需求：首先这是一个数据集—js的类型，我们需要把生成一个tree形式的对象 :
var data =[{ //模拟数据库接口返回的 分类数据
"status": 1,
"_id": "5b9a68538f041546600439e7",
"title": "技术团队",
"describe": "这是一个技术团队",
"keywords": "技术团队",
"pid": "0",
"addTime": "2018-01-01T00:00:00.000Z"
}, {
"status": 1,
"_id": "5b9a696c3e7dc24660bd9b7e",
"title": "数码",
"describe": "这是数码",
"keywords": "数码",
"pid": "0",
"addTime": "2018-01-01T00:00:00.000Z"
}, {
"status": 1,
"_id": "5b9a69a63e7dc24660bd9b7f",
"title": "前端开发1",
"describe": "这是前端开发",
"keywords": "前端",
"pid": "5b9a68538f041546600439e7",
"addTime": "2018-01-01T00:00:00.000Z"
}, {
"status": 1,
"_id": "5b9a69d83e7dc24660bd9b80",
"title": "后端开发",
"describe": "这是后端开发",
"keywords": "后端",
"pid": "5b9a68538f041546600439e7",
"addTime": "2018-01-01T00:00:00.000Z"
}, {
"status": 1,
"_id": "5b9a69fb3e7dc24660bd9b81",
"title": "iphone",
"describe": "这是iphone",
"keywords": "iphone",
"pid": "5b9a696c3e7dc24660bd9b7e",
"addTime": "2018-01-01T00:00:00.000Z"
}, {
"status": 1,
"_id": "5b9a6a173e7dc24660bd9b82",
"title": "华为",
"describe": "这是华为",
"keywords": "华为",
"pid": "5b9a696c3e7dc24660bd9b7e",
"addTime": "2018-01-01T00:00:00.000Z"
}, {
"status": 1,
"_id": "5b9a79f13e7dc24660bd9b83",
"title": "iphone6s",
"describe": "这是iphone6s",
"keywords": "iphone6s",
"pid": "5b9a69fb3e7dc24660bd9b81",
"addTime": "2018-01-01T00:00:00.000Z"
}]
js转换为上面数据集，实现数树级递归方法：
function toTreeAndMap(data) { //递归树算法 将pid-id的数据库返回的json 转为树json
// 删除 所有 children,以防止多次调用
data.forEach(function (item) {
delete item.children;
});
// 将数据存储为 以id为KEY的map索引数据列
let map = {};
data.forEach(function (item) {
map[item._id] = item;
});
// console.log(map);
let val = [];
data.forEach(function (item) {
// 以当前遍历项，的pid,去map对象中找到索引的id
var parent = map[item.pid];
// 好绕啊，如果找到索引，那么说明此项不在顶级当中,那么需要把此项添加到，他对应的父级中
if (parent) {
(parent.children || ( parent.children = [] )).push(item); //这里更改的是map对象的数据(索引数据)
// console.log(map);
} else {
//如果没有在map中找到对应的索引ID,那么直接把 当前的item添加到 val结果集中，作为顶级
val.push(item);
}
});
return {
treeData:val, //树结构json数据 可以渲染html
map //索引数据 方便通过ID查找所有子节点ID
};
}
调用方式
let jsonData = toTreeAndMap(data);
console.log(jsonData.treeData); //将data数据 转换成树
console.log(jsonData.map); //将data数据 转换成 map索引对象
id,与pid之间的对应关系，当pid不存在，或pid:0的时候，这一项，应该为树的顶端,那么我们需要去重新建一次索引，怎么建呢，，，以原数据集的id的值，重新生成一个数据如下:
[{
"status": 1,
"_id": "5b9a68538f041546600439e7",
"title": "技术团队",
"describe": "这是一个技术团队",
"keywords": "技术团队",
"pid": "0",
"addTime": "2018-01-01T00:00:00.000Z",
"children": [{
"status": 1,
"_id": "5b9a69a63e7dc24660bd9b7f",
"title": "前端开发1",
"describe": "这是前端开发",
"keywords": "前端",
"pid": "5b9a68538f041546600439e7",
"addTime": "2018-01-01T00:00:00.000Z"
}, {
"status": 1,
"_id": "5b9a69d83e7dc24660bd9b80",
"title": "后端开发",
"describe": "这是后端开发",
"keywords": "后端",
"pid": "5b9a68538f041546600439e7",
"addTime": "2018-01-01T00:00:00.000Z"
}]
}, {
"status": 1,
"_id": "5b9a696c3e7dc24660bd9b7e",
"title": "数码",
"describe": "这是数码",
"keywords": "数码",
"pid": "0",
"addTime": "2018-01-01T00:00:00.000Z",
"children": [{
"status": 1,
"_id": "5b9a69fb3e7dc24660bd9b81",
"title": "iphone",
"describe": "这是iphone",
"keywords": "iphone",
"pid": "5b9a696c3e7dc24660bd9b7e",
"addTime": "2018-01-01T00:00:00.000Z",
"children": [{
"status": 1,
"_id": "5b9a79f13e7dc24660bd9b83",
"title": "iphone6s",
"describe": "这是iphone6s",
"keywords": "iphone6s",
"pid": "5b9a69fb3e7dc24660bd9b81",
"addTime": "2018-01-01T00:00:00.000Z"
}]
}, {
"status": 1,
"_id": "5b9a6a173e7dc24660bd9b82",
"title": "华为",
"describe": "这是华为",
"keywords": "华为",
"pid": "5b9a696c3e7dc24660bd9b7e",
"addTime": "2018-01-01T00:00:00.000Z"
}]
}]
js通过pid 查找所有子节点方法：
function getAllChildrenNodes(treeParentNode,result = []){ //已知父节点 获取所有子节点ID 参数一 map对象(索引数据)父节点 参数二 存放子节点的数组
if (treeParentNode.children) { //如果是父节点
var childrenNodes = treeParentNode.children;
if (childrenNodes) {
childrenNodes.forEach((v,i)=>{
result.push(v);
result = getAllChildrenNodes(v, result);
});
}
}
return result;
}
调用方式
let result = getAllChildrenNodes(jsonData.map['5b9a696c3e7dc24660bd9b7e']); //通过父节点ID 查找所有子节点
console.log(result);
