CODEWITHSUNDEEP
ajaxjqueryhttpresponse
niko
niko

Reputation: 9393

Status of ajax or post request

status - contains the status of the request like

("success", "notmodified", "error", "timeout", or "parsererror") /ajax or post

I know what is success,not modified,error meant here but I am unable to find out how to handle this errors. If the call back is success then update my div, if there is any error not modified, error, time out, parse error then let me alert a pop up some error occurred.

What would be the cause for each type of error? I mean the situations where not modified,timeout,error and parseerror occurs.

If it results success, then does it mean my post request has successfully worked?

My local-server xampp never results any error, the status is always success. I guess, since its limited to my system but when I put my website online there exists several issues like traffic on server.

So how do I find out, whether my post request to some sample.php page was successfully sent and else pop out an alert to user if something went wrong?

Upvotes: 1

Views: 1796

Answers (3)

j7m
j7m

Reputation: 1085

The error types are a little self-explanatory. They simply provide a string for you to easily handle the different errors.

error callback option is invoked, if the request fails. It receives the jqXHR, a string indicating the error type, and an exception object if applicable. Some built-in errors will provide a string as the exception object: "abort", "timeout", "No Transport". Source: jQuery.Ajax documentation

Codes Explained:

Error: Any of the HTTP response codes, like the well-know 404 (not found) or other internal server errors.

Notmodified: Compares the cached version of the browser with the server's version. If they are the same, the server responds with a 304

Timeout: Ajax requests are time-limited, so errors can be caught and handled to provide a better user experience. Request timeouts are usually either left at their default or set as a global default using $.ajaxSetup() rather than being overridden for specific requests with the timeout option.

Parse Error: The jQuery data (JSON) cannot be parsed (usually due to syntax errors)

Handling these error codes: Here is some example of handling the errors

  $(function() {
    $.ajaxSetup({
        error: function(jqXHR, exception) {
            if (jqXHR.status === 0) {
                alert('Not connect.\n Verify Network.');
            } else if (jqXHR.status == 404) {
                alert('Requested page not found. [404]');
            } else if (jqXHR.status == 500) {
                alert('Internal Server Error [500].');
            } else if (exception === 'parsererror') {
                alert('Requested JSON parse failed.');
            } else if (exception === 'timeout') {
                alert('Time out error.');
            } else if (exception === 'abort') {
                alert('Ajax request aborted.');
            } else {
                alert('Uncaught Error.\n' + jqXHR.responseText);
            }
        }
    });
});

Source: Blog Post - jQuery Error Handling

Upvotes: 2

MrCode
MrCode

Reputation: 64536

Success

Response code is between 200-299 or is 304 Not Modified.

Not Modified

Response code is 304. If you employ caching, the browser can tell the server which version it currently has, and the server compares this with its version and if there has been no change, it can send a 304 Not Modified response, to indicate to the client that their version is up to date. In jQuery ajax, a 304 Not Modified response will still fire the success handler.

Error

Response code is between 400-599. This could be for example 404 not found, 403 forbidden, 500 internal server error etc.

Parse Error

This is a jQuery internal, not actually a HTTP response. This will happen if jQuery is trying to parse JSON or XML that is not in the valid format or has syntax errors.

Timeout

Again, this isn't a HTTP response. The ajax request has a timeout which if is exceeded before the server responds, will abort the request.

If you control the server side, in your example a PHP script, and you never change the response code using header() then your ajax will always receive 200 OK responses unless there is an unhandled exception in the PHP which will trigger a 500 internal server error.

It is acceptable to always send 200 OK response codes. For example, if the server outputs a JSON object which contains its own success/error flag then any errors can be handled by looking at the flag.

Upvotes: 1

Arun P Johny
Arun P Johny

Reputation: 388416

As far as I know

not modified: Server sends a Not Modified(304) response status

timeout: the server has not responded within the time period specified by the timeout property

error: server response with a error status like 4xx or 5xx

parseerror: there was an client side error when processing server response like an invalid json format/xml format

Upvotes: 0

Related Questions