New from Chevere is the Parameter package. This software provides a library around parameter-argument, with extra rules which can be used for both validation and to expose I/O schemas.

The package source is available at chevere/parameter.

What it does?

Parameter enables to create dynamic parameters of any type with extra rules.

For example, an integer of minimum value 10:

use function Chevere\Parameter\int;

$int = int(min: 10);
$int($var); // exception if $var < 10

In function or method parameters you can use attributes to define validation rules for parameters and return value.

use Chevere\Parameter\Attributes\FloatAttr;
use Chevere\Parameter\Attributes\IntAttr;
use Chevere\Parameter\Attributes\ReturnAttr;
use function Chevere\Parameter\returnAttr;
use function Chevere\Parameter\validated;

#[ReturnAttr(
    new FloatAttr(min: 0, max: 2400)
)]
function wageWeekWA(
    #[IntAttr(min: 1628)]
    int $cents,
    #[FloatAttr(min: 0, max: 40)]
    float $hours
) {
    return $cents*$hours/100;
}
validated('wageWeekWA', $cents, $hours);

Validation can be triggered using validated (example above), inline and/or delegated to a caller wrapper. Parameter provides helpers to access rules for both parameters and return value to ease wiring process.

Rules defined by each parameter provide a human-readable schema which allows to expose the validation criteria.

Supported types

Parameter supports built-in types including scalar (bool, int, string, float), null, array, object, union composite type and both mixed and iterable type alias.

Usage

Parameter offers introspection via helpers and schema definition which enables to understand and export parameter rules. The validation rules defined using this package can be read and re-used for multiple purposes.

The Action package wraps Parameter to offer a convention to work with. Action is the building block for Workflow and Http.

Parameter introspection is used at Router to generate path regex by reading attribute rules on Http Controller path parameters. Parameter schemas are used at Schwager which reads Http Controller attributes and expose that schema. Schwager HTML also uses parameter schemas.

I'm writing another Parameter-based package which generates parameters from a MySQL database schema. The concept is to describe MySQL tables using ArrayParameter, enabling to validate data retrieval and provide schema introspection for any set of columns.

Wrapping up

Parameter plays at low-level and is a flexible system which can be used to build anything on top of it. From simple wrappers up to full flagged conventions, it enables to build a solid foundation for your validation needs with a neat syntax backed on PHP's newest features introduced onwards PHP 8, like named arguments and attributes.

I'm looking forward to see what else I can built on top of it.