I have a web app, requesting and sending data via AJAX, and as a response, my server-side sends HTTP status codes, depending on the situation. so for example if a user tries to login while he's logged I probably return a 400 HTTP status code. And eventually i handle it with an alert, etc.
But handling these HTTP Status codes gets too heavy, since I'm making heavy use of AJAX. that means I'll be handling HTTP status code repeatedly with every AJAX request, which will result in duplicated code, and that's a bad practice.
So, what I'm looking for is a way to handle all these errors in one place, so I just handle all 400, 401, etc with the same code.
What i'm currently doing:
Handling the errors manually for each AJAX call. By using the statusCode in$.ajax().
statusCode: {
500: function(data) {
alert('Some friendly error message goes here.');
}
It seems like an overkill for me, as my web app develops, and as I create more ajax calls. I'll be repeating this piece of code again and again.
Currently, the only idea I have in mind is creating a function that will work on top of AJAX, something like:
function doAjax(type,url, data, moreVars) {
//this function is just a SIMPLE example, could be more complex and flexible.
$.ajax({
type: type,
url: url,
data: data,
moreOptions:moreVars,
//now handling all status code.
statusCode: {
//handle all HTTP errors from one place.
}
});
}
doAjax("POST", 'mydomain.com/login.php', dataObj);
You can use $.ajaxSetup() to register global error state handlers.
Description: Set default values for future Ajax requests.
Example:
$.ajaxSetup({
statusCode: {
500: function(data) {
alert('Some friendly error message goes here.');
}
}
});
Related
In my web application, I am trying to handle time out situations when calling a REST API. Here is my code which calls the API using jQuery ajax.
$.ajax({
type: "POST",
url: endpoint,
data: payload,
dataType: dataType,
timeout: 0,
success: successHandler,
error: failureHandler
});
The success and failure handlers are shown below.
function successHandler(data) {
//Got the data
}
function failureHandler(xhr, textStatus, thrownError) {
if(xhr.status==404) {
console.log('Page not found');
} else if(xhr.status==408) {
console.log('request timed out at server. You may want to retry') ;
}
}
If the timeout happens at the server, it is giving status 408. But sometimes, due network connectivity problems, the client (browser) itself is getting timed out because it is not able to connect to the service in specified time. I guess this is the browser behavior. What will be xhr.status and textStatus if the request gets timed out by the browser? How to handle this scenario?
[Edit] I found some explanation in Set timeout for ajax (jQuery). This explains how we can set timeout in the code. But my question is that I don't want to set timeout like this. Check the code in ajax request, I set timeout: 0 which means, there is no timeout and I am going to wait till I get the response from the server. Meanwhile, the browser may kill this request because of it's global timeout setting. I am looking for a solution which can handle this.
This looks like it is a very similar question to this post. Good luck!
How to detect timeout on an AJAX (XmlHttpRequest) call in the browser?
We're building a node.js application using Express, but are separating our layers. So the browser is running pure jQuery and javascript, the web server and application server are Node.js and Express. We're using REST APIs between them all.
We're using jQuery 1.10.2
Since the application server cannot be open to the public, the browser must make API calls to the web server, which manages making the call to the application server and returning the results. Here is what that looks like...
// Proxy all other API calls to the backend server
var request = require('request');
app.all('/api/*', function (req, res) {
var targeturl = apihost+req.originalUrl;
console.log("Proxy: "+targeturl);
request({
url: targeturl,
method: req.method,
json: req.body
}, function (error, response, data) {
if(error) {
res.send(error);
res.end();
} else {
console.log("SUCCESS...");
console.log(data);
res.send(data);
res.end();
}
});
});
Our data is a two-level hierarchy of Flows and one or more child Milestones on each Flow. When someone clicks the Save link on our page to save a Flow and its Milestones, the Javascript pulls the Flow data from the page, then makes an AJAX call to save the Flow information first, then waits for the "done()" handler before pulling the Milestone information from the page and making a second AJAX call to save that data. Here is the saveFlow() function executed in the browser...
