FluidTYPO3\Vhs\ViewHelpers\Condition\Variable\IssetViewHelper::renderStatic PHP Метод

    public static function renderStatic(array $arguments, \Closure $renderChildrenClosure, RenderingContextInterface $renderingContext)
    {
        $hasEvaluated = true;
        if (true === $renderingContext->getTemplateVariableContainer()->exists($arguments['name'])) {
            $result = static::renderStaticThenChild($arguments, $hasEvaluated);
            if ($hasEvaluated) {
                return $result;
            }
            return $renderChildrenClosure();
        } else {
            $result = static::renderStaticElseChild($arguments, $hasEvaluated);
            if ($hasEvaluated) {
                return $result;
            }
        }
        return '';
    }