;
 
DROP TABLE IF EXISTS `#__helloworld`;
  
 
CREATE TABLE `#__helloworld` (
 
CREATE TABLE `#__helloworld` (
  `id` int(11) NOT NULL auto_increment,
+
`id`       INT(11)     NOT NULL AUTO_INCREMENT,
  `greeting` varchar(25) NOT NULL,
+
`greeting` VARCHAR(25) NOT NULL,
  PRIMARY KEY (`id`)
+
`published` tinyint(4) NOT NULL,
) ENGINE=InnoDB AUTO_INCREMENT=0 DEFAULT CHARSET=utf8;
+
PRIMARY KEY (`id`)
 +
)
 +
ENGINE =MyISAM
 +
AUTO_INCREMENT =0
 +
DEFAULT CHARSET =utf8;
  
 
INSERT INTO `#__helloworld` (`greeting`) VALUES
 
INSERT INTO `#__helloworld` (`greeting`) VALUES
('Hello World!'),
+
('Hello World!'),
('Good bye World!');
+
('Good bye World!');
 +
 
 
</source>
 
</source>
 
</span>
 
</span>
  
The file ''install.mysql.utf8.sql'' will be executed when you install this component. The file ''0.0.6.sql'' is executed when you do an update.
+
<translate><!--T:7-->
 +
The file <tt>install.mysql.utf8.sql</tt> will be executed when you install this component. The file ''0.0.6.sql'' is executed when you do an update.</translate>
  
'''Important Note:''' When the component is installed, the files in the SQL updates folder (for example, ''admin/sql/updates/mysql'') are read and the name of the last file alphabetically is used to populate the component's version number in the <code>#__schemas</code> table. This value must be in this table in order for the automatic update to execute the update SQL files for future versions. For this reason, it is good practice to create a SQL update file for each version (even if it is empty or just has a comment). This way the <code>#__schemas</code> version will always match the component version.
+
<translate><!--T:8-->
 +
'''Important Note:''' When the component is installed, the files in the SQL updates folder (for example, ''admin/sql/updates/mysql'') are read and the name of the last file alphabetically is used to populate the component's version number in the <code>#__schemas</code> table. This value must be in this table in order for the automatic update to execute the update SQL files for future versions. For this reason, it is good practice to create a SQL update file for each version (even if it is empty or just has a comment). This way the <code>#__schemas</code> version will always match the component version.</translate>
  
'''Important Note:''' When saving the SQL files in utf8, be sure to save them as utf8 NO BOM or the query will fail with MySQL error #1064.
+
<translate><!--T:9-->
 +
'''Important Note:''' When saving the SQL files in utf8, be sure to save them as utf8 NOT BOM or the query will fail with MySQL error #1064.</translate>
  
This is the install file. It will be executed if you put an appropriate order in the ''helloworld.xml'' file
+
<translate><!--T:10-->
 +
This is the install file. It will be executed if you put an appropriate order in the <tt>helloworld.xml</tt> file.</translate>
  
 
<span id="helloworld.xml">
 
<span id="helloworld.xml">
''helloworld.xml''
+
<tt>'''helloworld.xml'''</tt>
<source lang="xml">
+
<source lang="xml" highlight="13,17-26,58-61">
 
<?xml version="1.0" encoding="utf-8"?>
 
<?xml version="1.0" encoding="utf-8"?>
 
<extension type="component" version="3.2.0" method="upgrade">
 
<extension type="component" version="3.2.0" method="upgrade">
Line 63: Line 76:
 
</sql>
 
</sql>
 
</uninstall>
 
</uninstall>
<update> <!-- Runs on update; New in 2.5 -->
+
<update> <!-- Runs on update; New since J2.5 -->
 
<schemas>
 
<schemas>
 
<schemapath type="mysql">sql/updates/mysql</schemapath>
 
<schemapath type="mysql">sql/updates/mysql</schemapath>
Line 83: Line 96:
 
<administration>
 
<administration>
 
<!-- Administration Menu Section -->
 
<!-- Administration Menu Section -->
<menu>Hello World!</menu>
+
<menu link='index.php?option=com_helloworld'>Hello World!</menu>
 
