Set parameter checkoutoption to combinedpage for iDEAL 2.0 (fix #4).

src/Client.php

@@ -137,6 +137,13 @@ class Client {
 	 */
 	private $transaction_datetime;
 
+	/**
+	 * Checkout option.
+	 *
+	 * @var string
+	 */
+	private $checkout_option;
+
 	/**
 	 * Construct and initialize an EMS e-Commerce object
 	 */
@@ -359,6 +366,25 @@ public function set_transaction_datetime( DateTime $datetime ) {
 		$this->transaction_datetime = $datetime;
 	}
 
+	/**
+	 * Get checkout option.
+	 *
+	 * @return string
+	 */
+	public function get_checkout_option() {
+		return $this->checkout_option;
+	}
+
+	/**
+	 * Set checkout option.
+	 *
+	 * @param string $checkout_option Checkout option.
+	 * @return void
+	 */
+	public function set_checkout_option( $checkout_option ) {
+		$this->checkout_option = $checkout_option;
+	}
+
 	/**
 	 * Get data
 	 *
@@ -397,6 +423,7 @@ public function get_data() {
 			'transactionNotificationURL' => $this->get_notification_url(),
 			'idealIssuerID'              => $this->get_issuer_id(),
 			'ems_notify_payment_id'      => (string) $this->get_payment_id(),
+			'checkoutoption'             => (string) $this->get_checkout_option(),
 		];
 
 		// @link http://briancray.com/2009/04/25/remove-null-values-php-arrays/

src/Gateway.php

@@ -89,6 +89,17 @@ public function get_output_fields( Payment $payment ) {
 		$this->client->set_amount( $payment->get_total_amount() );
 		$this->client->set_issuer_id( $payment->get_meta( 'issuer' ) );
 
+		/**
+		 * We set the checkout option to `combinedpage` for iDEAL 2.0 transactions:
+		 *
+		 * "For a standard hosted payment page integration, you should use the checkout option `combinedpage`
+		 * that consolidates the payment method choice and the typical next step in a single page."
+		 *
+		 * @link https://www.emspay.com/nl/en/support/implementation-guide-ideal-ipg
+		 * @link https://github.com/pronamic/wp-pronamic-pay-ems-e-commerce/issues/4
+		 */
+		$this->client->set_checkout_option( 'combinedpage' );
+
 		// Order ID.
 		$order_id = $payment->format_string( (string) $this->config->order_id );