[英]NodeJS :: TypeError: Cannot read property 'first_name' of undefined
I was learning the MEAN stack from a tutorial.我正在从教程中学习 MEAN 堆栈。 When I tried on my localhost, I got an error.
当我在本地主机上尝试时,出现错误。
TypeError: Cannot read property 'first_name' of undefined
类型错误:无法读取未定义的属性“first_name”
at router.post (/var/www/html/mean/contactlist/routes/route.js:17:28)
在 router.post (/var/www/html/mean/contactlist/routes/route.js:17:28)
I found some similar questions on the internet.我在网上找到了一些类似的问题。 But I didn't find the correct solution.
但我没有找到正确的解决方案。
Here is my app.js file这是我的app.js文件
//importing modules
var express = require('express');
var mongoose = require('mongoose');
var bodyparser = require('body-parser');
var cors = require('cors');
var path = require('path'); //core module
// calling express method
var app = express();
//connect to mongodb
mongoose.connect('mongodb://localhost/27017/contactlist');
//on connection
mongoose.connection.on('connected', () => {
console.log("connected to database database mongodb @ 27017 ");
});
mongoose.connection.on('error', (err) => {
if(err){
console.log('Error in Database connection : ' + err);
}
});
//adding middleware cors
app.use(cors());
//adding body parser
app.use(bodyparser.json());
//adding static files
app.use(express.static(path.join(__dirname, 'public')));
//setting port no
const port = 3000;
//routing
var route = require('./routes/route');
//using the route
app.use('/api', route);
//testing server
app.get('/', (req, res)=>{
res.send('foobar');
});
//binding the server with port no (callback)
app.listen(port,() =>{
console.log('Server Started at Port : '+ port);
});
From a stackOverflow solution, I found,从 stackOverflow 解决方案中,我发现,
I should use the following line before routing我应该在路由之前使用以下行
app.use(bodyparser.json());
So I changed it.所以我改变了它。
And my ./routes/route.js还有我的./routes/route.js
const express = require('express');
const router = express.Router();
const Contact = require('../models/contacts');
//Retrieving contacts
router.get('/contacts', (res, req, next) => {
contact.find(function(err,contacts){
res.json(contacts);
})
});
//Add contact
router.post('/contact', (res, req, next) => {
let newContact = new Contact({
first_name:req.body.first_name,
last_name:req.body.last_name,
phone:req.body.phone
});
newContact.save((err,contact) => {
if(err){
res.json({msg : 'Failed to add contact'});
}
else{
res.json({msg : 'Contact added successfully'});
}
});
});
//Deleting Contact
router.delete('/contact/:id', (res, req, next) => {
contact.remove({_id: req.params.id }, function(err, result){
if(err){
res.json(err);
}
else{
res.json(result);
}
});
});
module.exports = router;
Dependencies from package.json来自package.json 的依赖
"dependencies": {
"body-parser": "^1.17.1",
"cors": "^2.8.3",
"express": "^4.15.2",
"mongoose": "^4.9.8"
}
And the version of the nodejs is而nodejs的版本是
v7.10.0
I used Postman to test the API我使用 Postman 来测试 API
So I tested with POST method and following content-type option.所以我使用 POST 方法和以下内容类型选项进行了测试。
{"Content-Type":"application/x-www-form-urlencoded"}
This was my sample input这是我的示例输入
{
"first_name" : "RENJITH",
"last_name" : "VR",
"phone" : "1234567890"
}
Is it a version issue?是版本问题吗? Please suggest me the correct way of coding.
请建议我正确的编码方式。
Your content type is {"Content-Type":"application/x-www-form-urlencoded"}
In order to support URL-encoded bodies of data you need to use this:您的内容类型是
{"Content-Type":"application/x-www-form-urlencoded"}
为了支持 URL 编码的数据主体,您需要使用:
app.use(bodyparser.urlencoded({ // to support URL-encoded bodies
extended: true
}));
What you used is for JSON-encoded data, such as POST: {"name":"foo","color":"red"}
你使用的是 JSON 编码的数据,比如
POST: {"name":"foo","color":"red"}
EDIT:编辑:
The order of your route parameters are wrong.您的路由参数的顺序是错误的。 It's not
router.post('/contact', (res, req, next)
这不是
router.post('/contact', (res, req, next)
It's actually router.post('/contact', (req, res, next)
它实际上是
router.post('/contact', (req, res, next)
The first parameter is the request, the second is the response.第一个参数是请求,第二个参数是响应。
Just Move lines body-parse at the top before route (app.js)只需在路由前移动顶部的 body-parse 行(app.js)
app.use(bodyparser.json());
app.use('/api',route);
I was facing same issue but this is how it's been solved for me我遇到了同样的问题,但这就是为我解决的方法
At the top of the file before any routes and after require
statements use在任何路由之前和
require
语句之后的文件顶部使用
app.use(bodyParser.urlencoded({extended: true}))
app.use(bodyParser.json())
then in the post request route use res.json()
然后在 post 请求路由中使用
res.json()
here is sample code:这是示例代码:
var express = require('express');
var bodyParser = require('body-parser')
var app = express();
app.use(bodyParser.urlencoded({extended: false}))
app.use(bodyParser.json())
app.get('/', (req, res) => {
res.sendFile(__dirname + './index.html')
})
app.post("/name", (req, res) => {
let fullName = req.body.first + ' ' + req.body.last;
res.json({ name: fullName })
});
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