[DPC] PHP 5.4: The New Bits

PHP 5.4 is about to be unleashed into the world; bringing some of the most exciting changes to the PHP language to date. Learn about traits, array dereferencing, indirect method calls using array callback syntax and improvements to closures and streams.

Transcript

1. PHP 5.4: The New Bits Friday, June 8, 12
2. •Engineer at Engine Yard for Orchestra.io PHP Platform as a Service (PaaS) •Author of Zend PHP 5 Certification Study Guide, Sitepoints PHP Anthology: 101 Essential Tips, Tricks & Hacks & PHP Master: Write Cutting Edge Code •A long time contributor to PEAR, phpdoc; new contributor to internals, FRAPI, lithium •Original Contributor to Zend Framework •@dshafik •(Buy My Books!) Davey Shafik Friday, June 8, 12
3. One More Thing Friday, June 8, 12
4. Hard of hearing: PLEASE SPEAK UP! (Everybody Forgets This!) Friday, June 8, 12
5. About These Slides Friday, June 8, 12
6. About These Slides • Two slides per “slide” • Title Slide (for when I’m talking) • Details slide (for later) • Nobody likes it when you can read the slide just as well as the speaker can • I like slides that are useful Friday, June 8, 12
7. The Small Stuff Friday, June 8, 12
8. The Small Stuff • SessionHandlerInterface added, used with session_set_save_handler() • PHP_BINARY constant gives the path to the... PHP binary • Notice now shown on array-to-string conversions • Better Memory Usage and Performance Friday, June 8, 12
9. More on SessionHandlerInterface Friday, June 8, 12
10. interface SessionHandlerInterface { public function open($sessionid); public function close(); public function read($sessionid); public function write($sessiondata); public function destroy($sessionid); public function gc($maxlifetime); } // Corresponds to: session_set_save_handler( $open, $close, $read, $write, $destroy, gc ); // Implemented by new internal class: class SessionHandler { } Friday, June 8, 12
11. Language Changes Friday, June 8, 12
12. Short Echo Tags Friday, June 8, 12
13. Short Echo Tags <?="Now I Will Always Work!";?> No longer depends on short_open_tags Friday, June 8, 12
14. Binary Numbers Friday, June 8, 12
15. Binary Numbers $var = 0b01; // Binary (base 2) $var = 1234; // Integer $var = -123; // Signed Integer (+/-) $var = 1.23; // Float $var = 0123; // Octal (base 8) $var = 0x1A; // Hexadecimal (base 16) In Addition To: Friday, June 8, 12
16. New Array Syntax Friday, June 8, 12
17. New Array Syntax // Old $array = array(1, 2, 3); // New $array = [1, 2, 3]; // Old $a = array('a' => 'b', 'c' => 'd'); // New $a = ['a' => 'b', 'c' => 'd']; Friday, June 8, 12
18. Array Dereferencing Friday, June 8, 12
19. Array Dereferencing function returnArray() { return ['a' => 'b', 'c' => 'd']; } $foo = returnArray()['a']; // b Friday, June 8, 12
20. Dynamic Method Calls Friday, June 8, 12
21. Dynamic Method Calls // Variable static methods $var = "staticMethod"; ClassName::{$var}(); // Instantiation Time Access (new ClassName)->instanceMethod(); // UGLY. $var = "instanceMethod"; (new ClassName)->{$var}(); Friday, June 8, 12
22. Improvements to Closures & Callbacks Friday, June 8, 12
23. Closures & Callbacks • New callable type hint (closures, function names, arrays, __invoke()) • $this now accessible inside closures (based on creation location) • Array callbacks for variable function calls • Change $this and/or scope with Closure::bind() and Closure- >bindTo() Friday, June 8, 12
24. Callable Type hint function invokeCallback(callable $var) { $var(); } invokeCallback(function() { }); invokeCallback("functionName"); invokeCallback(['class', 'staticMethod']); invokeCallback([$object, 'method']); class Foo { public function __invoke() { } } invokeCallback(new Foo()); Friday, June 8, 12
