原因

Question

好吧，我对编码这种情况的最佳方法有一个疑问：我有一类需要在所有项目中使用静态变量的类：connection

没有名称空间的单子：

class Broker {
  static connection: Connection = undefined;
  static channel: Channel = undefined;
  static urli: string = process.env.RABBIT_URL || 'url';
  static start() {
    return new Promise<Connection>((resolve, reject) => {
      if (Broker.connection || !Broker.urli) {
        const message = !Broker.urli
          ? 'The host of rabbitmq was not found in the environment variables'
          : 'Connection has already been established';
        logger.info(message);
        reject(new Error(message));
      }
      retry<Connection>(() => connect(Broker.urli), 10, 1000)
        .then((conn) => {
          Broker.connection = conn;
          resolve(conn);
        })
        .catch((err) => reject(new Error(err)));
    });
  }
}
export const ConnectionMQ: Connection = Broker.connection;
export const ChannelMQ: Channel = Broker.channel;
export const start = () => {
  return Broker.start();
};

具有命名空间

//namespace
namespace Broker {
  export type QueuesToAssert = { queue: string; options?: Options.AssertQueue };
  export type ExchangesToAssert = {
    exchange: string;
    type: string;
    options?: Options.AssertExchange;
  };
  export type QueuesToBind = {
    queue: string;
    source: string;
    pattern: string;
    args?: any;
  };
  //static
  class BrokerMain {
    static connection: Connection = undefined;
    static channel: Channel = undefined;
    static urli: string = process.env.RABBIT_URL || 'url';
    static start() {
      return new Promise<Connection>((resolve, reject) => {
        if (BrokerMain.connection || !BrokerMain.urli) {
          const message = !BrokerMain.urli
            ? 'The host of rabbitmq was not found in the environment variables'
            : 'Connection has already been established';
          logger.info(message);
          reject(new Error(message));
        }
        retry<Connection>(() => connect(BrokerMain.urli), 10, 1000)
          .then((conn) => {
            this.connection = conn;
            resolve(conn);
          })
          .catch((err) => reject(new Error(err)));
      });
    }
  }
  export const Connection = BrokerMain.connection;
  export const Channel = BrokerMain.channel;
  export const start = () => {
    return BrokerMain.start();
  };
  export const close = () => {};
}
//usage
const connection = Broker.Connection ? Broker.start() : undefined;

我想知道在这种情况下最好/正确的选择是什么，或者我是否可以对这种情况采取另一种方法。记住我只需要类的2个唯一变量，它们是整个项目中唯一的静态变量。我怀疑在这种情况下是否需要单例或者只是静态已经解决了

Answer 1

我想知道在这种情况下最佳/正确的选择是什么

我绝对会推荐静态类方法。

原因

namespace是仅TypeScript的功能，许多现成的工具不支持，例如创建React应用。

具有静态变量/单例模式的打字稿类

1 个答案:

原因