When I make multiple post requests to my nodejs server and all of the parameters are correct, everything works fine (and doesnt freeze) but when I make multiple post requests with incorrect parameters that gives an error, my nodejs server just freezes/hangs for a few minutes. Why is this?
Here is my code btw
app.post('/pushtransaction', function(req, res) {
console.log(req.body);
console.log(5);
if (req.body.sigs) {
let sigver = xmf.modules.ecc.Signature.from(req.body.sigs).toString();
let lasig = [sigver];
console.log(req.body.packedTr);
let transi = JSON.parse(req.body.packedTr);
//let sigver = req.body.sigs;
let package = {
compression: 'none',
transaction: transi,
signatures: lasig
}
console.log(package);
//Pushes tx in correct format
xmf.pushTransaction(package).then(result=>{
res.send(result);
res.end();
console.log(result);
}).catch(err => {
console.log(err)
});
}
})
When your error is encountered, your Node server does not know what to do other than console.log() the error. It needs to end that request and send some response. You can res.status(400).send({ error: err }) when you're within the catch.
Make sure res.send() method gets called every time in your request.
Updated Javascript:
app.post('/pushtransaction', function(req, res) {
console.log(req.body);
console.log(5);
if (req.body.sigs) {
let sigver = xmf.modules.ecc.Signature.from(req.body.sigs).toString();
let lasig = [sigver];
console.log(req.body.packedTr);
let transi = JSON.parse(req.body.packedTr);
//let sigver = req.body.sigs;
let package = {
compression: 'none',
transaction: transi,
signatures: lasig
}
console.log(package);
//Pushes tx in correct format
xmf.pushTransaction(package).then(result=>{
res.send(result);
res.end();
console.log(result);
}).catch(err => {
console.log(err);
res.status(400).send();
});
}
res.status(400).send();
})
Additionally you don't have to call res.end() if you call res.send(). see Must res.end() be called in express with node.js?
Adding to other answers, you can add a middleware for timeouts, if any service fails to respond in some time, like
var timeout = require('connect-timeout');
app.use(timeout('5s'));
Related
Some context
I've created a service worker to send notifications to registered users.
It works well until I tried to implement a sort of id to each people who register to a service worker (to send notification).
I do that because I have to delete old registration from my database, so I took the choice to let each users three registration (one for mobile device and two others for different navigator on computer) and if there is more, I want to remove from the database the older.
Tools
I'm using nodejs, express and mySql for the database.
The issue
When I launch a subscription I got this error:
SyntaxError: Unexpected token o in JSON at position 1
at JSON.parse (<anonymous>)
I saw in an other post that it's because they try to JSON.parse what's already an object.
But in my case, I can't find where I parse, see the part which are concerned:
// service.js (service worker file)
// saveSubscription saves the subscription to the backend
const saveSubscription = async (subscription, usrCode) => {
const SERVER_URL = 'https://mywebsite:4000/save-subscription'
subscription = JSON.stringify(subscription);
console.log(subscription); // I got here what I expect
console.log(usrCode); // <-------------------------------- HERE I GOT UNDEFIND
const response = await fetch(SERVER_URL, {
method: 'post',
headers: {
'Content-Type' : 'application/json',
},
body : {
subscription: subscription,
usrCode: usrCode
}
})
return response
}
But when I console.log(usrCode) in my inspector, I got the good value.
So how should I do to get the value in service.js
Maybe the problem is from:
const bodyParser = require('body-parser')
app.use(bodyParser.json())
At the beginning I thought that the issue is from the back (because I'm not really good with async function).
And here is the back, If maybe I got something wrong.
// index.js (backend)
// Insert into database
const saveToDatabase = async (subscription, usrCode) => {
// make to connection to the database.
pool.getConnection(function (err, connection) {
if (err) throw err; // not connected!
console.log(usrCode);
console.log(subscription);
connection.query(`INSERT INTO webpushsub (webpushsub_info, webpushsub_code) VALUES ('${subscription}', '${usrCode}')`, function (err, result, fields) {
// if any error while executing above query, throw error
if (err) throw err;
// if there is no error, you have the result
console.log(result);
connection.release();
});
});
}
// The new /save-subscription endpoint
app.post('/save-subscription', async (req, res) => {
const usrCode = req.body.usrCode; // <------------------ I'm not sure about this part
const subscription = req.body.subscription
await saveToDatabase(JSON.stringify(subscription, usrCode)) //Method to save the subscription to Database
res.json({ message: 'success' })
})
By searching on google, I've found this tutorial. So the reason why usrCode is undefined is because the service worker doesn't have access to a data stored in front.
First you have to pass it in the URL as following:
// swinstaller.js (front)
// SERVICE WORKER INITIALIZATION
const registerServiceWorker = async (usrCode) => {
const swRegistration = await navigator.serviceWorker.register('service.js?config=' + usrCode); //notice the file name
return swRegistration;
}
And then get it in the service worker:
// service.js (service worker file)
// get the usrCode
const usrCode = new URL(location).searchParams.get('config');
I'm trying to get the temperature data from my node.js backend sent to react.js but i kept getting res.send is not a funtion
Sample code here
app.get("/gettemperature", (req, res) => {
const email = req.query.email;
let stmt = `SELECT * FROM users WHERE email=?`;
let todo = [email];
db.query(stmt, todo, (err, results, fields) => {
if (err) {
console.error(err.message);
}
if(results.length > 0 ){
let id = results[0].id;
let getID = `SELECT * FROM controlModules WHERE deviceowner=?`;
let getidData = [id];
db.query(getID, getidData, (err, resulta, fields) => {
if (err) {
console.error(err.message);
}
if(resulta.length > 0){
let lanip = resulta[0].ipaddress;
let url = "http://"+lanip+"/data";
http.get(url,(res) => {
let body = "";
res.on("data", (chunk) => {
body += chunk;
});
res.on("end", () => {
try {
let json = JSON.parse(body);
const temp_actual = json.temperature.value;
console.log(temp_actual);
res.setHeader('Content-Type', 'application/json');
res.end(
JSON.stringify({
value: temp_actual
})
);
} catch (error) {
console.error(error.message);
};
});
}).on("error", (error) => {
console.error(error.message);
});
}
});
}
});
});
i really need to return/send/respond the temperature data to my front end but i'm getting said error, is there a different way to return data?
