Module exports for Express Router / Functions - javascript

Hi I am trying to export both a function (so that other routes may use this function to verify certs and also a the express router so that I can add it to my main class to mount the route on. This is because I believe the function and the route both serve the same sort of "functionality" and I want to encapsulate it in one file, so I want to export both the function and the router to use! Here is the following code of which I get an error... Note I WANT to do verifytoken.router to refer to the router and then verifytoken.verify to refer to the function in other files
/routes/verifytoken.js file
const router = require('express').Router();
const jwt = require('jsonwebtoken');
function verify (req, res, next) {
const token = req.header("auth-token");
if (!token) return res.status(401).send("Access Denied");
try {
const verified = jwt.verify(token, process.env.TOKEN_SECRET);
req.user = verified;
next();
} catch (error) {
res.status(400).send("Invalid Token")
}
}
router.get("/tester", (req, res) => {
res.status(200).send("validation please work bro");
});
module.exports = {
verify:verify,
router:router
}
my main index.js file
const express = require('express');
//import routes
const verifytoken = require('./routes/verifytoken')
const app = express();
//route middlewares
app.use("/api/user". verifytoken.router);
app.listen(3000 , () => console.log('Server Running...'))
The stack trace is :
app.use("/api/user". verifytoken.router);
^
TypeError: Cannot read property 'router' of undefined

1) Another typo:
app.use("/api/user". verifytoken.router);
Should be: (note dot . instead of comma ,)
app.use("/api/user", verifytoken.router);
2) You're using the wrong filename in the imported module:
const verifytoken = require('./routes/verifytoken');
Should be:
const verifytoken = require('./routes/verify');
The required file is named verify.js not verifytoken.js

I think there's another typo (dot), try:
app.use("/api/user", verifytoken.router);

Related

repost: Setting up express.js Server

Im encountering this error on replit while setting up my express server, im still starting to learn express so i still dont know some of it means
/home/runner/log-in-API/node_modules/express/lib/router/index.js:513
this.stack.push(layer);
^
TypeError: Cannot read properties of undefined (reading 'push')
at Function.route (/home/runner/log-in-API/node_modules/express/lib/router/index.js:513:14)
at file:///home/runner/log-in-API/api/reviews.route.js:4:8
at ModuleJob.run (node:internal/modules/esm/module_job:198:25)
at async Promise.all (index 0)
at async ESMLoader.import (node:internal/modules/esm/loader:385:24)
here is my index.js
import app from "./server.js"
import mongodb from "mongodb"
/* import ReviewsDao from "./dao/reviewsDAO.js " */
const dbUser = process.env['MONGO_USERNAME']
const dbPword = process.env['MONGO_PASSWORD']
const MongoClient = mongodb.MongoClient
const uri = `SECRET`
const port = 8000
MongoClient.connect(uri, {
maxPoolSize: 50,
wtimeoutMS: 2500,
useNewUrlParser: true
})
.catch(err => {
console.error(err.stack)
process.exit(1)
})
.then(async client => {
await ReviewsDAO.injectDB(client)
app.listen(port, () => {
console.log(`Listening to ${port}`)
})
})
here is my server.js
import express from "express"
import cors from "cors"
import reviews from "./api/reviews.route.js"
const app = express()
app.use(cors())
app.use(express.json())
app.use("/api/v1/reviews", reviews)
app.use("*", (req, res) => res.status(404).json({error: "not found"}))
export default app
and here is my reviews.route.js that is located inside a folder named api
import express from 'express'
const router = express.Router
router.route('/').get((req, res) => {
res.send('Hello world')
})
export default router
Am i missing something im trying to follow this tutorial by free code camp and im currently at 6:16:30 timestamp
i tried to fix everything even typos, and im still encountering this problem what could be the problem ?
I think this problem is created because the way you structure your router, try router.get('/', (req, res) => { instead of router.route('/').get((req, res) => {. Does this work? And to initialise your router try const router = express.Router(); instead of const router = express.Router (so call the factory function)

How can I use my verifyToken middleware in express router modules?