function saveFlow(organization_id, user_id, flow_id) {
var name = $('#Name').val();
var purpose = $('#Purpose').val();
console.log("Trying to save flow: " + flow_id);
if (name && name.length > 0) {
$.ajax({
url: "/api/flow",
type: 'POST',
datatype: 'json',
data: {
flow_id: flow_id,
name: name,
purpose: purpose,
organization_id: organization_id,
user_id: user_id,
timestamp: (new Date())
}
})
.fail(function (error) {
console.log("Could not save the flow: " + error.message);
})
.done(function (flow) {
console.log("Saving milestones for flow "+flow.id+" ["+flow_id+"]");
saveMilestones(flow.id);
});
} else {
console.log("Refusing to save a flow that has no name");
}
}
The proxy code shows me that this call succeeded...
SUCCESS...
{ success: true,
message: 'Flow Updated!',
id: '56de8e346d229b492a0954f9' }
But the proxy code also demonstrates that the next API call never takes place. Moreover, the log statement in the Done block is never executed, nor are any log statements placed inside the saveMilestones() function.
Clearly, the .done() handler is never being called in this case. I use the done() handler in other parts of my code and it works. I've compared the code but don't see any differences. The proxy code we're using is driving every other API call made from our pages successfully, so I don't think that it's failing to return the success status.
I've done a lot of searching on this site and tried every suggestion I could find - adding a explicit "json" datatype parameter, switching from ":success" to ".done()" - but nothing has worked yet. I even tried switching from done() to always() - a bad idea but I wanted to see if it would get called...and it wasn't called.
It's also worth noting that the .fail() handler is also not being executed.
Is it possible that the JSON block we're sending back to indicate success is somehow failing to make jQuery realize that we were successful? Or is it possible that the AJAX call is crashing when it tries to process the successful return? If so, how do I catch that to prove it and fix it?
Hope someone can help.
I have a form that I have been submitting to Salesforce with standard form submit action. By default, you can tell Salesforce to redirect you to a given URL after the POST has completed.
I no longer wish to be redirected since I have other activities on the form page. No problem, my page is already using jQuery so I can use the handy $.ajax utility like this:
$('#wrapper').on('click', '#formsubmit', function(e) {
e.preventDefault();
var formData = $('#subForm').serialize();
$.ajax({
type: "POST",
url: "https://www.salesforce.com/servlet/servlet.WebToLead?encoding=UTF-8",
data: formData,
success: function() {
console.log('success!'); // or not!
},
error:function (xhr, ajaxOptions, thrownError){
console.log(xhr.status); // 0
console.log(thrownError); // empty
}
});
});
In my misguided brain, I imagined that Salesforce would return my good ol' redirect, which would count as a "success" that I can just discard/ignore. Misguided indeed!
I can see a 200 OK result (which usually means "success") but the success callback isn't tripped.
The lead is added to the Salesforce database
Inspecting the content of what's returned shows zero; there is no content in the response.
The error callback IS being tripped (despite the 200 OK) but maybe due to intentionally not redirecting it is seen as a "resource not available"? (therefore my status code is 0, and there is no content in the thrownError?).
Any advice on identifying this as a successful POST so that I can trigger additional actions in a callback? I don't want to TOTALLY ignore the response, or I could end up in a scenario in which I'm acting on a failed POST as if it was successful. I need to capture the success somehow.
It occurred to me that it could be a cross-site scripting issue as well, but since the application doesn't exchange data in JSONP, I'm not sure how to get around that (and I'm not sure how to identify it in the first place).
Few things here:
1) The redirect response being sent by salesforce's API is most likely being interpreted as an error code.
2) The response code of the subsequent page (after the redirect) is 200 OK, from the sound of it.
3) It is not possible to do a POST request using JSONP. This is a limitation of JSONP; which is not actually an AJAX request, but an HTTP GET request wrapped inside of a dynamically generated script tag. Also, JSONP only works if the request yields an HTTP response of 200 OK.
