#1

Do you trust your docblock?

class User {
  protected $id;
  protected $address;

  public function getAddress() {
    return $this->address;
  }
}

function compute_shipping($src, User $user) {
  $dest = $user->getAddress();

  $distance = distance_between($src, $dest);

  return $distance * .5; // 50 cents/mile
}
        

class User {
  protected $id;
  protected $address;

  /**
   * @return Address
   */
  public function getAddress() {
    return $this->address;
  }
}

function compute_shipping($src, User $user) {
  $dest = $user->getAddress();

  $distance = distance_between($src, $dest);

  return $distance * .5; // 50 cents/mile
}
        

class User {
  protected $id;
  protected $address;

  public function getAddress() : Address {
    return $this->address;
  }
}

function compute_shipping($src, User $user) {
  $dest = $user->getAddress();

  $distance = distance_between($src, $dest);

  return $distance * .5; // 50 cents/mile
}
        

Return types

• New in PHP 7!
• Not nullable (good)

$r = new UserRepository();

print $r->findById(123)->getAddress()->getStreet() . PHP_EOL;
        

          Method called on non-object
        

No NULL means:

• Exception
• "Empty" value object

For Repositories etc.

class UserRepository {
  // ...

  public function findById($id) : User {
    if (/* can't find the user */) {
     throw new InvalidArgumentException('No such User: ' . $id);
    }
    return $user;
  }

}
        

For Value objects

interface AddressInterface {
  public function getStreet();
  public function getCity();
  public function getState();
  public function getZip();
}

class EmptyAddress implements AddressInterface {
  public function getStreet() { return ''; }
  public function getCity() { return ''; }
  public function getState() { return ''; }
  public function getZip() { return ''; }
}

class Address implements AddressInterface {
    // ...
}
        

Returning false on error is a
big 'screw you' to your users

#2

function compute_shipping($src, AddressInterface $dest) {
  $distance = distance_between($src, $dest);

  return $distance * .5; // 50 cents/mile
}

function distance_between(AddressInterface $src, AddressInterface $dest) {
  // ...
}

$u_address = new Address(); // ...
$user = new User(123, $u_address);

$src = new Address(); // ...
compute_shipping($src, $user->getAddress());
        

What does distance_between() return?

function compute_shipping(AddressInterface $src, AddressInterface $dest) : float {
  $distance = distance_between($src, $dest);

  return $distance * .5; // 50 cents/mile
}

function distance_between(AddressInterface $src, AddressInterface $dest) : int {
  // ...
}

$u_address = new Address(); // ...
$user = new User(123, $u_address);

$src = new Address(); // ...
compute_shipping($src, $user->getAddress());
        

Everyone here owes
Andrea Faulds and Anthony Ferrara a drink

New type specs in PHP 7

• int
• float
• string
• bool

Full type list

• int
• float
• string
• bool
• array
• callable
• Any class name

interface AddressInterface {
  public function getStreet();
  public function getCity();
  public function getState();
  public function getZip();
}
        

Is getStreet() a string or object?

interface AddressInterface {
  public function getStreet() : string;
  public function getCity() : string;
  public function getState() : string;
  public function getZip() : string;
}
        

class Address implements AddressInterface {
  public function __construct(string $street, string $city, string $state, string $zip) {
    // ...
  }
  // ...
}
        

$u_address = new Address('45 Hull St', 'Boston', 'MA', 02113);
$user = new User(123, $u_address);

$src = new Address('2211 N Elston Ave', 'Chicago', 'IL', 60614);
compute_shipping($src, $user->getAddress());
        

Strict vs Weak mode

Weak by default

* string -> int may E_NOTICE

Strict mode

Address.php

declare(strict_types=1);

class Address implements AddressInterface {
  public function __construct(string $street, string $city, string $state, string $zip) {
    // ...
  }
  public function getZip() : string {
    return $this->zip;
  }

  // ...
}
        

Affects calls and returns from this file

Strict mode

setup.php

declare(strict_types=1);

$u_address = new Address('45 Hull St', 'Boston', 'MA', 02113);
$user = new User(123, $u_address);

$src = new Address('2211 N Elston Ave', 'Chicago', 'IL', 606014);
compute_shipping($src, $user->getAddress());
        

Affects calls and returns from this file

Casting in strict mode

* int converts to float automatically

Using strict types

90% of the time

(Everywhere except Input)

Also, Documentation

BC Warning!

