PHP II - Nov 2022

TODO

Q: Example using preg_replace_callback_array() doing document conversions?
A: https://github.com/dbierer/php7cookbook/blob/master/source/chapter01/chap_01_php5_to_php7_code_converter.php#L3
A: https://github.com/dbierer/php7cookbook/blob/master/source/Application/Parse/Convert.php
Q: What happened to POSIX character classes in PHP 8?
A: TBD
Q: Where are the built-in PCRE character classes documented?
A: https://www.php.net/manual/en/regexp.reference.escape.php
Q: When would you set age to a value other than zero?
A: If you want to set a specific # seconds the cache is considered valid.

header('Cache-Control: must-revalidate, max-age=0');

A: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control
A: https://stackoverflow.com/questions/6486805/html-cache-control-max-age
A: https://stackoverflow.com/questions/10314174/difference-between-pragma-and-cache-control-headers

Homework

For Fri 11 Nov 2022

Lab: Validate an Email Address

For Wed 9 Nov 2022

Lab: Prepared Statements
Lab: Stored Procedure
Lab: Transactions

For Mon 7 Nov 2022

Lab: Type Hinting
Lab: Build Custom Exception Class
Lab: Traits
Review the OrderApp (use course Module 3 as a guideline)

For Fri 4 Nov 2022

Lab: Magic Methods
Lab: Abstract Classes
Lab: Interfaces

For Wed 2 Nov 2022

Update the VM
Lab: Namespace
Lab: Create a Class
Lab: Create an Extensible Super Class

VM Notes

Info

Username: vagrant
Password: vagrant

Update everything!

Open a terminal window and run this command:

sudo apt update
sudo apt -y upgrade

NOTE: this task might take some time

Install phpMyAdmin

Download the latest version from https://www.phpmyadmin.net
Make note of the version number (e.g. 5.2.0)

cd
VER=5.2.0
unzip Downloads/phpMyAdmin-$VER-all-languages.zip
sudo cp -r phpMyAdmin-$VER-all-languages/* /usr/share/phpmyadmin
sudo cp /usr/share/phpmyadmin/config.sample.inc.php /usr/share/phpmyadmin/config.inc.php

Create the "blowfish secret"

sudo -i
export SECRET=`php -r "echo md5(date('Y-m-d-H-i-s') . rand(1000,9999));"`
echo "\$cfg['blowfish_secret']='$SECRET';" >> /usr/share/phpmyadmin/config.inc.php
exit

Set permissions

sudo chown -R www-data /usr/share/phpmyadmin

Snapshot

Be sure to take a snapshot of the VM before you start any of the labs!

System Problem

If you see this message: System program problem detected
Do this:

sudo rm -r /var/crash*

Resources

Code examples: https://github.com/dbierer/classic_php_examples PHP Road Map: https://wiki.php.net/rfc Where it all started:

Seminal work: "Design Patterns: Elements of Reusable Object-Oriented Software" PHP Road Map:
https://wiki.php.net/rfc Additional examples from PHP III class:
https://github.com/dbierer/php-iii-demos

Class Notes

Namespaces

Autoloader Examples:

https://github.com/dbierer/classic_php_examples/blob/master/oop/oop_autoload_example.php
https://github.com/dbierer/classic_php_examples/blob/master/oop/oop_autoload_class_example.php

Class example:

<?php
namespace My\Different\Space;

// you can identify PHP classes like this:
use ArrayObject;
class Test
{
    public function test()
    {
        return __NAMESPACE__;
    }
    public function getArrayObject(array $arr)
    {
        // or: use leading backslash:
        return new \ArrayObject($arr);
    }
}

Calling program:

<?php
include __DIR__ . '/Test.php';
use My\Different\Space\Test;

// alternatively, you can do this:
// $test = new \My\Different\Space\Test();

$test = new Test();
echo $test->test();

$arr = [1,2,3,4,5];
$obj = $test->getArrayObject($arr);
var_dump($obj);

Call methods from inside a class: use $this

<?php
class Test
{
        protected string $first = 'fred';
        protected string $last  = 'flintstone';
        public function getFirst()
        {
                return ucfirst($this->first);
        }
        public function getLast()
        {
                return ucfirst($this->last);
        }
        public function getName()
        {
                return $this->getFirst() . ' ' . $this->getLast();
        }
}
$test = new Test();
echo $test->getName();