<!-- Administration Main File Copy Section -->
 
<!-- Administration Main File Copy Section -->
 
<!-- Note the folder attribute: This attribute describes the folder
 
<!-- Note the folder attribute: This attribute describes the folder
Line 105: Line 118:
 
</span>
 
</span>
  
 +
<translate><!--T:11-->
 
Do the same for the uninstall file:
 
Do the same for the uninstall file:
  
With your favorite file manager and editor put a file ''admin/sql/uninstall.mysql.utf8.sql'' containing:
+
<!--T:12-->
 +
With your favorite file manager and editor put a file <tt>admin/sql/uninstall.mysql.utf8.sql</tt> containing:</translate>
  
 
<span id="admin/sql/uninstall.mysql.utf8.sql">
 
<span id="admin/sql/uninstall.mysql.utf8.sql">
''admin/sql/uninstall.mysql.utf8.sql''
+
<tt>'''admin/sql/uninstall.mysql.utf8.sql'''</tt>
 
<source lang="sql">
 
<source lang="sql">
 
DROP TABLE IF EXISTS `#__helloworld`;
 
DROP TABLE IF EXISTS `#__helloworld`;
Line 116: Line 131:
 
</span>
 
</span>
  
== Adding a new field type ==
+
<translate>== Adding a new field type == <!--T:13--></translate>
For the moment, we have used a [[Developing_a_Model-View-Controller_%28MVC%29_Component_for_Joomla!2.5_-_Part_03|hard coded field type for messages]]. We need to use our database for choosing the message.
+
<translate><!--T:14-->
 +
For the moment, we have used a [[S:MyLanguage/J3.3:Developing an MVC Component/Adding a menu type to the site part|hard coded field type for messages]]. We need to use our database for choosing the message.</translate>
  
Modify the ''site/views/helloworld/tmpl/default.xml'' file and put these lines
+
<translate><!--T:15-->
 +
Modify the <tt>site/views/helloworld/tmpl/default.xml</tt> file and put these lines</translate>
  
 
<span id="site/views/helloworld/tmpl/default.xml">
 
<span id="site/views/helloworld/tmpl/default.xml">
''site/views/helloworld/tmpl/default.xml''
+
<tt>'''site/views/helloworld/tmpl/default.xml'''</tt>
<source lang="xml">
+
<source lang="xml" highlight="8,11-16">
 
<?xml version="1.0" encoding="utf-8"?>
 
<?xml version="1.0" encoding="utf-8"?>
 
<metadata>
 
<metadata>
Line 130: Line 147:
 
</layout>
 
</layout>
 
<fields
 
<fields
name="request"
+
name="request"
addfieldpath="/administrator/components/com_helloworld/models/fields"
+
addfieldpath="/administrator/components/com_helloworld/models/fields"
>
+
>
 
<fieldset name="request">
 
<fieldset name="request">
 
<field
 
<field
name="id"
+
name="id"
type="helloworld"
+
type="helloworld"
label="COM_HELLOWORLD_HELLOWORLD_FIELD_GREETING_LABEL"
+
label="COM_HELLOWORLD_HELLOWORLD_FIELD_GREETING_LABEL"
description="COM_HELLOWORLD_HELLOWORLD_FIELD_GREETING_DESC"
+
description="COM_HELLOWORLD_HELLOWORLD_FIELD_GREETING_DESC"
/>
+
/>
 
</fieldset>
 
</fieldset>
 
</fields>
 
</fields>
Line 146: Line 163:
 
</span>
 
</span>
  
It introduces a new field type and tells Joomla to look for the field definition in the ''/administrator/components/com_helloworld/models/fields'' folder.
+
<translate><!--T:16-->
 +
It introduces a new field type and tells Joomla to look for the field definition in the <tt>/administrator/components/com_helloworld/models/fields</tt> folder.</translate>
  
With your favorite file manager and editor put a file ''admin/models/fields/helloworld.php'' file containing:
+
<translate><!--T:17-->
 +
With your favorite file manager and editor put a file ''admin/models/fields/helloworld.php'' file containing:</translate>
  
 
<span id="admin/models/fields/helloworld.php">
 
<span id="admin/models/fields/helloworld.php">
''admin/models/fields/helloworld.php''
+
<tt>'''admin/models/fields/helloworld.php'''</tt>
 