I would recommend using your own server-side intermediary to handle your AJAX POST request. This will act as a proxy between your front-end app and salesforce's API. This will also allow you to better control the response being sent to your app.
var formData = $('#subForm').serialize();
var response = $.ajax({
type: "POST",
url: "https://www.salesforce.com/servlet/servlet.WebToLead?encoding=UTF-8",
data: formData,
success: function() {
console.log('success!'); // or not!
},
error:function (xhr, ajaxOptions, thrownError){
console.log(xhr.status); // 0
console.log(thrownError); // empty
}
}).responseText;
where var response will contain the return value from your ajax call
I have a web site that is trying to call an MVC controller action on another web site. These sites are both setup as relying party trusts in AD FS 2.0. Everything authenticates and works fine when opening pages in the browser window between the two sites. However, when trying to call a controller action from JavaScript using the jQuery AJAX method it always fails. Here is a code snippet of what I'm trying to do...
$.ajax({
url: "relyingPartySite/Controller/Action",
data: { foobar },
dataType: "json",
type: "POST",
async: false,
cache: false,
success: function (data) {
// do something here
},
error: function (data, status) {
alert(status);
}
});
The issue is that AD FS uses JavaScript to post a hidden html form to the relying party.
When tracing with Fiddler I can see it get to the AD FS site and return this html form which should post and redirect to the controller action authenticated. The problem is this form is coming back as the result of the ajax request and obviously going to fail with a parser error since the ajax request expects json from the controller action. It seems like this would be a common scenario, so what is the proper way to communicate with AD FS from AJAX and handle this redirection?
You have two options.
More info here.
The first is to share a session cookie between an entry application (one that is HTML based) and your API solutions. You configure both applications to use the same WIF cookie. This only works if both applications are on the same root domain.
See the above post or this stackoverflow question.
The other option is to disable the passiveRedirect for AJAX requests (as Gutek's answer). This will return a http status code of 401 which you can handle in Javascript.
When you detect the 401, you load a dummy page (or a "Authenticating" dialog which could double as a login dialog if credentials need to be given again) in an iFrame. When the iFrame has completed you then attempt the call again. This time the session cookie will be present on the call and it should succeed.
//Requires Jquery 1.9+
var webAPIHtmlPage = "http://webapi.somedomain/preauth.html"
function authenticate() {
return $.Deferred(function (d) {
//Potentially could make this into a little popup layer
//that shows we are authenticating, and allows for re-authentication if needed
var iFrame = $("<iframe></iframe>");
iFrame.hide();
iFrame.appendTo("body");
iFrame.attr('src', webAPIHtmlPage);
iFrame.load(function () {
iFrame.remove();
d.resolve();
});
});
};
function makeCall() {
return $.getJSON(uri)
.then(function(data) {
return $.Deferred(function(d) { d.resolve(data); });
},
function(error) {
if (error.status == 401) {
//Authenticating,
//TODO:should add a check to prevnet infinite loop
return authenticate().then(function() {
//Making the call again
return makeCall();
});
} else {
return $.Deferred(function(d) {
d.reject(error);
});
}
});
}
If you do not want to receive HTML with the link you can handle AuthorizationFailed on WSFederationAuthenticationModule and set RedirectToIdentityProvider to false on Ajax calls only.
for example:
FederatedAuthentication.WSFederationAuthenticationModule.AuthorizationFailed += (sender, e) =>
{
if (Context.Request.RequestContext.HttpContext.Request.IsAjaxRequest())
{
e.RedirectToIdentityProvider = false;
}
};
This with Authorize attribute will return you status code 401 and if you want to have something different, then you can implement own Authorize attribute and write special code on Ajax Request.