25. $this in closures class foo { public function getClosure() { return function() { return $this; } } } class bar { public function __construct() { $foo = new foo(); $func = $foo->getClosure(); $obj = $func(); // PHP 5.3: $obj == null // PHP 5.4: $obj == foo, not bar } } Friday, June 8, 12
26. Array Callbacks class ClassName { public static function staticMethod() { var_dump(__METHOD__); } public function instanceMethod() { var_dump(__METHOD__); } } $callback = ['ClassName', 'staticMethod']; $callback(); // ClassName::staticMethod $callback = [new ClassName(), 'instanceMethod']; $callback(); // ClassName::instanceMethod Friday, June 8, 12
27. Rebinding $this Or: How to break the object model! Friday, June 8, 12
28. Rebinding $this • Doesn’t change the original closure — creates a duplicate • $this can be any object • $this and scope are separate — $this can be a different class to the access scope. Friday, June 8, 12
29. Rebinding $this class foo { public function getClosure() { return function() { echo $this->hello; $this->world(); }; } } class bar { public $hello = "Hello "; private function world() { echo "World"; } } $foo = new Foo(); $closure = $foo->getClosure(); $bar = new Bar(); $newClosure = $closure->bindTo($bar); $newClosure(); Friday, June 8, 12
30. Output Hello Fatal error: Call to private method bar::world() from context 'foo' Friday, June 8, 12
31. Rebinding $this class foo { public function getClosure() { return function() { echo $this->hello; $this->world(); }; } } class bar { public $hello = "Hello "; private function world() { echo "World"; } } $foo = new Foo(); $closure = $foo->getClosure(); $bar = new Bar(); $newClosure = $closure->bindTo($bar); $newClosure = $closure->bindTo($bar, $bar); $newClosure(); // Hello World Friday, June 8, 12
32. Traits AKA Horizontal Re-use Friday, June 8, 12
33. Traits • Compiler-level copy and paste (literally!) • New Keywords: trait, use, as and insteadof • Can use multiple traits • as and insteadof resolve conflicts • Can define methods, abstract methods, and properties Friday, June 8, 12
34. Traits trait sayHello { public function hello() { echo "Hello "; } } trait sayWorld { public function world() { echo "World"; } } class sayHelloWorld { use sayHello, sayWorld; } $say = new sayHelloWorld(); $say->hello(); // Hello $say->world(); // World Friday, June 8, 12
35. Inheritance/Scope trait getHello { public function hello() { return "Hello"; } } trait getWorld { public function world() { return "World"; } } trait sayHelloWorld { use getHello, getWorld; public function helloWorld() { echo $this->hello(), " ", $this->world(); } } class Greeting { use sayHelloWorld; } (new Greeting)->helloWorld(); // Hello World Friday, June 8, 12
36. Precedence class say { public function sayHello() { echo 'Hello '; } } trait sayWorld { public function sayHello() { parent::sayHello(); // parent is unknown echo 'World'; } } class HelloWorld extends say { use sayWorld; // parent == say } class HiMum extends HelloWorld { public function sayHello() { parent::sayHello(); // parent == HelloWorld == sayWorld echo ", Hi mum!", PHP_EOL; } } (new HelloWorld)->sayHello(); echo PHP_EOL; // Hello World (new HiMum)->sayHello(); // Hello World, Hi mum! Friday, June 8, 12
37. Method Visibility trait sayHello { public function hello() { echo "Hello "; } } trait sayWorld { private function world() { echo "World"; } } class sayHelloWorld { use sayHello, sayWorld { world as public; } } $say = new sayHelloWorld(); $say->hello(); // Hello $say->world(); // World Friday, June 8, 12
38. Method Aliases trait sayHello { public function hello() { echo "Hello "; } } trait sayWorld { private function world() { echo "World"; } } class sayHelloWorld { use sayHello, sayWorld { hello as greeting; world as public planet; } } $say = new sayHelloWorld(); $say->greeting(); // Hello $say->planet(); // World Friday, June 8, 12
