js实现claasFactory

JavaScript 实现 Class Factory

在 JavaScript 中，可以使用工厂函数或类工厂模式动态创建类。以下是一种常见的实现方式：

使用工厂函数创建类

function createClass(properties) {
  return class {
    constructor(...args) {
      if (properties.constructor) {
        properties.constructor.apply(this, args);
      }
    }
  };
}

添加方法和属性

function createClass(properties) {
  const klass = class {
    constructor(...args) {
      if (properties.constructor) {
        properties.constructor.apply(this, args);
      }
    }
  };

  Object.keys(properties).forEach(key => {
    if (key !== 'constructor') {
      klass.prototype[key] = properties[key];
    }
  });

  return klass;
}

使用示例

const Person = createClass({
  constructor: function(name) {
    this.name = name;
  },
  sayHello: function() {
    console.log(`Hello, I'm ${this.name}`);
  }
});

const john = new Person('John');
john.sayHello(); // 输出: Hello, I'm John

支持继承

function createClass(properties, parentClass = Object) {
  const klass = class extends parentClass {
    constructor(...args) {
      super(...args);
      if (properties.constructor) {
        properties.constructor.apply(this, args);
      }
    }
  };

  Object.keys(properties).forEach(key => {
    if (key !== 'constructor') {
      klass.prototype[key] = properties[key];
    }
  });

  return klass;
}

静态方法支持

function createClass(properties, parentClass = Object) {
  const klass = class extends parentClass {
    constructor(...args) {
      super(...args);
      if (properties.constructor) {
        properties.constructor.apply(this, args);
      }
    }
  };

  Object.keys(properties).forEach(key => {
    if (key === 'static') {
      Object.keys(properties.static).forEach(staticKey => {
        klass[staticKey] = properties.static[staticKey];
      });
    } else if (key !== 'constructor') {
      klass.prototype[key] = properties[key];
    }
  });

  return klass;
}

完整实现示例

const Animal = createClass({
  constructor: function(name) {
    this.name = name;
  },
  eat: function() {
    console.log(`${this.name} is eating`);
  },
  static: {
    createRandom: function() {
      const names = ['Fluffy', 'Spot', 'Rover'];
      const randomName = names[Math.floor(Math.random() * names.length)];
      return new this(randomName);
    }
  }
});

const dog = Animal.createRandom();
dog.eat(); // 输出类似: Fluffy is eating

这种方法提供了灵活的方式来动态创建类，并支持继承、实例方法和静态方法。