The PHP Standard Recommendation (PSR) is a PHP specification published by the PHP Framework Interop Group. The PHP-FIG is formed by several PHP frameworks founders. Each PSR is suggested by members and voted according to an established protocol to act consistently and in line with their agreed upon processes. All the Accepted, Draft, Rejected, Abondoned and Deprecated PSR submissions can be found on following URL: https://www.php-fig.org/psr/

1. PHP Standards
Recommendations
(PSR)
Akshay Khale
(Sr. Software Engineer)

2. – Martin Fowler
“Any fool can write code that a computer can
understand. Good programmers write code that
humans can understand.”

3. PSR-1: Basic Coding
Standards.
• MUST use only <?php and <?= tags.
• MUST use only UTF-8 Encoding.
• SHOULD either declare symbols or cause side-effects.
• Class names MUST be declared in CamelCase or
StudlyCaps.
• constants MUST be declared in all UPPER_SNAKE_CASE.
• Method names MUST be declared in camelCase.

4. Quiz Time: What is wrong with
following code snippets?

5. PSR-2: Coding Style Guide
• 4 Space indenting (No Tabs).
• Soft Line limit 120 Characters.
• Blank space after namespace declaration before use.
• Closing Brace “}” always on a separate line.
• Opening Brace “{” Same line (with a space before) for control statements
and next line for Classes and functions.
• Space before open parentheses “(” for control statements and not for
functions.
• Visibility mode is must for all properties and methods. abstract and final
before visibility and static after the visibility.

6. Quiz Time: What is wrong with
following code snippets?

7. PSR-3: Logger Interface
• Only allowed Log levels: debug, info, notice, warning, error,
critical, alert, emergency.
• MUST implement PsrLogLoggerInterface.
• MUST throw PsrLogInvalidArgumentException exception
on invalid log level.
• public function log($level, $message, array $context =
array());
• One can consider extending PsrLogAbstractLogger class
which implements LoggerInterface.

8. Sample Logger Class:
https://github.com/akshaykhale1992/luxio-logger

9. PSR-4: Autoloader
• Namespace: <vendor_namespace>/
<package_namespace>[/<subnamespace>/]/
<class_name>.
• Folder structure should also follow the namespace
pattern.

10. PSR-6: Caching Interface
• MUST implement PsrCacheCacheItemPoolInterface and
PsrCacheCacheItemInterface.
• Concepts: Pool, Items, Key, Data, TTL, Hit, Miss.
• Should not throw any Exception.

11. PSR-7: HTTP message
interfaces
• Request Structure
• Response Structure
• Interfaces: PsrHttpMessageRequestInterface and
PsrHttpMessageResponseInterface.

12. PSR-11: Container interface
• MUST implement PsrContainerContainerInterface.
• MUST throw PsrContainerNotFoundExceptionInterface
exception if object not found.
• Directly thrown exceptions must implement
PsrContainerContainerExceptionInterface interface.

13. Standards that most of the
developers follow.
• If a file defines a Class then it should not have any other declarations though PSR
allows.
• Files with functions should have only function definitions.
• Files with class / functions definitions should not have a closing PHP Tag (?>) and
should have an empty line before EOF.
• Helper files must have function_exists check.
• Code MUST be correctly formatted based on the PSR rules. (editor plugins can be used
for the same).
• Arrays properties should be on separate lines.
• All declarations MUST have dock-blocks.
• Branch names MUST follow bitbucket Branching Model.

14. Cont.
• Use static instead of self for calling static class members.
• Use die instead of exit.
• Make use of destructors for unsetting objects and/or closing opened files.
• There should not be any commented code or commented die / dd statements.
• SHOULD avoid else block in case of if statements.
• Recommended to make use of exceptions in-case of invalid details which should be
handles at calling end.
• Try to use User defined constants instead of System constants. A constants class should
be created for defining all the constants that are being used in the project. E.g. instead of
using “/” for directory paths use DIRECTORY_SEPARATOR or instead of using supplier_id
== 7 check use supplier_id == Constants::DELHIVERY_SUPPLIER_ID.
• PHP Unit Test cases are compulsory.

15. Samples:

16. Thank you!!!