com.cookingfox.lapasse.impl.logging.RxLoggerHelper Maven / Gradle / Ivy
package com.cookingfox.lapasse.impl.logging;
import com.cookingfox.lapasse.api.command.Command;
import com.cookingfox.lapasse.api.command.logging.CommandHandlerError;
import com.cookingfox.lapasse.api.command.logging.CommandHandlerResult;
import com.cookingfox.lapasse.api.command.logging.CommandLogger;
import com.cookingfox.lapasse.api.command.logging.CommandLoggerAware;
import com.cookingfox.lapasse.api.event.Event;
import com.cookingfox.lapasse.api.event.logging.EventHandlerError;
import com.cookingfox.lapasse.api.event.logging.EventHandlerResult;
import com.cookingfox.lapasse.api.event.logging.EventLogger;
import com.cookingfox.lapasse.api.event.logging.EventLoggerAware;
import com.cookingfox.lapasse.api.state.State;
import rx.Observable;
import rx.Subscriber;
import rx.functions.Action0;
import rx.subscriptions.Subscriptions;
import java.util.Collection;
/**
* Rx helper methods for logging features.
*/
public final class RxLoggerHelper {
//----------------------------------------------------------------------------------------------
// CONSTRUCTOR (disabled)
//----------------------------------------------------------------------------------------------
private RxLoggerHelper() {
throw new UnsupportedOperationException();
}
//----------------------------------------------------------------------------------------------
// PUBLIC METHODS
//----------------------------------------------------------------------------------------------
/**
* Creates an observable for command handler errors.
*
* @param commandLoggerAware The subject for which to observe command handler errors.
* @return An observable for command handler errors.
*/
public static Observable observeCommandHandlerErrors(
final CommandLoggerAware commandLoggerAware) {
return Observable.create(new Observable.OnSubscribe() {
@Override
public void call(final Subscriber subscriber) {
// create logger
final CommandLogger logger = new NoopCommandLogger() {
@Override
public void onCommandHandlerError(final Throwable e, final Command command) {
subscriber.onNext(new CommandHandlerError() {
@Override
public Command getCommand() {
return command;
}
@Override
public Throwable getError() {
return e;
}
});
}
};
// add logger
commandLoggerAware.addCommandLogger(logger);
// remove logger on unsubscribe
subscriber.add(Subscriptions.create(new Action0() {
@Override
public void call() {
commandLoggerAware.removeCommandLogger(logger);
}
}));
}
});
}
/**
* Creates an observable for command handler results.
*
* @param commandLoggerAware The subject for which to observe command handler results.
* @return An observable for command handler results.
*/
public static Observable observeCommandHandlerResults(
final CommandLoggerAware commandLoggerAware) {
return Observable.create(new Observable.OnSubscribe() {
@Override
public void call(final Subscriber subscriber) {
// create logger
final CommandLogger logger = new NoopCommandLogger() {
@Override
public void onCommandHandlerResult(final Command command,
final Collection events) {
subscriber.onNext(new CommandHandlerResult() {
@Override
public Command getCommand() {
return command;
}
@Override
public Collection getEvents() {
return events;
}
});
}
};
// add logger
commandLoggerAware.addCommandLogger(logger);
// remove logger on unsubscribe
subscriber.add(Subscriptions.create(new Action0() {
@Override
public void call() {
commandLoggerAware.removeCommandLogger(logger);
}
}));
}
});
}
/**
* Creates an observable for event handler errors.
*
* @param eventLoggerAware The subject for which to observe event handler errors.
* @param The concrete type of the state object.
* @return An observable for event handler errors.
*/
public static Observable observeEventHandlerErrors(
final EventLoggerAware eventLoggerAware) {
return Observable.create(new Observable.OnSubscribe() {
@Override
public void call(final Subscriber subscriber) {
// create logger
final EventLogger logger = new NoopEventLogger() {
@Override
public void onEventHandlerError(final Throwable e, final Event event) {
subscriber.onNext(new EventHandlerError() {
@Override
public Event getEvent() {
return event;
}
@Override
public Throwable getError() {
return e;
}
});
}
};
// add logger
eventLoggerAware.addEventLogger(logger);
// remove logger on unsubscribe
subscriber.add(Subscriptions.create(new Action0() {
@Override
public void call() {
eventLoggerAware.removeEventLogger(logger);
}
}));
}
});
}
/**
* Creates an observable for event handler results.
*
* @param eventLoggerAware The subject for which to observe event handler results.
* @param The concrete type of the state object.
* @return An observable for event handler results.
*/
public static Observable observeEventHandlerResults(
final EventLoggerAware eventLoggerAware) {
return Observable.create(new Observable.OnSubscribe() {
@Override
public void call(final Subscriber subscriber) {
// create logger
final EventLogger logger = new NoopEventLogger() {
@Override
public void onEventHandlerResult(final Event event, final S newState) {
subscriber.onNext(new EventHandlerResult() {
@Override
public Event getEvent() {
return event;
}
@Override
public State getNewState() {
return newState;
}
});
}
};
// add logger
eventLoggerAware.addEventLogger(logger);
// remove logger on unsubscribe
subscriber.add(Subscriptions.create(new Action0() {
@Override
public void call() {
eventLoggerAware.removeEventLogger(logger);
}
}));
}
});
}
//----------------------------------------------------------------------------------------------
// MEMBER CLASSES
//----------------------------------------------------------------------------------------------
/**
* No-operation implementation of {@link CommandLogger}.
*/
static class NoopCommandLogger implements CommandLogger {
@Override
public void onCommandHandlerError(Throwable e, Command command) {
// override in subclass
}
@Override
public void onCommandHandlerResult(Command command, Collection events) {
// override in subclass
}
}
/**
* No-operation implementation of {@link EventLogger}.
*
* @param The concrete type of the state object.
*/
static class NoopEventLogger implements EventLogger {
@Override
public void onEventHandlerError(Throwable e, Event event) {
// override in subclass
}
@Override
public void onEventHandlerResult(Event event, S newState) {
// override in subclass
}
}
}