It looks like you are mixing up an HTTP server you wrote in Node (although you haven't shown any relevant code) and an HTTP client you also wrote in Node.
res is an argument received by the callback you pass to http.get and contains data about the response received by your HTTP client.
Meanwhile, somewhere else (not shown) you have a different variable also called res which is the object your HTTP server uses to send its response to the browser running your React code.
You are calling res.send and wanting res to be the latter but it is really the former.
Since you haven't shown us the HTTP server code, it is hard to say where that res is, but there is a good chance you have shadowed it and can solve your problem by using different names (e.g. client_res and server_res).
That said. I strongly recommend avoiding using the http module directly as the API follows out of date design patterns and isn't very friendly. Consider using fetch or axios for making HTTP requests and Express.js for writing HTTP servers.
I am trying to verify if some data is in the session. If not the controller will redirect you to another route, to get that data.
The problem is that I am getting an error "Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client"
I search over StackOverflow and I find that everyone that had this problem fix it using it async/await, but i was already using async await.
Your help will be trully appreciated!
Thank you very much!
Jose
dashboardCtrl.init = async (req, res) => {
//
var frontdata = req.session;
if (!frontdata.user) {
frontdata.user = await userfacebook.findOne({ where: { 'email': frontdata.passport.user } });
};
if (!frontdata.store) {
tmpstoredata = await userstore.findOne({ where: { 'userfacebookId': frontdata.user.id } });
if (!tmpstoredata) {
res.redirect('/toURL');
};
};
};
Note: I am using EJS MATE.
If i do this
dashboardCtrl.init = async (req, res) => {
//
res.redirect('/toURL');
};
Redirect works, the problem is using await. So i dont know how to continue
That error says that you have already sent an answer to the cliente. In other words, you are trying to declare for the second time -> **res.*****.
Check the flow again in case you have twice declared any action on express's "res".
The solution below allows you to have a good structured and readable asynchronous code.
dashboardCtrl.init = (req, res) => {
// I think destructuring looks good
let { user, store } = req.session;
(async () => {
try {
if (!user) user = await userfacebook.findOne({ where: { 'email': frontdata.passport.user } });
let tmpstoredata;
if (!store) tmpstoredata = await userstore.findOne({ where: { 'userfacebookId': frontdata.user.id } });
if (!tmpstoredata) res.redirect('/toURL');
} catch (err) {
// don't forget ;)
}
})()
};
Hope this can help you.
Greetings.
The code was OK
The problem was the EJS MATE
I replace it with EJS
Here's my request:
axios.get(BASE_URI + '/birds/random', {Stuff: "STUFF"})
.then(randBird=>{
const birdData = randBird.data
const bird = {
age: birdData.age,
bio: birdData.profile.bio,
displayname: birdData.profile.displayname,
species: birdData.profile.species,
_id: birdData._id
}
this.setState({currentBird:bird})
})
Here's what happens on my router (on '/birds'):
birdRouter.route('/random').get((req, res)=>{
console.log('req.body = ', req.body)
User.count().exec((err, num)=>{
if(err){
console.log(err)
return res.send({error: err})
}
const random = Math.floor(Math.random() * num)
User.findOne().skip(random).exec((err, bird)=>{
if(err){
console.log(err)
return res.send({error: err})
}
console.log(bird)
res.send(bird)
})
})
Really, the only lines that are worth paying attention to in both snippets are the first and first two (for the first and second snippet, respectively).
The request goes through, but my console.log shows this:
req.body = {}
What did I do wrong here?
Some browsers and libraries don't support HTTP get method with a body. You can switch to POST/PUT and see if it works as expected.
Usually in GET method we are not passing body data. instead of body data you can pass in query string. and also if you are using express server than you need to install a package body-parser to get data in body. please take a reference of issue posted in axios
I have a Rest API in node.js that takes much time to respond because it sends a request to suppliers vendor and once the response is fully prepared then it returns the result what I want is as the result is being prepared it should be able to display it on the front react side. Thanks in advance for any help and your time
here is my controller
module.exports.search = async (req, res) => {
try {
let params = req.query;
params = _.extend(params, req.body);
const result = await modules.Hotel.Search.search(req.supplierAuth, params);
res.json(result);
} catch (e) {
global.cli.log('controller:hotels:search: ', e);
res.status(500).json({ message: e.message });
}
};
here is my front side service
export const getHotels = (filters, options = {}) => {
const queryString = new URLSearchParams(options).toString();
return post(`/api/hotels/search?${queryString}`, filters);
};
The best solution is to use streams and pipe() the results as they come into express's res object, similar to this guy's approach.
You'll have to modify the modules.Hotel.Search.search(....) and make that use streams.