I am trying to download array of objects in .csv format. below is the code snippet which converts an array to .csv and get stored in the file file.csv.
let downloadHelper = function(records){
let csvwriter = require('csv-writer');
createCsvWriter = csvwriter.createObjectCsvWriter;
const csvWriter = createCsvWriter({
path: './file.csv'
csvWriter.writeRecords(records).then(() => {
console.log('Done');
});
}
I need to download the file.csv to my local. tried using requests, didn't help as it is accepting only http requests. no clue, how to proceed..... Please help
You did not provide us a lot of information. But with Express you could do:
app.get("/", (req, res) => {
res.download("./file.csv", "your-custom-name.csv");
});
If this does not help you, please provide more info about the context, framework you are using and what front.
Thank you
For example, you can use Express like this:
// Libs
const express = require('express');
const http = require('http');
const path = require('path');
// Setup
const port = 8080;
const app = express();
const httpServer = http.createServer(app);
// http://localhost:8080/download
app.get('/download', (req, res) => {
res.sendFile(path.resolve(__dirname, './file.csv'));
});
// http://localhost:8080/csv/file.csv
app.use('/csv', express.static(path.resolve(__dirname, './csv_files/')));
// Run HTTP server
httpServer.listen(port, () => console.log('Server is listening on *:' + port));
If you run this snippet, you can open http://localhost:8080/download and ./file.csv would be downloaded.
Following part of code is responsible for that:
app.get('/download', (req, res) => {
res.sendFile(path.resolve(__dirname, './file.csv'));
});
Or if you want to give access to the whole directory ./csv_files/ you can do this:
app.use('/csv', express.static(path.resolve(__dirname, './csv_files/')));
Just create ./csv_files/foo.csv file and go to http://localhost:8080/csv/foo.csv.
Does it make sense to you?
PS Working example:
// Libs
const express = require('express');
const http = require('http');
const path = require('path');
const fs = require('fs');
// Setup
const port = 8080;
const app = express();
const httpServer = http.createServer(app);
// http://localhost:8080/download
app.get('/download', (req, res) => {
const filename = path.resolve(__dirname, './file' + (new Date()).getTime() + '.csv');
fs.writeFileSync(filename, 'foo,bar,baz');
res.sendFile(filename);
});
httpServer.listen(port, () => console.log('Server is listening on *:' + port));
Related
I have been attempting to respond to a client-side request with Node.JS. I have discovered Node JS - call function on server from client javascript, which seems to explain what I want, except that I can't seem to translate it to my program.
Here is the request via POST in index.html:
$.post("/", {data: 'hi'}, function(result){
$("body").html(result);
});
what I was hoping it would do would be write the result of the call, from my server.js (Node):
const express = require('express');
const path = require('path');
const http = require('http');
const fs = require('fs');
function handler(data, app){
if(req.method == "POST"){
app.setHeader('Content-Type', 'text/html');
app.writeHead(200);
app.end(data);
}
}
const BUILDPATH = path.join(__dirname);
const { PORT = 3000 } = process.env;
const app = express();
app.set('port', PORT);
app.use(express.static(BUILDPATH));
app.get('/*', (req, res) => res.sendFile('static/index.html', { root: BUILDPATH }));
const httpServer = http.createServer(app);
httpServer.listen(PORT);
console.info(`🚀 Client Running on: http://localhost:${PORT}`);
try this code:
const express = require('express');
const path = require('path');
const http = require('http');
const fs = require('fs');
function handler(data, app){
if(req.method == "POST"){
app.setHeader('Content-Type', 'text/html');
app.writeHead(200);
app.end(data);
}
}
const BUILDPATH = path.join(__dirname);
const { PORT = 3000 } = process.env;
const app = express();
app.set('port', PORT);
app.use(express.static(BUILDPATH));
app.get('/', (req, res) => {
res
// best practice is to always return an status code
.status(200)
// just return an json object
.json({"msg": "ok, it all works just fine"})
});
const httpServer = http.createServer(app);
httpServer.listen(PORT);
console.info(`🚀 Client Running on: http://localhost:${PORT}`);
The issue is, is that the only route your Node server listens to is the one you define with /*. As you can see, that route returns your index.html file to the client. You did not specify a route that listens for a request that comes from the client.
