Короткий код заполнения формы в админке модуля

$array_data = array(
			'payment_enot_merchant_id',
			'payment_enot_secret_word',
			'payment_enot_secret_word2',
			'payment_enot_title',
			'payment_enot_order_status_id',
			'payment_enot_status',
			'payment_enot_sort_order',
			'load_method_list',
		);

		foreach ($array_data as $v) {
			$data[$v] = (isset($this->request->post[$v])) ? $this->request->post[$v] : $this->config->get($v);
		}

Для кучи. Сохранение post формы в сеттингах Opencart

		if (($this->request->server['REQUEST_METHOD'] == 'POST') && $this->validate()) {
			$this->model_setting_setting->editSetting('payment_enot', $this->request->post);
			$this->session->data['success'] = $this->language->get('text_success');
			$this->response->redirect($this->url->link('marketplace/extension', 'user_token=' . $this->session->data['user_token'] . '&type=payment', true));
		}

Реализация валидации

	private function validate() {
		if (!$this->user->hasPermission('modify', 'extension/payment/enot')) {
			$this->error['warning'] = $this->language->get('error_permission');
		}

		if (!$this->request->post['payment_enot_merchant_id']) {
			$this->error['merchant_id'] = $this->language->get('error_merchant_id');
		}
		if (!$this->request->post['payment_enot_secret_word']) {
			$this->error['secret_word'] = $this->language->get('error_secret_word');
		}
		if (!$this->request->post['payment_enot_secret_word2']) {
			$this->error['secret_word2'] = $this->language->get('error_secret_word2');
		}
		return (!$this->error) ? true : false;
	}