Do you write extensions for Joomla? Do it the *right* way. You will save time and make friends amongst fellow developers (because they won't hate you when they have to read your code).
In this session we will share standards and suggestions about the best practices to adopt when you code your extensions.
Based on a true story. Our own.
4. About this speech
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
The quality of code in the Joomlasphere
5. Today roadmap:
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
● Tools
● Files and folders
● Reuse software
● MVC
● Other tips
● Conclusions
Feedback please!
6. No dev course
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
7. Our target
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
Good = not bad
Excellent = above the average
Good is enough for today
8. Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
9. IDE basic features
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
● multiple files edit
● syntax highlighting
● index for methods and variables
● autocompletion
● autoformatting
● compiler
● versioning / unit testing / phpdoc / ...
13. Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
14. Everything in its right place
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
Backend ● administrator
○ components
■ com_componentname
● componentname.xml
● componentname.php
● controllers
● models
● views
15. Everything in its right place
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
Backend ● administrator
○ components
■ com_componentname
● ...
● config.xml
● install.php
● sql
● tables
● helpers
16. ● media
○ com_componentname
■ css
■ js
■ img
● components
○ com_componentname
■ componentname.php
■ controllers
■ models
■ views
Everything in its right place
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
Frontend
● images
○ com_componentname
17. Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
18. CSS / JS
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
Use existing libraries
JavaScript
● MooTools (since Joomla 1.5)
● JQuery (since Joomla 2.5)
CSS + JavaScript
● Bootstrap (since Joomla 3.x)
P.S. got conflicts? Use JQueryEasy plugin.
19. CSS out of the door
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
Don't:
<div>...</div>
<br style="clear: both">
<div style="height: 200px">...</div>
Do:
<link rel=”stylesheet” href=”/media/componentname/styles.css”>
...
<div class=”clearfix”>...</div>
<div class="fixedheight">...</div>
.clearfix { … }
.fixedheight { height: 200px }
20. JS out of the door
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
<button id="submit" type=submit" value="ClickMe!" onclick="validateForm()" />
Do:
<script src=”/media/componentname/js/script.js”>
<button id="submit" type=submit" value="ClickMe!"/>
document.addEvent('load',function(){
$('submit').addEvent('click',function(){
validateForm();
});
});
Don't:
21. Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
23. PHP functions and classes
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
● pcre
● trim
● usort
● array_map
● array_unique
● json_encode
● json_decode
● microtime(true)
● glob
● curl
● DateTime
● Standard PHP Library
● Exception
● SimpleXML
● TCPDF
● PHPMailer
24. PHP version
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
● 16. Dec 2010: PHP 5.2 end of life
● 11. Jul 2013: PHP 5.3 end of life
● 01. Mar 2012: PHP 5.4 released
● 20 Jun 2013: PHP 5.5 released
● PHP 5.4 is 40% faster than PHP 5.2
25. Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
26. Real objects
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
book writer library
27. Bad design sample
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
● views/search
● views/editbook
● views/book
● views/books
● views/booksauthor
● views/topten
Don't:
28. The controller
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
● Filters input
● Decides what to do
● Checks access permissions
● Executes task(s)
● Optionally, calls the view
29. The model
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
● Retrieves object data
● Validates object data
● Gets object data
● Saves object data
● Hates to be mistaken as an helper
30. The view
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
● Ask the model for data
● Display object(s)
● Uses layouts!
31. Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
32. Header comment
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
<?php
/**
* @version mybooks.php 2013-08-10 15:23:00Z zanardi
* @package GiBi MyBooks
* @author GiBiLogic
* @authorUrl http://www.gibilogic.com
* @authorEmail info@gibilogic.com
* @copyright Copyright (C) 2013 GiBiLogic. All rights reserved.
* @license GNU/GPL v2 or later
* @description Backend entry point
*/
33. Entry point
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
<?php
...
defined('_JEXEC') or die();
jimport('joomla.application.component.controller');
$view = JFactory::getApplication()->input->get('view', 'book');
$task = JFactory::getApplication()->input->get('task', 'index');
JFactory::getApplication()->input->set('task', "$view.$task");
$controller = JController::getInstance('MyBooks');
$controller->execute($task);
$controller->redirect();
34. Controller - part 1
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
<?php
...
defined('_JEXEC') or die('The way is shut!');
jimport('joomla.application.component.controlleradmin');
/**
* MyBooksControllerBook class.
*
* @see JControllerAdmin
*/
class MyBooksControllerBook extends JControllerAdmin
{
/**
* Controller's view.
*
* @var JView
*/
private $view;
...
35. Controller - part 2
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
<?php
...
/**
* Class constructor.
*
* @param type $config
*/
public function __construct($config = array())
{
parent::__construct($config);
$this->model = $this->getModel();
$this->view = $this->getView(JFactory::getApplication()->input->get('view',
'book'), 'html');
$this->view->setModel($this->model, true);
$this->view->setModel($this->getModel('Author', 'MyBooksModel'), false);
$this->view->setModel($this->getModel('Editor', 'MyBooksModel'), false);
}
...
