PHP Contracts

A curated list of mature interfaces to build components on.

Good interfaces behave like a contract, a promise, a documentation. They don't have an opinion about the internals of a concrete implementation. So you can use interfaces while building huge applications to decouple different parts and hopefully gain a much better level of reusability, interchangeability and maintainability.

Rules:

1. A project must only consist of interfaces that have the character of a contract.
2. The project must ship a good documentation.
3. The project could include one or more implementations.
4. The project's documentation must use english language.
5. The interface(s) must comply with PSR-1.
6. The interface(s) should comply with PSR-12.
7. There should exist implementations that show the practical benefit of the offered interface(s).
8. The project should be available through Packagist.

Stable

(Click on an item to get a list of available implementations)

Project	Latest	Implementations
Logger Interface (PSR-03)		Compatible Packages
Simple Cache (PSR-16)		Compatible Packages
Caching Interface (PSR-06)		Compatible Packages
Container Interface (PSR-11)		Compatible Packages
HTTP Message Interface (PSR-07)		Compatible Packages
HTTP-Client (PSR-18)		Compatible Packages
HTTP Server-Handler (PSR-15)		Compatible Packages
HTTP Factories (PSR-17)		Compatible Packages
Hypermedia Links (PSR-13)		Compatible Packages
Event Dispatcher (PSR-14)		Compatible Packages
Clock (PSR-20)		Compatible Packages

Drafts

Project	Packagist	Status
adammbalogh/key-value-store		Draft
rkr/php-ioc-contract		Draft

Noteworthy projects

• illuminate/contracts – Subtree split of the Illuminate Contracts component (see laravel/framework)
• HttpKernelInterface – HttpKernelInterface handles a Request to convert it to a Response.
• FlySystem – Flysystem is a filesystem abstraction which allows you to easily swap out a local filesystem for a remote one. Reducing technical debt and chance of vendor lock-in.

Wishlist

• 3rd Party APIs (Amazon, Google etc)
• Authentication
• (More) Communication (Email, Sms, Notifications etc.)
• (More) Date-, Time-, Interval-, Calendar-Manipulation
• (More) Dependency-Injection-Container interfaces with more methods (make, call etc.)
• E-Commerce (Payment, common order structures, common address structures etc.)
• FileSystem-Abstraction
• Filetype-Abstraction
• Filtering
• Image-Manipulation
• Key-Value-Stores
• ORM / Data-Handling / Data-Structures
• Queues (like RabbitMQ / Gearman)
• Search-Server-Interfaces (querying, Responses, Facettes etc)
• Template-Engines
• URL-Manipulation
• Validation