php-i-jan-2019.md

PHP-II Jan 2019

file:///D:/Repos/PHP-Fundamentals-II/Course_Materials/index.html#/4/18

Homework

• For Fri 25 Jan 2019
  • Lab: Validate an Email Address
  • Lab: preg_split: the trick is to add the PREG_SPLIT_NO_EMPTY flag :-)

$words = preg_split('/[^a-z]/i', $test, 0, PREG_SPLIT_NO_EMPTY);
var_dump($words);

• Lab: Composer with OrderApp
• For Wed 23 Jan 2019
  • Lab: Email
• For Mon 21 Jan 2019
  • Lab: Prepared Statements
  • Lab: Stored Procedure
  • Lab: Transaction
• For Fri 18 Jan 2019
  • Lab: SQL Statements
• For Wed 16 Jan 2019
  • Lab: Type Hinting
  • Lab: Build Custom Exception Class
  • Lab: Traits
• For Mon 14 Jan 2019
  • Lab: Magic Methods
  • Lab: Abstract Classes
  • Lab: Interfaces
• For Fri 11 Jan 2019
  • Lab: Create an Extensible Super Class
• For Wed 09 Jan 2019
  • Lab: Namespace
  • Lab: Create a Class

Q & A

• Q: Are there any issues creating a stored procedure from PHP code?
• A: YES! See: https://stackoverflow.com/questions/11300595/the-mysql-delimiter-keyword-isnt-working
  • Commands between the BEGIN and END block of the stored procedure creation code need to have the delimiter ;
  • The shell command DELIMITER which is used to change the delimiter, is not part of SQL!
  • PDO will not send an SQL statement which contains DELIMITER: you will get a fatal error
  • The best approach is to create the stored procedure as a database administrator (DBA)
  • Alternatively ... and this is an extremely poor substitute, you can issue a command shell command as follows:

shell_exec('mysql -u vagrant -pvagrant -e "DELIMITER #"');

* You can then use PDO to send the commands to build the stored procedure

$pdo->exec($stored);

* Afterwards, shell out to reset the delimiter:

shell_exec('mysql -u vagrant -vagrant -e "DELIMITER ;"');

• Q: What's a good quick way to learn about the Domain Model?

• A: See: https://www.infoq.com/minibooks/domain-driven-design-quickly

• Q: How long are traditional RDBMS databases going to be around?

• A: See: https://db-engines.com/en/ranking

• Q: major diffs between PSR-0 and PSR-4?

• A: PSR-4 has the following differences:

  • Main difference: less restrictive
  • got rid of the "requirement" that the top-level of a namespace must be the "vendor" name
  • underscores (_) have no special meaning
  • removed implementation details/requirements: leaves that up to you

• Q: do you have an example of plugin manager functionality using __call()?

• A: you could implement an array of callbacks which could be consulted by __call()

• Q: Is there documentation on the effort to make __construct() method failures consistent by throwing Exceptions?

• A: See: https://wiki.php.net/rfc/internal_constructor_behaviour

• Q: Is realPath() useful or recommended?

• A: Yes: example from OrderApp:

// function to ensure path exists
function reallyRealPath($path)
{
	if ($newPath = realpath($path)) {
		return $newPath;
	} else {
		throw new RuntimeException('Base path undefined');
	}
}

define('BASE', reallyRealPath(__DIR__ . '/../'));

CLASS NOTES

• Magic Methods: https://secure.php.net/manual/en/language.oop5.magic.php
• Really cool function: array_column() : also works for arrays of objects
• Abstract Class / Interface Examples:
  • https://github.com/zendframework/zend-diactoros
    • implementation of PSR-7 interfaces
  • https://github.com/dbierer/oauth.unlikelysource.org/blob/master/module/AuthOauth/src/AuthOauth/Adapter/BaseAdapter.php
    • NOTE: need to add authenticate() as an abstract method as it's mandatory
• Traits example: https://github.com/dbierer/classic_php_examples/blob/master/oop/trait_insteadof_example.php
• Other PDO examples: https://github.com/dbierer/classic_php_examples/tree/master/db
• Excellent 3rd party library for mail: PHP Mailer
  • https://github.com/PHPMailer/PHPMailer
  • SMTP example: https://github.com/PHPMailer/PHPMailer/blob/master/examples/smtp.phps
• Example of preg_replace_callback_array()
  • https://github.com/dbierer/php7cookbook/blob/master/source/Application/Parse/Convert.php
• How to get PDO Sqlite to work in VM:
  • sudo pecl install pdo_sqlite worked ... but the build failed: not the current version
  • https://stackoverflow.com/questions/22551971/failed-to-install-pdo
  • https://stackoverflow.com/questions/8822209/pdo-sqlite-driver-not-present-what-to-do
  • Installed with apt-get using exact version of PHP

sudo apt-get install php7.2-sqlite

ERRATA

• file:///D:/Repos/PHP-Fundamentals-II/Course_Materials/index.html#/2/12: last bullet: underscores: not true
• file:///D:/Repos/PHP-Fundamentals-II/Course_Materials/index.html#/2/46: not necessarily! i.e. look at Zend\Diactoros as an example; otherwise, just use an interface
• General: OOP section: Need to discuss __invoke()!!!
• file:///D:/Repos/PHP-Fundamentals-II/Course_Materials/index.html#/2/73: there are more than 2!!!
• OrderApp: dates are not formatted properly!
• file:///D:/Repos/PHP-Fundamentals-II/Course_Materials/index.html#/4/25: remove the execute() statement!
• file:///D:/Repos/PHP-Fundamentals-II/Course_Materials/index.html#/6/3: can also use [] as delimiters
• file:///D:/Repos/PHP-Fundamentals-II/Course_Materials/index.html#/6/14: need to mention imprecise quantifiers (*+?)