bus

Documentation

Index

• func ExecCollectValues(ctx context.Context, bus Bus, dir directive.Directive, ...) ([]directive.Value, directive.Reference, error)
• func ExecOneOff(ctx context.Context, bus Bus, dir directive.Directive, returnIfIdle bool, ...) (directive.AttachedValue, directive.Reference, error)
• func ExecOneOffWatchCh(b Bus, dir directive.Directive) (<-chan directive.AttachedValue, directive.Reference, error)
• func NewCallbackHandler(valCb func(directive.AttachedValue), removedCb func(directive.AttachedValue), ...) directive.ReferenceHandler
• func NewPassThruHandler(passthru directive.ResolverHandler, disposeCb func()) directive.ReferenceHandler
• type Bus
• type CallbackHandler
  • func (h *CallbackHandler) HandleInstanceDisposed(directive.Instance)
  • func (h *CallbackHandler) HandleValueAdded(_ directive.Instance, v directive.AttachedValue)
  • func (h *CallbackHandler) HandleValueRemoved(_ directive.Instance, v directive.AttachedValue)
• type PassThruHandler
  • func (h *PassThruHandler) HandleInstanceDisposed(di directive.Instance)
  • func (h *PassThruHandler) HandleValueAdded(_ directive.Instance, v directive.AttachedValue)
  • func (h *PassThruHandler) HandleValueRemoved(_ directive.Instance, v directive.AttachedValue)

Functions

func ExecCollectValues

func ExecCollectValues(
	ctx context.Context,
	bus Bus,
	dir directive.Directive,
	valDisposeCallback func(),
) ([]directive.Value, directive.Reference, error)

ExecCollectValues collects one or more values while ctx is active and directive is not idle.

Returns err if the directive is idle and a resolver returned an error. Does not return an error if ctx was canceled. Does not release ref if err == nil.

func ExecOneOff

func ExecOneOff(
	ctx context.Context,
	bus Bus,
	dir directive.Directive,
	returnIfIdle bool,
	valDisposeCallback func(),
) (directive.AttachedValue, directive.Reference, error)

ExecOneOff executes a one-off directive. If returnIfIdle is set, returns nil, nil, nil if idle.

func ExecOneOffWatchCh

func ExecOneOffWatchCh(
	b Bus,
	dir directive.Directive,
) (<-chan directive.AttachedValue, directive.Reference, error)

ExecOneOffWatchCh executes a one-off directive and watches for changes. Returns a channel with size 1 which will hold the latest value. Continues to watch for changes until the directive is released.

func NewCallbackHandler

func NewCallbackHandler(
	valCb func(directive.AttachedValue),
	removedCb func(directive.AttachedValue),
	disposeCb func(),
) directive.ReferenceHandler

NewCallbackHandler wraps callback functions into a handler object.

func NewPassThruHandler

func NewPassThruHandler(
	passthru directive.ResolverHandler,
	disposeCb func(),
) directive.ReferenceHandler

NewPassThruHandler builds a new pass-through handler.

Types

type Bus

type Bus interface {
	// Controller is the directive controller.
	directive.Controller

	// GetControllers returns a list of all currently active controllers.
	GetControllers() []controller.Controller

	// ExecuteController adds a controller to the bus and calls Execute().
	// Any fatal error in the controller is returned.
	// The controller will receive directive callbacks.
	// If the controller returns nil, call RemoveController to remove the controller.
	ExecuteController(context.Context, controller.Controller) error
	// RemoveController removes the controller from the bus.
	// The controller will no longer receive callbacks.
	// Note: this might not cancel the Execute() context automatically.
	RemoveController(controller.Controller)
}

Bus manages running controllers. It has an attached directive controller, which is used to build declarative state requests between controllers.

type CallbackHandler

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

CallbackHandler is a reference handler that uses function callbacks.

func (*CallbackHandler) HandleInstanceDisposed

func (h *CallbackHandler) HandleInstanceDisposed(directive.Instance)

HandleInstanceDisposed is called when a directive instance is disposed. This will occur if Close() is called on the directive instance.

func (*CallbackHandler) HandleValueAdded

func (h *CallbackHandler) HandleValueAdded(
	_ directive.Instance,
	v directive.AttachedValue,
)

HandleValueAdded is called when a value is added to the directive.

func (*CallbackHandler) HandleValueRemoved

func (h *CallbackHandler) HandleValueRemoved(
	_ directive.Instance,
	v directive.AttachedValue,
)

HandleValueRemoved is called when a value is removed from the directive.

type PassThruHandler

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

PassThruHandler is a reference handler that passes through to a resolver handler.

func (*PassThruHandler) HandleInstanceDisposed

func (h *PassThruHandler) HandleInstanceDisposed(di directive.Instance)

HandleInstanceDisposed is called when a directive instance is disposed. This will occur if Close() is called on the directive instance.

func (*PassThruHandler) HandleValueAdded

func (h *PassThruHandler) HandleValueAdded(
	_ directive.Instance,
	v directive.AttachedValue,
)

HandleValueAdded is called when a value is added to the directive.

func (*PassThruHandler) HandleValueRemoved

func (h *PassThruHandler) HandleValueRemoved(
	_ directive.Instance,
	v directive.AttachedValue,
)

HandleValueRemoved is called when a value is removed from the directive.