The PHP Standard Recommendation (PSR) is a PHP specification published by the PHP Framework Interop Group. It serves as a standardization of programming concepts in PHP, aiming to enable interoperability of components. Here, Biswajeet Parida of Valuebound has discussed "basic coding standards, coding style guide, Logger Interface, Autoloader, and others."

1. PHP
Standards
Recommendation
(PSR)
Biswajeet Parida

2. ● Introduction
● List
● Overview
Agenda

3. INTRO
● The PHP Standard Recommendation (PSR) is a PHP
specification published by the PHP Framework Interop Group.
● It serves the standardization of programming concepts in PHP.
● The aim is to enable interoperability of components.
● The PHP-FIG is formed by several PHP frameworks founders.

4. PSR-0 Autoloading Standard X
PSR-1 Basic Coding Standard A
PSR-2 Coding Style Guide A
PSR-3 Logger Interface A
PSR-4 Autoloading Standard A
PSR-5 PHPDoc Standard D
PSR-6 Caching Interface A
PSR-7 HTTP Message Interface A
PSR-8 Huggable Interface D
PSR-9 Security Advisories D
PSR-10 Security Reporting Process D
PSR-11 Container Interface A
PSR-12 Extended Coding Style Guide D
PSR-13 Hypermedia Links A
PSR-14 Event Manager D
PSR-15 HTTP Middlewares D
PSR-16 Simple Cache A
PSR-17 HTTP Factories D
X : Deprecated_
A : Accepted
D : Draft

5. PSR-1: Basic Coding Standard
● Files MUST use only <?php and <?= tags.
● Files MUST use only UTF-8 without BOM for PHP code.
● Files SHOULD either declare symbols or cause side-effects but
SHOULD NOT do both.
● Namespaces and classes MUST follow an “autoloading” PSR: [PSR-0,
PSR-4].
● Class names MUST be declared in StudlyCaps.
● Class constants MUST be declared in all uppercase with underscore
separators.
● Method names MUST be declared in camelCase.

7. PSR-2: Coding Style Guide
● Code MUST follow a “coding style guide” PSR [PSR-1].
● Code MUST use 4 spaces for indentation, not tabs.
● There MUST NOT be a hard limit on line length; the soft limit MUST be
120 characters; lines SHOULD be 80 characters or less.
● There MUST be one blank line after the namespace declaration, and
there MUST be one blank line after the block of use declarations.
● Opening braces for classes MUST go on the next line, and closing braces
MUST go on the next line after the body.

8. ● Opening braces for methods MUST go on the next line, and closing
braces MUST go on the next line after the body.
● Visibility MUST be declared on all properties and methods; abstract and
final MUST be declared before the visibility; static MUST be declared after
the visibility.
● Control structure keywords MUST have one space after them; method
and function calls MUST NOT.
● Opening braces for control structures MUST go on the same line, and
closing braces MUST go on the next line after the body.
● Opening parentheses for control structures MUST NOT have a space
after them, and closing parentheses for control structures MUST NOT
have a space before.

10. PSR-3: Logger Interface
● The main goal is to allow libraries to receive a PsrLogLoggerInterface
object and write logs to it in a simple and universal way.
● Frameworks and CMSs that have custom needs MAY extend the
interface for their own purpose, but SHOULD remain compatible with
this document.
● This ensures that the third-party libraries an application uses can write to
the centralized application logs.

11. PSR-4: Autoloader
● This PSR describes a specification for autoloading classes from file
paths.
● It is fully interoperable, and can be used in addition to any other
autoloading specification, including PSR-0.
● This PSR also describes where to place files that will be autoloaded
according to the specification.

12. PSR-0 vs PSR-4

13. PSR-6: Caching Interface
● Cache-aware libraries that can be integrated into existing
frameworks and systems without the need for custom
development.

14. PSR-7: HTTP message interfaces
● The first line of a request is the “request line”, and contains, in
order, the HTTP request method, the request target (usually
either an absolute URI or a path on the web server), and the
HTTP protocol version.
● This is followed by one or more HTTP headers, an empty line,
and the message body.

15. PSR-11: Container interface
● Standardize how frameworks and libraries make use of a
container to obtain objects and parameters.

16. PSR-13: Link definition interfaces
● Serialize a response with hypermedia links into one or more
wire formats independently of the process of deciding what
those links should be.

17. PSR-16: Common Interface for
Caching Libraries
● Libraries can drop their own caching implementations and easily rely on
the one given to them by the framework, or another dedicated cache
library.
● It is independent of PSR-6 but has been designed to make compatibility
with PSR-6 as straightforward as possible.

18. CONCLUSION
The PHP Standard Recommendation is about how you should write
your code so that it’ll be easily readable and usable by others. It
covers coding style, file organization, autoloading and standardizes
various interfaces.

19. THANKS!
QUESTIONS?