<source lang="php">
 
<source lang="php">
 
<?php
 
<?php
 +
/**
 +
* @package    Joomla.Administrator
 +
* @subpackage  com_helloworld
 +
*
 +
* @copyright  Copyright (C) 2005 - 2015 Open Source Matters, Inc. All rights reserved.
 +
* @license    GNU General Public License version 2 or later; see LICENSE.txt
 +
*/
 +
 
// No direct access to this file
 
// No direct access to this file
defined('_JEXEC') or die;
+
defined('_JEXEC') or die('Restricted access');
  
// import the list field type
 
jimport('joomla.form.helper');
 
 
JFormHelper::loadFieldClass('list');
 
JFormHelper::loadFieldClass('list');
  
 
/**
 
/**
 
  * HelloWorld Form Field class for the HelloWorld component
 
  * HelloWorld Form Field class for the HelloWorld component
 +
*
 +
* @since  0.0.1
 
  */
 
  */
 
class JFormFieldHelloWorld extends JFormFieldList
 
class JFormFieldHelloWorld extends JFormFieldList
Line 169: Line 196:
 
* The field type.
 
* The field type.
 
*
 
*
* @var string
+
* @var         string
 
*/
 
*/
 
protected $type = 'HelloWorld';
 
protected $type = 'HelloWorld';
Line 176: Line 203:
 
* Method to get a list of options for a list input.
 
* Method to get a list of options for a list input.
 
*
 
*
* @return array An array of JHtml options.
+
* @return array An array of JHtml options.
 
*/
 
*/
protected function getOptions()  
+
protected function getOptions()
 
{
 
{
$db = JFactory::getDBO();
+
$db   = JFactory::getDBO();
 
$query = $db->getQuery(true);
 
$query = $db->getQuery(true);
 
$query->select('id,greeting');
 
$query->select('id,greeting');
 
$query->from('#__helloworld');
 
$query->from('#__helloworld');
$db->setQuery((string)$query);
+
$db->setQuery((string) $query);
 
$messages = $db->loadObjectList();
 
$messages = $db->loadObjectList();
$options = array();
+
$options = array();
 +
 
 
if ($messages)
 
if ($messages)
 
{
 
{
foreach($messages as $message)  
+
foreach ($messages as $message)
 
{
 
{
 
$options[] = JHtml::_('select.option', $message->id, $message->greeting);
 
$options[] = JHtml::_('select.option', $message->id, $message->greeting);
 
}
 
}
 
}
 
}
 +
 
$options = array_merge(parent::getOptions(), $options);
 
$options = array_merge(parent::getOptions(), $options);
 +
 
return $options;
 
return $options;
 
}
 
}
 
}
 
}
 +
 
</source>
 
</source>
 
</span>
 
</span>
  
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.
+
<translate><!--T:18-->
 +
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.</translate>
  
== Display the chosen message ==
+
<translate>== Display the chosen message == <!--T:19--></translate>
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.
+
<translate><!--T:20-->
 +
When a menu item of this component is created/updated, Joomla stores the identifier of the message. The <tt>HelloWorldModelHelloWorld</tt> model has now to compute the message according to this identifier and the data stored in the database.</translate>
  
Modify the ''site/models/helloworld.php'' file:
+
<translate><!--T:21-->
 +
Modify the <tt>site/models/helloworld.php</tt> file:</translate>
  
 
<span id="site/models/helloworld.php">
 
<span id="site/models/helloworld.php">
''site/models/helloworld.php''
+
<tt>'''site/models/helloworld.php'''</tt>
 
<source lang="php">
 
<source lang="php">
 
<?php
 
<?php
 +
/**
 +
* @package    Joomla.Administrator
 +
* @subpackage  com_helloworld
 +
*
 +
* @copyright  Copyright (C) 2005 - 2015 Open Source Matters, Inc. All rights reserved.
 +
* @license    GNU General Public License version 2 or later; see LICENSE.txt
 +
*/
 +
 
// No direct access to this file
 
// No direct access to this file
 
defined('_JEXEC') or die('Restricted access');
 
defined('_JEXEC') or die('Restricted access');
 
// import Joomla modelitem library
 
jimport('joomla.application.component.modelitem');
 
  
 
/**
 
/**
 
  * HelloWorld Model
 
  * HelloWorld Model
 +
*
 +
* @since  0.0.1
 
  */
 
  */
 
class HelloWorldModelHelloWorld extends JModelItem
 
class HelloWorldModelHelloWorld extends JModelItem
Line 229: Line 270:
  
 
/**
 
/**
* Returns a reference to the a Table object, always creating it.
+
* Method to get a table object, load it if necessary.
 
