Cmd class TUI

A command that produces a message asynchronously.

Commands represent side effects in the TUI architecture. They are async operations that, when complete, may produce a message to be sent back to the Model.update function.

• Msg: Represents an event (key press, timer tick, network response).
• Cmd: Represents an effect to be performed by the runtime (quitting, sending a message, running an external process).

Use BatchMsg to group multiple messages, and BatchCmd to group multiple commands.

Built-in Commands

• Cmd.none - No-op command
• Cmd.quit - Exit the program
• Cmd.tick - Single timer
• Cmd.every - Repeating timer
• Cmd.batch - Run multiple commands concurrently
• Cmd.sequence - Run commands in order
• Cmd.message - Immediately send a message

Custom Commands

Create custom commands by providing an async function:

Cmd fetchData() {
  return Cmd(() async {
    final response = await http.get(Uri.parse('https://api.example.com/data'));
    return DataLoadedMsg(response.body);
  });
}