Example for blog post "Live Projections ..."

BuildViewFrom.go

package customer

import (
	"github.com/AntonStoeckl/go-iddd/src/customeraccounts/hexagon/application/domain"
	"github.com/AntonStoeckl/go-iddd/src/shared/es"
)

type View struct {
	ID                      string
	EmailAddress            string
	IsEmailAddressConfirmed bool
	GivenName               string
	FamilyName              string
	IsDeleted               bool
	Version                 uint
}

func BuildViewFrom(eventStream es.EventStream) View {
	customerView := View{}

	for _, event := range eventStream {
		switch actualEvent := event.(type) {
		case domain.CustomerRegistered:
			customerView.ID = actualEvent.CustomerID().String()
			customerView.GivenName = actualEvent.PersonName().GivenName()
			customerView.FamilyName = actualEvent.PersonName().FamilyName()
			customerView.EmailAddress = actualEvent.EmailAddress().String()
		case domain.CustomerEmailAddressConfirmed:
			customerView.EmailAddress = actualEvent.EmailAddress().String()
			customerView.IsEmailAddressConfirmed = true
		case domain.CustomerEmailAddressChanged:
			customerView.EmailAddress = actualEvent.EmailAddress().String()
			customerView.IsEmailAddressConfirmed = false
		case domain.CustomerNameChanged:
			customerView.GivenName = actualEvent.PersonName().GivenName()
			customerView.FamilyName = actualEvent.PersonName().FamilyName()
		case domain.CustomerDeleted:
			customerView.IsDeleted = true
		default:
			panic("unknown event " + event.Meta().EventName())
		}

		customerView.Version = event.Meta().StreamVersion()
	}

	return customerView
}