Example where you want controlled access to a property:

<?php
class UserEntity {
    protected string $phone = '';
        // Method
        public function setPhoneNumber(int $num) : void {
                $str = (string) $num;
                $this->phone = substr($str, 0, 3) . '-' . substr($str, 3, 3) . '-' . substr($str, 6);
        }
        public function getPhoneNumber() : string {
                return $this->phone;
        }
}

$user = new UserEntity();
$user->setPhoneNumber(1112223333);
echo $user->getPhoneNumber();
echo PHP_EOL;

Example using __construct()

<?php
class UserEntity {
    protected string $firstName;
    protected string $lastName;
    public function __construct($firstName, $lastName) {
        $this->firstName = $firstName ;
        $this->lastName = $lastName ;
    }
    public function getName()
    {
                return $this->firstName . ' ' . $this->lastName;
        }
}

$user[] = new UserEntity('Jack' , 'Ryan');
$user[] = new UserEntity('Monte' , 'Python');
foreach ($user as $obj)
        echo $obj->getName() . "\n";

Constructor argument promotion example:

<?php
class Test
{
        // contructor argument promotion
        // only in PHP 8.0 and above
        public function __construct(public string $first = '', public string $last = '')
        {
                // do nothing
        }
        public function getFirst()
        {
                return ucfirst($this->first);
        }
        public function getLast()
        {
                return ucfirst($this->last);
        }
        public function getName()
        {
                return $this->getFirst() . ' ' . $this->getLast() . "\n";
        }
}
$test1 = new Test('Fred', 'Flintstone');
echo $test1->getName();

$test2 = new Test('Wilma', 'Flintstone');
echo $test2->getName();

var_dump($test1, $test2);

Practical anonymous class example:

https://github.com/dbierer/classic_php_examples/blob/master/oop/oop_spl_filteriterator_anon_class.php Example showing return info + added functionality:

<?php
class Test
{
        public function getCityInfo(string $city, string $country='', string $state='')
        {
                $json = file_get_contents("http://api.unlikelysource.com/api?city=$city&state_prov_code=$state&country=$country");
                // return an anonymous class with the desired info + added functionality
                return new class($json) {
                        public string $json = '';
                        public function __construct(string $json)
                        {
                                $this->json = $json;
                        }
                        public function getString()
                        {
                                return $this->json;
                        }
                        public function getArray()
                        {
                                return json_decode($this->json);
                        }
                };
        }
}

$test = new Test();
$obj  = $test->getCityInfo('Bangor','US','ME');
var_dump($obj->getArray());

Magic Methods

Example of __destruct()

https://github.com/dbierer/filecms-core/blob/main/src/Common/Image/Captcha.php Another Example:

<?php
class Test
{
        public $instance = NULL;
        public string $name = 'Fred Flintstone';
        public function __destruct()
        {
                echo __METHOD__ . ':' . $this->name . PHP_EOL;
        }
        public function whatever()
        {
                $this->instance = new self();
                $this->instance->name = __FUNCTION__;
        }
}


$test1 = new Test();
$test1->name = 'TEST1';
var_dump($test1);

$test2 = new Test();
$test2->name = 'TEST2';
$test2->whatever();

// actual output:
/*
object(Test)#1 (2) {
  ["instance"]=>
  NULL
  ["name"]=>
  string(5) "TEST1"
}
Test::__destruct:TEST2
Test::__destruct:whatever
Test::__destruct:TEST1
 */

Serialization example:

<?php
class UserEntity
{
        public $status = ['A','B','C'];
        public function __construct(
        protected string $firstName,
        protected string $lastName,
        protected float $balance,
        protected int $id
    ) {}
        public function getFullName()
        {
                return $this->firstName . ' ' . $this->lastName;
        }
}
$user = new UserEntity('Fred', 'Flintstone', 999.99, 101);
$text = serialize($user);
//$text = json_encode($user);
echo $text . "\n";
$obj = unserialize($text);
//$obj = json_decode($text);
echo $obj->getFullName() . "\n";
var_dump($obj);

