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?
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
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.
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
Related
When connecting via a non-secured protocol (http), my MVC 5 web application returns the error message properly. But the moment I connect via https, the error message is blank. Thought? NOTE: I try json return also. Thanks!
Browser debugger output
HTTP
HTTPS
MVC Controller:
string message = string.Join(" ", errors);
Response.StatusCode = (int)HttpStatusCode.RequestedRangeNotSatisfiable;
return new HttpStatusCodeResult(Response.StatusCode, string.Join(" ", message));
Script:
function ajaxOnFailure(response, status, error) {
debugger;
if (response.status == 500) {
error = "An internal error has occurred. Please try again. If the problem persists, please contact IT."
}
toastr.error("", error);
}
I ended up using a workaround. Instead of return a fail response, I return OK response and determine the type of message via jquery. It would have been nice if a fail response return the message via https.
I am doing an dropbox.js upload. I am checking for errors on the server and returning them to my frontend via json. So far so good.
header('HTTP/1.1 500 Internal Server Error');
header('Content-Type: application/json; charset=UTF-8');
die(json_encode(array('message' => 'ERROR', 'code' => 100)));
on my frontend I can catch the error and do some nice stuff to alert the user
error: function(file, errorMessage, xhr) {
console.log(xhr);
// catch the error and alert the user
}
The problem is the errors are not really 'server errors' so how should I return them in the header? A 500 does not seem appropriate. It does not I suppose really matter but would nice to return the right type of error.
The kind of errors include
filename is not unique
wrong file type
file is too large
What is the best status code to use?
Thanks.
I have a CORS Ajax call to a web api. I have a message handler which throws an:
var msg = new HttpResponseMessage(HttpStatusCode.Unauthorized) { ReasonPhrase = "Oops!!!" };
throw new HttpResponseException(msg);
On the client I can't get no response headers, tried:
error: function (xhr, error) {
var result = xhr.getResponseHeader("Response");
but result is null and no other heades are available.
The Debugger shows correctly a 401!
Should I return the Unauthorized Exception differently from the server?
Update:
I forgot the add the Origin header to my HttpResponseException, in order to get the headers.
But in IE10 I don't get any headers, only error message
"error"
How can I know what happend, when using IE10?
Here is related question.
As I cannot get the Headers when returning a 401 response.
No instead I return NoContent StatusCode, which triggers the AJAX success eventhandler.
Now I have to check the response header "response" (which I manually add on the server side) in the success eventhandler, in order to make it work in IE 10:
Server:
var msg = new HttpResponseMessage(HttpStatusCode.NoContent) { ReasonPhrase = "UNAUTHORIZED" };
msg.Headers.Add("RESPONSE", "401");
AddCORSHeaders(msg.Headers, request);
return await Task.FromResult(msg);
Client:
error: function (jqXhr, error) {
var isAuth= jqXhr.getResponseHeader("Response");
Now I get a "response" header with value 401.
IF SOMEONE HAS A BETTER APPROACH, I'LL EXCEPT THE ANSWER !
In IE10 the ajax error eventhandler you get readyState=0 and status="".
In Chrome you get a 401 and readyState=4.
I'm using the following lua script to forward all server responses that are served from Node. My error handling for a /signup route works as follows:
if authenticationResult.status ~= 201 then
...
ngx.status = authenticationResult.status
ngx.say(authenticationResult.body)
ngx.exit(401)
return
end
From the client I send a typical signup request like so, using the superagent-promise library:
request
.post(url)
.type('form')
.send(data)
.end()
.then((response) => {
console.log('the response', response)
})
.catch((error) => {
console.log('the error', error)
})
When I send a valid post request from the client, the response variable in the .then successfully contains the response body.
However, when I sent an improper post request with invalid credentials, neither the .then nor the .catch executes. Instead, the Chrome console immediately displays POST http://api.dockerhost/signup 401 (Unauthorized).
I would like to know what I can do differently to successfully access the server's error response and its contents, outside of just its status code.
Per the manual, you need to use ngx.HTTP_OK as the return if you want nginx to return content as part of the page. Otherwise it will simply return a 401.
ngx.status = authenticationResult.status
ngx.say(authenticationResult.body)
ngx.exit(ngx.HTTP_OK)
return
I have a login system that will hold the session for 2 hours. After 2 hours, when the client makes API calls, they get back an error:
{
"Success": false,
"Error": {
"ErrorCode": "002",
"ErrorMessage": "Session expired"
}
}
I need to then redirect the client to /login when that happens. The problem is that I get that error from individual API calls, so rather than change EVERY API call, is it possible to have a global interceptor?
Following the example for Interceptors found here, you can do something like the following in the response section of the interceptor:
response: function(resp){
// resp.data will contain your response object from the server
if(resp.data && !resp.data.Success){
// check for error code
if(resp.data.Error && resp.data.ErrorCode === '002'){
$location.path('/login');
return $q.reject(resp);
}
}
return resp || $q.when(resp);
},
This is assuming that your server is returning a 200 when you get this error message, not on a 401 or 403, but that's what it looks like you're doing. Hope that helps.