This document discusses PHP coding standards and interoperability. It describes the Framework Interoperability Group (FIG) which aims to improve interoperability between PHP frameworks. It then summarizes several PHP Standards Recommendations including PSR-0 and PSR-1 which define autoloading and basic coding standards, PSR-2 which defines coding style guidelines, and PSR-3 which defines a logger interface. It briefly mentions PSR-4 which extends the autoloading standard defined in PSR-0.

1. PSR: Standards in PHP

2. Story

3. PHP Standards for Writing Code
PEAR
Zend Framework
Drupal
Mine standards
… etc

4. Framework Interoperability Group - FIG
◦ Michael Dowling (AWS SDK for PHP)
◦ Larry Masters (CakePHP)
◦ Guilherme Blanco (Doctrine)
◦ Larry Garfield (Drupal)
◦ Filipe Guerra (SugarCRM)
◦ Bernhard Schussek (Symfony2)
◦ Alexander Makarov (Yii framework)
◦ Pádraic Brady (Zend Framework 2)

5. FIG’s Goal
The goal of the FIG is to create a dialogue
between project representatives, with the
aim of finding ways to work together
(interoperability)

6. PSR-0
AUTOLOADER STANDARD

7. Tools
require() in PHP 4
__autoload() in PHP 5
spl_autoload() and spl_autoload_register() in PHP 5.1.2

8. Requirements
◦ A fully-qualified namespace and class must have the following structure
<Vendor Name>(<Namespace>)*<Class Name>
◦ Each namespace must have a top-level namespace ("Vendor Name").
◦ Each namespace can have as many sub-namespaces as it wishes.
◦ Each namespace separator is converted to a DIRECTORY_SEPARATOR when loading from the file system.
◦ Each _ character in the CLASS NAME is converted to a DIRECTORY_SEPARATOR. The _ character has no
special meaning in the namespace.
◦ The fully-qualified namespace and class is suffixed with .php when loading from the file system.
◦ Alphabetic characters in vendor names, namespaces, and class names may be of any combination of
lower case and upper case.

9. Example
◦ DoctrineCommonIsolatedClassLoader =>
/path/to/project/lib/vendor/Doctrine/Common/IsolatedClassLoader.php
◦ SymfonyCoreRequest => /path/to/project/lib/vendor/Symfony/Core/Request.php
◦ ZendAcl => /path/to/project/lib/vendor/Zend/Acl.php
◦ ZendMailMessage => /path/to/project/lib/vendor/Zend/Mail/Message.php
◦ namespacepackageClass_Name =>
/path/to/project/lib/vendor/namespace/package/Class/Name.php
◦ namespacepackage_nameClass_Name =>
/path/to/project/lib/vendor/namespace/package_name/Class/Name.php

10. PSR-0: not for PHP core

11. PSR-1
BASIC CODING STANDARD

12. Basic Coding Standard
◦ Only use the <?php and <?= tags.
◦ Only use UTF-8 without BOM for PHP code.
◦ Separate side-effects (generate output, access a database etc.) and declarations.
◦ Enforce PSR-0.
◦ Class names must be defined in StudlyCaps.
◦ Class constants must be defined in upper case with underscore separators.
◦ Method names must be defined in camelCase.

13. PSR-2
CODING STYLE GUIDE

14. Coding Style Guide
https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-2-coding-style-guide.md

15. PSR-3
LOGGER INTERFACE

16. Logger Interface
◦ The LoggerInterface exposes eight methods to write logs to the eight RFC 5424 levels (debug, info,
notice, warning, error, critical, alert, emergency)
◦ A ninth method, log, accepts a log level as first argument. Calling this method with one of the log level
constants MUST have the same result as calling the level-specific method. Calling this method with a
level not defined by this specification MUST throw a PsrLogInvalidArgumentException if the
implementation does not know about the level. Users SHOULD NOT use a custom level without knowing
for sure the current implementation supports it.
https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-3-logger-interface.md

17. PSR-4 (PSR-0 extension)
IMPROVED AUTOLOADING

18. PSR-0 way

19. PSR-4 way

20. Criticism

21. Often hear
Too far
Subjective
Too specific
Not flexible

22. Become PHP-FIG community member
https://groups.google.com/forum/#!forum/php-fig

23. Thanks
• Email: ax.simanovich@gmail.com
• Skype: aliaksandr.simanovich
• Twitter: @simanjan
• Blog: simanovich.info