SPL, not a bridge too far

SPL, not a bridge too far Dutch PHP Conference 2009 - Amsterdam

Who am I ? Michelangelo van Dam Independent Enterprise PHP consultant @dragonbe http://dragonbe.com 2

Who are you ? You know OOP ? You know php.net ? You know arrays ? 3

What is SPL ? Standard PHP Library interfaces, classes and methods solve common development problems As of 5.3 SPL cannot be turned off from the source ! 4

Why use SPL ? SPL provides a huge toolkit that assists you to easily iterate over a diversity of data structures in a standardized way 5

What does it provide ? • ArrayObject - approach arrays as objects • Iterators - various iterators • Interfaces - Countable Interface • Exceptions - exceptions to streamline errorhandling • SPL Functions - extra functions and autoloader func • SplFileInfo - tools for ﬁlesystem access • Datastructures - structuring data sequences 6

ArrayObject • provides an interface - treat arrays as objects - elements are iteratable 7

ArrayObject methods • ArrayObject::append • ArrayObject::__construct • ArrayObject::count • ArrayObject::getIterator • ArrayObject::offsetExists • ArrayObject::offsetGet • ArrayObject::offsetSet • ArrayObject::offsetUnset 8

<?php ArrayObject w/o SPL // file: nospl_arrayobject01.php $myArray = array ( quot;monkeyquot; => quot;bananasquot;, quot;rabbitquot; => quot;carrotsquot;, quot;ogrequot; => quot;onionsquot;, ); echo quot;Ogres exists ? quot; . (key_exists('ogre', $myArray) ? quot;Yesquot; : quot;Noquot;) . quot;nquot;; echo quot;Ogres equals quot; . $myArray['ogre'] . quot;nquot;; 9

<?php ArrayObject Example // file: spl_arrayobject01.php $myArray = array ( quot;monkeyquot; => quot;bananasquot;, quot;rabbitquot; => quot;carrotsquot;, quot;ogrequot; => quot;onionsquot;, ); // create an object of the array $arrayObj = new ArrayObject($myArray); echo quot;Ogres exists ? quot; . ($arrayObj->offsetExists(quot;ogrequot;) ? quot;Yesquot; : quot;Noquot;) . quot;nquot;; echo quot;Ogres equals quot; . $arrayObj->offsetGet(quot;ogrequot;) . quot;nquot;; 10

ArrayObject Output $ /usr/bin/php ./nospl_arrayobject01.php Ogres exists ? Yes Ogres equals onions Execution time: 0.00064299999999995 microseconds. $ /usr/bin/php ./spl_arrayobject01.php Ogres exists ? Yes Ogres equals onions Execution time: 0.00054399999999999 microseconds. 11

Iterator • move back and forth in a stack • distinct methods to access keys and values 12

Iterators • ArrayIterator • CachingIterator • RecursiveCachingIterator • DirectoryIterator • RecursiveDirectoryIterator • FilterIterator • LimitIterator • ParentIterator • RecursiveIteratorIterator 13

The ArrayIterator iteration methods on array objects 14

ArrayIterator Example Case • Array with 3 elements - monkey => bananas, - rabbit => carrots, - ogre => onions • display total elements • display key/value pairs while looping • display key/value pair for 2nd element 15

<?php ArrayIterator w/o SPL // file: nospl_iterator01.php $myArray = array ( quot;monkeyquot; => quot;bananasquot;, quot;rabbitquot; => quot;carrotsquot;, quot;ogrequot; => quot;onionsquot;, ); echo quot;$myArray has {sizeof($myArray)} elementsnquot;; foreach ($myArray as $key => $value) { echo quot;{$key}: {$value}nquot;; } reset($myArray); next($myArray); echo quot;elem 2:quot; . key($myArray) . quot;: quot; . current($myArray) . quot;nquot;; 16

<?php ArrayIterator w/ SPL // file: spl_iterator01.php $myArray = array ( “monkey” => “bananas”, “rabbit” => “carrots”, “ogre” => “onions”, ); $arrayObj = new ArrayObject($myArray); $iterator = $arrayObj->getIterator(); echo quot;$myArray has {$arrayObj->count()} elementsnquot;; while ($iterator->valid()) { echo quot;{$iterator->key()}: {$iterator->current()}nquot;; $iterator->next(); } $iterator->seek(1); echo quot;elem 2:{$iterator->key()}: {$iterator->current()}nquot;; 17

ArrayIterator Output $ /usr/bin/php ./nospl_iterator01.php $myArray has 3 elements monkey: bananas rabbit: carrots ogre: onions elem 2:rabbit: carrots Execution time: 0.0020509999999999 microseconds. $ /usr/bin/php ./spl_iterator01.php $myArray has 3 elements monkey: bananas rabbit: carrots ogre: onions elem 2:rabbit: carrots Execution time: 0.001346 microseconds. 18

Interfaces • Countable - provides an internal counter • SeekableIterator - provides an internal stack seeker 19

<?php Countable Example //file: spl_countable01.php class TequillaCounter implements Countable { public function count() { static $count = 0; return ++$count; } public function order() { $order = $this->count(); echo ($order > 3 ? quot;Floor!quot; : quot;{$order} tequillaquot;) . PHP_EOL; } } 20

Countable continued... $shots = new TequillaCounter(); $shots->order(); $shots->order(); $shots->order(); $shots->order(); Output: $ /usr/bin/php ./countable01.php 1 tequilla 2 tequilla 3 tequilla Floor! 21

