loadTypeExtensions example

/** * Initializes the type extensions. * * @throws UnexpectedTypeException if any registered type extension is not * an instance of FormTypeExtensionInterface */
    private function initTypeExtensions(): void
    {
        $this->typeExtensions = [];

        foreach ($this->loadTypeExtensions() as $extension) {
            if (!$extension instanceof FormTypeExtensionInterface) {
                throw new UnexpectedTypeException($extension, FormTypeExtensionInterface::class);
            }

            foreach ($extension::getExtendedTypes() as $extendedType) {
                $this->typeExtensions[$extendedType][] = $extension;
            }
        }
    }

    /** * Initializes the type guesser. * * @throws UnexpectedTypeException if the type guesser is not an instance of FormTypeGuesserInterface */