I have an express app like so:
// index.js
const express = require('express');
const app = express();
const userRoutes = require('./routes/userRoutes');
app.use('/user', userRoutes);
const verifyToken = (req, res, next) => {
// validate req.cookies.token
next();
}
And I'm using an express router module like this:
// routes/userRoutes.js
const express = require('express');
const router = express.Router();
router.get('/:userid/data', verifyToken, async (req, res) => {
const data = await db.query()
res.json(data)
});
Obviously this doesn't work because verifyToken is not accesible within the module. How can I use the same verifyToken middleware function throughout different express modules?
Move verifyToken to a different file and export it from there.
Then you can import it in other places.
One thing that you can do, that works well is to group all your authed routes under a common path and use router.use to make sure that you apply the verifyToken middleware on all of them.

Dynamically changing routes in Express

I have an express server. This is my index.js
let some_parameter = some_value;
const configuredHandler = new Handler(some_parameter);
const server = express();
server
.get("*", configuredHandler.handleRequest)
.post("*", configuredHandler.handleRequest)
.put("*", configuredHandler.handleRequest)
.delete("*", configuredHandler.handleRequest);
I am trying to update the routes if some_parameter to the Handler changes. So it should create a new instance of configuredHandler and the routes should automatically pick the new handler.
Ideally I want to be able to change some_parameter anywhere else in the code.
I am not sure how to structure it for this.
Please help.
What you could do is use something similar to a factory. That factory would create a new middleware every time some_parameter changes and save that middleware for future reference.
Whenever one of your routes is called, express would then refer to the current handler in your factory.
I wrote a simple example:
const express = require('express');
class HandlerFactory {
static currentHandler = (req, res) => res.send('Hello');
static setValue(value) {
this.currentHandler = (req, res) => res.send(value);
}
}
const app = express();
app.post('/change-value', (req, res) => {
HandlerFactory.setValue(req.query.value);
res.send();
});
app.use('/handler', (req, res) => HandlerFactory.currentHandler(req, res));
app.listen(3000);
Just run the app, then test its functionality:
$ curl http://localhost:3000/handler
Hello
$ curl -X POST http://localhost:3000/change-value?value=SecondMessage
$ curl http://localhost:3000/handler
SecondMessage
You can use Router module from expressjs
import { Router } from 'express';
const route1 = new Router();
const route2 = new Router();
const route3 = new Router();
route1.get('/', handler1);
route2.get('/', handler2);
route3.get('/', handler3);
..
..
// similarly define other HTTP routes
const routeMap = {
route1,
route2
route3
}
let some_parameter = 'route1';
const server = express();
const selectedRouter = routerMap[some_parameter];
server.use('*', routerMap[some_parameter]);
I have a sample project on Github that uses similar pattern

How can I export the files that I created to my app.js

I'm structuring my code to become more readable and maintainable at the same time.
here is my GET.articles and my INSERT.articles is just the same with this.
const express = require('express');
const router = express.Router();
router.get('/sample', (req, res) => {
res.send("Nice")
})
module.exports = router;
my index.js
const GET_articles = require('./GET.articles');
const INSERT_articles = require('./INSERT.articles');
exports { GET_articles, INSERT_articles}
and I import it like this:
app.use('/example', require('./routes/articles_controller/index'));
This is my error:
SyntaxError: Unexpected token export
Look at your first block of code:
module.exports = router;
Do that.
Change:
exports { GET_articles, INSERT_articles}
to
module.exports = { GET_articles, INSERT_articles}
If you want to use import and export then see this question.
Then note that a plain object isn't something you can just use.
You should use the routers and not the object containing them.
const routers = require('./routes/articles_controller/index');
app.use('/example', routers.GET_articles);
app.use('/example', routers.INSERT_articles);
app.js file
const express = require('express');
const router = express.Router();
const exampleRoute = require('./routes/articles_controller/index');
var app = express();
app.use('/', router)
app.use('/example', router, exampleRoute);
router.get('/sample', (req, res) => {
res.send("Nice")
})
app.listen(3000, ()=>{
console.log("Listening on port 3000")
})
route file
const GET_articles = require('./GET.articles');
const INSERT_articles = require('./INSERT.articles');
module.exports = [GET_articles, INSERT_articles]
GET articles files
module.exports = function getArticle (req, res) {
//Logic as required goes here
res.send("Content to be rendered")
}

Structure event listeners in Node.js [duplicate]

