JavaScript设计模式总结-组合模式

const Folder = function(name) {
  this.name = name;
  this.parent = null;
  this.files = [];
};
Folder.prototype.add = function(file) {
  file.parent = this;
  this.files.push(file);
};
Folder.prototype.scan = function() {
  console.log(‘扫描文件夹：‘, this.name);
  this.files.forEach(file => {
    file.scan();
  });
};

Folder.prototype.remove = function() {
  if(!this.parent) { // 若为根节点，则不能移除
    return;
  };
  this.parent.files.forEach((file, index) => {
    if(file === this) {
      file.splice(index, 1);
    }
  });
};

const File = function(name) {
  this.name = name;
  this.parent = null;
};

File.prototype.add = function() {
  throw new Error(‘不能在文件下添加‘);
};
File.prototype.scan = function() {
  console.log(‘扫描文件：‘, this.name);
};
File.prototype.remove = function() {
  if(!this.parent) {
    return;
  }
  this.parent.files.forEach((file, index) => {
    if (file === this) {
      file.splice(index, 1);
    }
  });
};

const folder = new Folder(‘学习资料‘);
const folder1 = new Folder(‘Javascript‘);
const file1 = new Folder(‘深入浅出node.js‘);
folder1.add(new File(‘JavaScript设计模式与开发实践));
folder.add(folder1);
folder.add(file);
folder1.remove();
folder.scan();