Module query 

CQRS Query Pattern

Provides traits for implementing the Query side of CQRS. Queries represent requests for information without side effects.

Example

use backbone_core::{Query, QueryHandler};

// Define a query
pub struct GetUserByEmailQuery {
    pub email: String,
}

impl Query for GetUserByEmailQuery {
    type Result = Option<UserDto>;
}

// Implement the handler
pub struct GetUserByEmailHandler {
    read_model: Arc<dyn UserReadModel>,
}

#[async_trait::async_trait]
impl QueryHandler<GetUserByEmailQuery> for GetUserByEmailHandler {
    type Error = QueryError;

    async fn handle(&self, query: GetUserByEmailQuery) -> Result<Option<UserDto>, Self::Error> {
        self.read_model.find_by_email(&query.email).await
    }
}

Structs

PaginatedQueryResult

Result wrapper for paginated queries.

Traits

CacheableQuery

Trait for queries that support caching.

PaginatedQuery

Trait for paginated queries.

Query

Marker trait for CQRS queries.

QueryDispatcher

Query dispatcher for routing queries to their handlers.

QueryHandler

Handler for executing queries.