JavaScript树形结构中递归更新父子节点数据教程

const data = [
  {
    key: "id1",
    name: "Category 1",
    curr: 0,
    total: 0,
    nodes: [
      {
        key: "id2",
        name: "Applications",
        curr: 20,
        total: 30,
        nodes: [
          {
            key: "id3",
            name: "Gaming",
            curr: 5,
            total: 10,
            nodes: []
          },
          {
            key: "id4",
            name: "Operating System",
            curr: 15,
            total: 20,
            nodes: []
          }
        ]
      }
    ]
  },
  {
    key: "id5",
    name: "Category 2",
    curr: 0,
    total: 0,
    nodes: [
      {
        key: "id6",
        name: "Sub Category",
        curr: 12,
        total: 48,
        nodes: [
          {
            key: "id7",
            name: "Inside Sub",
            curr: 12,
            total: 48,
            nodes: []
          }
        ]
      }
    ]
  },
  {
    key: "id8",
    name: "Last One",
    curr: 0,
    total: 0,
    nodes: []
  }
];

const output = [
  {
    key: "id1",
    name: "Category 1",
    curr: 0, // 注意：id1 是根节点，不更新
    total: 0,
    nodes: [
      {
        key: "id2",
        name: "Applications",
        curr: 21, // id2 是 id4 的祖先，更新
        total: 30,
        nodes: [
          {
            key: "id3",
            name: "Gaming",
            curr: 5,
            total: 10,
            nodes: []
          },
          {
            key: "id4",
            name: "Operating System",
            curr: 16, // id4 是目标节点，更新
            total: 20,
            nodes: []
          }
        ]
      }
    ]
  },
  // ... 其他节点保持不变
];

const incrementRecursively = (nodes, key) => {
  const increment = (nodes, key) => {
    nodes.forEach((node) => {
      if (node.key === key) {
        node.curr++; // 仅更新目标节点
      }
      if (node.nodes && node.nodes.length) { // 检查 node.nodes 是否存在且有元素
        increment(node.nodes, key); // 递归调用，但没有向上级联的能力
      }
    });
  };
  increment(nodes, key);
  return nodes;
};

/**
 * 递归更新树形结构中指定key的节点及其所有祖先节点的curr值，但不更新根节点。
 * @param {Array<Object>} nodes - 当前层级的节点数组。
 * @param {string} key - 需要更新的目标节点的key。
 * @param {number} [depth=0] - 当前递归的深度，根节点深度为0。
 * @returns {boolean} 如果当前节点或其子节点被更新，则返回true；否则返回false。
 */
function updateParentChildCurr(nodes, key, depth = 0) {
    // 遍历当前层级的每个节点
    for (let node of nodes) {
        // 检查当前节点是否是目标节点，
        // 或者递归调用子节点，如果子节点中找到了目标并返回了true
        if (node.key === key || updateParentChildCurr(node.nodes ?? [], key, depth + 1)) {
            // 如果当前节点或其子节点被更新，并且当前节点不是根节点（depth > 0）
            if (depth > 0) {
                node.curr++; // 递增当前节点的curr值
            }
            return true; // 向上传播信号：此路径上的节点已被更新
        }
    }
    return false; // 当前层级没有找到目标节点或其子节点
}

// 示例数据
const data = [
  { key: "id1", name: "Category 1", curr: 0, total: 0, nodes: [ { key: "id2", name: "Applications", curr: 20, total: 30, nodes: [ { key: "id3", name: "Gaming", curr: 5, total: 10, nodes: [] }, { key: "id4", name: "Operating System", curr: 15, total: 20, nodes: [] } ] } ] },
  { key: "id5", name: "Category 2", curr: 0, total: 0, nodes: [ { key: "id6", name: "Sub Category", curr: 12, total: 48, nodes: [ { key: "id7", name: "Inside Sub", curr: 12, total: 48, nodes: [] } ] } ] },
  { key: "id8", name: "Last One", curr: 0, total: 0, nodes: [] }
];

// 调用函数进行更新
// updateParentChildCurr(data, 'id4');
// console.log("更新id4后的数据:", JSON.stringify(data, null, 2));

// 再次调用，例如更新id7
// updateParentChildCurr(data, 'id7');
// console.log("更新id7后的数据:", JSON.stringify(data, null, 2));