Ajax calling WEB API throwing a Parser Error - javascript

So I am trying to make an AJAX call to get JSON information from a WEB API. The WEB API method seems to be working properly and when I try to access it via Fiddler, it returns a result:
When I try to access it via JQUERY AJAX, it fails and says that there is a parser error. Below is my AJAX call:
$.ajax({
url: 'http://example:port/api/values/',
type: 'GET',
dataType: 'jsonp',
success: function (data) {
alert("works");
},
error: function (request, error) {
console.log(arguments);
alert(" Can't do because: " + error);
}
});
Below is my WEB API Method:
[System.Web.Http.HttpGet]
public List<Users> Get()
{
List<Users> user= (from m in new DataAccessLayer.MapRepository().GetUsersRelatingTo("UserName")
select new CommonLayer.Views.Markers
{
ID= m.UserID,
}).ToList();
return users;
}
I would appreciate any sort of tip, thanks!
Edit: Below is more information on the error:

Related

TypeScript : Ajax call call always calling Error rather than success on success

In typescript I have a DataAccess Class so that all Ajax calls are routed through a single object to save repetition of code in a lot of places within my application.
In using this approach I have needed to use call backs to get the response back to the calling class so that the success and error can be handled accordingly.
This is the typescript
ajaxCall(retVal, retError) {
$.ajax({
type: this.callType,
data: this.dataObject,
dataType: this.dataType,
url: this.url,
contentType: this.contentType,
traditional: this.traditional,
async: this._async,
error: retError,
success: retVal
});
}
This is the compiled Javascript
AjaxDataAccessLayer.prototype.ajaxCall = function (retVal, retError) {
$.ajax({
type: this.callType,
data: this.dataObject,
dataType: this.dataType,
url: this.url,
contentType: this.contentType,
traditional: this.traditional,
async: this._async,
error: retError,
success: retVal
});
};
return AjaxDataAccessLayer;
This calls through to the ASP.Net MVC controllers perfectly fine, however the problem that I have is regardless of Success or Error the call back is always retError.
This is the calling Typescript
var _this = this;
var dataAccess = new DataAccess.AjaxDataAccessLayer(Fe.Upsm.Enums.AjaxCallType.Post,
Fe.Upsm.Enums.AjaxDataType.json,
"../../PrintQueue/DeletePrintQueueItems",
jsonObj);
dataAccess.ajaxCall(data => {
// success
new Fe.Upsm.Head().showGlobalNotification("Selected Items Deleted");
_this.refreshPrintQueueGrid();
(window as any).parent.refreshOperatorPrintQueueCount();
}, xhr => {
// failure
alert("An Error Occurred. Failed to update Note");
});
When stepping through and looking at this the Status is OK and the response is 200.
So, Problem (as mentioned above) always calling xhr \ retError regardless of success.
Question: How do I get it to go into the right call back?
In your error handler, you were not passing all the parameters, so you are only checking whether the request finished successfully. However, there can be errors after that, like when the response is processed. You can handle errors betters like this:
dataAccess.ajaxCall(data => {
// success
new Fe.Upsm.Head().showGlobalNotification("Selected Items Deleted");
_this.refreshPrintQueueGrid();
(window as any).parent.refreshOperatorPrintQueueCount();
}, (xhr, errorText, errorThrown => {
// failure
console.log(xhr, errorTest, errorThrown);
alert("An Error Occurred. Failed to update Note");
});
Based on the discoveries using this method, the error is that your controllers are returning empty responses, so you're getting an exception when jQuery tries to parse them, because an empty string is not valid JSON.

ajax request not sending any data ASP.NET MVC project with jQuery

I'm fairly new to asp.net MVC but am baffled as to why my request isn't working.
I'm trying to send an ajax request with jquery as per:
jQuery(function ($) {
var total = 0,
share = $('div.share'),
googlePlusUrl = "https://plusone.google.com/_/+1/fastbutton?url=http://bookboon.com" + $(location).attr('pathname');
setTimeout(function() {
$.ajax({
type: 'GET',
data: "smelly",
traditional: true,
url: share.data('proxy'),
success: function(junk) {
//var $junk = junk.match(regex);
console.log(junk);
},
error: function (xhr, errorText) {
console.log('Error ' + xhr.responseType);
},
});
}, 4000);
And set a line in my RouteConfig as:
routes.MapRoute(null, "services/{site}/proxy", new { controller = "Recommendations", action = "Proxy" });
The markup has a data-attribute value as:
<div class="share" data-proxy="#Url.Action("Proxy", "Recommendations")">
And my Proxy action method starts with:
public ActionResult Proxy(string junk)
The problem is that the junk parameter is always null. I can see in the debug output that the route seems to correctly redirect to this method when the page loads (as per jQuery's document ready function), but I cannot seem to send any data.
I tried sending simple data ("smelly") but I don't receive that neither.
Any suggestions appreciated!
The model binder will be looking for a parameter in the request called junk, however you're sending only a plain string. Try this:
$.ajax({
type: 'GET',
data: { junk: "smelly" }, // <- note the object here
traditional: true,
url: share.data('proxy'),
success: function(junk) {
//var $junk = junk.match(regex);
console.log(junk);
},
error: function (xhr, errorText) {
console.log('Error ' + xhr.responseType);
},
});