*
 
*
* @param type The table type to instantiate
+
* @param   string  $type   The table name. Optional.
* @param string A prefix for the table class name. Optional.
+
* @param   string $prefix The class prefix. Optional.
* @param array Configuration array for model. Optional.
+
* @param   array   $config  Configuration array for model. Optional.
* @return JTable A database object
+
*
* @since 2.5
+
* @return JTable A JTable object
 +
*
 +
* @since   1.6
 
*/
 
*/
public function getTable($type = 'HelloWorld', $prefix = 'HelloWorldTable', $config = array())  
+
public function getTable($type = 'HelloWorld', $prefix = 'HelloWorldTable', $config = array())
 
{
 
{
 
return JTable::getInstance($type, $prefix, $config);
 
return JTable::getInstance($type, $prefix, $config);
 
}
 
}
 +
 
/**
 
/**
 
* Get the message
 
* Get the message
* @param  int    The corresponding id of the message to be retrieved
+
*
* @return string The message to be displayed to the user
+
* @param   integer $id Greeting Id
 +
*
 +
* @return string       Fetched String from Table for relevant Id
 
*/
 
*/
public function getMsg($id = 1)  
+
public function getMsg($id = 1)
 
{
 
{
 
if (!is_array($this->messages))
 
if (!is_array($this->messages))
Line 252: Line 298:
 
$this->messages = array();
 
$this->messages = array();
 
}
 
}
+
 
if (!isset($this->messages[$id]))  
+
if (!isset($this->messages[$id]))
 
{
 
{
                        //request the selected id
+
// Request the selected id
 
$jinput = JFactory::getApplication()->input;
 
$jinput = JFactory::getApplication()->input;
$id = $jinput->get('id', 1, 'INT' );
+
$id     = $jinput->get('id', 1, 'INT');
  
 
// Get a TableHelloWorld instance
 
// Get a TableHelloWorld instance
Line 268: Line 314:
 
$this->messages[$id] = $table->greeting;
 
$this->messages[$id] = $table->greeting;
 
}
 
}
+
 
 
return $this->messages[$id];
 
return $this->messages[$id];
 
}
 
}
 
}
 
}
 +
 
</source>
 
</source>
 
</span>
 
</span>
  
The model now asks the ''TableHelloWorld'' to get the message. This table class has to be defined in ''admin/tables/helloworld.php'' file
+
<translate><!--T:22-->
 +
The model now asks the ''TableHelloWorld'' to get the message. This table class has to be defined in <tt>admin/tables/helloworld.php</tt> file</translate>
  
 
<span id="admin/tables/helloworld.php">
 
<span id="admin/tables/helloworld.php">
''admin/tables/helloworld.php''
+
<tt>'''admin/tables/helloworld.php'''</tt>
 
<source lang="php">
 
<source lang="php">
 
<?php
 
<?php
 +
/**
 +
* @package    Joomla.Administrator
 +
* @subpackage  com_helloworld
 +
*
 +
* @copyright  Copyright (C) 2005 - 2015 Open Source Matters, Inc. All rights reserved.
 +
* @license    GNU General Public License version 2 or later; see LICENSE.txt
 +
*/
 
// No direct access
 
// No direct access
 
defined('_JEXEC') or die('Restricted access');
 
defined('_JEXEC') or die('Restricted access');
 
// import Joomla table library
 
jimport('joomla.database.table');
 
  
 
/**
 
/**
 
  * Hello Table class
 
  * Hello Table class
 +
*
 +
* @since  0.0.1
 
  */
 
  */
 
class HelloWorldTableHelloWorld extends JTable
 
class HelloWorldTableHelloWorld extends JTable
Line 295: Line 349:
 