To solve the issue, you will have to define a route that listens on a specific route for the request you are trying to make from your client.
I see you are using ExpressJS. here is the documentation on writing routes.
may be its dumb question but I can't find answer yet. :(
I made app using create-react-app, and server file:
server.js
const express = require('express');
const bodyParser = require('body-parser');
const fs = require('fs');
const path = require('path');
const PORT = process.env.PORT || 3000;
const app = express();
const p = path.parse(__dirname);
app.use(express.static('public'));
app.get('/', (req, res) => {
const filePath = path.join(p.dir, 'src', 'index.js');
fs.readFile(filePath, {encoding: 'utf-8'},(err, data) => {
if (err) {
throw err;
}
res.send(data);
});
});
app.listen(PORT, () => {
console.log(`Started at port ${PORT}`);
});
tryied to read index.js file from app src directory but all i got in browser is plain text. I can only run static files from public directory. What i did wrong and how should i run js files of react app using express in node?
You need to send the index.html file that is built by react. A browser can only open a web page from a html file.
You need to first build your react app using npm run build
Then serve it with express with something like
app.get('*', (req,res) => {
res.sendFile('/build/index.html'); // wherever react creates the index.html
});
To give you a basic idea on express,
const express = require('express')
const app = express()
app.get('', (req, res) => {
res.render('index') // index is an html file or a template (ejs, hbs, etc..)
})
// You can't directly send js files
app.get('/info', (req, res) => {
res.render('info', {
title: 'info page',
message: 'welcome to the info page'
})
})
// You can't directly send js files
app.listen(3000, () => {
console.log('Server is up on port 3000.')
})
If you want to send json
const leaderboardHistory = require("relativepath/leaderboardHistory.json")
app.get("/leaderboardhistory", function(req, res){
res.render("leaderboardhistory", {leaderboardHistory : leaderboardHistory});
});
I am looking to start including my route files in my Node.js and express application. However, when I require the local route files into my server.js file, and try to run that on Nginx, I get a 502 Bad Gateway error.
The code that is giving me trouble is currently commented out. Any ideas on what might be causing this performance?
server.js
require('dotenv').config();
const express = require('express');
const bodyparser = require('body-parser');
const session = require('express-session');
const MongoDBStore = require('connect-mongodb-session')(session);
// const oidc = require('./okta');
// const searchRouter = require('./routes/search');
// const inputRouter = require('./routes/input');
// const dataRouter = require('./routes/view-all');
const app = express();
app.use(express.static('public'));
app.set('view engine', 'ejs');
app.get('/', function(req, res) {
res.sendFile(__dirname + '/views/index.html');
});
app.get('/page', function(req, res) {
res.render(__dirname + '/views/optishop.ejs');
});
const listener = app.listen(8080, function() {
console.log('Your app is listening on port ' + listener.address().port);
});
Edit: This is the file being required in the searchRouter declaration.
search.js
const express = require('express');
const MongoClient = require('mongodb').MongoClient;
const assert = require('assert');
const oidc = require('../okta');
const router = express.Router();
router.post('/search', oidc.ensureAuthenticated(), async (req, res) => {
await MongoClient.connect(
process.env.MONGODB_URI,
{ useUnifiedTopology: true },
async (err, client) => {
assert.equal(null, err);
const db = client.db('test');
const arr = req.body.item.trim().split(/; */gi);
const user = req.session.passport.user.userinfo.sub;
const cursor = await db
.collection('test')
.find({
user
})
.toArray();
const filteredCursor = cursor.filter(obj => {
return arr.includes(obj.item);
});
res.render('index', {
cursor: filteredCursor
});
// res.send(filteredCursor);
client.close();
}
);
});
module.exports = router;
I am trying to serve an angular app using nodejs. But i get this error
"Cannot GET /" in the body of the page. I tried a number of things but still this does not work. do you folks have any suggestion?
