Predefined configurations

When you have multiple mix calls that share the same configuration, you can use the config parameter with MixConfig to avoid repetition and ensure consistency.

Basic usage

Create a reusable configuration:

// Define once
const checkInternetRetryAndLog = MixConfig(
  retry: retry(maxRetries: 5, initialDelay: 1.sec),
  checkInternet: checkInternet,
  before: () => Log.info("Starting"),
  after: () => Log.info("Finished"),
  catchError: (error, stackTrace) => Log.error("Failed", error),
);

// Use everywhere
void fetchUsers() {
  mix(
    key: this,
    config: checkInternetRetryAndLog, // Here!
    () async {
      final users = await api.getUsers();
      emit(state.copyWith(users: users));
    },
  );
}

Available configuration options

MixConfig supports all the same parameters as mix:

const myConfig = MixConfig(
  // Feature configurations
  retry: retry(...),
  checkInternet: checkInternet(...),
  nonReentrant: nonReentrant(...),
  throttle: throttle(...),
  debounce: debounce(...),
  fresh: fresh(...),
  sequential: sequential(...),

  // Callbacks
  before: () { ... },      // Called once before the first attempt
  after: () { ... },       // Called once after all attempts complete
  wrapRun: (action) { ... }, // Wraps each execution of the action
  catchError: (error, stack) { ... }, // Handle errors
);

Resolution order

Configuration values are resolved in this order (highest priority last):

1. Built-in defaults (e.g., RetryConfig.defaults)
2. Config parameter (config: myConfig)
3. Explicit parameters (e.g., retry: retry(...))

This means you can define base configurations and override specific values per-call:

const serverCallConfig = MixConfig(
  retry: retry(maxRetries: 5, multiplier: 3.0),
);

// Uses config's maxRetries=5 and multiplier=3.0
void normalCall() {
  mix(
    key: this,
    config: serverCallConfig,
    () async { ... },
  );
}

// Overrides maxRetries to 10, but keeps multiplier=3.0 from config
void importantCall() {
  mix(
    key: this,
    config: serverCallConfig,
    retry: retry(maxRetries: 10),
    () async { ... },
  );
}

Customizing defaults globally

Each config class has a static defaults property you can customize at app startup:

void main() {
  // Customize defaults for your app
  RetryConfig.defaults = retry(
    maxRetries: 5,
    initialDelay: Duration(milliseconds: 200),
    multiplier: 2.0,
    maxDelay: Duration(seconds: 10),
  );

  ThrottleConfig.defaults = throttle(
    duration: Duration(seconds: 1),
    removeLockOnError: false,
    ignoreThrottle: false,
  );

  runApp(MyApp());
}

Now any MixConfig or explicit parameter that doesn’t specify a value will use your custom defaults instead of the built-in ones.