* Constructor
 
* Constructor
 
*
 
*
* @param object Database connector object
+
* @param   JDatabaseDriver  &$db  A database connector object
 
*/
 
*/
function __construct(&$db)  
+
function __construct(&$db)
 
{
 
{
 
parent::__construct('#__helloworld', 'id', $db);
 
parent::__construct('#__helloworld', 'id', $db);
 
}
 
}
 
}
 
}
 +
 
</source>
 
</source>
 
</span>
 
</span>
  
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''
+
<translate><!--T:23-->
 +
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''.</translate>
  
== Packaging the component ==
+
<translate>== Packaging the component == <!--T:24--></translate>
 +
 
 +
<translate><!--T:25-->
 +
Content of your code directory</translate>
  
Content of your code directory
 
 
* ''[[#helloworld.xml|helloworld.xml]]''
 
* ''[[#helloworld.xml|helloworld.xml]]''
* ''[[J3.2:Developing_a_MVC_Component/Adding_a_view_to_the_site_part#site/helloworld.php|site/helloworld.php]]''
+
* ''[[S:MyLanguage/J3.2:Developing_an_MVC_Component/Adding_a_view_to_the_site_part#site/helloworld.php|site/helloworld.php]]''
* ''[[J3.2:Developing_a_MVC_Component/Developing_a_Basic_Component#index.html|site/index.html]]''
+
* ''[[S:MyLanguage/J3.2:Developing_an_MVC_Component/Developing_a_Basic_Component#index.html|site/index.html]]''
* ''[[J3.2:Developing_a_MVC_Component/Adding_a_view_to_the_site_part#site/controller.php|site/controller.php]]''
+
* ''[[S:MyLanguage/J3.2:Developing_an_MVC_Component/Adding_a_view_to_the_site_part#site/controller.php|site/controller.php]]''
* ''[[J3.2:Developing_a_MVC_Component/Developing_a_Basic_Component#index.html|site/views/index.html]]''
+
* ''[[S:MyLanguage/J3.2:Developing_an_MVC_Component/Developing_a_Basic_Component#index.html|site/views/index.html]]''
* ''[[J3.2:Developing_a_MVC_Component/Developing_a_Basic_Component#index.html|site/views/helloworld/index.html]]''
+
* ''[[S:MyLanguage/J3.2:Developing_an_MVC_Component/Developing_a_Basic_Component#index.html|site/views/helloworld/index.html]]''
* ''[[J3.2:Developing_a_MVC_Component/Adding_a_view_to_the_site_part#site/views/helloworld/view.html.php|site/views/helloworld/view.html.php]]''
+
* ''[[S:MyLanguage/J3.2:Developing_an_MVC_Component/Adding_a_view_to_the_site_part#site/views/helloworld/view.html.php|site/views/helloworld/view.html.php]]''
* ''[[J3.2:Developing_a_MVC_Component/Developing_a_Basic_Component#index.html|site/views/helloworld/tmpl/index.html]]''
+
* ''[[S:MyLanguage/J3.2:Developing_an_MVC_Component/Developing_a_Basic_Component#index.html|site/views/helloworld/tmpl/index.html]]''
 
* ''[[#site/views/helloworld/tmpl/default.xml|site/views/helloworld/tmpl/default.xml]]''
 
* ''[[#site/views/helloworld/tmpl/default.xml|site/views/helloworld/tmpl/default.xml]]''
* ''[[J3.2:Developing_a_MVC_Component/Adding_a_view_to_the_site_part#site/views/helloworld/tmpl/default.php|site/views/helloworld/tmpl/default.php]]''
+
* ''[[S:MyLanguage/J3.2:Developing_an_MVC_Component/Adding_a_view_to_the_site_part#site/views/helloworld/tmpl/default.php|site/views/helloworld/tmpl/default.php]]''
* ''[[J3.2:Developing_a_MVC_Component/Developing_a_Basic_Component#index.html|site/models/index.html]]''
+
* ''[[S:MyLanguage/J3.2:Developing_an_MVC_Component/Developing_a_Basic_Component#index.html|site/models/index.html]]''
 
* ''[[#site/models/helloworld.php|site/models/helloworld.php]]''
 