This question already has answers here:
How to separate routes on Node.js and Express 4?
(9 answers)
Closed 1 year ago.
In my NodeJS express application I have app.js that has a few common routes. Then in a wf.js file I would like to define a few more routes.
How can I get app.js to recognize other route handlers defined in wf.js file?
A simple require does not seem to work.
If you want to put the routes in a separate file, for example routes.js, you can create the routes.js file in this way:
module.exports = function(app){
app.get('/login', function(req, res){
res.render('login', {
title: 'Express Login'
});
});
//other routes..
}
And then you can require it from app.js passing the app object in this way:
require('./routes')(app);
Have a look at these examples: https://github.com/visionmedia/express/tree/master/examples/route-separation
In Express 4.x you can get an instance of the router object and import another file that contains more routes. You can even do this recursively so your routes import other routes allowing you to create easy-to-maintain URL paths.
For example, if I have a separate route file for my /tests endpoint already and want to add a new set of routes for /tests/automated I may want to break these /automated routes out into a another file to keep my /test file small and easy to manage. It also lets you logically group routes together by URL path which can be really convenient.
Contents of ./app.js:
var express = require('express'),
app = express();
var testRoutes = require('./routes/tests');
// Import my test routes into the path '/test'
app.use('/tests', testRoutes);
Contents of ./routes/tests.js:
var express = require('express'),
router = express.Router();
var automatedRoutes = require('./testRoutes/automated');
router
// Add a binding to handle '/tests'
.get('/', function(){
// render the /tests view
})
// Import my automated routes into the path '/tests/automated'
// This works because we're already within the '/tests' route
// so we're simply appending more routes to the '/tests' endpoint
.use('/automated', automatedRoutes);
module.exports = router;
Contents of ./routes/testRoutes/automated.js:
var express = require('express'),
router = express.Router();
router
// Add a binding for '/tests/automated/'
.get('/', function(){
// render the /tests/automated view
})
module.exports = router;
Building on #ShadowCloud 's example I was able to dynamically include all routes in a sub directory.
routes/index.js
var fs = require('fs');
module.exports = function(app){
fs.readdirSync(__dirname).forEach(function(file) {
if (file == "index.js") return;
var name = file.substr(0, file.indexOf('.'));
require('./' + name)(app);
});
}
Then placing route files in the routes directory like so:
routes/test1.js
module.exports = function(app){
app.get('/test1/', function(req, res){
//...
});
//other routes..
}
Repeating that for as many times as I needed and then finally in app.js placing
require('./routes')(app);
If you're using express-4.x with TypeScript and ES6, this would be the best template to use:
src/api/login.ts
import express, { Router, Request, Response } from "express";
const router: Router = express.Router();
// POST /user/signin
router.post('/signin', async (req: Request, res: Response) => {
try {
res.send('OK');
} catch (e) {
res.status(500).send(e.toString());
}
});
export default router;
src/app.ts
import express, { Request, Response } from "express";
import compression from "compression"; // compresses requests
import expressValidator from "express-validator";
import bodyParser from "body-parser";
import login from './api/login';
const app = express();
app.use(compression());
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
app.use(expressValidator());
app.get('/public/hc', (req: Request, res: Response) => {
res.send('OK');
});
app.use('/user', login);
app.listen(8080, () => {
console.log("Press CTRL-C to stop\n");
});
Much cleaner than using var and module.exports.
Full recursive routing of all .js files inside /routes folder, put this in app.js.
// Initialize ALL routes including subfolders
var fs = require('fs');
var path = require('path');
function recursiveRoutes(folderName) {
fs.readdirSync(folderName).forEach(function(file) {
var fullName = path.join(folderName, file);
var stat = fs.lstatSync(fullName);
if (stat.isDirectory()) {
recursiveRoutes(fullName);
} else if (file.toLowerCase().indexOf('.js')) {
require('./' + fullName)(app);
console.log("require('" + fullName + "')");
}
});
}
recursiveRoutes('routes'); // Initialize it
in /routes you put whatevername.js and initialize your routes like this:
module.exports = function(app) {
app.get('/', function(req, res) {
res.render('index', { title: 'index' });
});
app.get('/contactus', function(req, res) {
res.render('contactus', { title: 'contactus' });
});
}
And build yet more on the previous answer, this version of routes/index.js will ignore any files not ending in .js (and itself)
var fs = require('fs');
module.exports = function(app) {
fs.readdirSync(__dirname).forEach(function(file) {
if (file === "index.js" || file.substr(file.lastIndexOf('.') + 1) !== 'js')
return;
