Generated by XState Viz: https://xstate.js.org/viz

machine.js

  // Available variables:
  // - Machine
  // - interpret
  // - assign
  // - send
  // - sendParent
  // - spawn
  // - raise
  // - actions
  // - XState (all XState exports)
  

const checkoutMachine = Machine(
 {
  id: 'checkout',
  initial: 'cart',
  context: {
    items: [],
    subtotal: 0,
    shippingAddress: null,
    billingAddress: null,
    paymentMethod: null,
    orderNumber: null
  },
  states: {
    cart: {
      on: {
        ADD_TO_CART: {
          actions: assign({
            items: (context, event) => [...context.items, event.item]
          })
        },
        CHECKOUT: 'checkoutForm'
      }
    },
    checkoutForm: {
      initial: 'shipping',
      states: {
        shipping: {
          entry: assign({
            shippingAddress: (context, event) => {
              if (!context.shippingAddress) {
                // fetch data here
                return null;
              }
              return context.shippingAddress;
            }
          }),
          on: {
            NEXT: 'billing',
            PREVIOUS: undefined,
            SET_SHIPPING_ADDRESS: {
              actions: assign({
                shippingAddress: (_, event) => event.address
              })
            },
            UPDATE_SHIPPING_ADDRESS: {
              actions: assign({
                shippingAddress: (_, event) => {
                  // send updated shipping address to backend and fetch updated data
                  return null;
                }
              })
            }
          }
        },
        billing: {
          entry: assign({
            billingAddress: (context, event) => {
              if (!context.billingAddress) {
                // fetch data here
                return null;
              }
              return context.billingAddress;
            }
          }),
          on: {
            NEXT: 'payment',
            PREVIOUS: 'shipping',
            SET_BILLING_ADDRESS: {
              actions: assign({
                billingAddress: (_, event) => event.address
              })
            },
            UPDATE_BILLING_ADDRESS: {
              actions: assign({
                billingAddress: (_, event) => {
                  // send updated billing address to backend and fetch updated data
                  return null;
                }
              })
            }
          }
        },
        payment: {
          entry: assign({
            paymentMethod: (context, event) => {
              if (!context.paymentMethod) {
                // fetch data here
                return null;
              }
              return context.paymentMethod;
            }
          }),
          on: {
            NEXT: 'review',
            PREVIOUS: 'billing',
            SET_PAYMENT_METHOD: {
              actions: assign({
                paymentMethod: (_, event) => event.paymentMethod
              })
            },
            UPDATE_PAYMENT_METHOD: {
              actions: assign({
                paymentMethod: (_, event) => {
                  // send updated payment method to backend and fetch updated data
                  return null;
                }
              })
            }
          }
        },
        review: {
          on: {
            PLACE_ORDER: 'success',
            PREVIOUS: 'payment'
          }
        },
        success: {
          type: 'final'
        }
      }
    }
  }
}
);