SPL Exceptions • SPL Exceptions - templates - throw exceptions - common issues • Types of exceptions - LogicExceptions - RuntimeExceptions 22

SPL LogicException Tree 23

SPL RuntimeException Tree 24

<?php Exceptions Example //file: spl_exception01.php class MyClass { public function giveANumberFromOneToTen($number) { if($number < 1 || $number > 10) { throw new OutOfBoundsException('Number should be between 1 and 10'); } echo $number . PHP_EOL; } } $my = new MyClass(); try { $my->giveANumberFromOneToTen(5); $my->giveANumberFromOneToTen(20); } catch (OutOfBoundsException $e) { echo $e->getMessage() . PHP_EOL; } Output: $ /usr/bin/php ./spl_exception01.php 5 Number should be between 1 and 10 25

SPL Functions • class_implements Return the interfaces which are implemented by the given class • class_parents Return the parent classes of the given class • iterator_apply Apply a user function to every element of an iterator • iterator_count Count the elements in an iterator • iterator_to_array Copy the iterator into an array • spl_autoload_call Try all registered __autoload() function to load requested class 26

SPL Functions (2) • spl_autoload_functions Return all registered __autoload() functions • spl_autoload_register Register given function as __autoload() implementation • spl_autoload_unregister Unregister given function as __autoload() implementation • spl_autoload Default implementation for __autoload() • spl_classes Return available SPL classes • spl_object_hash Return hash id for given object 27

<?php SplFunctions Example interface foo {} interface bar {} class baz implements foo, bar {} class example extends baz {} var_dump(class_implements(new baz)); var_dump(class_implements(new example)); 28

Output of SplFunctions array(2) { [quot;fooquot;]=> string(3) quot;fooquot; [quot;barquot;]=> string(3) quot;barquot; } array(2) { [quot;barquot;]=> string(3) quot;barquot; [quot;fooquot;]=> string(3) quot;fooquot; } 29

SplFileInfo • SplFileInfo::__construct • SplFileInfo::getLinkTarget • SplFileInfo::getATime • SplFileInfo::getMTime • SplFileInfo::getBasename • SplFileInfo::getOwner • SplFileInfo::getCTime • SplFileInfo::getPath • SplFileInfo::getFileInfo • SplFileInfo::getPathInfo • SplFileInfo::getFilename • SplFileInfo::getPathname • SplFileInfo::getGroup • SplFileInfo::getPerms • SplFileInfo::getInode 30

SplFileInfo (2) • SplFileInfo::getRealPath • SplFileInfo::isReadable • SplFileInfo::getSize • SplFileInfo::isWritable • SplFileInfo::getType • SplFileInfo::openFile • SplFileInfo::isDir • SplFileInfo::setFileClass • SplFileInfo::isExecutable • SplFileInfo::setInfoClass • SplFileInfo::isFile • SplFileInfo::__toString • SplFileInfo::isLink 31

<?php SplFileInfo Example // use the current file to get information from $file = new SplFileInfo(dirname(__FILE__)); var_dump($file->isFile()); var_dump($file->getMTime()); var_dump($file->getSize()); var_dump($file->getFileInfo()); var_dump($file->getOwner()); //output bool(false) int(1244760945) int(408) object(SplFileInfo)#2 (0) { } int(501) 32

Data Structures • Available in PHP 5.3.x - SplDoublyLinkedList ✓ SplStack ✓ SplQueue ✓ SplHeap ✓ SplMaxHeap ✓ SplMinHeap ✓ SplPriorityQueue 33

Data Structures Example <?php // file: spl_stack01.php $stack = new SplStack(); $stack->push('Message 1'); $stack->push('Message 2'); $stack->push('Message 3'); echo $stack->pop() . PHP_EOL; echo $stack->pop() . PHP_EOL; echo $stack->pop() . PHP_EOL; Outputs: $ /usr/bin/php ./spl_stack01.php Message 3 Message 2 Message 1 34

Not a bridge too far... 35

Conclusion SPL can help you solve common PHP issues it’s built-in, so why not use it it requires no “advanced skills” to use 36

Only one minor thing... 37

Documentation problem • php.net/spl needs more documentation ! • you can help on that part: - see http://elizabethmariesmith.com/2009/02/setting-up-phd-on-windows - you can set up phpdoc on each platform ! - Efnet: #php.doc channel - http://doc.php.net - phpdoc@php.net 38

More about SPL... • main SPL documentation: http://php.net/spl • PHPro Tutorials on SPL: http://www.phpro.org/tutorials/Introduction-to-SPL.html • Lorenzo Alberton’s blog: http://www.alberton.info/php_5.3_spl_data_structures.html • http://www.colder.ch/news/01-08-2009/34/splobjectstorage-for- a-fa.html 39

License This presentation is released under the Creative Commons Attribution-Share Alike 3.0 Unported License You are free: - to share : to copy, distribute and transmit the work - to remix : to adapt the work Under the following conditions: - attribution :You must attribute the work in the manner speciﬁed by the author or licensor - share alike : If you alter, transform, or build upon this work, you may distribute the resulting work only under the same, similar or a compatible license See: http://creativecommons.org/licenses/by-sa/3.0/ 40

Credits Golden Gate Bridge - Felix De Vliegher http://www.ﬂickr.com/photos/felixdv/2883471022/ 41

Thank you Find my slides on http://slideshare.net/DragonBe Don’t forget to vote ! http://joind.in/586 42

SPL, not a bridge too far

by Michelangelo van Dam on Jun 12, 2009

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SPL, not a bridge too far — Presentation Transcript