所以这是我获取与其相应主题相关的所有帖子的方法。
const moment = require('moment');
const mongoose = require('mongoose');
mongoose.Promise = global.Promise;
const Post = require('../models/Post');
let posts = {
getPosts: function(req, res) {
return Post.find({ topicId: req.params._id })
.then(function(result) {
console.log('------------------------------------');
console.log('Headed to the Client: ', result);
console.log('------------------------------------');
res.json(result);
})
.catch(function(error) {
console.log('Nope! Nerd!');
return Promise.reject(error);
})
}
}
结果如下：
[ { _id: 58deac2223b5b92ce45bdfac,
topicId: '58dd6f541919c541dbf9632d',
parentId: null,
content: '1 Post',
author: 'Bob',
createdAt: 2017-03-31T19:21:06.698Z,
isAnon: false,
__v: 0,
comments: [],
isArchieved: false,
isParent: true },
{ _id: 58deac2c23b5b92ce45bdfad,
topicId: '58dd6f541919c541dbf9632d',
parentId: null,
content: '2 Post',
author: 'Bob',
createdAt: 2017-03-31T19:21:16.622Z,
isAnon: false,
__v: 0,
comments: [],
isArchieved: false,
isParent: true },
{ _id: 58deac3c23b5b92ce45bdfae,
topicId: '58dd6f541919c541dbf9632d',
parentId: null,
content: '3 Post',
author: 'Bob',
createdAt: 2017-03-31T19:21:32.682Z,
isAnon: false,
__v: 0,
comments: [],
isArchieved: false,
isParent: true },
{ _id: 58deac5e23b5b92ce45bdfaf,
topicId: '58dd6f541919c541dbf9632d',
parentId: '58deac3c23b5b92ce45bdfae',
content: '1 Comment',
author: 'Kat',
createdAt: 2017-03-31T19:22:06.974Z,
isAnon: false,
__v: 0,
comments: [],
isArchieved: false,
isParent: false },
{ _id: 58deac6c23b5b92ce45bdfb0,
topicId: '58dd6f541919c541dbf9632d',
parentId: '58deac2223b5b92ce45bdfac',
content: '2 Comment',
author: 'Dave',
createdAt: 2017-03-31T19:22:20.071Z,
isAnon: false,
__v: 0,
comments: [],
isArchieved: false,
isParent: false },
{ _id: 58deac7a23b5b92ce45bdfb1,
topicId: '58dd6f541919c541dbf9632d',
parentId: '58deac2c23b5b92ce45bdfad',
content: '4 Comment',
author: 'Bob',
createdAt: 2017-03-31T19:22:34.865Z,
isAnon: false,
__v: 0,
comments: [],
isArchieved: false,
isParent: false } ]
我遇到了问题，因为我需要在数据库出来之后修改这个列表以获取带有parentIds的帖子并将它们推送到相应的父级＆＃39; comments数组中。
所以实际发送给客户端的结果如下所示：
[{
_id: 58deac2223b5b92ce45bdfa',
topicId: '58dd6f541919c541dbf9632d',
parentId: null,
content: '1 Post',
author: 'Bob',
isAnon: false,
__v: 0,
comments: [{
_id: 58deac6c23b5b92ce45bdfb0,
topicId: '58dd6f541919c541dbf9632d',
parentId: '58deac2223b5b92ce45bdfac',
content: '2 Comment',
author: 'Dave',
isAnon: false,
__v: 0,
comments: [],
isArchieved: false,
isParent: false
}],
isArchieved: false,
isParent: true
},
{
_id: 58deac2c23b5b92ce45bdfad,
topicId: '58dd6f541919c541dbf9632d',
parentId: null,
content: '2 Post',
author: 'Bob',
isAnon: false,
__v: 0,
comments: [{
_id: 58deac7a23b5b92ce45bdfb1,
topicId: '58dd6f541919c541dbf9632d',
parentId: '58deac2c23b5b92ce45bdfad',
content: '4 Comment',
author: 'Bob',
isAnon: false,
__v: 0,
comments: [],
isArchieved: false,
isParent: false
}],
isArchieved: false,
isParent: true
},
{
_id: 58deac3c23b5b92ce45bdfae,
topicId: '58dd6f541919c541dbf9632d',
parentId: null,
content: '3 Post',
author: 'Bob',
isAnon: false,
__v: 0,
comments: [{
_id: 58deac5e23b5b92ce45bdfaf,
topicId: '58dd6f541919c541dbf9632d',
parentId: '58deac3c23b5b92ce45bdfae',
content: '1 Comment',
author: 'Kat',
isAnon: false,
__v: 0,
comments: [],
isArchieved: false,
isParent: false
}],
isArchieved: false,
isParent: true
}
]
我知道我需要通过阵列进行递归，但是我很难理解它们之间的逻辑。任何帮助，将不胜感激。非常感谢你。
答案 0 :(得分：0)
您可以使用对象收集所有节点，并将找到的子节点附加到comments属性。获取parentId === null作为根节点的节点。
此方法适用于任何深度的未排序数据，并使用单个循环来获取嵌套结果。
var data = [{ _id: '58deac2223b5b92ce45bdfac', topicId: '58dd6f541919c541dbf9632d', parentId: null, content: '1 Post', author: 'Bob', createdAt: '2017-03-31T19:21:06.698Z', isAnon: false, __v: 0, comments: [], isArchieved: false, isParent: true }, { _id: '58deac2c23b5b92ce45bdfad', topicId: '58dd6f541919c541dbf9632d', parentId: null, content: '2 Post', author: 'Bob', createdAt: '2017-03-31T19:21:16.622Z', isAnon: false, __v: 0, comments: [], isArchieved: false, isParent: true }, { _id: '58deac3c23b5b92ce45bdfae', topicId: '58dd6f541919c541dbf9632d', parentId: null, content: '3 Post', author: 'Bob', createdAt: '2017-03-31T19:21:32.682Z', isAnon: false, __v: 0, comments: [], isArchieved: false, isParent: true }, { _id: '58deac5e23b5b92ce45bdfaf', topicId: '58dd6f541919c541dbf9632d', parentId: '58deac3c23b5b92ce45bdfae', content: '1 Comment', author: 'Kat', createdAt: '2017-03-31T19:22:06.974Z', isAnon: false, __v: 0, comments: [], isArchieved: false, isParent: false }, { _id: '58deac6c23b5b92ce45bdfb0', topicId: '58dd6f541919c541dbf9632d', parentId: '58deac2223b5b92ce45bdfac', content: '2 Comment', author: 'Dave', createdAt: '2017-03-31T19:22:20.071Z', isAnon: false, __v: 0, comments: [], isArchieved: false, isParent: false }, { _id: '58deac7a23b5b92ce45bdfb1', topicId: '58dd6f541919c541dbf9632d', parentId: '58deac2c23b5b92ce45bdfad', content: '4 Comment', author: 'Bob', createdAt: '2017-03-31T19:22:34.865Z', isAnon: false, __v: 0, comments: [], isArchieved: false, isParent: false }],
tree = function (data, root) {
var r = [],
o = {};
data.forEach(function (a) {
a.comments = (o[a._id] && o[a._id].comments || []).concat();
o[a._id] = a;
if (a.parentId === root) {
r.push(a);
} else {
o[a.parentId] = o[a.parentId] || {};
o[a.parentId].comments = o[a.parentId].comments || [];
o[a.parentId].comments.push(a);
}
});
return r;
}(data, null);
console.log(tree);.as-console-wrapper { max-height: 100% !important; top: 0; }