value-objects

This package is part of the Apie library. The code is maintained in a monorepo, so PR's need to be sent to the monorepo

Documentation

This package is used in the entire Apie library to make value objects, but they can also be used outside Apie. Apie value objects implement ValueObjectInterface. ValueObjectInterface has 2 methods to implement. A static fromNative method to create a value object from a primitive value and a toNative method to convert a value object back to a primitive value.

Next to this interface we have two traits to make simple value objects for strings and enums.

Available classes/interfaces.

ValueObjectInterface

Interface to implement a value object for Apie. fromNative converts primitive to a value object and toNative converts a value object to a primitive.

ValueObjectCompareInterface

Interface to add a method to compare for equality where $object->toNative() === $object2->toNative() is false, but the objects value objects are the same.

StringTrait

Used to make value objects that are represented as a string. It implements all methods on ValueObjectInterface, but you require to make 2 methods to make it work: one for validating the input and one for sanitizing the input.

class StringTraitExample implements ValueObjectInterface
{
    use StringTrait;

    protected function validValue(string $value): bool
    {
        return !empty($value);
    }

    protected function sanitizeValue(string $value): string
    {
        return trim($value);
    }
}

And can be used like this:

$instance = new StringTraitExample(' example ');
$instance->toNative(); // returns 'example'
$instance2 = StringTraitExample::fromNative(' example '); // just calls the constructor.

StringTraitExample::fromNative(''); // throws exception

StringEnumTrait

Used to make Enum value objects.

Class example:

<?php
class StringEnumTraitExample implements ValueObjectInterface
{
    use StringEnumTrait;

    const A = 'OPTION_A';

    const B = 'OPTION_B';
}

And usage:

<?php
$instance = new StringEnumTraitExample('OPTION_A');
$instance->toNative(); //returns 'OPTION_A'

$instance2 = StringEnumTraitExample::fromNative('OPTION_A'); // same as constructor call

StringEnumTraitExample::fromNative('OPTION_C'); // throws exception