Example of __sleep() and __wakeup()

<?php
class UserEntity {
        public $hash = '';
        public function __construct(
        protected string $firstName,
        protected string $lastName)
    {
                $this->hash = bin2hex(random_bytes(8));
    }
    public function __sleep()
    {
                return ['firstName','lastName'];
        }
        public function __wakeup()
        {
                $this->hash = bin2hex(random_bytes(8));
        }
        public function getFullName()
        {
                return $this->firstName . ' ' . $this->lastName;
        }
    public function getNativeString(): string {
        return serialize($this);
    }
}
$userEntity = new UserEntity('Mark', 'Watney');
var_dump($userEntity);
echo PHP_EOL;

$native = $userEntity->getNativeString();
$obj  = unserialize($native);
echo $native;
echo PHP_EOL;
var_dump($obj);

Example of __serialize() and __unserialize()

<?php
class UserEntity {
        public $hash = '';
        public function __construct(
                protected string $firstName,
                protected string $lastName)
    {
                $this->hash = bin2hex(random_bytes(8));
    }
    public function __serialize()
    {
                return [
                        'firstName' => $this->firstName,
                        'lastName' => $this->lastName,
                        'sleep_date' => date('Y-m-d H:i:s')
                ];
        }
        public function __unserialize($array)
        {
                // $array contains values restored from the serialization
                $this->hash = bin2hex(random_bytes(8));
                $this->firstName = $array['firstName'];
                $this->lastName = $array['lastName'];
        }
        public function getFullName()
        {
                return $this->firstName . ' ' . $this->lastName;
        }
    public function getNativeString(): string {
        return serialize($this);
    }
}
$userEntity = new UserEntity('Mark', 'Watney');
var_dump($userEntity);
echo PHP_EOL;

$native = $userEntity->getNativeString();
$obj  = unserialize($native);
echo $native;
echo PHP_EOL;
var_dump($obj);

Example of when getters and setters are useful:

class Test
{
    protected $date;
    const DEFAULT_FMT = 'Y-m-d H:i:s';
    // use getters and setters if there's a need for further processing
    public function setDate(string $str) : void
    {
                $this->date = new DateTime($str);
        }
        public function getDate(string $fmt = self::DEFAULT_FMT) : string
        {
                return $this->date->format($fmt);
        }
}

Example of controlled unlimited properties

<?php
class Test
{
        public const FIELDS = ['fname','lname','balance'];
        public $vars = [];
    // Returns an inaccessible property
    public function __set($key, $value) {
        if (in_array($key, self::FIELDS)) {
                        $this->vars[$key] = $value;
                }
    }
    public function __get($key) {
        return $this->vars[$key] ?? '';
    }
}

$test = new Test();
$test->fname = 'Fred';
$test->lname = 'Flintstone';
$test->balance = 999.99;
$test->doesNotExist = 'TEST';
echo $test->fname . ' ' . $test->lname
         . ' has a balance of ' . $test->balance
         . ' and ' . $test->doesNotExist;

Allows direct access to protected properties

class UserEntity {
    public function __construct(
        protected string $firstName,
        protected string $lastName
    ) {}

    // Returns an inaccessible property
    public function __get($value) {
        return $this->$value ?? NULL;
    }
}

$userEntity = new UserEntity('Mark', 'Watney');
echo $userEntity->firstName;
// outputs: "Mark" even though property is protected

Other examples of magic methods:

https://github.com/dbierer/classic_php_examples/tree/master/oop
Look for oop_magic*.php

Example of Abstract class with abstract method:

https://github.com/laminas/laminas-mvc/blob/master/src/Controller/AbstractController.php Examples of what is callable
https://github.com/dbierer/classic_php_examples/blob/master/oop/callable_examples.php Example of going from a specific data type to a more general data type

<?php
interface Foo {
    public function test(array $input);
}

class Bar implements Foo {
    // type omitted for $input
    public function test(iterable $input) {
                $text = '';
                foreach($input as $item) $text .= ' ' . $item;
        return 'You requested ' . trim($text);
    }
}

$bar = new Bar();
echo $bar->test(['A','B','C']);
echo $bar->test(new ArrayIterator(['A','B','C']));

