Unable to get values in NodeJs Express - node.js

I am trying to make post request but unable to get values in Postman; it's sending undefined. I am using Express version 4.17.1. Below is my code:
const express = require('express');
const router = express.Router();
const MongoClient = require('mongodb').MongoClient;
const dburl = process.env.URL;
router.use(express.json());
router.use(express.urlencoded({extended:true}));
router.post('/register',(req,res) => {
var data = {
name:req.body.name,
email:req.body.email,
};
res.send(data);
});
module.exports = router;
What am I doing wrong?

Your code snippet works, tested with express 4.17.1 on node 12.19.0. The issue must be from elsewhere.
Possible issues are:
The parser for router could have been overridden by the parser for app (assuming you're calling app.use(router) somewhere).
Can you move this to app level?
router.use(express.json());
router.use(express.urlencoded({extended:true}));

Related

TypeError: Router.use() requires a middleware function but got a Object[using express router] --

The app, I am building with nodeJS expressJS is for connecting to a sqlserver database and retrieving data. Am trying to make the code as modular and
reusable as posssible. So different files for routing and controller. The error I am now facing is-
throw new TypeError('Router.use() requires a middleware function but got a ' + gettype(fn))
^
TypeError: Router.use() requires a middleware function but got a Object
For ease of understanding of the imports, my project structure is as such:
controller
|-- controller.js
db
|-- db.js
query
|-- queries.json
routes
|-- route.js
package.json
server.js
My main server.js file is
const express = require('express')
const bodyParser = require('body-parser')
const cors = require('cors')
const fs = require('fs')
const path = require('path')
const morgan = require('morgan')
const router=require('./routes/route');
const app = express()
app.use(cors());
app.use(bodyParser.urlencoded({ extended: false }));
// parse application/json
app.use(bodyParser.json());
app.use(morgan('dev'));
const port = 3200
app.listen(process.env.PORT || port , (err) => {
if(err)
{
console.log('Unable to start the server!');
}
else
console.log('NodeExpress Data API started running on : ' + port);
})
the controller file is
const express=require('express')
const { sql, poolPromise } = require('../db/db')
const fs = require('fs');
class MainController
{
async getAllData(req, resp)
{
try
{
const pool = await poolPromise
const result = await pool.request()
.query("select * from players");
resp.json(result.recordset)
}
catch (error)
{
resp.status(500)
resp.send(error.message)
}
}
}
const controller=new MainController();
module.exports=controller;
and the route file is
const express = require('express');
const controller = require('../controller/controller')
const router = express.Router();
router.get('/getAllData', controller.getAllData);
So when I insert this line
app.use('api/', router) in the server.js to wire all the modules together and make calls to api endpoint to get all data, I am getting that error mentioned.
What is it about, can anyone explain me in simple terms? Is the error being thrown from the controller file, since I am initializing a new instance of the controller type? Which line from which file is throwing this error? What is the code correction needed to remove this error?
under route.js change to router.get('/getAllData', controller.getAllData()); you have passed controller.getAllData as a handler function instead of controller.getAllData() as per the type of method you have used in class. hope this solves the error.
Try out one of these:
1- if your are using express and doing
const router = express.Router();
make sure to
module.exports = router ;
at the end of your page
2- If your are using express above 2.x, you have to declare app.router like below code. Please try to replace your code
app.use('/', routes);
with
app.use(app.router);
routes.initialize(app);

how to add custom function to express module

I am trying to add a method
loadSiteSettings to express module
In app.js
var express = require('express');
var path = require('path');
var mongoose = require('mongoose');
//Set up default monggose connection for mongo db
var mongoDB = 'mongodb+srv://***:*****#cluste******j.mongodb.net/cms?retryWrites=true&w=majority';
mongoose.connect(mongoDB,{useNewUrlParser: true});
//Get the default connection
var db = mongoose.connection;
//Bind connection to error event (to get notification of connection errors)
db.on('error',console.error.bind(console, 'MongoDB connection error:'));///????????
var app = express();
///////////////////////////////////////////////////////////
var indexRouter = require('./routes/index');
app.loadSiteSettings = async function()
{
let setting = await db.collection('settings').findOne();
app.locals.siteSettings = setting;
}
app.loadSiteSettings();
//////////////////////////////////////////////////////
module.exports = app;
Index.Js for router
var express = require('express');
var router = express.Router();
var app = require('../app');
var util = require('util');
/* GET home page. */
router.get('/', function(req, res, next) {
res.render('index');
});
///////////////////////////////////////////
router.get('/reloadSettings', function(req,res,next){
app.loadSiteSettings();
})
///////////////////////////////////////
module.exports = router;
so problem lies here, when server start it calls app.loadSiteSettings() in app.js
but when i use route '/reloadSettings' it seems app is undefined in index.js
This is an issue with circular dependencies and module.exports. This answer shows the same problem.
What's happening is app.js is required first and starts processing. The important thing to understand is that a file pauses execution while requiring a new file.
So when app.js requires ./routes/index, it has not finished processing, and has not reached module.exports = app. This means that when your routes file requires app.js, it's requiring it in its current state, which is the default export {}.
Thankfully there's a very simple fix:
// can be imported and tested separately from the app
const loadSiteSettings = function() {
return db.collection('settings').findOne();
}
router.get('/reloadSettings', async function(req,res,next){
let settings = await loadSiteSettings();
req.app.locals.siteSettings = settings
res.send(200); // signal the response is successful
})
This explains the issue in a lot more depth in case you're interested