* ''[[#site/models/helloworld.php|site/models/helloworld.php]]''
* ''[[J3.2:Developing_a_MVC_Component/Developing_a_Basic_Component#index.html|admin/index.html]]''
+
* ''[[S:MyLanguage/J3.2:Developing_an_MVC_Component/Developing_a_Basic_Component#index.html|admin/index.html]]''
* ''[[J3.2:Developing_a_MVC_Component/Developing_a_Basic_Component#admin/helloworld.php|admin/helloworld.php]]''
+
* ''[[S:MyLanguage/J3.2:Developing_an_MVC_Component/Developing_a_Basic_Component#admin/helloworld.php|admin/helloworld.php]]''
* ''[[J3.2:Developing_a_MVC_Component/Developing_a_Basic_Component#index.html|admin/sql/index.html]]''
+
* ''[[S:MyLanguage/J3.2:Developing_an_MVC_Component/Developing_a_Basic_Component#index.html|admin/sql/index.html]]''
 
* ''[[#admin/sql/install.mysql.utf8.sql|admin/sql/install.mysql.utf8.sql]]''
 
* ''[[#admin/sql/install.mysql.utf8.sql|admin/sql/install.mysql.utf8.sql]]''
 
* ''[[#admin/sql/uninstall.mysql.utf8.sql|admin/sql/uninstall.mysql.utf8.sql]]''
 
* ''[[#admin/sql/uninstall.mysql.utf8.sql|admin/sql/uninstall.mysql.utf8.sql]]''
* ''[[J3.2:Developing_a_MVC_Component/Developing_a_Basic_Component#index.html|admin/sql/updates/index.html]]''
+
* ''[[S:MyLanguage/J3.2:Developing_an_MVC_Component/Developing_a_Basic_Component#index.html|admin/sql/updates/index.html]]''
* ''[[J3.2:Developing_a_MVC_Component/Developing_a_Basic_Component#index.html|admin/sql/updates/mysql/index.html]]''
+
* ''[[S:MyLanguage/J3.2:Developing_an_MVC_Component/Developing_a_Basic_Component#index.html|admin/sql/updates/mysql/index.html]]''
* ''[[J3.2:Developing_a_MVC_Component/Developing_a_Basic_Component#admin/sql/updates/mysql/0.0.1.sql|admin/sql/updates/mysql/0.0.1.sql]]''
+
* ''[[S:MyLanguage/J3.2:Developing_an_MVC_Component/Developing_a_Basic_Component#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]]''
 
* ''[[#admin/sql/install.mysql.utf8.sql|admin/sql/updates/mysql/0.0.6.sql]]''
* ''[[J3.2:Developing_a_MVC_Component/Developing_a_Basic_Component#index.html|admin/models/index.html]]''
+
* ''[[S:MyLanguage/J3.2:Developing_an_MVC_Component/Developing_a_Basic_Component#index.html|admin/models/index.html]]''
* ''[[J3.2:Developing_a_MVC_Component/Developing_a_Basic_Component#index.html|admin/models/fields/index.html]]''
+
* ''[[S:MyLanguage/J3.2:Developing_an_MVC_Component/Developing_a_Basic_Component#index.html|admin/models/fields/index.html]]''
 
* ''[[#admin/models/fields/helloworld.php|admin/models/fields/helloworld.php]]''
 
* ''[[#admin/models/fields/helloworld.php|admin/models/fields/helloworld.php]]''
* ''[[J3.2:Developing_a_MVC_Component/Developing_a_Basic_Component#index.html|admin/tables/index.html]]''
+
* ''[[S:MyLanguage/J3.2:Developing_an_MVC_Component/Developing_a_Basic_Component#index.html|admin/tables/index.html]]''
 
* ''[[#admin/tables/helloworld.php|admin/tables/helloworld.php]]''
 
* ''[[#admin/tables/helloworld.php|admin/tables/helloworld.php]]''
  
Create a compressed file of this directory or directly download the [https://github.com/joomla/Joomla-3.2-Hello-World-Component/archive/step-6-using-the-database.zip archive] and install it using the extension manager of Joomla. You can add a menu item of this component using the menu manager in the backend.
+
<translate><!--T:26-->
 +
Create a compressed file of this directory or directly download the [https://github.com/scionescire/Joomla-3.2-Hello-World-Component/archive/step-6-using-the-database.zip archive] and install it using the extension manager of Joomla. You can add a menu item of this component using the menu manager in the backend.</translate>
  