Using static to get an instance of the lowest level in inheritance tree

<?php
class Foo
{
        public function whatever()
        {
                return 'Whatever';
        }
        public function getInstance() : static
        {
                // this returns an error:
                // return new self();
                return new static();
        }
}
class Bar extends Foo {}

$foo = new Foo();
$bar = new Bar();
var_dump($foo->getInstance());  // Foo
var_dump($bar->getInstance());  // Bar

Scalar type hinting

<?php
//declare(strict_types=1);
class Test
{
	public function add(int $a, int $b) : int
	{
		return $a + $b;
	}
}

$test = new Test();
echo $test->add(2, 2);
echo PHP_EOL;
echo $test->add(2.555, 2.6666);
echo PHP_EOL;
echo $test->add('2', '2');
echo PHP_EOL;
echo $test->add((int) '2A', (int) 'B');
echo PHP_EOL;
echo $test->add('2A', '2B');
echo PHP_EOL;

// actual output:
/*
4
4
4
2
PHP Fatal error:  Uncaught TypeError: Test::add(): Argument #1 ($a) must be of type int, string
given, called in C:\Users\ACER\Repos\classic_php_examples\oop\test.php on line 20 and defined in
 C:\Users\ACER\Repos\classic_php_examples\oop\test.php:5
Stack trace:
#0 C:\Users\ACER\Repos\classic_php_examples\oop\test.php(20): Test->add()
#1 {main}
  thrown in C:\Users\ACER\Repos\classic_php_examples\oop\test.php on line 5

 */

Exception / Error example:

<?php
try {
        $pdo = new PDO('sqlite://xyz');
} catch (PDOException $a) {
        // catches PDOException
        echo __LINE__ . ':' . get_class($a) . ':' . $a . "\n";
} catch (Exception $a) {
        echo __LINE__ . ':' . get_class($a) . ':' . $a . "\n";
} catch (Error $a) {
        echo __LINE__ . ':' . get_class($a) . ':' . $a . "\n";
}

try {
        $pdo = new PDO();
} catch (PDOException $a) {
        echo __LINE__ . ':' . get_class($a) . ':' . $a . "\n";
} catch (Exception $a) {
        echo __LINE__ . ':' . get_class($a) . ':' . $a . "\n";
} catch (Error $a) {
        // catches Error
        echo __LINE__ . ':' . get_class($a) . ':' . $a . "\n";
}
// actual output:
/*
6:PDOException:PDOException: SQLSTATE[HY000] [14] unable to open database file in C:\Users\ACER\Repos\classic_php_examples\oop\test.php:3
Stack trace:
#0 C:\Users\ACER\Repos\classic_php_examples\oop\test.php(3): PDO->__construct()
#1 {main}
21:ArgumentCountError:ArgumentCountError: PDO::__construct() expects at least 1 argument, 0 given in C:\Users\ACER\Repos\classic_php_examples\oop\test.php:14
Stack trace:
#0 C:\Users\ACER\Repos\classic_php_examples\oop\test.php(14): PDO->__construct()
#1 {main}
*/

Using static functionality to get a singleton instance

https://github.com/dbierer/filecms-core/blob/main/src/Common/Generic/Messages.php Other examples of static and traits
https://github.com/dbierer/classic_php_examples/tree/master/oop/*static*.php
https://github.com/dbierer/classic_php_examples/tree/master/oop/*trait*.php

Traits and visibility

<?php
class Base {
    public function sayHello() {
        echo 'Hello ';
    }
}

trait SayWorld {
    private function sayHello() {
        parent::sayHello();
        echo 'World!';
    }
}

class MyHelloWorld extends Base {
    use SayWorld;
}

$o = new MyHelloWorld();
$o->sayHello();

// actual output:
/*
PHP Fatal error:  Access level to SayWorld::sayHello() must be public (as in class Base) in C:\U
sers\ACER\Repos\classic_php_examples\oop\test.php on line 9
*/

Traits conflict resolution example:

<?php
namespace Traits;

class Hybrid {

    use GasPower, ElectricPower {
        GasPower::providePower insteadOf ElectricPower;
        GasPower::providePower as protected provideGasPower;
        ElectricPower::providePower as protected provideElectricPower;
    }

    public function __construct() {
        echo 'New Hybrid on the line.';
        echo PHP_EOL;
    }

	// This is done to override the Trait `providePower()`
	// so that it's no longer visible
	private function providePower() {
		return NULL;
	}

    public function useWhatever() {
        $this->providePower();
    }

    public function useGas() {
        $this->provideGasPower();
    }

    public function useElectric() {
        $this->provideElectricPower();
    }

}

Domain Model

Factory design pattern:

https://github.com/laminas/laminas-diactoros/blob/master/src/ServerRequestFactory.php Builder pattern:
https://www.doctrine-project.org/projects/doctrine-orm/en/2.13/reference/query-builder.html Adapter pattern:
https://php.net/PDO Pub/Sub pattern:
https://www.php.net/manual/en/class.splobserver.php
https://www.php.net/manual/en/class.splsubject.php
https://www.doctrine-project.org/projects/doctrine-orm/en/2.13/reference/events.html Examples of Hydrators
https://github.com/laminas/laminas-hydrator/blob/4.9.x/src/ClassMethodsHydrator.php
https://github.com/laminas/laminas-hydrator/blob/4.9.x/src/ArraySerializable.php

PDO

Adding options as 4th argument:

try {
    // Get the connection instance
    $opts = [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION];
    $pdo = new PDO('mysql:host=localhost;dbname=phpcourse', 'vagrant', 'vagrant', $opts);
    // Statements ...
} catch (PDOException $e ){
    // Handle exception...
}

To find the exact DSN for a given database in PDO, look at the Driver class documentation

Example: DSN for PostgreSQL: https://www.php.net/manual/en/ref.pdo-pgsql.connection.php Example of handling a large result set:

try {
    // Execute a one-off SQL statement and get a statement object
    $stmt = $pdo->query('SELECT * FROM orders');

    // Returns an associative array indexed by column name
    while ($row = $stmt->fetch(PDO::FETCH_ASSOC) {
                // do something with the resulting row
        }

} catch (PDOException $e){
    //Handle error
}

Alternative way to execute without using bindParam()

Modifies: https://github.com/ealebrun/PHPII/blob/main/HW-2022-04-27

$data = [
        'eventTitle' => 'Wagner, Bryant',
        'eventURL' => 'http://bryant.prestosports.com/sports/bsb/2021-22/schedule#6irpaohben8y4ati',
        'eventDescription' => 'Baseball on May 21, 2022 at 3:00 PM: Wagner, Bryant, Conaty Park',
        'eventCategory' => 'Baseball',
        'eventDateString' => 'Sat, 21 May 2022 19:00:00 GMT',
        'eventGUID' => 'http://bryant.prestosports.com/sports/bsb/2021-22/schedule#6irpaohben8y4at',
        'eventOpponent' => 'Wagner',
];
$stmt->execute($data);

Example of PDO::FETCH_CLASS mode:

See: https://github.com/dbierer/classic_php_examples/blob/master/db/db_pdo_fetch_class.php

Example of PDO::FETCH_ASSOC using a factory to produce OrderEntity instances:

<?php
class OrderEntity
{
	public function __construct(
		public int $id,
		public float $timestamp,
		public string $status,
		public float $amount,
		public string $description,
		public int $customer)
	{
		// do nothing
	}
}
class OrderFactory
{
	public static function buildOrder(array $data)
	{
		return new OrderEntity(
			$data['id'],
			$data['date'],
			$data['status'],
			$data['amount'],
			$data['description'],
			$data['customer']
		);
	}
}

/**
 * Application Entry
 */

define('BASE', realpath(__DIR__ . '/../'));
$config = include __DIR__ . '/../config/config.php';
$dsn = $config['db']['dsn'];
$usr = $config['db']['username'];
$pwd = $config['db']['password'];
$opts = $config['db']['options'];

try {
	$data = [];
	$pdo = new PDO($dsn, $usr, $pwd, $opts);
	$stmt = $pdo->query('SELECT * FROM orders');
    while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
		$data[] = OrderFactory::buildOrder($row);
	}
} catch (Throwable $t) {
	echo $t;
}
var_dump($data);

