Checkout steps

The checkout process consists of the following steps:

• Entry step (cart creation)
• Customer step
• Address step
• Shipment step
• Payment step
• Summary step
• Place order step
• Success step

Read on to learn more on each step.

Entry step

The entry step redirects the customer to the correct step based on the QuoteTransfer state. This step requires input = false, so it is not rendered.

Customer step

The customer step provides three forms:

• Login
• Register
• Checkout as a guest

This step is responsible for filling CustomerTransfer with corresponding data. The authentication logic is left to the customer module, this step only delegates calls to and from the customer module and mapping data with forms.

Address step

The address step is the step where the customer fills billing and shipping addresses in QuoteTransfer::billingAddress and QuoteTransfer::shippingAddress, respectively. This step lets the returning customers select one of the existing addresses or create a new one. A new address will be created only if the Save new address to address book checkbox is selected. Otherwise, it is saved in the order but is not stored in the database. This allows a customer to skip the new address saving if they want to. New and guest customers can only create a new address. If a new address is selected, it’s only created when the order is placed, and the OrderCustomerSavePlugin plugin is enabled.

Shipment step

Get shipment method information and store it in the quote. This step requires additional configuration because different shipment providers and different ways forms must be handled for each.

Form handling

ShipmentForm uses subforms and each subform is implemented as a plugin that implements CheckoutSubFormInterface and is provided in CheckoutFactory::createShipmentMethodsSubForms(). The main form uses quote transfer as a data store. Shipment data is stored under QuoteTransfer::shipment as a ShipmentTransfer object.

ShipmentTransfer contains:

Data handling

Data handling happens after a valid form is submitted during ShipmentStep; the step receives plugins that implement CheckoutStepHandlerPluginInterface and are provided in CheckoutFactory::createShipmentPlugins(). When execute() is called on ShipmentStep then the plugin identified by the ShipmentTransfer::shipmentSelection string is selected and the method CheckoutStepHandlerPluginInterface::addToQuote() is called to update QuoteTransfer with payment data. From this part, the data handling is left to concrete CheckoutStepHandler.

The approach to implementing shipment and payment handlers and forms is the same PaymentStep.

• shipmentSelection (string)—the name of the form for the selected shipment.
• carrier (ShipmentCarrierTransfer)—includes information on the shipment carrier.
• method (ShipmentMethodTransfer)—contains information about the shipment method that is currently selected.

Payment step

Get payment information and store it into a quote for later processing when a state machine is triggered.

The Payment step has a similar structure and data handling mechanics as the shipment step does.

Form handling

PaymentForm uses subforms. Each subform is implemented as a plugin that implements CheckoutSubFormPluginInterface and is provided in CheckoutFactory::createPaymentMethodSubForms(). The main form uses QuoteTransfer as a data store. Data for payment is stored under QuoteTransfer::payment as a PaymentTransfer object.

The main form has radio buttons, which the customer can select from the available payment methods. Choices are built from the subform name. Each provided subform corresponds to radio input.

When the form is created, it requires the property path to be provided so that it knows how to map its subform to QuoteTransfer—see property_path. The property path is built out of a few parts of PaymentTransfer::payment and the subform provides getPropertyPath() that returns a string; this string must return the property that exists under PaymentTransfer.

PaymentTransfer includes the following:

• paymentProvider (string)—The payment provider’s name (Paypal or Payolution).
• paymentMethod (string)—The payment method (credit card or invoice).
• paymentSelection (string)—The subform name that is currently selected.

Data handling

Data handling happens after a valid form is submitted during PaymentStep. The step receives plugins that implement CheckoutStepHandlerPluginInterface and that are provided in the CheckoutFactory::createPaymentPlugins(). When execute() method is called on PaymentStep, the plugin that is identified by PaymentTransfer::paymentSelection string is selected and the CheckoutStepHandlerPluginInterface::addToQuote() is called to update QuoteTransfer with the payment data. From this part, all population or data handling is left to concrete CheckoutStepHandler.

Summary step

Display order information about the item to be placed, details, and order totals.

Place order step

Place the order into the system. This step requires input = false. This step makes a Zed HTTP request, which sends QuoteTransfer. In this step, all order saving is happening.

Success page

When the success page is executed, QuoteTransfer is cleared. The customer’s session is also marked as dirty so that with the next request, it reloads with the updated data (new customer address).

Checkout step interface

  <?php
  interface StepInterface
  {
	/**
	 * Requirements for this step, return true when satisfied.
	 *
	 * @param QuoteTransfer $quoteTransfer
	 *
	 * @return bool
	 */
	public function preCondition(QuoteTransfer $quoteTransfer);
	/**
	 * Require input, should we render view with form or just skip step after calling execute.
	 *
	 * @return bool
	 */
	public function requireInput();
	/**
	 * Execute step logic, happens after form submit if provided, gets QuoteTransfer filled by data from form.
	 *
	 * @param Request $request
	 * @param QuoteTransfer $quoteTransfer
	 *
	 * @return QuoteTransfer
	 */
	public function execute(Request $request, QuoteTransfer $quoteTransfer);
	/**
	 * Conditions that should be met for this step to be marked as completed. returns true when satisfied.
	 *
	 * @param QuoteTransfer $quoteTransfer
	 *
	 * @return bool
	 */
	public function postCondition(QuoteTransfer $quoteTransfer);
	/**
	 * Current step route.
	 *
	 * @return string
	 */
	public function getStepRoute();
	/**
	 * Escape route when preConditions are not satisfied user will be redirected to provided route.
	 *
	 * @return string
	*/
	public function getEscapeRoute();
 }

Step with external redirect interface

 <?php
   interface StepWithExternalRedirectInterface extends StepInterface
   {
   	/**
   	 * Return external redirect url, when redirect occurs not within same application. Used after execute.
   	 *
   	 * @return string
   	 */
   	public function getExternalRedirectUrl();
   }

Current constraints

All the stores inside a project share a single checkout with the same steps.