Mix with context

The mix.ctx function is identical to mix, but passes a MixContext object to the action callback. Use it when you need access to runtime information, such as the current retry attempt number or queue position.

Basic usage

void loadData() {
  mix.ctx( // Instead of `mix`
    key: this,
    (ctx) async { // Here we now have access to `ctx`
      ...
    },
  );
}

Retry context

ctx.retry is non-null only when the retry param is used. It provides access to the current retry attempt:

• attempt: The number of retry attempts so far (0-based). On the initial attempt it’s 0, after the first retry it’s 1, etc.

• config: The retry configuration with fields maxRetries, initialDelay, multiplier, and maxDelay.

void loadData() {
  mix.ctx(
    key: this,
    retry: retry(maxRetries: 5),
    (ctx) async {
      var retryInfo = ctx.retry!;
      print('Attempt ${retry.attempt + 1} of ${retry.config.maxRetries + 1}');
      var data = await api.loadData();
      emit(data);
    },
  );
}

Sequential context

SequentialContext provides access to queue status information:

• wasQueued: true if this call had to wait in the queue before executing, false if it executed immediately.

• index: The position in the queue when the call was added. 0 means it executed immediately (no calls ahead), 1 means one call was ahead, etc.

• config: The resolved sequential configuration (ResolvedSequentialConfig).

void sendMessage(String chatId, String message) {
  mix.ctx(
    key: this,
    sequential: sequential(key: (ChatCubit, chatId)),
    (ctx) async {
      var sequential = ctx.sequential!;
      if (sequential!.wasQueued) print('Message queued at ${sequential.index}');
      await api.sendMessage(chatId, message);
    },
  );
}

Other contexts

The other context types provide access to their configurations:

• ctx.nonReentrant.config
• ctx.throttle.config
• ctx.debounce.config
• ctx.fresh.config
• ctx.checkInternet.config

When to use mix.ctx vs mix

Use mix for most cases — it’s simpler and sufficient when you don’t need the context.