const express = require('express')
const app = express()
var cors = require('cors')
const bodyParser = require('body-parser')
const fileUpload = require('express-fileupload')
const couchDb = require('./modules/couchDb')
const db = couchDb.db
const schedules = require('./modules/schedules')
const stations = require('./modules/stations')
const testConfigs = require('./modules/testConfigs')
app.use(cors())
app.use(bodyParser.json())
app.use(bodyParser.urlencoded({extended: true}))
app.use(fileUpload())
app.listen(5000, () => console.log('Listening on port 5000'))
////////////////////////////////////////
// View
////////////////////////////////////////
const viewOptions = { include_docs: true }
app.route('/api/schedules').get((req, res) => {
couchDb.getType('schedule', viewOptions).then(docs => {
res.send(docs)
}).catch(err => {
console.log(err)
res.send({})
})
})
app.route('/api/stations').get((req, res) => {
couchDb.getType('station', viewOptions).then(docs => {
res.send(docs)
}).catch(err => {
console.log(err)
res.send({})
})
})
app.route('/api/tests').get((req, res) => {
couchDb.getType('testConfig', viewOptions).then(docs => {
res.send(docs)
}).catch(err => {
console.log(err)
res.send({})
})
})
you are missing your routes e.g
app.get('/', function (req, res) {
res.send('hello world')
})
or you need to include your all routes through middle ware.
You are getting that error because you are not declaring any endpoints or telling the server to serve anything. It is listening on port 5000, but no responses to any urls have been defined. Here is a piece of example code that will resolve your issue.
const express = require('express')
const app = express()
var cors = require('cors')
const bodyParser = require('body-parser')
const fileUpload = require('express-fileupload')
app.use(cors())
app.use(bodyParser.json())
app.use(bodyParser.urlencoded({extended: true}))
app.use(fileUpload())
// This block will make it so that every path on port 5000 responds with "Hello, World!"
app.get('*', (req, res) => {
res.status(200).send("Hello, World!");
});
app.listen(5000, () => console.log('Listening on port 5000'))
This will make it respond with basic text, if you want to serve an angular application, you will need to look into serving static content from express: https://expressjs.com/en/starter/static-files.html
You have to use a routing middleware and map your modules to the required modules.Also make sure your modules are mounted in router instance.
Something like
const express = require('express')
const app = express()
var cors = require('cors')
const bodyParser = require('body-parser')
const fileUpload = require('express-fileupload')
const couchDb = require('./modules/couchDb')
const db = couchDb.db
const schedules = require('./modules/schedules')
const stations = require('./modules/stations')
const testConfigs = require('./modules/testConfigs')
app.use(cors())
app.use(bodyParser.json())
app.use(bodyParser.urlencoded({extended: true}))
app.use(fileUpload())
//All requests with /schedules will go to './modules/schedules'
app.use('/schedules', schedules);
app.use('/stations', stations);
app.listen(5000, () => console.log('Listening on port 5000'))
your ./modules/station should look like
var express = require('express')
var router = express.Router()
router.get('/', function (req, res) {
res.send('You are in /station')
})
router.get('/new', function (req, res) {
res.send('You are in /station/new')
})
module.exports = router
For more : https://expressjs.com/en/guide/routing.html
Whenever I'm hitting the endpoint, I keep getting empty file while locally generated file is correct and contains all the fields I need. I've tried piping directly to response but I would be getting:
Cannot pipe, not readable
Of course there might be something I'm doing wrong.
Similar question.
const PORT = 3000;
const express = require('express');
const fs = require('fs');
const csv = require('fast-csv');
const app = express();
app.listen(PORT, () => {
console.log(`Express server is listening on ${PORT}`);
});
app.get('/rates/csv', (req, res) => {
let ws = fs.createWriteStream(__dirname + '/tmp/rates.csv');
csv.write([
["a", "b"],
["a1", "b1"],
["a2", "b2"]
], {headers: true})
.pipe(ws);
console.log('FILE SAVED');
res.download(ws.path, 'rates.csv')
});
You can't pipe a writable stream to another writable stream.
https://medium.freecodecamp.org/node-js-streams-everything-you-need-to-know-c9141306be93