[−][src]Crate cqrs_es

cqrs

A lightweight, opinionated CQRS and event sourcing framework targeting serverless architectures.

cqrs-es is available from Crates.io or Github.

[dependencies]
cqrs-es = "0.0.13"

Aggregate persistence is via event sourcing only.
Metadata is implemented only as a HashMap<String,String>. Further, the MetadataSupplier that the user provides has no insight into the event or aggregate that it supplies metadata for. This may be changed.
JSON serialization only.
Generics are preferred over boxed traits.
Persistence is implemented through a Postgres database.

Event upcasters.
Explore options for increasing the usefulness of MetadataSupplier.
Event serialization uses the event type as the root node of the JSON tree. This simplifies deserialization but is non-standard.
Persistence implementation for DynamoDb.

mem_store	An in-memory event store suitable for local testing.
test	Test provides a test framework for building a resilient test base around aggregates.

CqrsFramework	This is the base framework for applying commands to produce events.
MessageEnvelope	`MessageEnvelope` is a data structure that encapsulates an event with along with it's pertinent information. All of the associated data will be transported and persisted together.
UserErrorPayload	Payload for an `AggregateError::UserError`, somewhat modeled on the errors produced by the (`validator`)[https://github.com/Keats/validator] package. This payload implements `Serialize` with the intention of allowing the user to return this object as the response payload.

The base error for the framework.

Aggregate	A trait that defines an `Aggregate`, the fundamental component in CQRS that encapsulates the state and business logic for the application. An `Aggregate` is always an entity along with all objects associated with it.
Command	A `Command` represents a request to modify the state of an `Aggregate` by producing `DomainEvent`s.
DomainEvent	A `DomainEvent` represents any business change in the state of an `Aggregate`. `DomainEvent`s are immutable and with event sourcing they are the source of truth.
EventStore	The abstract central source for loading past events and committing new events.
Query	Downstream `Query`s are the read elements in a CQRS system. As events are emitted these queries , or views, are updated to reflect the currente state of the system.
QueryProcessor	Each CQRS platform should have one or more `QueryProcessor`s where it will distribute committed events, it is the responsibility of the `QueryProcessor` to update any interested queries.