{{notice|Please create a pull request or issue at https://github.com/joomla/Joomla-3.2-Hello-World-Component for any code descprepancies or if editing any of the source code on this page.}}
+
{{notice|<translate><!--T:27-->
 
+
Please create a pull request or issue at https://github.com/joomla/Joomla-3.2-Hello-World-Component for any code discrepancies or if editing any of the source code on this page.</translate>}}
{{:J3.2:Developing a MVC Component/Navigate
+
|prev=Adding a variable request in the menu type <!-- previous article subpage name -->
+
|next=Basic backend <!-- next article subpage name -->}}
+
  
 
== Contributors ==
 
== Contributors ==
 
*[[User:cdemko|Christophe Demko]]
 
*[[User:cdemko|Christophe Demko]]
 
*[[User:oaksu|Ozgur Aksu]]
 
*[[User:oaksu|Ozgur Aksu]]
 +
*[[User:scionescire|Scionescire]]
 +
 +
<div class="row">
 +
<div class="large-6 columns">{{Basic button|<translate><!--T:28-->
 +
S:MyLanguage/J3.x:Developing_an_MVC_Component/Adding a variable request in the menu type|Prev: Adding a variable request in the menu type</translate>|class=expand success}}</div>
 +
<div class="large-6 columns">{{Basic button|<translate><!--T:29-->
 +
S:MyLanguage/J3.x:Developing_an_MVC_Component/Basic backend|Next: Basic backend</translate>|class=expand}}</div>
 +
</div>
  
 +
<noinclude>
 +
<translate>
 +
<!--T:30-->
 +
[[Category:Joomla! 3.x]]
 
[[Category:Joomla! 3.0]]
 
[[Category:Joomla! 3.0]]
 
[[Category:Joomla! 3.1]]
 
[[Category:Joomla! 3.1]]
 
[[Category:Joomla! 3.2]]
 
[[Category:Joomla! 3.2]]
 +
[[Category:Joomla! 3.3]]
 +
[[Category:Joomla! 3.4]]
 
[[Category:Beginner Development]]
 
[[Category:Beginner Development]]
 
[[Category:Component Development]]
 
[[Category:Component Development]]
 +
[[Category:Tutorials]]
 +
[[Category:Tutorials in a Series]]
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</translate>
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</noinclude>

Latest revision as of 10:05, 10 July 2015

Other languages:
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Joomla! 
3.x
Tutorial
Developing an MVC Component


This is a multiple-article series of tutorials on how to develop a Model-View-Controller Component for Joomla! VersionJoomla 3.x.

Begin with the Introduction, and navigate the articles in this series by using the navigation button at the bottom or the box to the right (the Articles in this series).



Introduction

This tutorial is part of the Developing an MVC Component for Joomla! 3.3 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 create two files called admin/sql/install.mysql.utf8.sql and admin/sql/updates/mysql/0.0.6.sql. They should both have the same content, as follows:

admin/sql/install.mysql.utf8.sql and admin/sql/updates/mysql/0.0.6.sql

DROP TABLE IF EXISTS `#__helloworld`;
 
CREATE TABLE `#__helloworld` (
	`id`       INT(11)     NOT NULL AUTO_INCREMENT,
	`greeting` VARCHAR(25) NOT NULL,
	`published` tinyint(4) NOT NULL,
	PRIMARY KEY (`id`)
)
	ENGINE =MyISAM
	AUTO_INCREMENT =0
	DEFAULT CHARSET =utf8;
 
INSERT INTO `#__helloworld` (`greeting`) VALUES
('Hello World!'),
('Good bye World!');

The file install.mysql.utf8.sql will be executed when you install this component. The file 0.0.6.sql is executed when you do an update.

Important Note: When the component is installed, the files in the SQL updates folder (for example, admin/sql/updates/mysql) are read and the name of the last file alphabetically is used to populate the component's version number in the #__schemas table. This value must be in this table in order for the automatic update to execute the update SQL files for future versions. For this reason, it is good practice to create a SQL update file for each version (even if it is empty or just has a comment). This way the #__schemas version will always match the component version.

