README

An interface package for wrapping different implementations of validation and sanitizing systems.

Package Scope

This package defines contracts. It ships exactly one concrete class, FilterResult, and that is a deliberate, bounded exception rather than a precedent.

The boundary is set by Aura's core principles. The base rule is that library packages are "decoupled, not only from any particular framework, but also from each other". Aura 3.x relaxes it only so far:

Under the relaxed rule, an Aura library may depend on an interface package, but not on an implementation.

That exception exists to preserve the decoupling, not to create a back door around it. So the test for shipping a concrete class here is does it carry behavior? A tuple carries none. A data structure with algorithms in it is an implementation, and libraries may not depend on one — no matter which package it is published from.

FilterResult passes. FilterInterface::apply() is declared to return a FilterResultInterface, so every implementation must return something, and that something is three readonly properties behind three accessors, with no branching and nothing to decide. Shipping it prescribes nothing about how anyone filters; it only names the shape of a value the interface already requires.

FailureCollection does not pass, and this is worth stating plainly because the two implementations in aura/filter and aura/input are very nearly identical — near enough that sharing them looks like obvious cleanup. It is not. Such a class holds real logic: dot-notation path splitting, nested-message construction, storage decisions. getNestedMessages() does not describe a shape, it decides one. Publishing that here would make both packages depend on a shared implementation of failure storage, coupling them to each other's semantics through this package — precisely the coupling the base rule exists to prevent. It would also nudge every third-party implementation toward the same class, which is how an interface package quietly becomes the framework that 3.x set out not to provide.

Concrete Failure classes stay with the implementing packages for the weaker but sufficient reason that nothing forces them here: implementations mint their own failures and return them behind FailureInterface.

Note also that FilterResult is not final. Its immutability comes from readonly properties, and callers wanting different behavior should implement FilterResultInterface directly.

Installation and Autoloading

This package is installable and PSR-4 autoloadable via Composer as aura/filter-interface.

Alternatively, download a release, or clone this repository, then map the Aura\Filter_Interface\ namespace to the package src/ directory.

Dependencies

This package requires PHP 8.4 or later, and has no other dependencies. We recommend using the latest available version of PHP as a matter of principle.

Quality

This project adheres to Semantic Versioning.

This package attempts to comply with PSR-1, PSR-2, and PSR-4. If you notice compliance oversights, please send a patch via pull request.

Community

To ask questions, provide feedback, or otherwise communicate with other Aura users, please join our Google Group, follow @auraphp, or chat with us on Freenode in the #auraphp channel.

Documentation

This package is fully documented here.