Kursus Joomla : j2.5 : 12. Adding categories

Modifying the SQL

In order to manage categories, we have to change the SQL tables.
With your favorite editor, modify admin/sql/install.mysql.utf8.sql and put these lines:
admin/sql/install.mysql.utf8.sql

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

admin/sql/updates/mysql/0.0.12.sql

ALTER TABLE `#__helloworld` ADD `catid` INT(11) NOT NULL DEFAULT '0'

Modifying the form

A HelloWorld message can now belong to a category. We have to modify the editing form. In the admin/models/forms/helloworld.xml file, put these lines:
admin/models/forms/helloworld.xml

<?xml version="1.0" encoding="utf-8"?>
<form
        addrulepath="/administrator/components/com_helloworld/models/rules"
>
        <fieldset>
                <field
                        name="id"
                        type="hidden"
                />
                <field
                        name="greeting"
                        type="text"
                        label="COM_HELLOWORLD_HELLOWORLD_FIELD_GREETING_LABEL"
                        description="COM_HELLOWORLD_HELLOWORLD_FIELD_GREETING_DESC"
                        size="40"
                        class="inputbox validate-greeting"
                        validate="greeting"
                        required="true"
                        default=""
                />
                <field
                        name="catid"
                        type="category"
                        extension="com_helloworld"
                        class="inputbox"
                        default=""
                        label="COM_HELLOWORLD_HELLOWORLD_FIELD_CATID_LABEL"
                        description="COM_HELLOWORLD_HELLOWORLD_FIELD_CATID_DESC"
                        required="true"
                >
                        <option value="0">JOPTION_SELECT_CATEGORY</option>
                </field>
        </fieldset>
</form>

Note that the category can be 0 (representing no category).

Modifying the menu type

The HelloWorld menu type displays a drop down list of all messages. If the message is categorized, we have to add the category in this display.
In the admin/models/fields/helloworld.php file, put these lines:
admin/models/fields/helloworld.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 = new JDatabaseQuery; WARNING - There's an error in this line, JDatabaseQuery is an abstract class
                $query = $db->getQuery(true); // THIS IS THE FIX, WARNING IT MUST BE FIXED IN THE ZIP FILES
 
                $query->select('#__helloworld.id as id,greeting,#__categories.title as category,catid');
                $query->from('#__helloworld');
                $query->leftJoin('#__categories on catid=#__categories.id');
                $db->setQuery((string)$query);
                $messages = $db->loadObjectList();
                $options = array();
                if ($messages)
                {
                        foreach($messages as $message) 
                        {
                                $options[] = JHtml::_('select.option', $message->id, $message->greeting .
                                                      ($message->catid ? ' (' . $message->category . ')' : ''));
                        }
                }
                $options = array_merge(parent::getOptions(), $options);
                return $options;
        }
}

It will now display the category between parenthesis.

Managing the submenu

The com_categories component allows to set the submenu using a helper file. With your favorite file manager and editor, put a admin/helpers/helloworld.php file containing these lines:
admin/helpers/helloworld.php

<?php
// No direct access to this file
defined('_JEXEC') or die;
 
/**
 * HelloWorld component helper.
 */
abstract class HelloWorldHelper
{
        /**
         * Configure the Linkbar.
         */
        public static function addSubmenu($submenu) 
        {
                JSubMenuHelper::addEntry(JText::_('COM_HELLOWORLD_SUBMENU_MESSAGES'),
                                         'index.php?option=com_helloworld', $submenu == 'messages');
                JSubMenuHelper::addEntry(JText::_('COM_HELLOWORLD_SUBMENU_CATEGORIES'),
                                         'index.php?option=com_categories&view=categories&extension=com_helloworld',
                                         $submenu == 'categories');
                // set some global property
                $document = JFactory::getDocument();
                $document->addStyleDeclaration('.icon-48-helloworld ' .
                                               '{background-image: url(../media/com_helloworld/images/tux-48x48.png);}');
                if ($submenu == 'categories') 
                {
                        $document->setTitle(JText::_('COM_HELLOWORLD_ADMINISTRATION_CATEGORIES'));
                }
        }
}

