JS Factory demo

categoryTree.js

const categories = [
  {id:'animals', parent:null},
  {id:'mammals', parent:'animals'},
  {id:'cats', parent:'mammals'},
  {id:'dogs', parent:'mammals'},
  {id:'chihuahua', parent:'dogs'},
  {id:'labrador', parent:'dogs'},
  {id:'persian', parent:'cats'},
  {id:'siamese', parent:'cats'},
]
//经典Abstract Factory
class AbstractTreeNode {
  constructor(data){
    this.id = data.id;
    this.children = [];
    this.map = new Map();
    this.map.set(this.id, this);
  }
  insert(factory, item){
    const node = factory.create(item);
    if(this.map.get(item.parent))
      this.map.get(item.parent).append(node);
  }
  append(node){
    node.parent = this;
    this.children.push(node);
    var current = this;
    while(current) {
      current.map.set(node.id, node);
      current = current.parent;
    }
  }
}
AbstractTreeNode.fromItems = function fromItems(factory, items) {
  let root = null;
  
  for(let item of items) {
    if(item.parent != null)
      root.insert(factory, item);
    else
      root = factory.create(item);
  }
  return root;
}

class TreeNode1 extends AbstractTreeNode {
  
}

class AbstractTreeNodeFactory {
}

class TreeNode1Factory extends AbstractTreeNodeFactory{
  create(item){
    return new TreeNode1(item);
  }
}

AbstractTreeNode.fromItems(new TreeNode1Factory, categories)

categoryTreeProto.js

const categories = [
  {id:'animals', parent:null},
  {id:'mammals', parent:'animals'},
  {id:'cats', parent:'mammals'},
  {id:'dogs', parent:'mammals'},
  {id:'chihuahua', parent:'dogs'},
  {id:'labrador', parent:'dogs'},
  {id:'persian', parent:'cats'},
  {id:'siamese', parent:'cats'},
]
//经典Abstract Factory
const abstractTreeNodePrototype = {
  init(data) {
    this.id = data.id;
    this.children = [];
    this.map = new Map();
    this.map.set(this.id, this);
  },
  insert(item){
    const node = Object.create(this);
    node.init(item);
    if(this.map.get(item.parent))
      this.map.get(item.parent).append(node);
  },
  append(node){
    node.parent = this;
    this.children.push(node);
    var current = this;
    while(current) {
      current.map.set(node.id, node);
      current = current.parent;
    }
  },
  fromItems(items) {
    let root = null;

    for(let item of items) {
      if(item.parent != null)
        root.insert(item);
      else {
        root = Object.create(this);
        root.init(item);
      }
    }
    return root;
  }
};

const tree1NodePrototype = Object.create(abstractTreeNodePrototype)

tree1NodePrototype.fromItems(categories)