39. Conflicts trait hello_en { public function greet() { echo "Hello "; } } trait mother_en_US { public function mother() { echo "Mom"; } } trait mother_en_UK { public function mother() { echo "Mum"; } } class HiMother { use hello_en, mother_en_US, mother_en_UK; public function sayHi($locale = 'UK') { $this->greet(); ($locale != 'US') ? $this->mother() : $this->mom(); } } (new HiMother)->sayHi('UK'); (new HiMother)->sayHi('US'); Fatal error: Trait method mother has not been applied, because there are collisions with other trait methods on HiMother on line 28 Friday, June 8, 12
40. Conflict Resolution trait hello_en { public function greet() { echo "Hello "; } } trait mother_en_US { public function mother() { echo "Mom"; } } trait mother_en_UK { public function mother() { echo "Mum"; } } class HiMother { use hello_en, mother_en_US, mother_en_UK { mother_en_UK::mother insteadof mother_en_US; mother_en_US::mother as mom; } public function sayHi($locale = 'UK') { $this->greet(); ($locale != 'US') ? $this->mother() : $this->mom(); } } (new HiMother)->sayHi('UK'); // Hello Mum (new HiMother)->sayHi('US'); // Hello Mom Friday, June 8, 12
41. Trait Detection Friday, June 8, 12
42. Trait Detection • instanceof doesn’t work because it’s literally engine-level copy and paste • class_uses() returns an array • Both keys and values are the trait names • We can use array dereferencing (another PHP 5.4 feature) to check! Friday, June 8, 12
43. Trait Detection trait HelloWorld { public function hi() { echo "Hello World", PHP_EOL; } } class greeting { use HelloWorld; } $greeting = new greeting(); // This doesn’t work if ($greeting instanceof HelloWorld) { echo "instanceof: ", $greeting->hi(); } // This does - using array dereferencing! if (isset(class_uses($greeting)['HelloWorld'])) { echo "class_uses: ", $greeting->hi(); } Friday, June 8, 12
44. Built-in CLI Server Friday, June 8, 12
45. Built in CLI Server • Use -S <host>:<port> (capital S) flag to initiate • Document Root: Current working directory • Default file: index.php • Serves static assets (e.g. images, js, css) • Allows URL routing with simple PHP script Friday, June 8, 12
46. Running the CLI Server davey@maat ~ $ /usr/local/php5/bin/php -S localhost:8080 PHP 5.4.0RC6 Development Server started at Sun Jan 29 22:15:32 2012 Listening on localhost:8080 Document root is /Users/davey Press Ctrl-C to quit. [Sun Jan 29 22:15:36 2012] 127.0.0.1:49956 [200]: / [Sun Jan 29 22:15:37 2012] 127.0.0.1:49957 [404]: / favicon.ico - No such file or directory Friday, June 8, 12
47. Output: /index.php array (size=21) 'DOCUMENT_ROOT' => string '/Users/davey' (length=12) 'REMOTE_ADDR' => string '127.0.0.1' (length=9) 'REMOTE_PORT' => string '49956' (length=5) 'SERVER_SOFTWARE' => string 'PHP 5.4.0RC6 Development Server' (length=31) 'SERVER_PROTOCOL' => string 'HTTP/1.1' (length=8) 'SERVER_NAME' => string 'localhost' (length=9) 'SERVER_PORT' => string '8080' (length=4) 'REQUEST_URI' => string '/' (length=1) 'REQUEST_METHOD' => string 'GET' (length=3) 'SCRIPT_NAME' => string '/index.php' (length=10) 'SCRIPT_FILENAME' => string '/Users/davey/index.php' (length=22) 'PHP_SELF' => string '/index.php' (length=10) 'HTTP_HOST' => string 'localhost:8080' (length=14) 'HTTP_CONNECTION' => string 'keep-alive' (length=10) 'HTTP_USER_AGENT' => string 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_2) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.77 Safari/ 535.7' (length=116) 'HTTP_ACCEPT' => string 'text/html,application/xhtml+xml,application/ xml;q=0.9,*/*;q=0.8' (length=63) 'HTTP_ACCEPT_ENCODING' => string 'gzip,deflate,sdch' (length=17) 'HTTP_ACCEPT_LANGUAGE' => string 'en-US,en;q=0.8' (length=14) 'HTTP_ACCEPT_CHARSET' => string 'ISO-8859-1,utf-8;q=0.7,*;q=0.3' (length=30) 'REQUEST_TIME_FLOAT' => float 1327893336.7823 'REQUEST_TIME' => int 1327893336 Friday, June 8, 12