OrderApp rewrites

OrderApp\Model\CustomersModel

// rewrote this method:
public function getCustomer(int $id): array
{
	//Initialize a statement
	$stmt = null;

	// Build a query using a positional placeholder
	$query = "SELECT * FROM " . static::TABLE . " WHERE id = ?";

	try{
		// changed to prepare/execute methodology
		$stmt = $this->db->pdo->prepare($query);
		if ($stmt->execute([$id])) {
			return $stmt->fetch(PDO::FETCH_ASSOC);
		} else {
			throw new ModelException('Query error: No customer returned');
		}
	} catch (ModelException $e) {
		//Append the error to the defined log
		error_log($e->getMessage(), 3, static::ERROR_LOG);
	}

	//On failure ...
	return false;
}

OrderApp\Model\OrdersModel

// rewrote this method:
public function save(array $data)
{
	$customer = $data['customer'];
	$data = $data['data'];

	// Build a query using named placeholders
	$query = 'INSERT INTO ' . static::TABLE
		   . "({$this->date}, {$this->status}, {$this->amount}, {$this->desc}, {$this->customerId}) "
		   . 'VALUES (:order_date, :status_filter, :amount, :description, :cust_id);';

	//Save the data
	try {
		// changed to prepare/execute methodology
		$stmt = $this->db->pdo->prepare($query);
		if (!$stmt->execute($data)) {
			throw new ModelException('Query error');
		}
	} catch (ModelException | PDOException $e) {
		//Append the error to the defined log
		error_log($e->getMessage(), 3, static::ERROR_LOG);
		return false;
	}
	//On success ...
	return true;
}

Output Buffering

To start output buffering automatically, in the php.ini file:

// sets buffer size to 4K + activates it
output_buffering=4096

See: https://www.php.net/manual/en/outcontrol.configuration.php#ini.output-buffering

Email

Headers can include any valid headers as per RFC 2822

See: http://www.faqs.org/rfcs/rfc2822

Regex

Alternatives to finding chars at beginning or end of a string:

<?php
$str = '/home/doug/whatever/';

// Any PHP above 4
echo ($str[0] ==='/') ? 'Y' : 'N';
echo ($str[-1] ==='/') ? 'Y' : 'N';

// PHP 8
echo (str_starts_with($str,'/')) ? 'Y' : 'N';
echo (str_ends_with($str,'/')) ? 'Y' : 'N';

Examples using sub-patterns

<?php
$str = '<p>One</p><p>Two</p><p>Three</p>';
$pat = '/<p>(.*?)<\/p>/';
preg_match_all($pat, $str, $match);
var_dump($match);


$str = 'Click here to go to <a target="_blank" href="http://zend.com/">Zend</a>!';
$pat = '/<a.*?href=("|\')(.*?)("|\').*?>/';
preg_match_all($pat, $str, $match);
var_dump($match);

Composer

Example of advanced usage including scripts

https://github.com/laminas/laminas-mvc-skeleton/blob/master/composer.json You can add alternates to packagist.org using the repositories key in the composer.json file
Example: https://wpackagist.org/ Automated WordPress installation using Composer:
https://github.com/dbierer/automated_wp_installation

Web Services

Example of SOAP Client

https://github.com/dbierer/classic_php_examples/blob/master/web/soap_client.php How to generate an HTTP PUT, POST, etc.
See: https://www.php.net/stream_context_create

<?php
$data = array ('foo' => 'bar', 'bar' => 'baz');
$data = http_build_query($data);
$context_options = array (
        'http' => array (
            'method' => 'POST',
            'header'=> "Content-type: application/x-www-form-urlencoded\r\n"
                . "Content-Length: " . strlen($data) . "\r\n",
            'content' => $data
            )
        );

$context = stream_context_create($context_options)
$fp = fopen('https://url', 'r', false, $context);

Study by Oracle that compares SOAP and REST

https://www.ateam-oracle.com/post/performance-study-rest-vs-soap-for-mobile-applications

Output Control

Example using output buffering to create inner content

<?php
ob_start ();

