I am trying to respond to a POST from a web page by sending a file generated by Node.js on-the-fly. I would rather avoid the naive way of saving the file to disk and then calling res.download.
Following this post, I have tried the following coffee:
app.post "/post", (req, res, next) ->
mydata = "I want to write this to a file"
res.setHeader 'Content-disposition', 'attachment; filename="myFile.txt"'
res.setHeader 'Content-type', 'text/plain'
res.write mydata
res.end()
It does not work, though. I just get the same page where my form was, as if it refreshed. I have redirecting to a GET with res.redirect and app.get, but it doesn't work either.
EDIT
I have tried the above code together with a very simple express server. It works if I submit a form data with method="post". However, what I want to do is to send data through jQuery's post(). This is my JS:
$('form').find(':submit').click();
if ($('form')[0].checkValidity()) {
$.post('/post', js);
}
Here, js is simply a javascript object. I have tried removing the click() and even the checkValidity() parts; that helps with the reloading of the page, but I still cannot download myFile.txt.
Can anyone shed some light?
Thanks
Related
i have a react native frontend and a nodejs backend. In one of my API calls i am getting a redirectHTML from a gateway to display to the users. The redirectHTML obtained is used in react native Webview to get displayed. my problem is the only way to know that the transaction is success or not is from the url. I have tried res.redirect and res.writeHead and both change the content of the screen but the URL still remains the same.
Server side
router.get(
"/pay/authenticate/result",
async(req, res) => {
console.log(req.query)
// res.redirect(302,"/");
res.writeHead(302,{'Location':'https://www.google.com/'});
res.end("");
});
client Side
<WebView
style={{flex:1}}
source={{html:`${authenticateWebViewUrl}`}} //this is the redirectHTML that came from the response
onNavigationStateChange={(navState) => {
console.log(navState)
}}
scalesPageToFit={false}
javaScriptEnabled={true}
/>
res.redirect with 302 will add the temporary redirection, if you want a permanent redirection, prefer HTTP 301. Reference
res.writeHead + res.end does not, on its own, cause the redirection to a new URL.
Edit: Typo req and res.
I have node.js 5.2.0, express 4.2.0 and formidable 1.0.17.
I created a simple form to save a textfield and a photo. It works fine, but the problem is, after the data are uploaded, I can see in the console that the POST is not finished, its still Pending.
In order to finish it I added this to my code
form.on('end', function() {
res.writeHead(200, {'Content-Type': 'text/plain'});
});
I just want to send the headers and nothing on the page. I want the system to get a 200 ok response without having to print anything on the page. But the POST is still pending.
How do I fix this, without having to print anything? What kind of headers I have to send?
Thanks
UPDATE
If I do
form.on('end', function() {
res.end();
});
The POST finishes normally, but I get a blank page. Why is that? I just want to upload some stuff, not print anything on the page, not redirect, stay in the same page.
Thanks again
Try this instead:
res.sendStatus(200);
Or if you want to continue using explicitly defined headers, I believe res.end() needs to be called at some point. You can see how res.end() is utilized in the Formidable example.
The blank page is most likely the result of your client-side form handling. You may want to override the form's submit method and manually post to your express service to prevent the automated redirection you are seeing. Here are some other stackoverflow responses to a question involving form redirection. The answers are jQuery specific, but the basic idea will remain the same.
I've been struggling for 2 days on this one, googled and stackoverflowed all I could, but I can't work it out.
I'm building a simple node app (+Express + Mongoose) with a login page that redirects to the home page. Here's my server JS code :
app
.get('/', (req, res) => {
console.log("Here we are : root");
return res.sendfile(__dirname + '/index.html');
})
.get('/login', (req, res) => {
console.log("Here we are : '/login'");
return res.sendfile(__dirname + '/login.html');
})
.post('/credentials', (req, res) => {
console.log("Here we are : '/credentials'");
// Some Mongoose / DB validations
return res.redirect('/');
});
The login page makes a POST request to /credentials, where posted data is verified. This works. I can see "Here we are : '/credentials'" in the Node console.
Then comes the issue : the res.redirect doesn't work properly. I know that it does reach the '/' route, because :
I can see "Here we are : root" in the Node console
The index.html page is being sent back to the browser as a reponse, but not displayed in the window.
Chrome inspector shows the POST request response, I CAN see the HTML code being sent to the browser in the inspector, but the URL remains /login and the login page is still being displayed on screen.
(Edit) The redirection is in Mongoose's callback function, it's not synchronous (as NodeJS should be). I have just removed Mongoose validation stuff for clarity.
