Json serialization trait

JsonSerializableTrait.php

<?php

declare(strict_types=1);

use RuntimeException;
use ReflectionClass;
use ReflectionProperty;

/**
 * Model to json serrializaton helper
 */
trait JsonSerializableTrait
{

    /**
     * @return array|null
     */
    public function fields(): ?array
    {
        return null;
    }

    /**
     * @see \JsonSerializable
     */
    public function jsonSerialize(): array
    {
        $fields = $this->fields();
        $props = [];
        if ($fields !== null) {
            foreach ($fields as $attribute => $callable) {
                if (!is_string($attribute)) {
                    if (!$this->canGetProperty($callable)) {
                        throw new RuntimeException("Property $callable is undefined");
                    }
                    $props[$callable] = $this->$callable;
                    continue;
                }
                if (is_string($callable)) {
                    if (!$this->canGetProperty($callable)) {
                        throw new RuntimeException("Property $callable is undefined");
                    }
                    $props[$attribute] = $this->$callable;
                } else if (is_callable($callable)) {
                    $props[$attribute] = ($callable)();
                } else {
                    throw new RuntimeException("Property $callable is undefined");
                }
            }
        } else {
            $reflect = new ReflectionClass($this);
            $properties = $reflect->getProperties(ReflectionProperty::IS_PUBLIC);
            foreach ($properties as $property) {
                $props[$property->getName()] = $this->{$property->getName()};
            }
        }
        return $props;
    }

    /**
     * @param string $property
     * @return bool
     */
    public function canGetProperty(string $property): bool
    {
        if (isset($this->$property)) {
            return true;
        }

        return false;
    }
}

Model.php

<?php

declare(strict_types=1);

class Model
{
    use JsonSerializableTrait;
    
    const STATUSES = ['pass', 'warn', 'fail'];
    
    public string $title = "Default title";
    
    public string $shortDescription = "Some description";
    
    private int $status = 0;
    
    public function fields(): array
    {
        return [
            'title',
            'short_description' => 'shortDescription',
            'status' => function () {
                return self::STATUSES[$this->status];
            },
        ];
    }
}

result.json

{
  "title": "Default title",
  "short_description": "Some description",
  "status": "pass"
}