Entity Event

In es-entity it is assumed that an Entity has an associated EntityEvent enum that represents all of the state changes (ie. types of events) that can originate from mutations of said Entity. This enum must be serializable and is stored as a JSON-blob in the associated events table.

#![allow(unused)]
fn main() {
extern crate es_entity;
extern crate sqlx;
extern crate serde;
use serde::{Deserialize, Serialize};
use es_entity::*;

// Entities must always have an associated id type
type UserId = String;
// es_entity::entity_id! { UserId }; Can be used to create a Uuid wrapper struct.

#[derive(EsEvent, Debug, Serialize, Deserialize)]
// The `EsEvent` must have `serde(tag = "type")` annotation.
#[serde(tag = "type", rename_all = "snake_case")]
// Tell the macro what the `id` type is
#[es_event(id = "UserId")]
pub enum UserEvent {
    // Typically there is a 'first' event that records the initial state of an `Entity`.
    Initialized { id: UserId, name: String },
    // Every mutation should result in an `Event` that represents the 
    // change that happened.
    // This event represents that the `name` attribute of a user was updated.
    NameUpdated { name: String },
}
}