src/CoreBundle/EventListener/DcGeneral/MetaModel/CreateVariantButtonListener.php
public function createButton(GetOperationButtonEvent $event)
    {
        if ('createvariant' !== $event->getCommand()->getName()) {
            return;
        }
        /** @var Model $model */
        $model     = $event->getModel();
        $metamodel = $model->getItem()->getMetaModel();

        if (!$metamodel->hasVariants() || $model->getProperty('varbase') === '0') {
            $event->setHtml('');
        }
    }
public function createButton(GetOperationButtonEvent $event)
    {
        if ('createvariant' !== $event->getCommand()->getName()) {
            return;
        }
        /** @var Model $model */
        $model     = $event->getModel();
        $metamodel = $model->getItem()->getMetaModel();

        if (!$metamodel->hasVariants() || $model->getProperty('varbase') === '0') {
            $event->setHtml('');
        }
    }
Check if we have to add the "Create variant" button.

@param GetOperationButtonEvent $event The event.

@return void