Exploring Strategies for Optimizing HTTP Error Messages

Question

Exploring Strategies for Optimizing HTTP Error Messages

My current challenge involves sending a JSON-encoded data string to a remote machine via AJAX. Every time I attempt to transmit the data string, one of two error messages emerges:

XMLHttpRequest cannot load http://10.1.0.139:8000/. 
No 'Access-Control-Allow-Origin' header is present on 
the requested resource. Origin 'http://localhost' is 
therefore not allowed access.

This message occurs when the remote machine is operational and accepting connections. Despite this error, my code successfully sends the correct data string to the remote machine.

POST http://10.1.0.139:8000/ net::ERR_CONNECTION_REFUSED

The second message appears when the remote machine is turned off or doesn't have its own server running to accept incoming requests and connections.

My main issue lies in distinguishing between these two error messages. Traditional AJAX callbacks like error() or fail() are not effective since there will always be an error, even if the HTTP status 200 confirms that everything is functioning correctly (as shown by the first error).

Is there any way to implement a pseudo command that states 'IF I FAIL TO CONNECT TO REMOTE MACHINE, THEN...'

EDIT

Upon further observation, my remote machine fails to display incoming connections made from Internet Explorer, instead showing the following:

XMLHttpRequest: Network Error 0x2efd,   
Could not complete the operation due to error 00002efd.

javascript ajax http

Answer 1

Answer №1

Utilize the XMLHttpRequest timeout feature

let xhr = new window.XMLHttpRequest();
let requestData = 'x=1';
xhr.open('POST', 'http://10.1.0.139:8000/');
xhr.timeout = 5000;
xhr.addEventListener('timeout', function(event) {
    // handle server timeout
    console.log('request timed out');
    console.error(event);
});
xhr.addEventListener('error', function(event) {
    // handle CORS error or other errors
    console.log('an error occurred');
    console.error(event);
});
xhr.addEventListener('load', function(event) {
    // handle successful response
    console.log('request successful');
    console.info(event);
});
xhr.send(requestData);

This will result in an error if there is a CORS issue, and a timeout if the server is unresponsive

Answer 2

Utilize the XMLHttpRequest timeout feature

let xhr = new window.XMLHttpRequest();
let requestData = 'x=1';
xhr.open('POST', 'http://10.1.0.139:8000/');
xhr.timeout = 5000;
xhr.addEventListener('timeout', function(event) {
    // handle server timeout
    console.log('request timed out');
    console.error(event);
});
xhr.addEventListener('error', function(event) {
    // handle CORS error or other errors
    console.log('an error occurred');
    console.error(event);
});
xhr.addEventListener('load', function(event) {
    // handle successful response
    console.log('request successful');
    console.info(event);
});
xhr.send(requestData);

This will result in an error if there is a CORS issue, and a timeout if the server is unresponsive

Exploring Strategies for Optimizing HTTP Error Messages

Is there any way to implement a pseudo command that states 'IF I FAIL TO CONNECT TO REMOTE MACHINE, THEN...'

Answer №1

Similar questions

Discovering a device's model using JavaScript

Is it possible to bind computed values in Ember using .properties(...) with ember-model?

Vue.js Issue: Image not properly redirected to backend server

I'm having trouble mocking the image import correctly when trying to pass a test using jest with next.js. Why am I encountering this error?

Creating a Select component in React without relying on the Material-UI library involves customizing a dropdown

angularJS controller does not seem to be functioning properly due to a certain

Can I construct an html table-esque layout employing fabric js?

"Compactly condensing" an abundance of boolean values in JSON through manual effort

Creating a fixed navigation bar that stays at the top of the page when scrolling

Leveraging an array retrieved through JQuery AJAX for auto-complete data in materializecss

Setting a default year in a React datepicker: A step-by-step guide

specialized html elements within data-ng-options

What strategies can be implemented to maximize memory and CPU efficiency in NodeJS and Express?

How does bodyParser determine the specific view to populate in req.body?

Ways to embed one block of javascript code within another block of javascript code

Displaying JavaScript Array Elements in an Aligned Table Format

How can milliseconds be formatted to a date within a map in a React component?

Merge arrays in map function based on label and aggregate information

What is the purpose of importing React from "react" in a .jsx file? Is there any distinction between the .jsx and .js extensions?

In Vue.js, leverage the power of slots to access content from deeply nested child components