toArray + toString

functions.php

function convertToValue($name, $value)
{
    if (is_scalar($value) === true) {
        return $value;
    }
    if ($value === null) {
        return null;
    }

    $callable = [$value, 'toArray'];
    if (is_object($value) === true && is_callable($callable)) {
        return $callable();
    }
    if (is_object($value) === true && $value instanceof \DateTime) {
        return $value->format("Y-m-d\TH:i:s.uP");
    }

    if (is_array($value) === true) {
        $values = [];
        foreach ($value as $key => $entry) {
            $values[$key] = convertToValue($key, $entry);
        }

        return $values;
    }

    $message = "Unsupported type [" . gettype($value) . "] for toArray for property $name.";


    if (is_object($value) === true) {
        $message = "Unsupported type [" . gettype($value) . "] of class [" . get_class($value) . "] for toArray for property $name.";
    }

    throw new \Exception($message);
}

ToArray.php

<?php

trait ToArray
{
    public function toArray(): array
    {
        $data = [];
        foreach ($this as $name => $value) {
            if (strpos($name, '__') === 0) {
                //Skip
                continue;
            }

            $data[$name] = \convertToValue($name, $value);
        }

        return $data;
    }
}

ToString.php

<?php

trait ToString
{
    public function toArray(): array
    {
        $data = [];
        foreach ($this as $name => $value) {
            if (strpos($name, '__') === 0) {
                //Skip
                continue;
            }

            $data[$name] = \convertToValue($name, $value);
        }

        return $data;
    }

    public function toString()
    {
        return json_encode_safe($this->toArray());
    }
}