Joel Simpson presented on PHP reflection and annotation driven development at the Seattle PHP User's Group on September 12, 2013. He discussed PHP's built-in reflection methods, the ReflectionAPI, and how reflection can be used at development time for documentation and autocomplete and at runtime for request routing, ORM/DBAL, design patterns, and aspect oriented programming. He then demonstrated how to use annotations to implement basic request routing in under 100 lines of code.

1. Seattle PHP User’s Group
September 12, 2013 – LightningTalk
Joel Simpson

2.  15+ yrs professional software engineering
and consulting experience (~6 yrs with PHP)
 Founder, CEO of Alegion®
 Enterprise Crowdsourcing as a Service
 Lover of Open Source Software (and PHPStorm)
 ..and far too many interests than would fit readably on this slide:
Alegion, sailing, go/weiqi/igo/baduk, micro-controllers and electronics, shakuhachi, settlers of catan
style board games, 3d modeling/rendering/printing, science, technology, start-ups, philosophy, process
engineering, soccer, mountain biking, snow boarding, hiking, obstacle course racing (Spartan), Zen.

3.  It’s Meta
 PHP 4, the early predecessors, built in methods:
 method_exists()
 class_exists()
 is_a()
 is_subclass_of()
 get_parent_class()

4.  class_exists — Checks if the class has been defined
 get_called_class — the "Late Static Binding" class name
 get_class_methods — Gets the class methods' names
 get_class_vars — Get the default properties of the class
 get_class — Returns the name of the class of an object
 get_declared_classes — Returns an array with the name of the defined classes
 get_declared_interfaces — Returns an array of all declared interfaces
 get_declared_traits — Returns an array of all declared traits
 get_object_vars — Gets the properties of the given object
 get_parent_class — Retrieves the parent class name for object or class
 interface_exists — Checks if the interface has been defined
 is_a — Checks if the object is of this class or has this class as one of its parents
 is_subclass_of — Checks if the object has this class as one of its parents
 method_exists — Checks if the class method exists
 property_exists — Checks if the object or class has a property
 trait_exists — Checks if the trait exists
Source: http://www.php.net/manual/en/ref.classobj.php

5.  The ReflectionAPI
 http://php.net/manual/en/book.reflection.php
 BIG, comprehensive, but not complex

6.  Dev-time
 Generating Documentation
 Auto-complete in IDEs
 Run-time
 Request Routing
 ORM/DBAL
 Design Patterns
 Aspect Oriented Programming
 PHP (“duck” typing – no strict types)
http://hyperboleandahalf.blogspot.com

7.  A function that populates properties automatically for
quickly smoke testing/debugging field mapping in a
class.
 Our example, a User:
 FirstName
 LastName
 UserName
 EmailAddress
 Password

8.  Annotation Driven Development (ADD)
 Describe/configure right along side the code
 Advanced ExampleChallenge
 Write a rudimentary “frontController” in 100 lines
of code or less
 Implement request routing via annotations
▪ @url /my/route/

9.  class Router{private static $a=array();static function
route($b){if(count(self::$a)==0){self::loadRoutableClasses();}foreach(self:
:$a as $c){$d=new ReflectionClass($c);foreach($d->getMethods()as
$e){$f=$e->getDocComment();preg_match_all('/@urls+[
t]*/?(S*)/s',$f,$g,PREG_SET_ORDER);if(!$g){continue;}foreach($g[0]as
$h){if(self::cleanUrl($b)==self::cleanUrl($h)){$i=$d-
>newInstance();$j=$e->getShortName();return $i->$j();}}}}return(new
DefaultController())->notFoundAction();}private static function
cleanUrl($b){return strtolower(trim($b,"/"));}private static function
loadRoutableClasses(){foreach(get_declared_classes()as
$c){if(is_subclass_of($c,'Routable')){self::$a[]=$c;}}}}
 Or ~70 lines of readable, commented code. Let’s take a look….

10. Me
Joel.Simpson@gmail.com | skype: joelrsimpson |
Linkedin.com/in/joelsimpson | http://alegion.com
Presentation
Content
Slides:https://Speakerdeck.com/JoelSimpson
Code: http://bit.ly/1b7Oo5o
Additional
Information
http://php.net/manual/en/book.reflection.php

11. C:|$ php –r? <name>
Source: http://www.php.net/manual/en/features.commandline.options.php
--rf <name>
• Show
information
about
function
--rc <name>
• Show
information
about class
--re <name>
• Show
information
about
extension
--rz <name>
• Show
information
about Zend
extension
--ri <name>
• Show
configuration
for extension
(“I” ni)