webservco / constant-value-class

v1.5.1 2024-06-22 20:13 UTC

Requires

• php: ^7.4||^8.1

Requires (Dev)

• pds/skeleton: ^1
• phan/phan: ^5
• php-parallel-lint/php-console-highlighter: ^1
• php-parallel-lint/php-parallel-lint: ^1
• phpcompatibility/php-compatibility: @dev
• phpmd/phpmd: ^2
• phpstan/phpstan: ^1
• phpstan/phpstan-strict-rules: ^1
• phpunit/phpunit: ^9
• slevomat/coding-standard: ^8
• squizlabs/php_codesniffer: ^3
• vimeo/psalm: ^4

Suggests

• phpdocumentor/phpdocumentor: phpDocumentor v3 (global installation)

MIT

• Radu Maier

• webservco

Published on Packagist.org on 2024-06-22 20:14 UTC

README

A PHP library.

Type-checked constants for PHP 7: a class whose only instances are its own constant values, so it can stand in for an enum.

Note: PHP 8.1 and later have native enumerations. Prefer those in new code.

• Requires: PHP 7.4 or 8.1+
• Based on: "Expressive, type-checked constants for PHP"

Installation

composer require webservco/constant-value-class

Usage

Implement the interface, use the trait, and add a static method for each constant.

use WebServCo\ConstantValueClass\ConstantValueClassInterface;
use WebServCo\ConstantValueClass\ConstantValueClassTrait;

final class ShipmentType implements ConstantValueClassInterface
{
    use ConstantValueClassTrait;

    private const EXPORT = 1;
    private const IMPORT = 5;

    public static function export(): self
    {
        return self::constant(self::EXPORT);
    }

    public static function import(): self
    {
        return self::constant(self::IMPORT);
    }
}

Type-hint against the class, then pass a named instance or build one from a raw value.

function send(ShipmentType $type): void
{
}

send(ShipmentType::import());
// From user input. Throws InvalidArgumentException for an unknown value.
send(ShipmentType::fromValue(5));

// 5 (int)
ShipmentType::import()->value();
// "5"
(string) ShipmentType::import();
// true
ShipmentType::fromValue(5) === ShipmentType::import();

Contracts

Interface	Implementation	Purpose
ConstantValueClassInterface	ConstantValueClassTrait	value(), fromValue() and __toString() for the implementing class.

Namespaces are relative to WebServCo\ConstantValueClass\.

Notes

Only int and string constants count as values. fromValue() uses a strict comparison, so fromValue('5') throws when the constant is 5.

Each value has only one instance per script run. That's why === works. An instance restored from a serialized session is a different object, though, so compare value() there.

Development

# Lint, code style, static analysis (PHPStan, Phan, PHPMD, Psalm) and unit tests.
composer all
# Run unit tests.
composer test:d

License

MIT