Trait Projection 

pub trait Projection {
    type SourceId: Eq;
    type Event;
    type Error;

    // Required method
    fn project<'a>(
        &'a mut self,
        event: Persisted<Self::SourceId, Self::Event>,
    ) -> BoxFuture<'a, Result<(), Self::Error>>;
}

A Projection is an optimized read model (or materialized view) of an Aggregate model(s), that can be assembled by left-folding its previous state and a number of ordered, consecutive events.

The events passed to a Projection have been persisted onto an EventStore first.

Required Associated Types

type SourceId: Eq

Type of the Source id, typically an AggregateId.

type Event

Event to be stored in the EventStore, typically an Aggregate::Event.

type Error

Type of the possible error that might occur when projecting the next state.

Required Methods

fn project<'a>( &'a mut self, event: Persisted<Self::SourceId, Self::Event>, ) -> BoxFuture<'a, Result<(), Self::Error>>

Updates the next value of the Projection using the provided event value.

Implementors