I have tried adding res.end(), doesn't work
I have tried
req.method = 'get';
res.redirect('/');
and
res.writeHead(302, {location: '/'});
res.end();
Doesn't work
What am I doing wrong? How can I actually leave the '/login' page, redirect the browser to '/' and display the HTML code that it received?
Thanks a million for your help in advance :)
The problem might not lie with the backend, but with the frontend. If you are using AJAX to send the POST request, it is specifically designed to not change your url.
Use window.location.href after AJAX's request has completed (in the .done()) to update the URL with the desired path, or use JQuery: $('body').replaceWith(data) when you receive the HTML back from the request.
If you are using an asynchronous request to backend and then redirecting in backend, it will redirect in backend (i.e. it will create a new get request to that URL), but won't change the URL in front end.
To make it work you need to:
use window.location.href = "/url"
change your async request (in front end) to simple anchor tag (<a></a>)
It's almost certain that you are making an async call to check Mongoose but you haven't structured the code so that the redirect only happens after the async call returns a result.
In javascript, the POST would look like something this:
function validateCredentials(user, callback){
// takes whatever you need to validate the visitor as `user`
// uses the `callback` when the results return from Mongoose
}
app.post('/credentials', function(req, res){
console.log("Here was are: '/credentials'";
validateCredentials(userdata, function(err, data){
if (err) {
// handle error and redirect to credentials,
// display an error page, or whatever you want to do here...
}
// if no error, redirect
res.redirect('/');
};
};
You can also see questions like Async call in node.js vs. mongoose for parallel/related problems...
I've been working on implementing nodemailer into my NextJS app with Express. Was having this issue and came across this. I had event.preventDefault() in my function that was firing the form to submit and that was preventing the redirect as well, I took it off and it was redirecting accordingly.
Add the following in your get / route :
res.setHeader("Content-Type", "text/html")
Your browser will render file instead of downloading it
I need to dynamically load/render part of a page in nodejs (v1.8.15) with express (>3.0) framework. Generally, I want to create a single-page app.
I have a menu at the top of the page with links. Clicking on the links will change the content below, as in AJAX page loading.
For example:
>home|login|signup|chat
..content for home..
If I press the 'signup' link:
home|login|>signup|chat
..content for signup..
In express I have routes on the server:
var express = require('express');
var app = express();
app.get('/signup', function(req, res) {
// render signup.jade
res.render('signup');
}
app.post('/signup', function(req, res) {
// .. work with information
if (ok) res.send('ok', 200); else res.send(error, 200);
}
After reading this, I figured out that I should use socket.io. I know sockets well, so it will be easy to send data about 'clicking on link' from the client to the server.
Q1: How do I render/load pages dynamically like I wrote in express?
Yes, I could use AJAX for page loading, but will it work for .post methods in express?
How should I organize my thoughts to create such a site?
By the way, I've read about Derby and SocketStream, but I didn't understand.
Q2: Can I use Derby or SocketStream in my aims (site functions: login, signup, chat)? How?
If SocketStream is what I need, that would be very bad, because Heroku doesn't work with it.
Q1) This is in fact very simple, no need for Socket.io, Derby or whatever. You can call any expess route with any method through ajax, using jQuery makes ajax very easy. In your example, let's suppose your container HTML file has a div with id 'container', which is where you want the ajax-loaded content to go:
$.ajax({ url: 'http://yoursite.com/signup'
, type: 'GET'
, dataType: 'html'
})
.done(function(data) {
$('#container').html(data);
})
.fail(function() {
console.log("Something went wrong!");
});
Express supports all HTTP verbs (GET, POST, PUT etc.). For loading pages dynamically, use GET, then when a user enters some login information you can POST it to an Express route that will tell you if it is valid or not, and you use jQuery to modify the DOM accordingly.
Q2) As said in Q1, no need to use Derby or SocketStream. Plain old jQuery + basic Express will get you where you want!
To learn node.js I'm creating a small app that get some rss feeds stored in mongoDB, process them and create a single feed (ordered by date) from these ones.
It parses a list of ~50 rss feeds, with ~1000 blog items, so it's quite long to parse the whole, so I put the following req.connection.setTimeout(60*1000); to get a long enough time out to fetch and parse all the feeds.
Everything runs quite fine, but the request is called twice. (I checked with wireshark, I don't think it's about favicon here).
I really don't get it.
You can test yourself here : http://mighty-springs-9162.herokuapp.com/feed/mde/20 (it should create a rss feed with the last 20 articles about "mde").
