Constant validation by value

Model.php

<?php

namespace Application\Model;

class Model
{
    /**
     * @var string
     */
    const TYPE_PDF = 'pdf';
    /**
     * @var string
     */
    const TYPE_EMAIL_MARKETING = 'mkt';
    /**
     * @var string
     */
    const TYPE_BUSINESS_CARD = 'business_card';
    /**
     * @var string
     */
    const TYPE_TIMBER_PAPER = 'timbred_paper';
    /**
     * @var string
     */
    const TYPE_LANDING_PAGE = 'landing_page';

    /**
     * Inform if given type is a valid constant
     * @param string $type
     * @return bool
     */
    public static function isValidType($type) {
        $reflectedClass = new \ReflectionClass(self::class);
        $constants = $reflectedClass->getConstants();

        foreach ($constants as $constName => $constValue) {
            if (substr($constName, 0, 4) === 'TYPE' && $constValue === $type) {
                return true;
            }
        }
        return false;
    }
}