How to execute a function after ajax post type request?

Question

JavaScript

Authorization in progress.

$(document.forms['someName']).on('submit', function() {
    
    var form = $(this);
    $(':submit', form).button('loading');

    $.ajax({
        url: '/signin',
        method: 'POST',
        data: form.serialize(),
        complete: function() {
            $(':submit', form).button('reset');
        },
        statusCode: {
            200: function() {
                    window.location.href = '/';
            },
            403: function(jqXHR) {
                var error = JSON.parse(jqXHR.responseText);
                window.location.href = '/signin';
            }
        }
    });
    return false;
});

After the server responds with a 403 error, I want to redirect to the authorization page window.location.href = '/signin'and display an informational message indicating the reason for the error. At the same time, I don’t want to specify any parameters through ?, like this window.location.href = '/signin?login_fail=1'.

Thus, is it possible to call the js function only if the user came to this page after an unsuccessful post request?

Answer 1

UPD: a flag in cookie or localstorage will help, for example: localStorage.lastResult = "error";
Next to complete in the $.ajax call, add another error: function() {} or error: functionName if it has already been defined somewhere.

Answer 2

the jquery $.ajax method has such a parameter as success (formulated in the same way as complete and statusCode) - it fires when the method succeeds: i.e. if the request is completed and some information is returned.
You can use success to process received data. I see that you are getting the response in JSON. Throw in some flag, for example "is403" with values ​​true or false. And set the flag only if the 403 worked.
then the script part will be as follows:

....
success: function(data) {
   var answer = JSON.parse(data);
   if (answer.is403 === true) {
      //делаем редирект
   } else {
      //делаем что-нибудь другое, если флаг 403 не установлен, а значит, возвращены какие-то данные
   }
}