class ImageStyleFlushForm

class ImageStyleFlushForm extends EntityConfirmFormBase {
    
    /**
     * {@inheritdoc}
     */
    public function getQuestion() {
        return $this->t('Are you sure you want to apply the updated %name image effect to all images?', [
            '%name' => $this->entity
                ->label(),
        ]);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDescription() {
        return $this->t('This operation does not change the original images but the copies created for this style will be recreated.');
    }
    
    /**
     * {@inheritdoc}
     */
    public function getConfirmText() {
        return $this->t('Flush');
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCancelUrl() {
        return $this->entity
            ->toUrl('collection');
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
        $this->entity
            ->flush();
        $this->messenger()
            ->addStatus($this->t('The image style %name has been flushed.', [
            '%name' => $this->entity
                ->label(),
        ]));
        $form_state->setRedirectUrl($this->getCancelUrl());
    }

}