javascript xmlhttprequest synchronous onerror

Question

Good day. Can you please tell if the onerror event works in a synchronous request. Thank.

My code is:

var xhr = new XMLHttpRequest(); xhr.open('GET',"/customer/"+login,false); xhr.onerror = function(){ alert("XMLHttpRequest error"); console.log("XMLHttpRequest error"); authorizedCustomer = new Customer("Username","Password"); authorizedCustomer.authorities = [{"name":"ROLE_ADMIN"}]; alert(JSON.stringify(authorizedCustomer)); return; } xhr.send(); authorizedCustomer = JSON.parse(xhr.responseText);

but, when working in the background (without communication with the server), the error code does not work.

judging by the specification, browsers should now throw an exception when using synchronous requests not in the webwoker.
And if you look at error handling , then with a synchronous request there should be an exception.

akrasnov87 akrasnov87 370 1 silver mark 5 bronze marks · Answer 1 · 2016-10-10T08:19:22

To get error codes in XMLHttpRequest, I use this code

 var xhr = new XMLHttpRequest(); var readyStateChange = function () { if (xhr && xhr.readyState == 4) { var status = xhr.status; // статус-код запроса, 200-все хорошо, 404-страница не найдена var result = xhr.responseText; // результат запроса // здесь что-то делаешь } }; xhr.onreadystatechange = readyStateChange; xhr.send();

I'm interested in the onerror function. Does it not work in a synchronous request?
in a synchronous request, the status can be checked after send ();
This I know, I probably did not quite clearly set out the question ... I need that the code worked not with an error, but with an exception.
if send returns this (Uncaught NetworkError: Failed to execute 'send' on 'XMLHttpRequest': Failed to load) exception to make return, and the script goes on ...

javascript xmlhttprequest synchronous onerror

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