server/io.spine.server.model/SelectiveHandler

SelectiveHandler

public interface SelectiveHandler<T, C extends MessageClass<?>, E extends MessageEnvelope<? extends Object, ? extends Object, ? extends Object>, R extends MessageClass<?>> implements HandlerMethod<T, C, E, R>

A handler method which accept only instances of messages that match the filtering conditions.

Having two or more methods that accept the same message type but instances of different values to avoid if-elif branches (that filter by the value of the message in a bigger method).

It is possible to filter by the same field of the same message type.

See also

io.spine.core.ByField

HandlerFieldFilterClashError

Inheritors

SubscriberMethod

Functions

public abstract ArgumentFilter filter()

Obtains the filter to apply to the messages received by this method.

Inherited functions

public abstract Set<Attribute<? extends Object>> attributes()

Obtains the set of method attributes configured for this method.

discoverAttributes

public abstract void discoverAttributes()

ensureExternalMatch

public void ensureExternalMatch(boolean expectedValue)

Ensures that the external attribute of the method is the one expected.

public abstract DispatchOutcome invoke(T target, E envelope)

Invokes the method to handle message with the context.

public boolean isDomestic()

Tells if the passed method is domestic, that is not marked as external).

public boolean isExternal()

Tells if the passed method is external.

public DispatchKey key()

Creates a handler method dispatch key out of the message class.

public abstract C messageClass()

Obtains the type of the incoming message class.

public abstract MethodParams params()

Obtains parameters of the method.

producedMessages

public abstract Set<R> producedMessages()

Retrieves the message classes produced by this handler method.

public abstract Method rawMethod()

Obtains the handling method.

toSuccessfulOutcome

public abstract Success toSuccessfulOutcome(Object rawResult, T target, E handledSignal)

Converts the raw method result to a successful propagation outcome.