I'm using express and trying to download a file, then load the page. I understood that the problem is stopping res.download with res.render but I can' t figure out how to resolve this. I also tried to put res.render() inside the callback function of res.download(), the only thing that happen is that res.render stopped working but the file would download.
app.get("/", function(req, res) {
res.download(
"./public/sample-zip/Lost Sky - Dreams.zip",
"Lost Sky - Dreams.zip",
err => {
if (err) console.log("Errore nel dw: " + err);
}
);
res.render("index");
});
You can't end the same request in multiple ways - download behind the scenes will call sendFile which sends a file to the client and ends the request, similarly render will send page content and also end the request.
The correct approach here is to allow the file to be downloaded to the client and then have the client redirect the page on the back of a successful download.
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 want to handle all my cookies and session stuff in a function then redirect to the destination path. I use this function in Express:
app.all('*', function(req, res, next){
if('_id' in req.session)
next()
else if('userInfo' in req.cookies){
req.session._id = req.cookies.userInfo._id
next()
} else {
res.redirect('../login')
}
res.end()
})
but browser print this error:
net::ERR_TOO_MANY_REDIRECTS
what's the problem?
This error occurs when a web browser is redirecting you to another web page which then that web page redirects you back to the same browser again. Your configurations are wrong. app.all('*', ..) runs again and again whenever a request is made, which causing repetition.
You need to have better configurations than app.all(*..) //all. You need to specify it more so that it doesn't repeat itself.
I would say limit it down to some urls and not all of them. You could do
app.get('/cookieCheckerPage', function(req, res){
//code here
});
Also please see Error 310 (net::ERR_TOO_MANY_REDIRECTS):
I wanted to provide a Node.JS Express route wrapper for users who needed to logout and didn't have JavaScript enabled on the front-end. DB is my reference to my Firebase:
router.get('/logout', function(req, res) {
DB.unauth();
res.redirect(302, '/');
});
When I try to logout this way having been logged in, I get the following error:
Error: Can't set headers after they are sent.
The documentation for Firebase.unauth() is pretty light, but calling it in a route (with or without the res.redirect) causes the error. Does anyone have a suggestion or workaround for this issue?
So i was running into the same problem. For me it was that i was using the asynchronous authDataCallback function.
Apparently onAuth sets your headers so when you try to go to /logout your headers are set and the redirect will fail. So what i did is i switch the authDataCallback
that i had checking for login states to:
var authData = ref.getAuth();
if (authData) {
console.log("User " + authData.uid + " is logged in with " + + authData.provider);
} else {
console.log("User is logged out");
}
then my route for log out work flawlessly.
app.get('/logout', function(req , res){
ref.unauth();
res.redirect('/');
});
Looks like that error is being thrown on the redirect - you can't headers once the body has been sent. Maybe try:
response.writeHead(302, { Location: '/' });
response.end();
If that doesn't work, I'd put money on that .unauth() is actually setting headers, and if it is, you'll probably need to use the ol' <noscript> tag.
All of this said though: you're building an app that uses JavaScript to integrate with Firebase on the back end. Why build a modern web-app that (presumably) relies heavily on JavaScript only to support logging out users when they don't support it? Could they even log in in the first place?
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 have got a reverse proxy and a node.js server which sends a plain/text response back to the proxy which, in turn, does a bunch of front-end stuff 0% related to my problem.
The plain/text response comes from multiple asynchronous functions and the user is informed of the progress as each async function completes through the usage of
res.write("Example");
The problem is, the node.js server is supposed to prompt the browser for a download after all the async functions are complete. It's irrelevant how or where the file is downloaded.
I have tried to set the headers to Content-Disposition: attachment, but Node just throws something like Error: Can't set headers after they are sent.
Here's a code example:
app.post('/', function(req, res) {
res.statusCode = 200;
/*
Bunch of async functions
*/
res.download("some_file"); // This is included in the callback after all async functions are done
});
app.listen(3000, function() {
console.log('The server is running at http://whatever:3000/');
});
The async functions make use of eachSeries from the async module. This is another example of what I'm trying to accomplish:
async.eachSeries(func1,func2,function(err){
// something to prompt the user for download
});
Do I have to create another instance of express just to serve the download or is there some way to do everything within one express() instance?