TypeError:无法在字符串"{""[object Object]":“""}"上创建属性"_id" [英] TypeError: Cannot create property '_id' on string '{"[object Object]":""}'

问题描述

我正在尝试发布表单数据，但是在提交时遇到以下错误:

I'm trying to post form data, but I'm getting the following error on submit:

TypeError:无法在字符串'{"[object Object]":"}''上创建属性'_id'.

TypeError: Cannot create property '_id' on string '{"[object Object]":""}'.

我的信息被成功捕获:

电影{id:"8"，名字:"test"，姓氏:"test"，英雄:"test"，照片:"xxxxxxxx"}

Movie {id: "8", firstname: "test", lastname: "test", hero: "test", photo: "xxxxxxxx"}

但是数据未保存在MongoDB中.我在Angular2中使用MEAN堆栈.

But the data is not saved in MongoDB. I'm using the MEAN stack with Angular2.

我的 server.js :

//Need to write the Express code

var express = require('express');
var path = require('path');
var bodyParser = require('body-parser');

var indexApi = require('./routes/index');
var movieApi = require('./routes/movie');

var port = 3000;

var app = express();

// parse application/x-www-form-urlencoded
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());
// parse application/vnd.api+json as json
//app.use(bodyParser.json({ type: 'application/json' }))

app.use('/',indexApi);
// Register the movie.js file
app.use('/api',movieApi);

// View Engine
app.set('views',path.join(__dirname, 'views'));
app.set('view engine','ejs');
app.engine('html',require('ejs').renderFile);

// Set static folder so that our all the things we read from client folder
app.use(express.static(path.join(__dirname,'client')));

app.listen(port,function(){
  console.log("Server started at port number : "+ port);
});

我将数据发布如下:

 my app.component.ts:

 saveDetails(movieObj){
            //Note: I am getting the movie object here
            this.moviesService.saveMovie(movieObj).
                                            subscribe((data=> this.movieObj = JSON.stringify(data._body);
                                            console.log(this.movieObj);
                                             );

   }

  and movies.service.ts: 

    saveMovie(movie){
       //Note: I am getting the movie object here also
       var headers = new Headers();
       headers.append('Content-Type', 'application/x-www-form-urlencoded');
       return this.http.post('http://localhost:3000/api/movie',
                                        movie, {
                                        headers: headers});
    }

    movie.js:

    router.post('/movie',function(req,res){
        console.log("Under Post call....");
       var movieObj= req.body;

       // Note: here in the console everthing is comming as undefined thats is the problem
       console.log("[_id]"+movieObj._id+"[id]"+movieObj.id+"[firstname]"+movieObj.firstname+"[lastname]"+movieObj.lastname+"[hero]"+movieObj.hero+"[photo]"+movieObj.photo);

        db.movies.save(movieObj,function(err,docs){
            if(err){
            res.send(err);
             }
             res.json(docs);
       });
});

我得到的输出是{"_id":"590aad3ec7133419f056bc77"，"\" {\\"[对象对象] \\":\\"\\"，\\"_ id \\":\ \"590aa9c455f16d0eb440673e \\"} \":"}]

The output what i am getting is {"_id":"590aad3ec7133419f056bc77","\"{\\"[object Object]\\":\\"\\",\\"_id\\":\\"590aa9c455f16d0eb440673e\\"}\"":""}]

点击 http://localhost:3000/api/movies 网址时.

注意: 目的是将数据保存在MongoDB中.

Note: The aim is to save data in MongoDB.

推荐答案

当您传递String时，MongoDB接受Object.

MongoDB accepts an Object whereas you are passing a String.

错

var jsontest = JSON.stringify(movieObj); 

正确

var jsontest=movieObj;

P.S:假设主体是正确的电影对象.

P.S : assuming req.body is correct movie object.

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