48. Using a Router davey@maat ~ $ /usr/local/php5/bin/php -S localhost:8080 router.php PHP 5.4.0RC6 Development Server started at Sun Jan 29 22:15:32 2012 Listening on localhost:8080 Document root is /Users/davey Press Ctrl-C to quit. [Sun Jan 29 22:15:36 2012] 127.0.0.1:49956 [200]: / [Sun Jan 29 22:15:41 2012] 127.0.0.1:49956 [200]: /index.php Note: custom routed URLs do not show here (might be a bug!) Friday, June 8, 12
49. Using a Router if (realpath(__DIR__ . "/. {$_SERVER['REQUEST_URI']}")) { // file exists, serve it — will execute PHP return false; } else { // route the request (could be ZF, li3, etc) MyRouter::route($_SERVER['REQUEST_URI']); } class MyRouter { static public function route($path) { echo "Requested Resource: $path"; } // Check if we’re using the cli-server if (PHP_SAPI == 'cli-server') { ... } Example Router Friday, June 8, 12
50. Output: /index.php array (size=21) 'DOCUMENT_ROOT' => string '/Users/davey' (length=12) 'REMOTE_ADDR' => string '127.0.0.1' (length=9) 'REMOTE_PORT' => string '49956' (length=5) 'SERVER_SOFTWARE' => string 'PHP 5.4.0RC6 Development Server' (length=31) 'SERVER_PROTOCOL' => string 'HTTP/1.1' (length=8) 'SERVER_NAME' => string 'localhost' (length=9) 'SERVER_PORT' => string '8080' (length=4) 'REQUEST_URI' => string '/' (length=1) 'REQUEST_METHOD' => string 'GET' (length=3) 'SCRIPT_NAME' => string '/index.php' (length=10) 'SCRIPT_FILENAME' => string '/Users/davey/index.php' (length=22) 'PHP_SELF' => string '/index.php' (length=10) 'HTTP_HOST' => string 'localhost:8080' (length=14) 'HTTP_CONNECTION' => string 'keep-alive' (length=10) 'HTTP_USER_AGENT' => string 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_2) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.77 Safari/535.7' (length=116) 'HTTP_ACCEPT' => string 'text/html,application/xhtml+xml,application/ xml;q=0.9,*/*;q=0.8' (length=63) 'HTTP_ACCEPT_ENCODING' => string 'gzip,deflate,sdch' (length=17) 'HTTP_ACCEPT_LANGUAGE' => string 'en-US,en;q=0.8' (length=14) 'HTTP_ACCEPT_CHARSET' => string 'ISO-8859-1,utf-8;q=0.7,*;q=0.3' (length=30) 'REQUEST_TIME_FLOAT' => float 1327893336.7823 'REQUEST_TIME' => int 1327893336 Friday, June 8, 12
51. Output: /foo/bar Requested Resource: /foo/bar array (size=23) 'DOCUMENT_ROOT' => string '/Users/davey/Dropbox/Talks/2012/PHP 5.4 - The New Bits/ cli-server' (length=65) 'REMOTE_ADDR' => string '::1' (length=3) 'REMOTE_PORT' => string '52584' (length=5) 'SERVER_SOFTWARE' => string 'PHP 5.4.0RC6 Development Server' (length=31) 'SERVER_PROTOCOL' => string 'HTTP/1.1' (length=8) 'SERVER_NAME' => string 'localhost' (length=9) 'SERVER_PORT' => string '8080' (length=4) 'REQUEST_URI' => string '/foo/bar' (length=8) 'REQUEST_METHOD' => string 'GET' (length=3) 'SCRIPT_NAME' => string '/index.php' (length=10) 'SCRIPT_FILENAME' => string '/Users/davey/Dropbox/Talks/2012/PHP 5.4 - The New Bits/cli-server/index.php' (length=75) 'PATH_INFO' => string '/foo/bar' (length=8) 'PHP_SELF' => string '/index.php/foo/bar' (length=18) 'HTTP_HOST' => string 'localhost:8080' (length=14) 'HTTP_CONNECTION' => string 'keep-alive' (length=10) 'HTTP_CACHE_CONTROL' => string 'max-age=0' (length=9) 'HTTP_USER_AGENT' => string 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_2) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.77 Safari/535.7' (length=116) 'HTTP_ACCEPT' => string 'text/html,application/xhtml+xml,application/xml;q=0.9,*/ *;q=0.8' (length=63) 'HTTP_ACCEPT_ENCODING' => string 'gzip,deflate,sdch' (length=17) 'HTTP_ACCEPT_LANGUAGE' => string 'en-US,en;q=0.8' (length=14) 'HTTP_ACCEPT_CHARSET' => string 'ISO-8859-1,utf-8;q=0.7,*;q=0.3' (length=30) 'REQUEST_TIME_FLOAT' => float 1327903577.3323 'REQUEST_TIME' => int 1327903577 Friday, June 8, 12
52. Thank You! • Feedback: • http://joind.in/talk/view/6252 • @dshafik • dshafik@engineyard.com • Slides: • http://daveyshafik.com/slides Friday, June 8, 12