LoggingMiddleware<State> class

Connects a Logger to a Redux Store.

Every action that is dispatched will be logged to the Logger, along with the new State that was created as a result of the action reaching your Store's reducer.

By default, this class does not print anything to your console or to a web service, such as Fabric or Sentry. It simply logs entries to a Logger instance.

You can then listen to the Logger.onRecord Stream, and print to the console or send these actions to a web service.

If you simply want to print the latest action and state to your console / terminal, create a new LoggingMiddleware.printer() and pass it to your Store upon creation.

Simple Printing example

If you just want an easy way to print actions as they are dispatched to your console / terminal, use the new LoggingMiddleware.printer() factory.

final store = new Store<int>(
  (int state, action) => state + 1,
  initialValue: 0,
  middleware: [new LoggingMiddleware.printer()]
);

store.dispatch('Hi'); // prints {Action: 'Hi', Store: 1, Timestamp: ...}

Example

If you only want to log actions to a Logger, use the default constructor.

// Create your own Logger
final logger = new Logger('Redux Logger');

// Pass it to your Middleware
final middleware = new LoggingMiddleware(logger: logger);
final store = new Store<int>(
  (int state, action) => state + 1,
  initialState: 0,
  middleware: [middleware],
);

// Note: One quirk about listening to a logger instance is that you're
// actually listening to the Singleton instance of *all* loggers.
logger.onRecord
  // Filter down to [LogRecord]s sent to your logger instance
  .where((record) => record.loggerName == logger.name)
  // Print them out (or do something more interesting!)
  .listen((loggingMiddlewareRecord) => print(loggingMiddlewareRecord));