Intent.Application.CQRS.CRUD

This module implements the business logic of Command and Query handlers generated by any transport module (Wolverine, MediatR, etc.) using transport-agnostic conventions. It generates no files of its own — it extends handler templates discovered by role, implementing their Handle method bodies from the modelled Domain Interactions.

What This Module Generates

This module owns no templates. Its CqrsHandlerCrudExtension factory extension modifies the Handle method of any handler template registered under the following roles:

  • TemplateRoles.Application.Handler.Command — command handlers.
  • TemplateRoles.Application.Handler.Query — query handlers.

A transport module (e.g. Intent.Application.Wolverine, Intent.Application.MediatR) supplies the handler class itself; this module fills in its body.

Role-Based Handler Discovery

Unlike transport-specific CRUD modules that target a single handler template type directly, this module discovers handlers purely by role. This means the same CRUD conventions apply automatically to any transport module that registers its handler templates under TemplateRoles.Application.Handler.Command / .Query, without this module needing a dependency on that transport.

var templates = application.FindTemplateInstances<ICSharpFileBuilderTemplate>(TemplateRoles.Application.Handler.Command);

Domain Interaction Implementation

When a Command or Query has one or more modelled Domain Interactions (Create Entity Action, Update Entity Action, Delete Entity Action, Query Entity Action, etc.), the module clears the handler's Handle method and regenerates it from those interactions, using the standard mapping resolvers (entity creation/update, value objects, data contracts, service operations, enums) to translate the command/query payload into domain calls.

// Modelled: CreateOrderCommand -> Create Entity Action -> Order
public async Task Handle(CreateOrderCommand command, CancellationToken cancellationToken)
{
    var order = new Order(command.CustomerId);
    await _orderRepository.AddAsync(order, cancellationToken);
}

Convention-Based "Get All" Fallback

A Query with no modelled Domain Interactions falls back to a convention: if it returns a collection of a DTO that is mapped from a domain entity (and that entity is not a nested compositional child), the handler is generated as a repository FindAllAsync call followed by an AutoMapper projection to the DTO list. This mirrors the legacy MediatR CRUD module's unfiltered "get all" behaviour so conventionally modelled queries are not left as stubs.

public async Task<List<OrderDto>> Handle(GetOrdersQuery query, CancellationToken cancellationToken)
{
    var orders = await _orderRepository.FindAllAsync(cancellationToken);
    return orders.MapToOrderDtoList(_mapper);
}
Note

OData queries require a modelled Domain Interaction and are not covered by this fallback — see ODataQueryInteractionStrategy in Intent.Application.DomainInteractions.

Convention-Based Paged Query

A Query with no modelled Domain Interactions that returns a PagedResult<TDto> is generated as a paged "get all": if the nested DTO is mapped from a domain entity (not a nested compositional child) and the query exposes a page-number field (Page, PageNo, PageNum, PageNumber) and a page-size field (Size, PageSize), the handler is generated as a paged repository FindAllAsync(pageNo, pageSize) call followed by a MapToPagedResult projection. This mirrors the legacy MediatR CRUD module's paged behaviour.

public async Task<PagedResult<OrderDto>> Handle(GetOrdersQuery request, CancellationToken cancellationToken)
{
    var results = await _orderRepository.FindAllAsync(request.PageNo, request.PageSize, cancellationToken);
    return results.MapToPagedResult(x => x.MapToOrderDto(_mapper));
}
Note

Paging is only applied on the convention path — a query with a modelled Query Entity Action takes the Domain Interaction path instead and will not receive paged generation.

Intent.Application.Wolverine

Registers command and query handler templates under TemplateRoles.Application.Handler.Command / .Query, which this module discovers and implements.

Intent.Application.DomainInteractions

Supplies the IInteractionStrategy implementations and mapping resolvers this module uses to translate modelled Domain Interactions into C# statements.