cqrs

type Action ¶

type Action interface {
	// Kind returns whether this action is a Command or a Query.
	Kind() ActionKind
}

Action is the base interface for all commands and queries.

type ActionKind ¶

type ActionKind int

ActionKind distinguishes commands from queries.

const (
	Command ActionKind = iota
	Query
)

type BaseCommand ¶

type BaseCommand struct{}

BaseCommand is embedded by command types to mark them as commands.

func (BaseCommand) Kind() ActionKind

type BaseQuery ¶

type BaseQuery struct{}

BaseQuery is embedded by query types to mark them as queries.

func (BaseQuery) Kind() ActionKind

type Behavior ¶

type Behavior interface {
	// Handle intercepts command/query execution; call next to continue the pipeline.
	Handle(ctx context.Context, action Action, next func(ctx context.Context) (any, error)) (any, error)
}

Behavior is a Bus middleware that can intercept all commands/queries.

type BehaviorFunc ¶

type BehaviorFunc func(ctx context.Context, action Action, next func(ctx context.Context) (any, error)) (any, error)

BehaviorFunc is a function adapter for Behavior.

func (f BehaviorFunc) Handle(ctx context.Context, action Action, next func(ctx context.Context) (any, error)) (any, error)

type Bus ¶

type Bus interface {
	// contains filtered or unexported methods
}

Bus is the command/query dispatch bus interface.

func NewBus(behaviors []Behavior) Bus

type CommandQueryBus ¶

type CommandQueryBus struct {
	// contains filtered or unexported fields
}

CommandQueryBus is the concrete Bus implementation.

type Dispatcher ¶

type Dispatcher interface {
	// contains filtered or unexported methods
}

Dispatcher is the type-erased interface used for map lookup.

type Handler ¶

type Handler[TAction Action, TResult any] interface {
	// Handle executes the given command or query and returns the result.
	Handle(ctx context.Context, action TAction) (TResult, error)
}

Handler is a type-safe command/query handler.

type HandlerFunc ¶

type HandlerFunc[TAction Action, TResult any] func(ctx context.Context, action TAction) (TResult, error)

HandlerFunc is a function adapter for Handler.

func (f HandlerFunc[TAction, TResult]) Handle(ctx context.Context, action TAction) (TResult, error)

type Ordered ¶ added in v0.24.0

type Ordered interface {
	// Order returns the sort key for the behavior. Lower values wrap
	// outer; behaviors share an Order at the cost of an unstable relative
	// position between them.
	Order() int
}

Ordered is an optional interface for Behavior implementations that need deterministic wrapping order. The Bus sorts behaviors by Order ascending at construction time, so a behavior with a lower Order wraps a behavior with a higher Order (outermost first → innermost last). Behaviors that do not implement Ordered default to Order 0, in the order Uber FX produced them — which is not stable for value groups, so any behavior whose position matters MUST implement Ordered.

Order 0 is the outermost transactional band: an unordered behavior shares that band and wraps everything, which is rarely what a custom host behavior wants. Custom host behaviors must implement Ordered with a value in the 1000+ band to run inside the framework's own behaviors.

Conventional bands:

• 0–99 : transactional / contextual setup (must wrap everything; the default Order 0 falls here)
• 100–199 : audit / collector lifecycle (writes after handler succeeds)
• 200–299 : event publish / outbox (last buffered side effect)
• 1000+ : custom host behaviors (must implement Ordered to reach this band)

type TypedHandler ¶

type TypedHandler[TAction Action, TResult any] struct {
	// contains filtered or unexported fields
}

TypedHandler wraps a generic Handler and provides a type-erased dispatch method.

type Unit ¶

type Unit struct{}

Unit is a placeholder return type for commands that produce no result.