36. Controller - part 3
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
<?php
...
public function index()
{
$this->view->setLayout('index')
$this->view->display();
}
public function create()
{
$this->view->setLayout('create');
$this->view->display();
}
public function save()
{
$data = JFactory::getApplication()->input->get('jform', null);
if (!$data || !$this->model->validate($data)) {
$msg = 'Invalid data!';
$type = 'error';
$this->setRedirect('index.php?option=com_mybooks&view=book&task=create',
$msg, $type);
return false;
}
37. Model - part 1
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
<?php
...
defined('_JEXEC') or die('The way is shut!');
jimport('joomla.application.component.model');
jimport('joomla.html.pagination');
class MybooksModelBook extends JModel
{
private $table = '#__mybooks_book';
public function __construct($config = array())
{
parent::__construct($config);
$app = JFactory::getApplication();
$limit = $app->getUserStateFromRequest('global.list.limit', 'limit', $app-
>getCfg('list_limit'), 'int');
$limitstart = $app->input->get('limitstart', 0, '', 'int');
$this->setState('limit', $limit);
$this->setState('limitstart', $limitstart);
$this->setState('author_id', $app->getUserStateFromRequest('com_mybooks.filters.
author_id', 'author_id', 0, 'int'));
}
38. Model - part 2
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
<?php
...
public function getList() {
return $this->_getList(
$this->buildQuery(), $this->getState('limitstart'), $this->getState('limit')
);
}
public function getLast() {
$query = $this->_db->getQuery(true);
$query->select('*')->from($this->table)->orderby('created_at DESC');
$this->_db->setQuery($query,0,1);
$results = $this->_db->loadObjectList('id');
return $results ? $results : array();
}
public function getLastByAuthor($author_id) {
$query = $this->_db->getQuery(true);
$query->select('*')->from($this->table)->where(“author_id = '$author_id'”)-
>orderby('created_at DESC');
$this->_db->setQuery($query,0,1);
return $this->_db->loadObject();
}
39. Model - part 3
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
<?php
...
public function create($data) {
if (!$data) {
return 0;
}
$data['created_at'] = date('Y-m-d H:i:s');
$query = $this->_db->getQuery(true);
$query->insert($this->table)->columns(array_keys($data))->values(sprintf("'%s'",
implode("','", array_values($data))));
$this->_db->setQuery($query);
return false === $this->_db->execute() ? 0 : $this->_db->insertid();
}
...
40. Model - part 4
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
<?php
...
public function delete($ids) {
$query = $this->_db->getQuery(true);
$query->delete()->from($this->table)->where('id IN '.implode(',', $ids));
return false !== $this->_db->execute();
}
public function getPagination(){
return new JPagination(
$this->_getListCount($this->buildQuery()), $this->getState('limitstart'),
$this->getState('limit')
);
}
private function buildQuery(){
$where = $this->buildWhere();
$query = $this->_db->getQuery(true);
return $query->select('*')->from($this->table)->where($where)->orderby
('created_at DESC');
}
...
41. View - part 1
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
<?php
...
defined('_JEXEC') or die('The way is shut!');
jimport('joomla.application.component.view');
class MyBooksViewBook extends JView
{
public function display($tpl = null)
{
$this->pagination = $this->getModel()->getPagination();
$this->filter_author_id = $this->getModel()->getState('author_id');
$this->books = $this->getModel()->findAll();
$this->authors = $this->getModel('Authors')->getList();
$this->editors = $this->getModel('Editors')->getList();
$this->addToolbar($tpl);
parent::display($tpl);
}
42. View - part 2
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
<?php
...
protected function addToolbar($tpl){
$methodName = 'addToolBar' . ucfirst(!$tpl ? 'default' : $tpl);
$this->{$methodName}();
}
private function addToolBarDefault(){
JToolBarHelper::title(JText::_('COM_MYBOOKS') . ': ' . JText::_
('COM_MYBOOKS_BOOK_LIST'));
JToolBarHelper::addNew('create');
JToolBarHelper::preferences('com_mybooks');
JToolBarHelper::divider();
JToolBarHelper::deleteList('COM_MYBOOKS_BOOK_LIST_DELETE_CONFIRM', 'delete');
}
private function addToolBarCreate(){
JToolBarHelper::title(JText::_('COM_MYBOOKS') . ': ' . JText::_
('COM_MYBOOKS_BOOK_NEW'));
JToolBarHelper::apply('save');
JToolBarHelper::divider();
JToolBarHelper::back('JTOOLBAR_BACK', 'index.php?option=com_mybooks');
}
}
43. Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
44. Helpers
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
Common (usually static) functions not related
to a specific object
● Get date / time / external info
● Format date and numbers
● Build title and/or other HTML snippets
● Log/error management
● Handle CURL connections
45. Table classes
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
Interface to and from the database
Active Record pattern
● Define table name and unique id
● load, store, delete, and so on
46. Table classes - sample code
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
<?php
class TableBook extends JTable
{
public function __construct(&$db)
{
parent::__construct(‘#__books’, ‘id’, $db);
}
}
47. Layouts
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
Page types related to a single view (object)
"tmpl" subfolder (template override)
● List
● Single item (readonly)
● Single item (edit form)
● Blog
● ...
48. Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
49. System messages
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
$app = JFactory::getApplication();
$app->enqueueMessage( $msg, $type )
50. JError / JException / JLog
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
Error handling vs. logging
● JError is deprecated
● JException is deprecated
● Use PHP Exception class(es)
● JLog is a way to track what's happening
51. Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
52. Visibility
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
Variables and methods
● "var ..." is deprecated since PHP 5.1.2
● public : available from other classes
● private : available only from the class
● protected : available from the class and
from inherited or parent classes
53. Constants
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
● constants instead of variables
● drop DS
● drop DIRECTORY_SEPARATOR
● use Joomla constants:
http://docs.joomla.org/Constants
● warning: JPATH_SITE vs JPATH_BASE vs
JPATH_ROOT vs JPATH_ADMINISTRATOR
54. Versioning
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
● version format: major.minor.release (es. v3.1.5)
● variant: v3.1.5 Free, v3.1.5 Pro
55. And the road goes on and on
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
56. Thanks :)
f.abeni@gibilogic.com
@f_abeni / @gibilogic
http://www.slideshare.net/FrancescoAbeni/best-practices-for-joomla-extensions-developers-25353320
Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
Feedback please!