Package zendesk.support.suas

Interface Middleware

public interface Middleware

Middleware definition.
A middleware can be used to implement

• Logging that is called before and after the dispatcher
• Asynchronous operations by consuming an Action
• And probably a million more use-cases I can't think about right now

Method Summary

Modifier and Type	Method and Description
void	onAction(Action<?> action, GetState state, Dispatcher dispatcher, Continuation continuation) Called before an Action gets passed to the Reducers.

Method Detail

onAction

void onAction(Action<?> action,
              GetState state,
              Dispatcher dispatcher,
              Continuation continuation)

Called before an Action gets passed to the Reducers.

Examples: Log state changes:

 void onAction(...) {
    State oldState = state.getState();
    continuation.next(action);
    State newState = state.getState();

    System.out.println(stateDiff(oldState, newState));
 }
 

Consume an Action and dispatch it on a background thread:

 void onAction(...) {
    if(action.getData() instanceof AsyncAction) {
        // consume action
        backgroundTask.start(action.getData, dispatcher);
    } else {
        continuation.next(action);
    }
 }
 

Parameters:

action - a dispatched action

state - access to the current state

dispatcher - access to the dispatcher for dispatching a new action

continuation - callback for passing the action to the next middleware