This document discusses design patterns in programming and provides examples of common patterns like singleton, registry, dependency injection, factory, and decorator. It explains what each pattern is used for and provides PHP code samples to illustrate how each pattern can be implemented. The document also discusses programming frameworks and languages like PHP, Java, and others. It aims to explain the power and usefulness of design patterns in programming.

1. Design Patterns
as power of programming
Lukas Lesniewski

2. About me
PHP Programmer
Experience with Zend
Framework 1 and 2
Speaker at Joomla! Day
2013 Poland

3. Power of Open Source:
PHP
PHP
24%
PHP as language
Java PHP Python
Ruby .NET Perl
ASP
PHP
75%
Servers usage
Java PHP
Python Ruby
.NET Perl
ColdFusion

4. PHP Frameworks
Zend
CakePHP
Symfony
YiiWACT
Prado
Akelos
CodeIgniter
Joomla
Wordpress
Laravel
Phalcon
…and more!

5. Framework’s features
Inversion controll
Default Behavior
Extensibility
Non-moditiable

6. Close & Open
plugin2
plugin3
plugin1
Shop

7. tekst
How to use it?
Time to learn patterns!

8. Singleton
Programmer

9. Singleton
class SimpleSingleton {
private static $_instance = null;
private function __constructor() {}
public static function getInstance() {
if (!static::$_instance)
static::$_instance = new SimpleSingleton();
return static::$_instance;
}
}
// $bad = new SimpleSingleton();
$good = SimpleSingleton::getInstance();
JApplicationCms

10. Registry
class MyRegistry {
private static $_data = array();
public static function setItem($key, $value) {
static::$_data[$key] = $value;
}
public static function getItem($key) {
return static::$_data[$key];
}
public static function hasItem($key) {
return array_key_exists($key, static::$_data);
}
public static function getItems() {
return static::$_data;
}
}
Register::setItem("key1", new stdClass);
Register::setItem("key2", 2);
JRegistry

11. Dependency injectionProgrammer Interface
Interface
Interface
Interface
Interface

12. DI
interface ComputerInterface {
public function start();
public function shutdown();
public function hideMyFavoritesVideosFolder();
public function cleanBrowserHistory();
public function getJoomla();
}
class LinuxComputer implements ComputerInterface {…}
class MacComputer implements ComputerInterface {…}
class WinComputer implements ComputerInterface {…}
Container

13. DI
class Programmer {
private $computer;
public function setComputer(ComputerInterface $c) {
$this->computer = $c;
}
public function __construct(ComputerInterface $c) {
$this->setComputer($c);
}
public function code() {
if ($this->computer->getJoomla() == NULL) {
throw new Exception('Impossible!', 1);
}
return 'You're so lucky!';
}
}
$c = new LinuxComputer();
$p = new Programmer($c);
$p->code();
Container

15. Factory
abstract class Programmer {
abstract public function code();
private $computer;
public function setComputer(ComputerInterface $c) {
$this->computer = $c;
}
}
class JavaProgrammer extends Programmer {
public function code() {
echo 'I use Java 8 on my' . $this->computer;
}
}
class PHPProgrammer extends Programmer {
public function code() {
echo 'I use Joomla on my' . $this->computer;
}
}
class CPPProgrammer extends Programmer {
public function code() {
echo 'I use c++ on my' . $this->computer;
}
}
JFractory

16. Factory
class ProgrammerFactory {
public static function createProgrammer($lang, $computer) {
$p;
switch ($lang) {
case 'JAVA':
$p = new JavaProgrammer();
break;
case 'PHP':
$p = new PHPProgrammer();
break;
case 'C++':
$p = new CPPProgrammer();
break;
default:
$p = new PHPProgrammer();
break;
}
switch ($computer) {
default:
$p->setComputer(new LinuxComputer);
break;
}
return $p;
}
}
JFractory

17. JoomlaSiteWithMyPlugin
WpSiteWithMyPlugin
DrupalSiteWithMyPlugin
JoomlaSiteWithTemplate
JoomlaSite
DrupalSiteWithTemplate
WpSiteDrupalSite
WpSiteWithTemplate
Site

18. Template
getPrice()
Plugin
getPrice()
DecoratorJoomlaSite
getPrice()

19. Decorator
abstract class Site {
abstract public function getPrice();
private $desc = "There is no description";
public function getDesc() {
return $desc;
}
}
class WordpressSite extends Site {
private $desc = "This is a Wordpress site";
public function getPrice() {
return 99;
}
}
class JoomlaSite extends Site {
private $desc = "This is a Joomla Site";
public function getPrice() {
return 99;
}
}
class DrupalSite extends Site {
private $desc = "This is a Drupal Site";
public function getPrice() {
return 99;
}
}

20. Decorator
class AmazingTemplate extends Site {
private $site;
public function __construct (Site $site) {
$this->site = $site;
}
public function getPrice() {
return $this->site->getPrice() + 199;
}
}
class MyPlugin extends Site {
private $site;
public function __construct (Site $site) {
$this->site = $site;
}
public function getPrice() {
return $this->site->getPrice() + 49;
}
}
$site = new JoomlaSite();
$site = new AmazingTemplate($site);
$site = new MyPlugin($site);
$site = new MyPlugin($site);

21. Template
return 199
Plugin
return 49
JoomlaSite
return 99

23. –Steve Jobs
„When you first start off trying to solve a problem,
the first solutions you come up with are very
complex, and most people stop there. But if you
keep going, and live with the problem and peel
more layers of the onion off, you can often times
arrive at some very elegant and simple
solutions.”

24. facebook.com/LLUKAS.DE

25. Sources
http://en.wikipedia.org/wiki/Software_framework
http://blog.websitesframeworks.com/2013/03/program
ming-language-statistics-in-server-side-161/
http://langpop.com/