This function will be automatically called by the com_categories component. Note that it will

change the submenu
change some css properties (for displaying icons)
change the browser title if the submenu is categories
change the title and add a preferences button

We have to change the general controller to call this function and modify the component entry point (the .icon-48-helloworld css class is now set in the addSubmenu function)
admin/controller.php

<?php
// No direct access to this file
defined('_JEXEC') or die('Restricted access');
 
// import Joomla controller library
jimport('joomla.application.component.controller');
 
/**
 * General Controller of HelloWorld component
 */
class HelloWorldController extends JController
{
        /**
         * display task
         *
         * @return void
         */
        function display($cachable = false) 
        {
                // set default view if not set
                $input = JFactory::getApplication()->input;
                $input->set('view', $input->getCmd('view', 'HelloWorlds'));
 
                // call parent behavior
                parent::display($cachable);
 
                // Set the submenu
                HelloWorldHelper::addSubmenu('messages');
        }
}

admin/helloworld.php

<?php
// No direct access to this file
defined('_JEXEC') or die('Restricted access');
 
// require helper file
JLoader::register('HelloWorldHelper', dirname(__FILE__) . DS . 'helpers' . DS . 'helloworld.php');
 
// 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
$input = JFactory::getApplication()->input;
$controller->execute($input->getCmd('task'));
 
// Redirect if set by the controller
$controller->redirect();

Adding some translation strings

Some strings have to be translated. In the admin/language/en-GB/en-GB.com_helloworld.ini file, put these lines:
admin/language/en-GB/en-GB.com_helloworld.ini

COM_HELLOWORLD="Hello World!"
COM_HELLOWORLD_ADMINISTRATION="HelloWorld - Administration"
COM_HELLOWORLD_ADMINISTRATION_CATEGORIES="HelloWorld - Categories"
COM_HELLOWORLD_HELLOWORLD_CREATING="HelloWorld - Creating"
COM_HELLOWORLD_HELLOWORLD_DETAILS="Details"
COM_HELLOWORLD_HELLOWORLD_EDITING="HelloWorld - Editing"
COM_HELLOWORLD_HELLOWORLD_ERROR_UNACCEPTABLE="Some values are unacceptable"
COM_HELLOWORLD_HELLOWORLD_FIELD_CATID_DESC="The category the messages belongs to"
COM_HELLOWORLD_HELLOWORLD_FIELD_CATID_LABEL="Category"
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"
COM_HELLOWORLD_MANAGER_HELLOWORLD_EDIT="HelloWorld manager: Edit Message"
COM_HELLOWORLD_MANAGER_HELLOWORLD_NEW="HelloWorld manager: New Message"
COM_HELLOWORLD_MANAGER_HELLOWORLDS="HelloWorld manager"
COM_HELLOWORLD_N_ITEMS_DELETED_1="One message deleted"
COM_HELLOWORLD_N_ITEMS_DELETED_MORE="%d messages deleted"
COM_HELLOWORLD_SUBMENU_MESSAGES="Messages"
COM_HELLOWORLD_SUBMENU_CATEGORIES="Categories"

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.
helloworld.xml

<?xml version="1.0" encoding="utf-8"?>
<extension type="component" version="2.5.0" method="upgrade">
 
        <name>COM_HELLOWORLD</name>
        <!-- The following elements are optional and free of formatting constraints -->
        <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>0.0.12</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 2.5 -->
                <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>
                <folder>language</folder>
        </files>
 
        <media destination="com_helloworld" folder="media">
                <filename>index.html</filename>
                <folder>images</folder>
        </media>
 
        <administration>
                <!-- Administration Menu Section -->
                <menu img="../media/com_helloworld/images/tux-16x16.png">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>
                        <!-- controllers files section -->
                        <folder>controllers</folder>
                        <!-- helpers files section -->
                        <folder>helpers</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>

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Thursday, October 18, 2012

j2.5 : 12. Adding categories

Modifying the SQL

Modifying the form

Modifying the menu type

Managing the submenu

Adding some translation strings

Packaging the component

Zips

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