Best practices for Joomla extensions developers - Joomla Day 2013

Joomla Extensions
Development Best
Practices
Francesco Abeni
GiBiLogic
extensions.gibilogic.com

Francesco Abeni for GiBiLogic
http://extensions.gibilogic.com - info@gibilogic.com
¡Hola, mundo!

Shameless self-promotion
Francesco
Abeni
sPrintAddCSSPizzaBox

About this speech
The quality of code in the Joomlasphere

Today roadmap:
● Tools
● Files and folders
● Reuse software
● MVC
● Other tips
● Conclusions
Feedback please!

No dev course

Our target
Good = not bad
Excellent = above the average
Good is enough for today

IDE basic features
● multiple files edit
● syntax highlighting
● index for methods and variables
● autocompletion
● autoformatting
● compiler
● versioning / unit testing / phpdoc / ...

Some IDEs

Versioning
http://git-scm.com/book

Standard

Everything in its right place
Backend ● administrator
○ components
■ com_componentname
● componentname.xml
● componentname.php
● controllers
● models
● views

Backend ● administrator
○ components
■ com_componentname
● ...
● config.xml
● install.php
● sql
● tables
● helpers

● media
○ com_componentname
■ css
■ js
■ img
● components
■ componentname.php
■ controllers
■ models
■ views
Frontend
● images

CSS / JS
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.

CSS out of the door
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 }

JS out of the door
<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:

Joomla framework
● JApplication
● JDatabase
● JUser
● JSession
● JDocument
● JHTML
● JForm
● JConfig
● JUri
● JFile
● JFolder
● JLog
● JFilterInput
● JError and JException
● JDate
● JUtilities
● JVersion
● JLayout

PHP functions and classes
● pcre
● trim
● usort
● array_map
● array_unique
● json_encode
● json_decode
● microtime(true)
● glob
● curl
● DateTime
● Standard PHP Library
● Exception
● SimpleXML
● TCPDF
● PHPMailer

PHP version
● 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

Real objects
book writer library

Bad design sample
● views/search
● views/editbook
● views/book
● views/books
● views/booksauthor
● views/topten
Don't:

The controller
● Filters input
● Decides what to do
● Checks access permissions
● Executes task(s)
● Optionally, calls the view

The model
● Retrieves object data
● Validates object data
● Gets object data
● Saves object data
● Hates to be mistaken as an helper

The view
● Ask the model for data
● Display object(s)
● Uses layouts!

Header comment
<?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
*/

Entry point
<?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();

Controller - part 1
<?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;
...

Controller - part 2
<?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);
}
...

Controller - part 3
<?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;
}

Model - part 1
<?php
...
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'));
}

Model - part 2
<?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) {
$query->select('*')->from($this->table)->where(“author_id = '$author_id'”)-
>orderby('created_at DESC');
$this->_db->setQuery($query,0,1);
return $this->_db->loadObject();
}

Model - part 3
<?php
...
public function create($data) {
if (!$data) {
return 0;
}
$data['created_at'] = date('Y-m-d H:i:s');
$query->insert($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();
}
...

Model - part 4
<?php
...
public function delete($ids) {
$query->delete()->from($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();
return $query->select('*')->from($this->table)->where($where)->orderby
('created_at DESC');
}
...

View - part 1
<?php
...
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);
}

View - part 2
<?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');
}
}

Helpers
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

Table classes
Interface to and from the database
Active Record pattern
● Define table name and unique id
● load, store, delete, and so on

Table classes - sample code
<?php
class TableBook extends JTable
{
public function __construct(&$db)
{
parent::__construct(‘#__books’, ‘id’, $db);
}
}

Layouts
Page types related to a single view (object)
"tmpl" subfolder (template override)
● List
● Single item (readonly)
● Single item (edit form)
● Blog
● ...

System messages
$app = JFactory::getApplication();
$app->enqueueMessage( $msg, $type )

JError / JException / JLog
Error handling vs. logging
● JError is deprecated
● JException is deprecated
● Use PHP Exception class(es)
● JLog is a way to track what's happening

Visibility
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

Constants
● 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

Versioning
● version format: major.minor.release (es. v3.1.5)
● variant: v3.1.5 Free, v3.1.5 Pro

And the road goes on and on

Thanks :)
f.abeni@gibilogic.com
@f_abeni / @gibilogic
http://www.slideshare.net/FrancescoAbeni/best-practices-for-joomla-extensions-developers-25353320
Feedback please!

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