$values = ['TH'=>'Thailand','GB'=>'Great Britain','FR'=>'France'];
foreach ($values as $key => $val)
        echo '<tr><th>' . $key . '</th><td>' . $val . '</td></tr>';

$contents = ob_get_clean();

echo '<h1>My Cool Webpage</h1>';
echo '<table>';
echo $contents;
echo '</table>';

Regex

Misc examples

<?php
$data = [
        '/^[A-Z].*/'     => ['The quick brown fox', '12345'],
        '/.*(jpg|png)$/' => ['image.png', 'info.php'],
        '/\bERROR\b/'    => ['ERROR 309: undefined error','This contains ERROR_REPORTING'],
        '/^[A-Za-z ]*$/'  => ['The quick brown fox', '9977 quick brown foxes'],
        '/^[^A-Za-z]*$/' => ['997799989887777','The quick brown fox'],
        '!^http(s)?://\w*!i' => ['https://zend.com','http://sandbox','ftp://whatever.com'],
];

foreach ($data as $pattern => $value) {
        foreach ($value as $item) {
                echo "Testing $item\n";
                echo (preg_match($pattern, $item)) ? 'MATCH' : 'NO MATCH';
                echo PHP_EOL;
        }
}

PHP 5 to PHP 7 code converter using preg_replace_callback_array()

https://github.com/dbierer/php7cookbook/blob/master/source/chapter01/chap_01_php5_to_php7_code_converter.php#L3
https://github.com/dbierer/php7cookbook/blob/master/source/Application/Parse/Convert.php

Q & A

Q: Can you use the keyword "new" in property or const definition in 8.1?
A: Yes, but with restrictions.
A: Full discussion: https://wiki.php.net/rfc/new_in_initializers
Q: Locate original article on why __unserialize() was introduced
A: https://wiki.php.net/rfc/custom_object_serialization
Q: URL for database survey website
A: https://db-engines.com/en/ranking
Q: Find example of multi-use PDO prepare/execute for Geonames data insert
A: Will be published here by next week (not published yet):
- https://github.com/dbierer/classic_php_examples/blob/master/db/db_pdo_multi_prepare_execute_create_geonames_table.php
Q: Do you have a practical example of __call()
A: Yes: using the "plugin" architecture
A: https://github.com/laminas/laminas-mvc/blob/master/src/Controller/AbstractController.php
- Look for public function __call($method, $params)
- Also, look for any references to PluginManager
Q: What major features are in PHP 8.2?
A: See: https://wiki.php.net/rfc#php_82
A: PHP Roadmap: https://wiki.php.net/rfc
Q: Why is this not working?
A: (1) Base::__construct() is marked private and doesn't get inherited
A: (2) Once the first call to Base::getInstance() is called, an instance is created of type Base

<?php
interface TestInterface
{
	public function test();
}

class Base implements TestInterface
{
	protected static $instance;
	// this doesn't get inherited
	private function __construct() {}
	public function test()
	{
		return 'TEST';
	}
	public static function getInstance() : static
	{
		if (empty(static::$instance))
			static::$instance = new static();
		return static::$instance;
	}
}

// problem #1: __construct() doesn't get inherited
class A extends Base {}

class B extends Base {}


$base = Base::getInstance();
// this doesn't work because Base::__construct() is marked private
$a    = (new A)::getInstance();
// this doesn't work because $instance is already created from line 30
$b    = B::getInstance();
var_dump($base, $a, $b);

Errata

http://localhost:8882/#/3/125
- Not "enumeraction"
http://localhost:8882/#/6/4
- This line should be removed:

$content = ob_get_contents();

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php-ii-nov-2022.md

php-ii-nov-2022.md

PHP II - Nov 2022

TODO

Homework

VM Notes

Resources

Class Notes

Namespaces

Magic Methods

Domain Model

PDO

Output Buffering

Email

Regex

Composer

Web Services

Output Control

Regex

Q & A

Errata

Files

php-ii-nov-2022.md

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History

php-ii-nov-2022.md

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PHP II - Nov 2022

TODO

Homework

VM Notes

Resources

Class Notes

Namespaces

Magic Methods

Domain Model

PDO

Output Buffering

Email

Regex

Composer

Web Services

Output Control

Regex

Q & A

Errata