Flutter命令处理插件nyxx_commands的使用

nyxx_commands 是一个用于轻松创建 Discord 应用中的 slash 命令和文本命令的框架，它基于 nyxx 库构建。本文将介绍如何使用 nyxx_commands 创建并管理你的命令。

特性

• 简单的命令创建
• 自动兼容 Discord 的 slash 命令
• 与 nyxx 库兼容
• 参数解析支持

编译 nyxx_commands

由于 nyxx_commands 使用了 dart:mirrors 来加载命令参数，在使用 dart compile exe 编译时可能会遇到问题。为了避免这种情况，需要在所有命令回调中使用 id 包装，并为每个函数提供唯一的 ID。

例如：

final ping = ChatCommand(
  'ping',
  'Ping the bot',
  id('ping', (IChatContext context) => context.respond(MessageBuilder.content('Pong!'))),
);

如果忘记添加 id，将会收到类似以下的错误：

Error: Command Exception: Couldn't load function data for function Closure: (IChatContext) => Null

确保对所有命令使用 id 后，可以通过运行 dart run nyxx_commands:compile 脚本来编译程序。

示例代码

下面是一个完整的示例，演示了如何设置和使用 nyxx_commands：

import 'package:nyxx/nyxx.dart';
import 'package:nyxx_commands/nyxx_commands.dart';

void main() async {
  // 初始化 CommandsPlugin
  final commands = CommandsPlugin(
    prefix: (message) => '!',
    guild: Snowflake.parse(Platform.environment['GUILD']!),
    options: CommandsOptions(logErrors: true),
  );

  // 连接到 Discord
  await Nyxx.connectGateway(
    Platform.environment['TOKEN']!,
    GatewayIntents.allUnprivileged | GatewayIntents.guildMembers,
    options: GatewayClientOptions(plugins: [commands]),
  );

  // 注册一个简单的 ping 命令
  final ping = ChatCommand(
    'ping',
    'Checks if the bot is online',
    id('ping', (ChatContext context) {
      context.respond(MessageBuilder(content: 'pong!'));
    }),
  );

  commands.addCommand(ping);

  // 注册一个带有子命令的命令组
  final throwGroup = ChatGroup(
    'throw',
    'Throw an object',
    children: [
      ChatCommand(
        'coin',
        'Throw a coin',
        id('throw-coin', (ChatContext context) {
          bool heads = Random().nextBool();
          context.respond(MessageBuilder(content: 'The coin landed on its ${heads ? 'head' : 'tail'}!'));
        }),
      ),
    ],
  );

  throwGroup.addCommand(ChatCommand(
    'die',
    'Throw a die',
    id('throw-die', (ChatContext context) {
      int number = Random().nextInt(6) + 1;
      context.respond(MessageBuilder(content: 'The die landed on the $number!'));
    }),
  ));

  commands.addCommand(throwGroup);

  // 注册一个带参数的命令
  final say = ChatCommand(
    'say',
    'Make the bot say something',
    id('say', (ChatContext context, String message) {
      context.respond(MessageBuilder(content: message));
    }),
  );

  commands.addCommand(say);

  // 注册一个带有自定义转换器的命令
  enum Shape { triangle, square, pentagon }
  enum Dimension { twoD, threeD }

  Converter<Shape> shapeConverter = Converter<Shape>(
    (view, context) {
      switch (view.getQuotedWord().toLowerCase()) {
        case 'triangle':
          return Shape.triangle;
        case 'square':
          return Shape.square;
        case 'pentagon':
          return Shape.pentagon;
        default:
          return null;
      }
    },
    choices: [
      CommandOptionChoiceBuilder(name: 'Triangle', value: 'triangle'),
      CommandOptionChoiceBuilder(name: 'Square', value: 'square'),
      CommandOptionChoiceBuilder(name: 'Pentagon', value: 'pentagon'),
    ],
  );

  commands.addConverter(shapeConverter);

  final favoriteShape = ChatCommand(
    'favorite-shape',
    'Outputs your favorite shape',
    id('favorite-shape', (ChatContext context, Shape shape, Dimension dimension) {
      String favorite;

      switch (shape) {
        case Shape.triangle:
          favorite = dimension == Dimension.twoD ? 'triangle' : 'pyramid';
          break;
        case Shape.square:
          favorite = dimension == Dimension.twoD ? 'square' : 'cube';
          break;
        case Shape.pentagon:
          favorite = dimension == Dimension.twoD ? 'pentagon' : 'pentagonal prism';
          break;
      }

      context.respond(MessageBuilder(content: 'Your favorite shape is $favorite!'));
    }),
  );

  commands.addCommand(favoriteShape);
}