PHP 5

PHP Foundations
Rafael Corral, Lead Developer 'corePHP'
CMS Expo 2011

What is New

  Object model
  Assignments and Object Copying
  Constructors
  Standard PHP Library (SPL)
  New Functions / Extensions
  Much More.. .

Object Model

  Completely rewritten
  Reference
  Visibility
  OO Classes
  Constants
  Magicness
  __autoload

Passed by Reference

  All objects are now passed by reference
  To copy an object use the clone keyword
  Stop using the & operator

http://us.php.net/manual/en/language.oop5.references.php!

Class Properties

Constant Static

  Per-class basis   Can be applied to variables
  Accessed by :: operator and methods
  No $ symbol to access   $this cannot be used within a
  The value must be an static method
expression only   Static variables are shared
  No initialization required between subclasses
  No initialization required

http://php.net/manual/en/language.oop5.constants.php! http://php.net/manual/en/language.oop5.static.php!

Visibility

  Class methods and properties now have visibility
  Three levels of visibility
  Public
 Most visible, anyone can access. Read/Write
  Protected
 Access by subclasses, parent and itself
  Private
 Access only by class itself

http://php.net/manual/en/language.oop5.visibility.php!

Construct or Destruct

  Unified constructor/destructor names
  Prefixed by two (2) underscores (__)
  __construct()
  Method works the same as on PHP4
  Backwards Compatible
  __destruct()
  All references to object are destroyed
  Script shutdown phase
  To run parents, one must use parent::__construct()

http://php.net/manual/en/language.oop5.constants.php!

Abstract Classes

  Cannot be initiated
  Used as a blue print for other classes to extend
  Any class with abstract methods, must be abstract
  Subclasses must declare abstract methods from parent
  These must be defined with less or equal visibility

http://php.net/manual/en/language.oop5.abstract.php!

Interfaces

  Used to design APIs
  Defines the methods a class should implement
  Not a blueprint but a way to standardize an API
  A Class can implement any number of them
  Unlike extending to only one
  All methods must be public
  Methods don’t have any content defined

http://php.net/manual/en/language.oop5.interfaces.php!

cont... Interfaces

  Use implement operator implement in class
  Use interface to declare interface
  A Class can implement more than one interface
  Interfaces can be extended with extend
  Implemented interfaces cannot share function names
  Interfaces can have constants just like classes

Magic Methods

  These methods are called “automatically”
  These are prefixed by two (2) underscores (__)
  __construct, __destruct, __call, __callStatic, __get, __set,
__isset, __unset, __sleep, __wakeup, __toString, __invoke,
__set_state and __clone

http://php.net/manual/en/language.oop5.magic.php!

More Magicness

  __sleep and __wakeup
  Run before Object is serialized/
unserialized
  __toString
  Run when class is converted to
string
  __call and __callStatic
  Run when invoking inaccessible
methods

Finality

  PHP5 introduces the final keyword
  Can be applied to methods and classes
  For methods -
  It prevents subclasses from overriding them
  For classes -
  States that it is the final class, no subclasses

http://php.net/manual/en/language.oop5.ﬁnal.php!

__autoload()

  Used to automatically load PHP files
  Runs when PHP encounters an undefined class
  Can be useful instead of having many include()’s
  The SPL library contains a similar function

http://php.net/manual/en/language.oop5.ﬁnal.php!

Standard PHP Library

  Functions to solve problems
  Class Implements
  Class Parents

Just cool functions

About

  The SPL library is a collection of interfaces and classes
  These are meant to help solve standard problems

http://www.php.net/manual/en/intro.spl.php!

Some Functions

  class_implements( mixed $class )
  Returns all interfaces implemented by a class
  class_parents( mixed $class )
  Returns all parent classes for a given class
  spl_autoload_register([ callback $autoload_function ])
  Better than using __autload()
  Can register multiple functions to load class files

http://www.php.net/manual/en/ref.spl.php!

ArrayObject

  Turns an array into an object
  This class contains helpful functions such as:
  Counting elements
  Finding a key
  Get key
  Set key
  Unset key

http://www.php.net/manual/en/class.arrayobject.php!

SplFileInfo

  OO Class to get information about an individual file
  Some included functions are:
  Last access time
  Base name
  Target of a link
  Get owner/permissions
  Size/File type
  If directory
  isReadable/isWritable

http://www.php.net/manual/en/class.splﬁleinfo.php!

Other Features
Misc.

  Type Hinting
  Exceptions
  foreach By-Reference
  New Functions
  New Extensions

Type Hinting

  Enforce the type of variable passed to functions
  Functions and Class functions
  Can only be used for classes or arrays (at this time)
  No other scalar types (integer, string)
  If null is the default parameter value
  It is allowed as an argument

http://www.php.net/manual/en/class.splﬁleinfo.php!

Exceptions

  Exceptions are just errors
  Used to catch exceptions
  Gain control over error notices
  Use when executing “risky” code
  They work similar to other programming languages
  Each try{} must have a corresponding catch{} block

http://php.net/manual/en/language.exceptions.php!

E_strict

  In PHP5 a new error level is introduced E_STRICT
  It is not included within E_ALL
  Value 2048
  To call it: error_reporting( E_ALL ^ E_STRICT );
  Triggered when using deprecated code
  Useful in development environment

http://us3.php.net/manual/en/errorfunc.conﬁguration.php#ini.error-reporting!

foreach by-reference

  Reference to value while looping through foreach
  Careful:
  After foreach is done reference won’t go away
  Use unset to remove reference

http://us2.php.net/foreach!

New Functions

  array_combine()
  array_walk_recursive()
  time_nanosleep()
  str_split()
  strpbrk()
  substr_compare()
  curl_copy_handle()
  file_put_contents()
  get_headers()
  headers_list()
  http_build_query()
  php_strip_whitespace()
  scandir()
  a lot more...
http://php.net/manual/en/migration5.functions.php!

New Extensions

  Simple XML
  Processing of XML (pretty simple)
  DOM and XSL
  Building XML/XSL files
  Hash Functions
  Library of hash functions (more than md5 or sha1)

Compatibility

  array_merge()
  Gives error if one of the parameter is not an array
  array_merget( (array) $var1, (array) $var2 );
  To copy objects you must use the clone keyword
  get_class(), get_parent_class(), get_class_methods()
  Are not case sensitive
  An object with no properties is no longer considered “empty”
  strpos() and strripos()
  Now use the entire string as a needle

Let go of PHP4 and start developing in PHP5

Thank You!
Rafael Corral!
Email: rafael@corephp.com!
Skype: rafa.corral!

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