Symfony Form Data Mapper helper

AbstractTypedDataMapper.php

<?php

declare(strict_types=1);

namespace App\Form\DataMapper;

use Symfony\Component\Form\DataMapperInterface;
use Symfony\Component\Form\Exception\UnexpectedTypeException;
use Symfony\Component\Form\FormInterface;

/**
 * @template TObject of object
 */
abstract class AbstractTypedDataMapper implements DataMapperInterface
{
    /**
     * {@inheritDoc}
     * @psalm-suppress MoreSpecificImplementedParamType
     */
    public function mapDataToForms(mixed $viewData, \Traversable $forms): void
    {
        if (null === $viewData) {
            return;
        }

        $expectedType = $this->getType();

        if (false === ($viewData instanceof $expectedType)) {
            throw new UnexpectedTypeException($viewData, $this->getType());
        }

        /**
         * @var array<string, FormInterface> $form
         * @psalm-suppress InvalidArgument
         */
        $form = \iterator_to_array($forms);

        if ($this->isNew($viewData)) {
            $this->populateEmptyFormWhenCreating($form);
        } else {
            $this->populateFormWhenUpdating($viewData, $form);
        }
    }

    /**
     * {@inheritDoc}
     * @psalm-suppress MoreSpecificImplementedParamType
     */
    public function mapFormsToData(\Traversable $forms, mixed &$viewData): void
    {
        $expectedType = $this->getType();

        if (false === ($viewData instanceof $expectedType)) {
            throw new UnexpectedTypeException($viewData, $this->getType());
        }

        /**
         * @var array<string, FormInterface> $form
         * @psalm-suppress InvalidArgument
         */
        $form = \iterator_to_array($forms);

        if (false === $this->isNew($viewData)) {
            $this->update($viewData, $form);
            return;
        }

        if (null === ($new = $this->createNew($form))) {
            return;
        }

        $viewData = $new;
    }

    /** @param TObject $viewData */
    protected function isNew(object $viewData): bool
    {
        if (\method_exists($viewData, 'getId')) {
            /** @psalm-suppress MixedMethodCall */
            return \in_array($viewData->getId(), [null, 0], true);
        }

        throw new \LogicException(\sprintf(
            'Could not determine whether object is new. Overload method "%s" and fill with custom logic',
            __METHOD__,
        ));
    }

    /** @return class-string<TObject> */
    abstract protected function getType(): string;

    /**
     * @param array<string, FormInterface> $form
     */
    abstract protected function populateEmptyFormWhenCreating(array $form): void;

    /**
     * @param TObject $viewData
     * @param array<string, FormInterface> $form
     */
    abstract protected function populateFormWhenUpdating(object $viewData, array $form): void;

    /**
     * @param array<string, FormInterface> $form
     * @return TObject|null
     */
    abstract protected function createNew(array $form): ?object;

    /**
     * @param TObject $viewData
     * @param array<string, FormInterface> $form
     */
    abstract protected function update(object $viewData, array $form): void;
}

//
// Example usage
//

/** @template-extends AbstractTypedDataMapper<Article> */
final class NodeFormMapper extends AbstractTypedDataMapper
{
    /** @inheritDoc */
    protected function getType(): string
    {
        return Article::class;
    }

    /** @inheritDoc */
    protected function populateEmptyFormWhenCreating(array $form): void
    {
        $form['title']->setData('');
        $form['content']->setData('');
    }

    /** @inheritDoc */
    protected function populateFormWhenUpdating(object $viewData, array $form): void
    {
        $form['title']->setData($viewData->getTitle());
        $form['content']->setData($viewData->getContent());
    }

    /** @inheritDoc */
    protected function createNew(array $form): ?object
    {
        /** @var string $title */
        $title = $form['title']->getData();

        /** @var string $content */
        $content = $form['content']->getData();

        $article = new Article($this->userContext()->getUser());

        try {
            $article->changeTitle($title);
        } catch (AssertionFailedException $exception) {
            $form['title']->addError(new FormError($exception->getMessage()));

            return null;
        }

        try {
            $article->changeContent($content);
        } catch (AssertionFailedException $exception) {
            $form['content']->addError(new FormError($exception->getMessage()));

            return null;
        }

        return $article;
    }

    /** @inheritDoc */
    protected function update(object $viewData, array $form): void
    {
        /** @var string $title */
        $title = $form['title']->getData();

        /** @var string $content */
        $content = $form['content']->getData();

        $viewData->changeTitle($title);
        $viewData->changeContent($content);
    }
}