In the project which I currently work with, we had the same issue with SAML token expiration on the clientside and causing issues with ajax calls. In our particular case we needed all requests to be enqueud after the first 401 is encountered and after successful authentication all of them could be resent. The authentication uses the iframe solution suggested by Adam Mills, but also goes a little further in case user credentials need to be entered, which is done by displaying a dialog informing the user to login on an external view (since ADFS does not allow displaying login page in an iframe atleast not default configuration) during which waiting request are waiting to be finished but the user needs to login on from an external page. The waiting requests can also be rejected if user chooses to Cancel and in those cases jquery error will be called for each request.
Here's a link to a gist with the example code:
https://gist.github.com/kavhad/bb0d8e4a446496a6c05a
Note my code is based on usage of jquery for handling all ajax request. If your ajax request are being handled by vanilla javascript, other libraries or frameworks then you can perhaps find some inspiration in this example. The usage of jquery ui is only because of the dialog and stands for a small portion of the code which could easly be swapped out.
Update
Sorry I changed my github account name and that's why link did not work. It should work now.
First of all you say you are trying to make an ajax call to another website, does your call conforms to same origin policy of web browsers? If it does then you are expecting html as a response from your server, changedatatype of the ajax call to dataType: "html", then insert the form into your DOM.
Perhaps the 2 first posts of this serie will help you. They consider ADFS and AJAX requests
What I think I would try to do is to see why the authentication cookies are not transmitted through ajax, and find a mean to send them with my request. Or wrap the ajax call in a function that pre authenticate by retrieving the html form, appending it hidden to the DOM, submitting it (it will hopefully set the good cookies) then send the appropriate request you wanted to send originally
You can do only this type of datatype
"xml": Treat the response as an XML document that can be processed via jQuery.
"html": Treat the response as HTML (plain text); included script tags are evaluated.
"script": Evaluates the response as JavaScript and evaluates it.
"json": Evaluates the response as JSON and sends a JavaScript Object to the success callback.
If you can see in your fiddler that is returning only html then change your data type to html or if that only a script code then you can use script.
You should create a file anyname like json.php and then put the connection to the relayparty website this should works
$.ajax({
url: "json.php",
data: { foobar },
dataType: "json",
type: "POST",
async: false,
cache: false,
success: function (data) {
// do something here
},
error: function (data, status) {
alert(status);
}
});
I've got an Ajax app I would like to add sessions and logins to.
Currently the app uses jQuery get shorthand to send a request
that.ajaxRequest = $.get(query_string, function(data, textStatus, xhr) {
// do somthing with data
});
I have a system on the server that throws an error message if the session has expired.
On the client I know I can deal with this using the following:
that.ajaxRequest = $.get(query_string, function(data, textStatus, xhr) {
if (data == "E_TIMEOUT") {
// redirect to login
} else {
// do something
}
});
However I would prefer not to have to write the same timeout code for every $.get - there are a bunch of them throughout the app.
Is there a way to monitor the result of a request and take action if necessary, without rewriting all of my $.get statements?
Thanks,
You can use $.ajaxSetup() for this:
$.ajaxSetup({
complete: function (xhr) {
if (xhr.getResponseHeader('E_TIMEOUT') == "1") {
//redirect to login
}
}
});
This approach is slightly different, it uses response headers which you can get without parsing data an extra time every request (that is possible, though not documented and subject to break), which you would have to do otherwise, in a global situation.
On the server-side where you're sending E_TIMEOUT for the response, just change it to add a header as well, E_TIMEOUT=1 (or whatever header you want). I actually put this header on my login page only, the timeouts redirect via a 302 (which XmlHttpRequest transparently follows), so if the user timeouts and the AJAX request actually ended up at the login page, I do a location.reload() to reflect this on the page. That's just another option if you go that route, it looks like this:
$.ajaxSetup({
complete: function (xhr) {
if (xhr.getResponseHeader('LoginPage') == "1") {
location.reload();
}
}
});
Without knowing what server platform you're using I can't say how to set headers, but it's pretty easy on every common platform.
You should use firefox and download a program called 'FireBug'. This will show you all the requests being sent out, and the response that comes back from the AJAX call. It is action packed with goodness & web dev tools.