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PSRs

Why PSRs Matter for Dotkernel API

  • Vendor Lock-In Prevention: By following PSRs, you're not locked into Dotkernel API. Your code can be reused in other PSR-compliant frameworks.
  • Ecosystem Compatibility: Any library that follows PSRs can integrate with Dotkernel API without custom adapters.
  • Team Collaboration: Developers familiar with PSRs can immediately understand Dotkernel API's code structure.
  • Long-Term Maintenance: PSRs are stable standards maintained by the PHP community, ensuring longevity.
  • Code Quality: Following standards encourages best practices and makes code more maintainable.

PHP Standards Recommendations (PSRs)

Dotkernel API adheres to PHP Standards Recommendations (PSRs) established by the PHP-FIG (Framework Interoperability Group). These standards ensure code interoperability and allow Dotkernel API to work seamlessly with other PSR-compliant libraries.

Some PSRs are at the core of Dotkernel API's architecture, while others are installed as dependencies through third-party packages.

Core PSRs (Essential to Dotkernel API)

PSR-7: HTTP Message Interfaces

Repository: php-fig/http-message

Defines standardized interfaces for HTTP messages (requests and responses) and URIs.

Why it matters:

  • Dotkernel API uses PSR-7 for all HTTP communication.
  • Ensures requests and responses follow a universal standard.
  • Allows middleware and handlers to work with consistent interfaces.
  • Implemented via Laminas\Diactoros.

PSR-15: HTTP Server Request Handlers and Middleware

Repository: php-fig/http-server-handler and php-fig/http-server-middleware

Defines the interface for HTTP request handlers and middleware components that process PSR-7 HTTP messages.

Why it matters:

  • Dotkernel API's entire architecture is built on PSR-15.
  • All handlers implement RequestHandlerInterface.
  • Middleware pipeline processes requests in a chain.
  • Single-action handlers follow this pattern for clean separation of concerns.

PSR-11: Container Interface

Repository: php-fig/container

Defines the standard interface for dependency injection containers.

Why it matters:

  • Dotkernel API uses PSR-11 for managing service dependencies.
  • All services are registered in and retrieved from a container.
  • Enables loose coupling between components.
  • Implemented via Laminas\ServiceManager.

Supporting PSRs (Installed via Dependencies)

PSR-3: Logger Interface

Repository: php-fig/log

Provides a standard interface for logging libraries.

Usage: Error handling, debugging, audit trails Implemented in: dotkernel/dot-errorhandler

PSR-4: Autoloader

Repository: php-fig/log

Defines how PHP files are automatically loaded based on namespaces and file paths.

Usage: Automatic class loading without manual require statements Implemented in: Laminas\Loader

PSR-6: Caching Interface

Repository: php-fig/cache

Defines standard interfaces for caching systems to improve application performance.

Usage: Caching query results, configuration, templates Implemented in: dotkernel/dot-cache

Repository: php-fig/link

Describes how to represent hypermedia links independently of serialization format.

Usage: HAL (Hypertext Application Language) resource links Implemented in: mezzio/mezzio-hal

PSR-14: Event Dispatcher

Repository: php-fig/event-dispatcher

Mechanism for event-based extension and collaboration between components.

Usage: Triggering events on user actions, logging events, notifications Implemented in: Third-party packages as needed

PSR-17: HTTP Factories

Repository: php-fig/http-factory

Standard for factories that create PSR-7 compliant HTTP objects.

Usage: Creating requests, responses, and streams programmatically Implemented in: Laminas\Diactoros

PSR-18: HTTP Client

Repository: php-fig/http-client

Interface for sending HTTP requests and receiving HTTP responses.

Usage: Calling external APIs from your Dotkernel API Implemented in: symfony/http-client or similar packages

PSR-20: Clock

Repository: php-fig/clock

Provides a standard interface for reading the system clock.

Usage: Getting current time in a testable way Implemented in: Third-party packages as needed

PSR Implementation Hierarchy

┌───────────────────────────────────────────┐
│  PSR-7: HTTP Messages (Requests/Responses)│
└───────────────────────────────────────────┘
                    ▲
                    │
┌───────────────────────────────────────────┐
│ PSR-15: Handlers & Middleware             │
│ (Process PSR-7 messages)                  │
└───────────────────────────────────────────┘
                    ▲
                    │
┌───────────────────────────────────────────┐
│ PSR-11: Container                         │
│ (Manages services for handlers)           │
└───────────────────────────────────────────┘
                    ▲
                    │
┌───────────────────────────────────────────┐
│ PSR-4: Autoloader                         │
│ (Loads services automatically)            │
└───────────────────────────────────────────┘