[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
   

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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
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3. One More Thing
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4. Hard of hearing:
   PLEASE SPEAK UP!
   (Everybody Forgets This!)
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5. About These
   Slides
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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
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7. The Small Stuff
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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
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9. More on
   SessionHandlerInterface
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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 { }
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11. Language Changes
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12. Short Echo Tags
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13. Short Echo Tags
    ="Now I Will Always Work!";?>
    No longer depends on short_open_tags
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14. Binary Numbers
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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:
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16. New Array Syntax
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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'];
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18. Array
    Dereferencing
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19. Array
    Dereferencing
    function returnArray() {
    return ['a' => 'b', 'c' => 'd'];
    }
    $foo = returnArray()['a']; // b
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20. Dynamic Method
    Calls
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21. Dynamic Method
    Calls
    // Variable static methods
    $var = "staticMethod";
    ClassName::{$var}();
    // Instantiation Time Access
    (new ClassName)->instanceMethod();
    // UGLY.
    $var = "instanceMethod";
    (new ClassName)->{$var}();
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22. Improvements to
    Closures &
    Callbacks
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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()
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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());
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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
    }
    }
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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
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27. Rebinding $this
    Or: How to break the object model!
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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.
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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();
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30. Output
    Hello
    Fatal error: Call to private
    method bar::world() from context
    'foo'
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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
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32. Traits
    AKA Horizontal Re-use
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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
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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
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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
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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!
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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
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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
    $say->planet(); // World
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39. Conflicts
    trait hello_en {
    public function greet() { echo "Hello "; }
    }
    trait mother_en_US {
    public function mother() { echo "Mom"; }
    }
    trait mother_en_UK {
    public function mother() { echo "Mum"; }
    }
    class HiMother {
    use hello_en, mother_en_US, mother_en_UK;
    public function sayHi($locale = 'UK') {
    $this->greet();
    ($locale != 'US') ? $this->mother() : $this->mom();
    }
    }
    (new HiMother)->sayHi('UK');
    (new HiMother)->sayHi('US');
    Fatal error: Trait method mother has not been applied, because there are
    collisions with other trait methods on HiMother on line 28
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40. Conflict Resolution
    trait hello_en {
    public function greet() { echo "Hello "; }
    }
    trait mother_en_US {
    public function mother() { echo "Mom"; }
    }
    trait mother_en_UK {
    public function mother() { echo "Mum"; }
    }
    class HiMother {
    use hello_en, mother_en_US, mother_en_UK {
    mother_en_UK::mother insteadof mother_en_US;
    mother_en_US::mother as mom;
    }
    public function sayHi($locale = 'UK') {
    $this->greet();
    ($locale != 'US') ? $this->mother() : $this->mom();
    }
    }
    (new HiMother)->sayHi('UK'); // Hello Mum
    (new HiMother)->sayHi('US'); // Hello Mom
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41. Trait Detection
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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!
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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();
    }
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44. Built-in CLI Server
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45. Built in CLI Server
    • Use -S : (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
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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
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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
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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!)
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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
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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
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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
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52. Thank You!
    • Feedback:
    • http://joind.in/talk/view/6252
    • @dshafik
    • dshafik@engineyard.com
    • Slides:
    • http://daveyshafik.com/slides
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