ExpressJS Middleware Method to make variable available in other (module) files

I am playing around with making a NodeJS app that combines REST API functionality with MongoDB CRUD persistence. I'm pretty new to NodeJS.
Right now I've managed to connect to the Database and figured out that the rest of my code belongs inside the callback - ie only process REST request after the DB is up and available.
The challenge I'm running into in this case is understanding how to "attach" the 'client' (from mongodb.connect) to the 'request'. I need to somehow make it available in other files because I want to keep my routes separate as a best practice.
The same question applies to any variables in the main server.js file which I need to be able to access in my modules.
Here is the relevant code:
//server.js
const express = require('express')
const mongodb = require('mongodb')
const bodyParser = require('body-parser')
const routes = require('./routes')
const url = 'mongodb://localhost:27017/testDB'
let app = express();
app.use(logger('dev'))
app.use(bodyParser.json())
mongodb.connect(url, {useNewUrlParser:true},(error, dbClient) => {
if (error) {
console.log(`Error: ${error}`)
process.exit(1)
}
//connected
console.log(`Connected to mongoDB`)
//what do I do here to make sure my routes can access dbClient?
app.get('/accounts', routes.getAccounts(req, res) )
app.listen(3000)
})
//./routes/index.js
const bodyParser = require('body-parser')
const errorhandler = require('errorhandler')
const mongodb = require('mongodb')
const logger = require('morgan')
module.exports = {
getAccounts: (req, res) => {
console.log("in getAccounts")
//how can I use dbClient in here?
}
}
Thank you in advance for your help!
My apologies if anything about my post isn't according to the normal standards, I'm brand new here! All critique appreciated, coding and otherwise!

Node express param issue

we are using Node.js + Express as back-end for an Angular2 app. One of the modules of the back-end is responsible for the information gathering about products, based on barcode, which is a param for the Express router. Currently, we're facing an issue when adding a GET request route that does not use the barcode param.
The router file looks as follows:
'use strict';
const express = require('express');
const router = express.Router();
const prodCtrl = require('./controller');
const auth = require('../middlewares/authenticationBearer');
module.exports.init = function(app) {
router.param('barcode', prodCtrl.findById);
router.get('/products/:barcode', auth.bearer(), prodCtrl.getProduct);
router.post('/products/article', auth.bearer(), prodCtrl.getProductData);
router.get('/products/csv', auth.bearer(), prodCtrl.csv);
return router;
}
The problem is the /products/csv route. In its current position, calling the route gives a 404 error seemingly because the param barcode is expected, as the function prodCtrl.findById is called first. By moving this route before the /products/:barcode route like so:
'use strict';
const express = require('express');
const router = express.Router();
const prodCtrl = require('./controller');
const auth = require('../middlewares/authenticationBearer');
module.exports.init = function(app) {
router.param('barcode', prodCtrl.findById);
router.get('/products/csv', auth.bearer(), prodCtrl.csv);
router.get('/products/:barcode', auth.bearer(), prodCtrl.getProduct);
router.post('/products/article', auth.bearer(), prodCtrl.getProductData);
return router;
}
the code works fine. Is this a bug in Express? Or am I missing something here?
You should put '/products/:barcode' route after '/products/article' because it blocks the request to get to the article (the barcode param catch any suffix)

Context object is empty while receiving POST request , in Koa?

I am new in Koa and I am creating a demo app. I want to create an API to handle POST request, But when I console.log(ctx); then there is nothing in ctx in indexRouter.js, the console only printing empty object like {}.
I don't know why this is happening. Please anyone suggest me where I am doing wrong?
And please help me to get the request.body by POST Method.
serverKoa.js:
var koa = require('koa');
var router = require('koa-router');
var app = new koa();
var route = router(); //Instantiate the router
app.use(route.routes()); //Use the routes defined using the router
const index = require('./router/indexRouter')(route);
app.listen(3005 ,function(){
console.log("\n\nKoa server is running on port: 3005");
});
indexRouter.js:
var indexController=require('../controller/indexController');
module.exports = function (route) {
route.post('/postnew',async ( ctx, next) => {
console.log(ctx); // here printing {}
});
}
and my request object ( by postman ) is:
Method: POST,
url:http://localhost:3005/postnew
body:{
"firstName":"viki",
"lastName":"Kumar",
"userName":"vk12kq14",
"password":"098765432"
}
content-type:application/json
It looks like your code has two issues:
you're not using the "next" version of koa-router, which is required if you want to use async/await. You can install it like this:
npm i koa-router#next --save
you're not using koa-bodyparser to parse the request data:
npm i koa-bodyparser --save
To use:
var koa = require('koa');
var router = require('koa-router');
var bodyParser = require('koa-bodyparser');
var app = new koa();
app.use(bodyParser());
...
The parsed body data will be available in your route handlers as ctx.request.body.

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