The stateful relay is based on RxJava and RxRelay.

The Stateful Relay is a test to simplify the creation of managed objects with a reactive lifecycle. Objects wrapped within may have the following attributes:

Objects can be created with an initial state. Initial state can be one of the following.

• T - Object reference.
• Maybe<T> - Maybe provides an initial state.
• Callable<T> - Provide an initial state through a custom callable.

Objects can be invalidated. Invalidation can be triggered in different ways.

• TTL - A time to live can be assigned to the object to force a refresh after a certain time. (TTL is only checked in doOnSubscribe, i.e. when accessing the object. TTL is not checked via background timer.)
• Invalidator<T> - Custom invalidator to check for properties of the object (for example dirty flag).
• .invalidate() - Invoking the invalidate() method on the relay, which either marks the object as invalidated or invokes the object's invalidate method if it implements the Invalidatable interface.

Objects can be update-able. The process may be defined through one of the following.

• Maybe<T>
• Callable<T>

StatefulRelay<String> relay = new StatefulRelay.Builder<String>()
        .withInitialization("Initial Value")
        .withTTL(5, TimeUnit.SECONDS)
        .withUpdater(new Callable<String>() {
            @Override
            public String call() throws Exception {
                return "Updated at " + new Date().toGMTString();
            }
        })
        .withInvalidator(new Invalidator<String>() {
            @Override
            public boolean isInvalidated(String s) {
                return s != null && s.contains("invalid");
            }
        })
        .build();

Invalidation can be triggered by calling

relay.invalidate();

This software is released under the Apache License v2.

RxJava and RxRelay are also licensed under Apache License v2.

Copyright 2017 Damian Burke