var name = file.substr(0, file.indexOf('.'));
require('./' + name)(app);
});
}
I am trying to update this answer with "express": "^4.16.3". This answer is similar to the one from ShortRound1911.
server.js:
const express = require('express');
const mongoose = require('mongoose');
const bodyParser = require('body-parser');
const db = require('./src/config/db');
const routes = require('./src/routes');
const port = 3001;
const app = new express();
//...use body-parser
app.use(bodyParser.urlencoded({ extended: true }));
//...fire connection
mongoose.connect(db.url, (err, database) => {
if (err) return console.log(err);
//...fire the routes
app.use('/', routes);
app.listen(port, () => {
console.log('we are live on ' + port);
});
});
/src/routes/index.js:
const express = require('express');
const app = express();
const siswaRoute = require('./siswa_route');
app.get('/', (req, res) => {
res.json({item: 'Welcome ini separated page...'});
})
.use('/siswa', siswaRoute);
module.exports = app;
/src/routes/siswa_route.js:
const express = require('express');
const app = express();
app.get('/', (req, res) => {
res.json({item: 'Siswa page...'});
});
module.exports = app;
If you want a separate .js file to better organize your routes, just create a variable in the app.js file pointing to its location in the filesystem:
var wf = require(./routes/wf);
then,
app.get('/wf', wf.foo );
where .foo is some function declared in your wf.js file. e.g
// wf.js file
exports.foo = function(req,res){
console.log(` request object is ${req}, response object is ${res} `);
}
One tweak to all of these answers:
var routes = fs.readdirSync('routes')
.filter(function(v){
return (/.js$/).test(v);
});
Just use a regex to filter via testing each file in the array. It is not recursive, but it will filter out folders that don't end in .js
I know this is an old question, but I was trying to figure out something like for myself and this is the place I ended up on, so I wanted to put my solution to a similar problem in case someone else has the same issues I'm having. There's a nice node module out there called consign that does a lot of the file system stuff that is seen here for you (ie - no readdirSync stuff). For example:
I have a restful API application I'm trying to build and I want to put all of the requests that go to '/api/*' to be authenticated and I want to store all of my routes that go in api into their own directory (let's just call it 'api'). In the main part of the app:
app.use('/api', [authenticationMiddlewareFunction], require('./routes/api'));
Inside of the routes directory, I have a directory called "api" and a file called api.js. In api.js, I simply have:
var express = require('express');
var router = express.Router();
var consign = require('consign');
// get all routes inside the api directory and attach them to the api router
// all of these routes should be behind authorization
consign({cwd: 'routes'})
.include('api')
.into(router);
module.exports = router;
Everything worked as expected. Hope this helps someone.
index.js
const express = require("express");
const app = express();
const http = require('http');
const server = http.createServer(app).listen(3000);
const router = (global.router = (express.Router()));
app.use('/books', require('./routes/books'))
app.use('/users', require('./routes/users'))
app.use(router);
routes/users.js
const router = global.router
router.get('/', (req, res) => {
res.jsonp({name: 'John Smith'})
}
module.exports = router
routes/books.js
const router = global.router
router.get('/', (req, res) => {
res.jsonp({name: 'Dreams from My Father by Barack Obama'})
}
module.exports = router
if you have your server running local (http://localhost:3000) then
// Users
curl --request GET 'localhost:3000/users' => {name: 'John Smith'}
// Books
curl --request GET 'localhost:3000/books' => {name: 'Dreams from My Father by Barack Obama'}
I wrote a small plugin for doing this! got sick of writing the same code over and over.
https://www.npmjs.com/package/js-file-req
Hope it helps.
you can put all route functions in other files(modules) , and link it to the main server file.
in the main express file, add a function that will link the module to the server:
function link_routes(app, route_collection){
route_collection['get'].forEach(route => app.get(route.path, route.func));
route_collection['post'].forEach(route => app.post(route.path, route.func));
route_collection['delete'].forEach(route => app.delete(route.path, route.func));
route_collection['put'].forEach(route => app.put(route.path, route.func));
}
and call that function for each route model:
link_routes(app, require('./login.js'))
in the module files(for example - login.js file), define the functions as usual:
const login_screen = (req, res) => {
res.sendFile(`${__dirname}/pages/login.html`);
};
const forgot_password = (req, res) => {
console.log('we will reset the password here')
}
and export it with the request method as a key and the value is an array of objects, each with path and function keys.
module.exports = {
get: [{path:'/',func:login_screen}, {...} ],
post: [{path:'/login:forgotPassword', func:forgot_password}]
};

Categories

Resources