Trait cqrs_es2::IEvent

pub trait IEvent: Debug + PartialEq + Clone + Serialize + DeserializeOwned + Sync + Send { }

An IEvent represents any business change in the state of an Aggregate. IEvents are immutable and with event sourcing they are the source of truth.

The name of an IEvent should always be in the past tense, e.g.,

• AdminPrivilegesGranted
• EmailAddressChanged
• DependencyAdded

To simplify serialization, an event should be an enum, and each element should have a payload. By convention, the payload has the same name as the element, and elements that do not require additional information use an empty payload.

Though the IEvent trait only has a single function, the events must also derive a number of standard traits.

• Clone - events may be cloned throughout the framework, particularly when applied to queries
• Serialize and Deserialize - required for persistence
• PartialEq and Debug - needed for effective testing

Examples

use serde::{
    Deserialize,
    Serialize,
};
use std::fmt::Debug;

use cqrs_es2::IEvent;

#[derive(
    Debug,
    PartialEq,
    Clone,
    Serialize,
    Deserialize
)]
pub enum CustomerEvent {
    NameAdded(NameAdded),
    EmailUpdated(EmailUpdated),
}

#[derive(
    Debug,
    PartialEq,
    Clone,
    Serialize,
    Deserialize
)]
pub struct NameAdded {
    changed_name: String,
}

#[derive(
    Debug,
    PartialEq,
    Clone,
    Serialize,
    Deserialize
)]
pub struct EmailUpdated {
    new_email: String,
}

impl IEvent for CustomerEvent {};

Implementors