JS 发布订阅模式实现的一个字典工具恢复类

JS 发布订阅模式实现的一个字典工具恢复类

class Dictionary {
  constructor() {
    this.data = {};
    this.events = {};
  }

  add(key, value) {
    this.data[key] = value;
    this.trigger('add', key, value);
  }

  remove(key) {
    const value = this.data[key];
    delete this.data[key];
    this.trigger('remove', key, value);
  }

  get(key) {
    return this.data[key];
  }

  getAll() {
    return this.data;
  }

  on(event, callback) {
    if (!this.events[event]) {
      this.events[event] = [];
    }
    this.events[event].push(callback);
  }

  off(event, callback) {
    if (!this.events[event]) {
      return;
    }
    const index = this.events[event].indexOf(callback);
    if (index !== -1) {
      this.events[event].splice(index, 1);
    }
  }

  trigger(event, ...args) {
    if (!this.events[event]) {
      return;
    }
    this.events[event].forEach(callback => {
      callback(...args);
    });
  }
}

const dict = new Dictionary();
dict.on('add', (key, value) => {
  console.log(`Added ${key}: ${value}`);
});
dict.on('remove', (key, value) => {
  console.log(`Removed ${key}: ${value}`);
});

dict.add('key1', 'value1'); // 输出：Added key1: value1
dict.add('key2', 'value2'); // 输出：Added key2: value2
dict.remove('key1'); // 输出：Removed key1: value1
console.log(dict.getAll()); // 输出：{ key2: 'value2' }

该类实现了添加、删除、获取单个和获取所有键值对的方法，并且支持订阅“add”和“remove”事件。当添加或删除键值对时，会触发相应的事件并调用相应的回调函数。用户可以通过on()方法订阅事件，通过off()方法取消订阅，通过trigger()方法触发事件