Category: JavaScript Answers

Sometimes, we want to add a response timeout with Express.js and Node.js.

In this article, we’ll look at how to add a response timeout with Express.js and Node.js.

How to add a response timeout with Express.js and Node.js?

To add a response timeout with Express.js and Node.js, we can use the connect-timeout module.

To install it, we run

npm i connect-timeout

Then we use it by writing

const timeout = require('connect-timeout');

const haltOnTimedout = (req, res, next) => {
  if (!req.timedout) {
    next();
  }
}
app.use(timeout(120000));
app.use(haltOnTimedout);

to define the haltOnTimeout function.

We check if the request has timed out with req.timedout.

If it’s false, then we call next to call the next middleware.

And we add the middleware returned by timeout called with the request timeout in milliseconds and the halfOnTimedout function with app.use in the order they’re listed to lets us set a timeout for all requests to 120000 milliseconds.

Conclusion

To add a response timeout with Express.js and Node.js, we can use the connect-timeout module.

Sometimes, we want to return a complex JSON response with Node.js and Express.

In this article, we’ll look at how to return a complex JSON response with Node.js and Express.

How to return a complex JSON response with Node.js and Express?

To return a complex JSON response with Node.js and Express, we can use the res.json method.

For instance, we write

res.json({
  fileName
})

to call res.json with the JSON object that we want to return as the response.

As a result, the client would get a JSON string with the stringified JSON object as the response.

Conclusion

To return a complex JSON response with Node.js and Express, we can use the res.json method.

Sometimes, we want to update all clients using Socket.io.

In this article, we’ll look at how to update all clients using Socket.io.

How to update all clients using Socket.io?

To update all clients using Socket.io, we call socket.broadcast.emit to broadcast to all sockets except the socket that starts it.

For instance, we write

socket.broadcast.emit('users_count', clients);

to call socket.broadcast.emit with the event name and the value we want to send.

Conclusion

To update all clients using Socket.io, we call socket.broadcast.emit to broadcast to all sockets except the socket that starts it.

Sometimes, we want to write formatted JSON in Node.js.

In this article, we’ll look at how to write formatted JSON in Node.js.

How to write formatted JSON in Node.js?

To write formatted JSON in Node.js, we can call JSON.stringify with the 3rd argument set to the number of spaces to indent.

For instance, we write

JSON.stringify(object, null, 2)

to call JSON.stringify with the object to convert to a JSON string and 2 to indent each level of the JSON string to 2.

Conclusion

To write formatted JSON in Node.js, we can call JSON.stringify with the 3rd argument set to the number of spaces to indent.

Sometimes, we want to fix the req.user undefined error with Node.js, Express, and Passport.

In this article, we’ll look at how to fix the req.user undefined error with Node.js, Express, and Passport.

How to fix the req.user undefined error with Node.js, Express, and Passport?

To fix the req.user undefined error with Node.js, Express, and Passport, we should make sure Passport session state is set up in our app.

For instance, we should write

app.use(session({
  secret: 'anything'
}));
app.use(passport.initialize());
app.use(passport.session());

to call session to enable session storage with session.

Then we call passport.initialize to initialize Passport.

And then we call passport.session to let Passport handle sessions in our Express app.

Then when a user is logged in, req.user should be set.

Conclusion

To fix the req.user undefined error with Node.js, Express, and Passport, we should make sure Passport session state is set up in our app.