Calling a C# method from JavaScript

I want to to call a method GetAccount from my controller AccountController.cs, in my JavaScript factory LoginFactory.js. Something like this:
AccountController.cs:
public Account GetAccount(string userName)
{ ... }
LoginFactory.js:
if(x>y) {
var account = <%AccountController.GetAccount(someParam);%>
}
I've tried using [WebMethod] and Ajax, but I can't get it to work: I get a 404 response.
Assuming your GetAccount method can be reached at /Account/GetAccount when your application runs, you could use the following:
$.ajax({
type: 'GET',
url: '/Account/GetAccount',
data: { 'username' : 'a-username' },
dataType: 'json',
success: function(jsonData) {
alert(jsonData);
},
error: function() {
alert('error');
}
});
Note - this is dependant on jQuery.
This causes the browser to make a request to /Account/GetAccount as if you had done so by entering the URL in the URL bar, but of course, captures the returned json for use in your client side (javascript) script.
If this returns a 404, it would be worth checking your routing.

Web service Spring ajax call

I'm trying to call a web service with ajax. The service is up, and it can shows the result on the RestClient on firefox, but, in mi application call, gives me Status error "Pending".
This is my simple web service.
#Controller
#RequestMapping("/hello")
public class HelloWs {
#RequestMapping(value= "/helloWorld", method = RequestMethod.GET, headers = "Accept=application/xml, application/json")
public #ResponseBody String HelloWorld() {
return "Hello Worldssss¡¡";
}
And this is my ajax call.
function hellowsfunction() {
$.ajax({
type: "GET",
url:"http://localhost:8080/ehCS-ui/rest/hello/helloWorld",
crossDomain: true,
dataType: "JSON",
headers : {Accept : "applicationjson","Access-Control-Allow-Origin" : "*"},
success: function(msg) {
var returnedData = jQuery.parseJSON(msg);
$("#lblResult")
.text(result)
.slideUp("hide", function() { $(this).slideDown("slow") });
},
error: function (e) {
$("#lblResult").removeClass("loading");
alert('failed:'+e);
console.log(e);
}
});
what is wrong? Ideas?¿ please help.
Thanks
Your #RequestMapping is wrong... you should not map based on Accept header like this. Instead you should use produces parameter.
#RequestMapping(value="/helloWorld", method=RequestMethod.GET,
produces={"application/xml", "application/json"})
Also your header in the JS is incorrect. Just remove their specification completely.

ASP.NET MVC HttpException message not shown on client

I'm building a RESTful web api with asp.net mvc, which returns pure json data. On my client, I'm using backbone.js to communicate to it.
My question is, how do I capture the message in javascript? For eg. What if a user has no permission to delete or there was no item matching the id? I've been told to throw http errors instead of custom json.
So my code would be:
[HttpDelete]
public ActionResult Index(int id)
{
if (id == 1)
{
throw new HttpException(404, "No user with that ID");
}
else if (id == 2)
{
throw new HttpException(401, "You have no authorization to delete this user");
}
return Json(true);
}
How do I access the message in my javascript callback? The callback would look like:
function (model, response) {
alert("failed");
//response.responseText would contain the html you would see for asp.net
}
I do not see message i threw in the exception anywhere at all in the data that was returned from the server.
You should use the error callback on the client. The success callback is triggered only when the request succeeds:
$.ajax({
url: '/home/index',
type: 'DELETE',
data: { id: 1 },
success: function (result) {
alert('success'); // result will always be true here
},
error: function (jqXHR, textStatus, errorThrown) {
var statusCode = jqXHR.status; // will equal to 404
alert(statusCode);
}
});
Now there is a caveat with 401 status code. When you throw 401 HTTP exception from the server, the forms authentication module intercepts it and automatically renders the LogIn page and replaces the 401 status code with 200. So the error handler will not be executed for this particular status code.
I just answered this in my question What is the point of HttpException in ASP.NET MVC, but you can actually get that string if you use the HttpStatusCodeResult like this:
In your controller:
return new HttpStatusCodeResult(500,"Something bad happened")
And you can access "Something bad happened" using, say, jQuery $.ajax() like this:
$.ajax: {
url: "#Url.Action("RequestsAdminAjax", "Admin")",
type: "POST",
data: function(data) { return JSON.stringify(data); },
contentType: "application/json; charset=utf-8",
error: function (xhr, textStatus,errorThrown) {
debugger;
toggleAlert('<strong>Error: </strong>Unable to load data.', 'alert alert-danger');
}
},
and errorThrown will contain "Something bad happened".
HTH.

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