I have a multiple file uploader but while it's uploading sometimes 1 out of 10 files doesn't make it and it returns a Failed to load resource: net::ERR_CONNECTION_RESET in chrome console. I tried to catch it with the try-catch, but it acts as if no error occurred. What am I doing wrong?

var ajax = new XMLHttpRequest();
ajax.open("POST", "/multiFileUploadHandler.php");
try {
    ajax.send(formdata);
} catch (err) {
    alert('Error: '+err);
}

I have a multiple file uploader but while it's uploading sometimes 1 out of 10 files doesn't make it and it returns a Failed to load resource: net::ERR_CONNECTION_RESET in chrome console. I tried to catch it with the try-catch, but it acts as if no error occurred. What am I doing wrong?

var ajax = new XMLHttpRequest();
ajax.open("POST", "/multiFileUploadHandler.php");
try {
    ajax.send(formdata);
} catch (err) {
    alert('Error: '+err);
}

• javascript
• xmlhttprequest
• try-catch

• usually this error happens when the server's transport detected a error condition and thus it does reset your TCP/IP connection ! :) – Mehdi Maghrouni Commented Mar 26, 2014 at 16:43

1 Answer 1

This is likely because it is async. Try catching this with an onerror event handler.

ajax.onerror = function(error) {
    // handle error
};

edit: corrected syntax.