PHP Foundations. Rafael Corral, Lead Developer 'corephp' CMS Expo 2011

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1 PHP Foundations Rafael Corral, Lead Developer 'corephp' CMS Expo 2011

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

3 Object Model Completely rewritten Reference Visibility OO Classes Constants Magicness autoload

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

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

6 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

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8 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()

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10 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

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12 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

13 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

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15 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

16 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

17 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

18 Finality

19 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

20 Standard PHP Library Functions to solve problems Class Implements Class Parents Just cool functions

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

22 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

23 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

24 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

25 Other Features Misc. Type Hinting Exceptions foreach By-Reference New Functions New Extensions

26 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

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28 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

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30 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

31 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

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33 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...

34 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)

35 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

36 Let go of PHP4 and start developing in PHP5

37 Questions?

38 Thank You! Rafael Corral Skype: rafa.corral