io.simplesource.saga.action.http

Interface HttpSpec.UndoFunction<A,K,B,O>

Enclosing class:

HttpSpec<A,K,B,O,R>

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public static interface HttpSpec.UndoFunction<A,K,B,O>

The UndoFunction functional interface.

Method Summary

Modifier and Type	Method and Description
Optional<UndoCommand<A>>	apply(HttpRequest<K,B> decodedInput, O output) The UndoFunction is a mechanism to take the result of the async http invocation and turning it into an undo action command.

Method Detail

apply

Optional<UndoCommand<A>> apply(HttpRequest<K,B> decodedInput,
                               O output)

The UndoFunction is a mechanism to take the result of the async http invocation and turning it into an undo action command. This action command is passed back to the saga coordinator, and if the saga fails, this undo function will be invoked.

For example, if the async function calls an endpoint to book a hotel, the return value will include a booking reference. This booking reference is then used to create an undo action command that calls the corresponding cancel endpoint, passing in the booking reference

Parameters:

decodedInput - the decoded input type

output - the result of the async invocation

Returns:

an undo command, or Optional.empty() if no undo function is to be generated