Question

我正在尝试创建一个api，它将在expressjs中创建一个包含成员的组。这是它到目前为止的工作方式：

使用req.body中的JSON对象发布帖子请求，我将使用该对象创建一个新组。如果req.body对象的成员数组包含成员标识，则将其添加到组成员数组中，否则创建新用户，然后将其id添加到数组中。

基本上只添加现有用户，将创建新用户然后添加。为此，我需要遍历req.body中的成员数组并检查对象。

但是下面的代码似乎没有正常工作。我console.log(group_info.members);的结果很奇怪。我期望这包含一个数组中id的对象，但得到随机结果。在foreach循环中似乎有些错误。请帮我搞清楚。

var express = require('express');
var router = express.Router();
var Group = require('../models/GroupModel');
var User = require('../models/UserModel');
var async = require("async");

router.post('/', function (req, res, next) {
var group_members = [];
var group_info = req.body;

//see if a member object is sent, create user for that else just add the user id to group_members array

async.forEach(group_info.members, function (member, callback) {
    if (typeof member == "object") {
        //create new user and add the _id to members array
        var user = new User(member);
        user.save(function (err) {
            if (err) return res.status(500).send(err);
            var member_object = {id: user._id};
            group_members.push(member_object);
        }).then(callback);
    } else {
        var member_object = {id: member };
        group_members.push(member_object);
        callback();
    }
}, function (err) {
    //final call back
    group_info.members = group_members; //replace the original array in request body with the new array of users
    console.log(group_info.members);
    var group = new Group(group_info);
    group.save(function (err) {
        if (err) return res.status(500).send(err);
        res.json(group);
    });
});
});

Answer 1

var group_members = [];
var group_info = req.body;

var todo = group_info.members.length;
var done = 0;
if(todo == 0)
{
    return saveGroup(res, group_members);
}
else
{
    group_info.members.forEach(function (member, index, array) {
       if (typeof member == "object") {
            //create new user and add the _id to members array
            var user = new User(member);
            user.save(function (err, savedObject) {
                if (err || !savedObject)
                {
                    return res.status(500).send(err);
                }
                else
                {

                    var member_object = {id: savedObject._id};
                    group_members.push(member_object);
                    if(++done >= todo)
                    {
                        return saveGroup(res, group_info, group_members);
                    }
                }
            });
        } else {
           var member_object = {id: member };
           group_members.push(member_object);
           if(++done >= todo)
           {
                return saveGroup(res, group_info, group_members);
            }
        }
    });
}

function saveGroup(res, group_info, group_members)
{
    group_info.members = group_members; //replace the original array in request body with the new array of users
    console.log(group_info.members);
    var group = new Group(group_info);
    group.save(function (err) {
        if (err) return res.status(500).send(err);
        res.json(group);
    });
}

Answer 2

Looks like you made a mistake its eachSeries并非forEach，所以只需替换：

 async.forEach(group_info.members, function (member, callback)

使用：

async.eachSeries(group_info.members, function (member, callback)

<强>更新

正如评论中指出的那样 forEach 是async each API的别名，您可以阅读文档here，感谢@megawac指点这个。

如何使用async和foreach迭代数组

2 个答案: