Extending value objects via enrichment

Enrichment traits

Value objects can be enriched with PHP traits.

Create a folder in the root of your project called enrichments. You can configure the location of your enrichments folder using a configuration file.

Place PHP traits within your enrichments folder. Then use PHP 8 attributes to link them to your value objects. For example, if you had a value object called MyValueObject you can enrich it like this:

<?php

declare(strict_types=1);

namespace MyProject\Enrichments;

use ChrisHarrison\VoGenerator\Attributes\Enriches;

#[Enriches('MyValueObject')]
trait MyValueObjectEnrichment
{
    public function full(): string
    {
        return "{$this->root()->toNative()}/{$this->name()->toNative()}";
    }
}

When you regenerate your value objects (vendor/bin/vogen), the full method provided by the trait will be available in your MyValueObject.

Hooks

Value objects can define hooks on their methods. For example, the value objects that ship with the package all have hooks in their __construct methods.

To hook into a method in a value object, add a method to an enrichment trait that follows the format:

public function hook<<methodToHook>>(callable $inner, ...$values);

Note that underscores in method names (e.g. __construct) are ignored.

• $inner is a callable that represents the original method.
• ...$values are all the original values that are passed to the method.

For example, to hook into the construct method of a value object of type string:

public function hookConstruct(callable $inner, string $value)
{
  // Do something before construct
  $inner($value);
  // Do something after construct
}