09_model_lifecycle2.php

<?php
declare(strict_types=1);

/**
 * Example 09 — Real-World Pattern: Domain Model with Event-Driven Lifecycle
 *
 * This example shows the intended usage pattern: a domain model whose
 * getters and setters go through event chains, allowing external code to
 * hook into every property change and read.
 *
 * This is the same pattern used in production (e.g. finance library) where
 * traits like StatusTrait, CostTrait, NamedTrait wrap every property
 * access in EventExecutor::run() + CommonEvents helpers.
 */

require __DIR__ . '/../vendor/autoload.php';

use Minfra\Chains\EventExecutor;
use Minfra\Chains\EventInterface;
use Minfra\Chains\CallbackTrait;
use Minfra\Chains\CommonEvents;
use Minfra\Chains\Result;
use Minfra\Chains\BasicResultInterface;
use Minfra\Chains\Meta;

class Product2 implements \Minfra\Chains\CallbackInterface {
    use CallbackTrait;

    protected string $price;
    protected int $type;

    const EVENT_ON_SET_TYPE = "set_type";
    const EVENT_ON_GET_TYPE = "get_type";

    const EVENT_ON_SET_PRICE = "set_price";
    const EVENT_ON_GET_PRICE = "get_price";

    function setType(int $type): BasicResultInterface {
        return EventExecutor::run($this, static::EVENT_ON_SET_TYPE, ...CommonEvents::setter(['type' => $type]));
    }

    function getType(): Result {
        $type = $this->type ?? null;
        return EventExecutor::run($this, static::EVENT_ON_GET_TYPE, ...CommonEvents::getter('type', $type));
    }

    function setPrice(string $price): BasicResultInterface {
        list($meta, $setter_cb) = CommonEvents::setter(['price' => $price]);

        return EventExecutor::run($this, static::EVENT_ON_SET_PRICE, $meta, [
            EventInterface::ON_BEFORE => [[$this, "_ensure_correct_price"], [$this, "_ensure_correct_decimal_price"]],
            EventInterface::ON_MID    => [$setter_cb],
            EventInterface::ON_OK     => fn(Meta $meta) => error_log("price is: {$meta->price}"),
        ]);  // CommonEvents provides wheels for working with properties
    }

    function getPrice(): Result {
        $price = $this->price ?? null;
        return EventExecutor::run($this, static::EVENT_ON_GET_PRICE, ...CommonEvents::getter('price', $price));
    }

    protected function _ensure_correct_price(Meta $meta): BasicResultInterface|true {
        if (!is_numeric($meta->price)) {
            return Result::false("invalid_price", $meta);  // Or simply: Result::false("invalid_price");
        }

        return true;  // when returning true. it automatically passes the $meta to the next phase.
    }

    protected function _ensure_correct_decimal_price(Meta $meta): BasicResultInterface|true {
        // $meta->price = bcmath($meta->price, '1', 2);
        return true;
    }
}

$product = new Product2();
$product->appendCallback((new \Minfra\Chains\CallbackEntry($product::EVENT_ON_SET_PRICE, \Minfra\Chains\CallbackEntryInterface::EVENT_PRE))->setCallback(function(Meta $meta) {
    /** @var Product2 $product */
    $product = $meta->this;
    if ($product->getType()->data()->type === 222) {
        if ($meta->price > "20") {
            return Result::false("invalid_product_222_issue", ['reason' => 'cannot be higher than 20']);
            // or if you prefer using meta: return Result::false("invalid_product_222_issue", Meta::make(reason: 'cannot be higher than 20'));
        }
    }

    return true;
}));
$product->appendCallback((new \Minfra\Chains\CallbackEntry($product::EVENT_ON_SET_PRICE, \Minfra\Chains\CallbackEntryInterface::EVENT_POST))->setCallback(function(Meta $meta) {
    var_dump("I got the price: {$meta->price}. let's do something with it.");
}));


$product->setType(222);
var_dump($product->setPrice('21')->ok()); // false
var_dump($product->setPrice('19')->ok()); // true