Domain Events

System State Change Events

For each Domain Command, we need to create a Domain Event representing the System Change State.

Domain Events in Evento Framework are implemented by extending the abstract class com.evento.common.modeling.messaging.payload.DomainEvent. This class has no required method to implement but extends the generic Event class that includes a property called Context which we will discuss later.

Use Past verbs to indicate Events and Present for Commands.

Events can contain more information than the relative command for optimization purposes. (See TodoListTodoCheckedEvent)

Usually, each event has a very similar name to the relative command but with an ending Event and a Partial verbal time.

import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import com.evento.common.documentation.Domain;
import com.evento.common.modeling.messaging.payload.DomainEvent;

@Domain(name = "TodoList")
@NoArgsConstructor
@AllArgsConstructor
@Getter
@Setter
public class TodoListCreatedEvent extends DomainEvent {

    private String identifier;
    private String content;
}

import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import com.evento.common.documentation.Domain;
import com.evento.common.modeling.messaging.payload.DomainEvent;

@Domain(name = "TodoList")
@NoArgsConstructor
@AllArgsConstructor
@Getter
@Setter
public class TodoListDeletedEvent extends DomainEvent {

    private String identifier;
}

import com.evento.common.documentation.Domain;
import com.evento.common.modeling.messaging.payload.DomainCommand;
import com.evento.common.modeling.messaging.payload.DomainEvent;
import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;

@Domain(name = "TodoList")
@NoArgsConstructor
@AllArgsConstructor
@Getter
@Setter
public class TodoListTodoAddedEvent extends DomainEvent {

    private String identifier;
    private String todoIdentifier;
    private String content;
}

import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import com.evento.common.documentation.Domain;
import com.evento.common.modeling.messaging.payload.DomainEvent;

@Domain(name = "TodoList")
@NoArgsConstructor
@AllArgsConstructor
@Getter
@Setter
public class TodoListTodoCheckedEvent extends DomainEvent {

    private String identifier;
    private String todoIdentifier;
    // Communicate if all Todos inside this TodoList are checked with this check
    private boolean allChecked;
}

import com.evento.common.documentation.Domain;
import com.evento.common.modeling.messaging.payload.DomainCommand;
import com.evento.common.modeling.messaging.payload.DomainEvent;
import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;

@Domain(name = "TodoList")
@NoArgsConstructor
@AllArgsConstructor
@Getter
@Setter
public class TodoListTodoRemovedEvent extends DomainEvent {

    private String identifier;
    private String todoIdentifier;
}