Develop Reference

jsonp and REST GET call

I have two projects, an older one, which works, and a newer one. Both projects have to make a cross-domain call.
On the older project, I use jsonp to talk to the server and get a response, such as:
var myUrl = "http://www.myserver.whatever/somepage.php";
jsonp(myUrl, "ajaxResponse");
function ajaxResponse(data) { alert(data.response); }
In my new totally unrelated project, I have to talk to a service. The web page is a local file on the client talking to a CentOS daemon written by a software vendor. I can communicate to the daemon through REST GET calls. An example of a call would be, which works, as I entered the following in a Mozilla Firefox browser window:
localhost:8080/mfds/info
I thought that the easiest way to communicate to the daemon would be through jsonp, like I did previously, so:
var myUrl = "http://localhost:8080/mfds/info";
jsonp(myUrl, "ajaxResponse2");
function ajaxResponse2(data) { alert(data.response); }
Sadly, I never get to the ajaxResponse2() function. What am I doing wrong? Is jsonp() not a REST GET call? How do I fix the code?
I am using:
<script type="text/javascript" src="js/jsonpCrossDomain.js"></script>
to load the jsonp script. As mentioned earlier, if I use the URL associated with my old project, the code works, just not with localhost:8080:/mfds/info, which works nicely in a browser. The daemon service returns html code.
UPDATE:
Based on the comment below, I did not realize that jsonp has to be on both sides. I originally tried the following code, but this code threw a cross domain error (or so I think, actual error below), which led me to try the JSONP call, but I cannot use that either.
$.ajax({
url: 'localhost:8080/mfds/info',
type: "GET",
dataType: "html",
error: function (error)
{
alert(JSON.stringify(error));
},
complete: function (data_response)
{
alert(data_response.responseText);
},
success: function (data)
{
alert(data);
}
});
Error message from the $.ajax call:
{"readyState":0,"status":0,"statusText":"[Exception... \"\" nsresult: \"0x805e0006 ()\" location:\"js frame ::file:///home/user/Documents/myproejct/js/jquery-2.0.3.min.js :: :: line 6\" data: no]"}

Feeding webpage data via remote Web API

I'm trying to operate two servers.
MVC Web API service.
MVC Web application.
The idea is that the web application renders a page filled with javascript requests, which populate the actual data from the remote API service. The web application will never itself touch the database, or the API service (besides setting up authorisation tokens initially).
What is the best way to achieve this?
So far I've been using JQuery AJAX requests, attempting to use JSONP. However I always get "x was not called" exceptions.
$.ajax({
url: '#(ViewBag.API)api/customer',
type: 'get',
dataType: 'jsonp',
jsonp: false,
jsonpCallback: function (data) {
debugger;
// code to load to ko
},
error: function (xhr, status, error) {
alert(error.message);
}
});
Also the jsonpCallback function is called before the request is sent, so I assume its actually trying to call a function to generate a string? If I reform this request:
window.success = function (data) {
debugger;
// code to load to ko
};
... with jsonpCallback being "success", I still get the same error (but the success method is never called.
Any ideas? Thanks.
Edit: I've gotten started on the right course from this:
http://www.codeproject.com/Tips/631685/JSONP-in-ASP-NET-Web-API-Quick-Get-Started
Added the formatter, and replaced jsonCallback with success, like a normal ajax. However this only seems to work for get. I cannot delete or update. :(

Can you get it to work using the $.getJSON method?
$.getJSON( "ajax/test.json", function( data ) {
//handle response
});
Have you fired up developer tools in IE and watched the network traffic to see precisely what is being sent and returned?

Creating an API in yii for cross domain communication

I am planning to create a Restful API in yii for cross domain communication. As what I have researched, cross domain communication can only be done via jsonp and my implementation is as follows:
UsersController:: actionCrossDomain
public function actionCrossDomain(){
$this->layout=false;
$data['data']['User']['name']= 'Johny';
$this->_sendResponse(200, CJSON::encode($data),'application/json');
}
UsersController::_sendResponse methdod it is the same as you can see in :Click here
On another server that i configured using virtual host, I am invoking the above method via ajax:
$( document ).ready(function() {
$.ajax({
type: "POST",
dataType: "jsonp",
url:'http:'http//uxaserver.local/alpha2/app/users/crossDomain' ,
data: null,
processData: false,
crossDomain: true,
contentType: "application/json",
success: function (data) {
console.log("done");
},
error: function (request, status, error) {
console.log(request);
}
});
});
The issue is my firebug is is complaining that : SyntaxError: invalid label
My requirement is such because I am helping my client's to do some customized analytic to his other websites and I need to put a script in his web pages of different domains so that the analytic data is recorded in the main server. I understand that I need to use the rest interface to communicate thus I am taking this approach. I am not sure if I have taken the right approach and please advice. I want to make it in a way where a client has an api key and can communicate with the api provided by me.
Is there any other approach to do this? Rather than jsonp?

As i see this string contents error
url:'http:'http//uxaserver.local/alpha2_uxarmy/app/users/crossDomain' ,
Should be
url:'http//uxaserver.local/alpha2_uxarmy/app/users/crossDomain' ,

How I get respone text in application and bind to the label in cross ajax call

I am calling the web service from other domain using Ajax call and I want to get returned response from server in my application by using following code I get response text in firebug but not in my JavaScript code. Control are not showing success and error response it goes out directly.
I want response in my success or error section but both not handling in this.
I am trying lot but not finding any solution please any one help me.
I am in a trouble. I hope somebody can help me for calling cross domain web service by using Ajax call. I am trying from 1 week but didn't find any solution till. I am getting response on browser but not getting it on my actual code.
My JavaScript code.
crossdomain.async_load_javascript(jquery_path, function () {
$(function () {
crossdomain.ajax({
type: "GET",
url: "http://192.168.15.188/Service/Service.svc/GetMachineInfo?serialNumber="+123,
success: function (txt) {
$('#responseget').html(txt);
alert("hii get");
}
});
crossdomain.ajax({
type: "POST",
url: "http://192.168.15.188/Server/Service.svc/GetEvents/",
// data: "origin=" + escape(origin),
success: function (txt) {
$('#responsepost').html(txt);
alert("hii post");
}
});
});
});
</script>

You can't simply ignore the Same Origin Policy.
There are only three solutions to fetch an answer from a web-service coming from another domain :
do it server-side (on your server)
let the browser think it comes from the same domain by using a proxy on your server
change the web service server, by making it JSONP or (much cleaner today) by adding CORS headers

AD FS 2.0 Authentication and AJAX

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);
}
});