Important Note: When saving the SQL files in utf8, be sure to save them as utf8 NOT BOM or the query will fail with MySQL error #1064.

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

helloworld.xml

<?xml version="1.0" encoding="utf-8"?>
<extension type="component" version="3.2.0" method="upgrade">
 
	<name>Hello World!</name>
	<!-- The following elements are optional and free of formatting constraints -->
	<creationDate>January 2014</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>0.0.6</version>	<!-- The description is optional and defaults to the name -->
	<description>Description of the Hello World component ...</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 since J2.5 -->
		<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>
	</files>
 
	<administration>
		<!-- Administration Menu Section -->
		<menu link='index.php?option=com_helloworld'>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>
			<!-- tables files section -->			<folder>tables</folder>			<!-- models files section -->			<folder>models</folder>		</files>
	</administration>
 
</extension>

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

DROP TABLE IF EXISTS `#__helloworld`;

Adding a new field type

For the moment, we have used a 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

<?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>

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

<?php
/**
 * @package     Joomla.Administrator
 * @subpackage  com_helloworld
 *
 * @copyright   Copyright (C) 2005 - 2015 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE.txt
 */
 
// No direct access to this file
defined('_JEXEC') or die('Restricted access');
 
JFormHelper::loadFieldClass('list');
 
/**
 * HelloWorld Form Field class for the HelloWorld component
 *
 * @since  0.0.1
 */
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;
	}
}

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

<?php
/**
 * @package     Joomla.Administrator
 * @subpackage  com_helloworld
 *
 * @copyright   Copyright (C) 2005 - 2015 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE.txt
 */
 
// No direct access to this file
defined('_JEXEC') or die('Restricted access');
 
/**
 * HelloWorld Model
 *
 * @since  0.0.1
 */
class HelloWorldModelHelloWorld extends JModelItem
{
	/**
	 * @var array messages
	 */
	protected $messages;
 
	/**
	 * Method to get a table object, load it if necessary.
	 *
	 * @param   string  $type    The table name. Optional.
	 * @param   string  $prefix  The class prefix. Optional.
	 * @param   array   $config  Configuration array for model. Optional.
	 *
	 * @return  JTable  A JTable object
	 *
	 * @since   1.6
	 */
	public function getTable($type = 'HelloWorld', $prefix = 'HelloWorldTable', $config = array())
	{
		return JTable::getInstance($type, $prefix, $config);
	}
 
	/**
	 * Get the message
	 *
	 * @param   integer  $id  Greeting Id
	 *
	 * @return  string        Fetched String from Table for relevant Id
	 */
	public function getMsg($id = 1)
	{
		if (!is_array($this->messages))
		{
			$this->messages = array();
		}
 
		if (!isset($this->messages[$id]))
		{
			// Request the selected id
			$jinput = JFactory::getApplication()->input;
			$id     = $jinput->get('id', 1, 'INT');
 
			// Get a TableHelloWorld instance
			$table = $this->getTable();
 
			// Load the message
			$table->load($id);
 
			// Assign the message
			$this->messages[$id] = $table->greeting;
		}
 
		return $this->messages[$id];
	}
}

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

<?php
/**
 * @package     Joomla.Administrator
 * @subpackage  com_helloworld
 *
 * @copyright   Copyright (C) 2005 - 2015 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE.txt
 */
// No direct access
defined('_JEXEC') or die('Restricted access');
 
/**
 * Hello Table class
 *
 * @since  0.0.1
 */
class HelloWorldTableHelloWorld extends JTable
{
	/**
	 * Constructor
	 *
	 * @param   JDatabaseDriver  &$db  A database connector object
	 */
	function __construct(&$db)
	{
		parent::__construct('#__helloworld', 'id', $db);
	}
}

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

Create a compressed file of this directory or directly download the archive and install it using the extension manager of Joomla. You can add a menu item of this component using the menu manager in the backend.

Info non-talk.png
General Information

Please create a pull request or issue at https://github.com/joomla/Joomla-3.2-Hello-World-Component for any code discrepancies or if editing any of the source code on this page.

Contributors