New reserved words!

#3

usort($array, function ($a, $b) {
  if ($a < $b) {
    return -1;
  }
  elseif ($a > $b) {
    return 1;
  }
  else {
    return 0;
  }
});
        

T_SPACESHIP

<=>

usort ($array, function($a, $b) {
  return $a <=> $b;
});
        

usort($people, function (Person $a, Person $b) {
  if ($a->lastName() < $b->lastName()) {
    return -1;
  }
  elseif ($a->lastName() > $b->lastName()) {
    return 1;
  }
  else {
    if ($a->firstName() < $b->firstName()) {
      return -1;
    }
    elseif ($a->firstName() > $b->firstName()) {
      return 1;
    }
    else {
      return 0;
    }
  }
});
        

usort($people, function (Person $a, Person $b) {
  return $a->lastName() < $b->lastName() ? -1
    : ($a->lastName() > $b->lastName() ? 1
      : $a->firstName() < $b->firstName() ? -1
        : ($a->firstName() > $b->firstName() ? 1 : 0));
});
        

You're Fired!

usort($people, function (Person $a, Person $b) {
 return [$a->lastName(), $a->firstName()] <=> [$b->lastName(), $b->firstName()];
});
        

#4

$username = $username ? $username : 'Anonymous';
        

$username = $username ?: 'Anonymous';
        

But what if $username doesn't exist?

Notice: Undefined variable: username on line 3
        

$username = isset($username) && !is_null($username) ? $username : 'Anonymous';
        

NULL coalesce!

$username = $username ?? 'Anonymous';
        

$username = $submitted['username'] ?? $user->username() ?? 'Anonymous';
        

?? checks setness, not truthiness

#5

Cryptography is hard

Don't we have this already?

• rand() isn't really random
• mcrypt() isn't really random (also unsupported)
• fread(fopen('/dev/urandom'), 16) isn't portable
• openssl is hard to use

What we want is an easy
Cryptographically Secure Pseudo-Random Number Generator

CSPRNG!

Ask and ye shall receive…

$junk = random_bytes(16);

$val = random_int(1, 100);
       

If you're not using these functions for security...

• password_hash() / password_verify()
• random_bytes()
• random_int()

You're Doing It Wrong!

#6

Mocking is hard

$mock_repository = $this
  ->getMockBuilder(ThingieRepository::class)
  ->disableOriginalConstructor()
  ->getMock();

$obj1 = new Thingie();
$obj1->setVal('abc');

$obj2 = $this->getMockBuilder(Thingie::class)
  ->disableOriginalConstructor()
  ->getMock();
$obj1 ->method('getVal')->willReturn('def');

$map = [ [1, $obj1], [2, $obj2] ];

$mock_repository
  ->method('load')->will($this->returnValueMap($map));

$subject = new ClassUnderTest($mock_repository);
$this->assertTrue($subject->findThings());
         

Fakes are easy

$fake_repository = new class extends ThingieRepository {
  public function __construct() {}

  public function load($id) {
    switch ($id) {
      case 1:
        $obj1 = new Thingie();
        $obj1->setVal('abc');
        return $obj1;
      case 2:
        return new class extends Thingie {
          public function getVal() {
            return 'def';
          }
        };
    }
  }
};

$subject = new ClassUnderTest($fake_repository);
$this->assertTrue($subject->findThings());
         

One-off dependencies

new Service(new class implements LoggerInterface {
  use LoggerTrait;

  public function log($message) {
    print $message . PHP_EOL;
  }
});
         

Constructors, too

new class($logger) implements ServiceInterface {
  public function __construct(LoggerInterface $logger) {
    $this->logger = $logger;
  }

  public function doServiceStuff() { }
};
         