The code is here: https://github.com/xseignard/rss-unify
And if we focus on the interesting bits :
I have a route defined like this : app.get('/feed/:name/:size?', topics.getFeed);
And the topics.getFeed is like this :
function getFeed(req, res) {
// 1 minute timeout to get enough time for the request to be processed
req.connection.setTimeout(60*1000);
var name = req.params.name;
var callback = function(err, topic) {
// if the topic has been found
if (topic) {
// aggregate the corresponding feeds
rssAggregator.aggregate(topic, function(err, rssFeed) {
if (err) {
res.status(500).send({error: 'Error while creating feed'});
}
else {
res.send(rssFeed);
}
},
req);
}
else {
res.status(404).send({error: 'Topic not found'});
}};
// look for the topic in the db
findTopicByName(name, callback);
}
So nothing fancy, but still, this getFeed function is called twice.
What's wrong there? Any idea?
This annoyed me for a long time. It's most likely the Firebug extension which is sending a duplicate of each GET request in the background. Try turning off Firebug to make sure that's not the issue.
I faced the same issue while using Google Cloud Functions Framework (which uses express to handle requests) on my local machine. Each fetch request (in browser console and within web page) made resulted in two requests to the server. The issue was related to CORS (because I was using different ports), Chrome made a OPTIONS method call before the actual call. Since OPTIONS method was not necessary in my code, I used an if-statement to return an empty response.
if(req.method == "OPTIONS"){
res.set('Access-Control-Allow-Origin', '*');
res.set('Access-Control-Allow-Headers', 'Content-Type');
res.status(204).send('');
}
Spent nearly 3hrs banging my head. Thanks to user105279's answer for hinting this.
If you have favicon on your site, remove it and try again. If your problem resolved, refactor your favicon url
I'm doing more or less the same thing now, and noticed the same thing.
I'm testing my server by entering the api address in chrome like this:
http://127.0.0.1:1337/links/1
my Node.js server is then responding with a json object depending on the id.
I set up a console log in the get method and noticed that when I change the id in the address bar of chrome it sends a request (before hitting enter to actually send the request) and the server accepts another request after I actually hit enter. This happens with and without having the chrome dev console open.
IE 11 doesn't seem to work in the same way but I don't have Firefox installed right now.
Hope that helps someone even if this was a kind of old thread :)
/J
I am to fix with listen.setTimeout and axios.defaults.timeout = 36000000
Node js
var timeout = require('connect-timeout'); //express v4
//in cors putting options response code for 200 and pre flight to false
app.use(cors({ preflightContinue: false, optionsSuccessStatus: 200 }));
//to put this middleaware in final of middleawares
app.use(timeout(36000000)); //10min
app.use((req, res, next) => {
if (!req.timedout) next();
});
var listen = app.listen(3333, () => console.log('running'));
listen.setTimeout(36000000); //10min
React
import axios from 'axios';
axios.defaults.timeout = 36000000;//10min
After of 2 days trying
you might have to increase the timeout even more. I haven't seen the express source but it just sounds on timeout, it retries.
Ensure you give res.send(); The axios call expects a value from the server and hence sends back a call request after 120 seconds.
I had the same issue doing this with Express 4. I believe it has to do with how it resolves request params. The solution is to ensure your params are resolved by for example checking them in an if block:
app.get('/:conversation', (req, res) => {
let url = req.params.conversation;
//Only handle request when params have resolved
if (url) {
res.redirect(301, 'http://'+ url + '.com')
}
})
In my case, my Axios POST requests were received twice by Express, the first one without body, the second one with the correct payload. The same request sent from Postman only received once correctly. It turned out that Express was run on a different port so my requests were cross origin. This caused Chrome to sent a preflight OPTION method request to the same url (the POST url) and my app.all routing in Express processed that one too.
app.all('/api/:cmd', require('./api.js'));
Separating POST from OPTIONS solved the issue:
app.post('/api/:cmd', require('./api.js'));
app.options('/', (req, res) => res.send());
I met the same problem. Then I tried to add return, it didn't work. But it works when I add return res.redirect('/path');
I had the same problem. Then I opened the Chrome dev tools and found out that the favicon.ico was requested from my Express.js application. I needed to fix the way how I registered the middleware.
Screenshot of Chrome dev tools
I also had double requests. In my case it was the forwarding from http to https protocol. You can check if that's the case by looking comparing
req.headers['x-forwarded-proto']
It will either be 'http' or 'https'.
I could fix my issue simply by adjusting the order in which my middlewares trigger.