public static StateEvaluationResult ClearSelectedPaymentMethod(StateMachineContext context, StateEvaluationResult previousResult)
{
// Copy everything but the selected payment method
return(new StateEvaluationResult(
state: previousResult.State,
checkoutStageContext: previousResult.CheckoutStageContext,
selections: new CheckoutSelectionContext(
selectedPaymentMethod: null,
selectedBillingAddress: context.Selections.SelectedBillingAddress,
selectedShippingAddress: context.Selections.SelectedShippingAddress,
selectedShippingMethodId: context.Selections.SelectedShippingMethodId,
creditCard: context.Selections.CreditCard,
eCheck: context.Selections.ECheck,
payPalExpress: context.Selections.PayPalExpress,
amazonPayments: context.Selections.AmazonPayments,
purchaseOrder: context.Selections.PurchaseOrder,
acceptJsDetailsCreditCard: context.Selections.AcceptJsDetailsCreditCard,
braintree: context.Selections.Braintree,
sagePayPi: context.Selections.SagePayPi,
termsAndConditionsAccepted: context.Selections.TermsAndConditionsAccepted,
over13Checked: context.Selections.Over13Checked,
email: context.Selections.Email)));
}
StateEvaluationResult EvaluateStateMachine(StateMachineContext context)
{
// Set up the initial state
var previousResult = new StateEvaluationResult(
state: CheckoutState.Start,
checkoutStageContext: new CheckoutStageContext(
account: new CheckoutStageStatus(
required: Guards.CustomerAccountRequired(context),
available: null,
fulfilled: null,
disabled: null),
paymentMethod: new CheckoutStageStatus(
required: Guards.PaymentMethodRequired(context),
available: Guards.PaymentMethodPresent(context),
fulfilled: null,
disabled: null),
billingAddress: new CheckoutStageStatus(
required: Guards.BillingAddressRequired(context),
available: Guards.BillingAddressPresent(context),
fulfilled: null,
disabled: null),
shippingAddress: new CheckoutStageStatus(
required: Guards.ShippingAddressRequired(context),
available: Guards.ShippingAddressPresent(context),
fulfilled: null,
disabled: !Guards.AllowShipToDifferentThanBillTo(context) || Guards.SkipShippingOnCheckout(context)),
shippingMethod: new CheckoutStageStatus(
required: Guards.ShippingMethodRequired(context),
available: Guards.ShippingMethodPresent(context),
fulfilled: null,
disabled: Guards.SkipShippingOnCheckout(context)),
giftCardSetup: new CheckoutStageStatus(
required: Guards.CartContainsGiftCard(context),
available: null,
fulfilled: Guards.GiftCardSetupComplete(context),
disabled: null),
placeOrderButton: new CheckoutStageStatus(
required: null,
available: null,
fulfilled: true,
disabled: null)),
selections: context.Selections);
// Loop until we find an exit condition
while (true)
{
// Find a transition from the current state where all guards pass
var passedTransition = StateMachine.ContainsKey(previousResult.State)
? StateMachine[previousResult.State]
.Where(transition => transition
.Guards
.Select(guard => guard(context))
.All(guardResult => guardResult == true))
.FirstOrDefault()
: null;
// If there's nothing to transition to, we've hit a terminal state and need to return
if (passedTransition == null)
{
return(previousResult);
}
// Build up the next state
var currentResult = new StateEvaluationResult(
state: passedTransition.Target,
checkoutStageContext: previousResult.CheckoutStageContext,
selections: previousResult.Selections);
// Run any triggers on the target state
foreach (var trigger in passedTransition.Triggers)
{
currentResult = trigger(context, currentResult);
}
// If we're just looping back to the same state or we've hit the final state, we're done
if (currentResult.State == previousResult.State || currentResult.State == CheckoutState.Valid)
{
return(currentResult);
}
// Set up the current state as the previous state and loop
previousResult = currentResult;
}
}