#7

Fatal errors suck

Recoverable errors… aren't

PHP 5

function doStuff(Request $r) {
  // ...
}

$u = new User();

doStuff($u);
        

Catchable fatal error: Argument 1 passed to doStuff() must be an instance of Request,
instance of User given

PHP 7

function doStuff(Request $r) {
  // ...
}

$u = new User();

try {
  doStuff($u);
}
catch (\TypeError $e) {
  print "Wrong variable type, dummy." . PHP_EOL;
}
        

try {
  include 'buggy_file.php';
}
catch (\ParseError $e) {
  $logger->error("That file is buggy!");
}
        

try {
  nonexistant_function();
}
catch (\Error $e) {
  print "The error was " . $e->getMessage();
}
        

E_FATAL, E_RECOVERABLE_ERROR, E_PARSE, E_COMPILE_ERROR

Exceptions: The user screwed up

Errors: The coder screwed up

BC Warning!

New reserved class names

Global exception handler

PHP 5

set_exception_handler(function(\Exception $e) {
  // ...
});
        

set_exception_handler(function(\Throwable $e) {
  // ...
});
          

set_exception_handler(function($e) {
  // ...
});
          

#8

Assertions suck

function doStuff(array $def) {
  assert(isset($def['key']) && isset($def['value']), 'Invalid def');
  // ...
}
        

function doStuff(array $def) {
  assert('isset($def[\'key\']) && isset($def[\'value\'])', 'Invalid def');
  // ...
}
          

PHP 7: Expectations

ini_set('assert.exception', 1);
ini_set('zend.assertions', 1);

class InvalidDef extends AssertionError {}

function doStuff(array $def) {
  assert(isset($def['key']) && isset($def['value']), new InvalidDef('Invalid def'));
  // ...
}
        

Assertions are actually not-broken!

#9

You're not still doing iterators
the hard way, are you?

class RemoteSource implements Iterator {
  protected $key;

  protected $current;

  protected $client;

  public function __construct(Client $client) {
    $this->client = $client;
    $this->key = 0;
  }

  public function current() {
    return $this->current;
  }

  public function next() {
    $this->current = $this->client->get('http://api.com/entry/' . $this->key);
    $this->key++;
  }

  public function key() {
    return $this->key;
  }

  public function valid() {
    return (bool)$this->current;
  }

  public function rewind() {
    throw new Exception();
  }
}
        

$result = $db->query(...);

$iterator = new AppendIterator();
$iterator->append(new RemoteSource($client));
$iterator->append($result);

foreach ($iterator as $item) {
  // Do something.
}
        

In PHP 7...

function getRemoteValues($client) {
  $key = 0;
  while ($val = $client->get('http://api.com/entry/' . $key++)) {
    yield $val;
  }
}

function getLocalValues() {
  foreach (db()->query(...) as $record) {
    yield $record;
  }
}

function getValues($client) {
  // This is the new part.
  yield from getRemoteValues($client);
  yield from getLocalValues();
  return 'done';
}

$values = getValues($client);
foreach ($values as $item) {
  // Do stuff
}
print $val->getReturn() . PHP_EOL;
        

#10

What does this do?

$$foo['bar']['baz']
        

$foo->$bar['baz']
        

$foo->$bar['baz']()
        

Foo::$bar['baz']()
        

Foo::$bar[1][2][3]()
        

Uniform variable syntax

Always Left-To-Right

It's logical

$foo()['bar']()
[$obj1, $obj2][0]->prop
getStr(){0}
$foo['bar']::$baz
$foo->bar()::baz()
$foo()()
        

(...)['foo']
(...)->foo
(...)->foo()
(...)()

(function() { ... })()
($obj->closure)()
        

BC Break

Complex cases change meaning

When in doubt, use () or {}

Credit: Rasmus Lerdorf

Credit: Rasmus Lerdorf

Credit: Rasmus Lerdorf

Credit: Rasmus Lerdorf

But I'm scared of .0 releases!

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