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ASP.Net C# POST not returning view

Using ASP.NET, C# and Javascript, I'm trying to dynamically get Data for the user, POST it to a controller, and return a view that changes depending on the Data.
Here's the code :
Javascript function :
function editEntry(id) {
var xmlhttp = new XMLHttpRequest();
xmlhttp.open("POST", "Edit?id=" + id, true);
xmlhttp.send({ id: id });
//xmlhttp.send();
}
Controller handling post (a portion) :
[HttpPost]
public ActionResult Edit(EditEvenementiel edit)
{
var contexte = new intranetEntities1();
SqlParameter Id_viewBag = new SqlParameter("#id", edit.id);
ViewBag.edit = contexte.evenementiel
.SqlQuery("SELECT * FROM evenementiel WHERE id_evenementiel = #id", Id_viewBag);
return View();
}
when i fire the javascript, i can see the POST in the firebug console (working fine), i can see the variable getting the correct value in Visual Studio's Debugger, but the view doesn't change.
I even see the expected view (with all the treatements expected) returned in the firebug console; but my page still doesn't change.
How can i do that ?

By default, you should have 2 Actions, one that should process/get the data through a Post method and one that collects data for the View. (it's called Post/Redirect/Get - more details on wiki)
Having this in mind, you can leave your post method as :
[HttpPost]
public ActionResult Edit(int id)
{
var contexte = new intranetEntities1();
SqlParameter Id_viewBag = new SqlParameter("#id", id);
EditEvenementiel edit = contexte.evenementiel.SqlQuery("SELECT * FROM evenementiel WHERE id_evenementiel = #id", Id_viewBag);
return RedirectToAction("Edit",new { edit = edit} );
}
and create a new action which sends the data to the view.
Something like:
public ActionResult Edit(EditEvenementiel edit)
{
//logic here
return View(edit);
}
Please be aware that this is just an example, modify it according to your scenario.

As you are using Ajax (XMLHttpRequest) to fetch this data you also need to present it on your page, it wont happen automatically.
Maybe something like this?
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == XMLHttpRequest.DONE) {
alert(xmlhttp.responseText); // or put the responseText in a HTML element of your choice to do whatever you want to do
}
}

Where do you actually update anything on the page? All you do is send the request:
var xmlhttp = new XMLHttpRequest();
xmlhttp.open("POST", "Edit?id=" + id, true);
xmlhttp.send({ id: id });
But you ignore the response. The browser isn't going to know what you want to do with that response, you have to tell it. Which could be something as simple as:
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
document.getElementById('someElement').innerHTML = xmlhttp.responseText;
}
}
Basically, use the AJAX response (which is an HTML view?) to update the page content.

Returning JSONResult without switching views

I want to return a JSON result. To do this I have a controller method as follows that is called from a Ajax.BeginForm on the View:
#using (Ajax.BeginForm("Update", new AjaxOptions { OnSuccess = "MySuccessMethod()" }))
{
<!-- some form stuff -->
<input type="submit" value="Submit"/>
}
This is the controller that handles it:
[HttpPost]
public JsonResult Update(FormCollection fc)
{
// Process form stuff
return Json (new {success = true });
}
What I want is to process the success response with MySuccessMethod. What I see is that the view on submit goes to the correct controller method above, which then redirects the page to the URL /Home/Update with the following string in the screen:
{"success": true }
Not sure if it is relevant but I am using Mono.
How can I make the framework not switch pages to /Home/Update nor display the JSON string on the view and just process the JSON in the back?

For your first question, check the following:
1) Make sure you have Microsoft.jQuery.Unobtrusive.Ajax included and referenced
2) OnSuccess = "MySuccessMethod()" should be OnSuccess = "MySuccessMethod" (where MySuccessMethod is a JavaScript method, not a C# one)
For your second question, you could have your method return ActionResult instead of JsonResult (see here for more information). JsonResult is a type of ActionResult, which means that updating your action to return ActionResult will allow your method to return multiple types of ActionResult depending on the scenario:
[HttpPost]
public ActionResult SomeThing(int randomParam)
{
if (randomParam == 0)
{
return Json("Zero!");
}
else if (randomParam == 1)
{
return View("Not zero!");
}
else
{
return HttpNotFound("Error: I can only find zeroes and ones");
}
}
As a general rule of thumb (although sometimes rules are meant to be broken), having your action return one type (like your example, JsonResult instead of ActionResult) makes your action less error-prone as, for example, Visual Studio will let you know if you accidentally try to return another type of result - use ActionResult when your action returns more than one type of result.

MVC #Html.ActionLink no-op from controller

I have an #Html.ActionLink inside of a partial view that when clicked I'd like to have either send the user to another view or stay on the current view without changing anything. Is this possible?
Our controller looks like:
public ActionResult Edit(int id)
{
if (ShouldAllowEdit(id))
{
return this.View("Edit", ...edit stuff...)
}
return ????????
}
We tried return new EmptyResult(); but that just dumps the user to a blank page.

This is a little different approach to the issue, but it should do what you want.
Instead of giving the user a link to navigate to, do an ajax call on link/button click, and do the id check. Return either the url to navigate to in a JsonResult, or nothing if the id is invalid.
On return of the ajax call, navigate to the url if appropriate.
(swap out the hard coded ids and the == 0 with your ShouldAllowEdit function in the example of course)
In the View:
<div class="btn btn-danger" id="myButton">Button</div>
#section scripts{
<script>
$("#myButton").click(function () {
$.ajax("#Url.Action("Edit", new { id = 0 })", { type : "POST" })
.success(function (data) {
if (data.url !== "") {
window.location.href = data.url;
}
});
});
</script>
}
In the controller:
[HttpPost]
public JsonResult Edit(int id)
{
if (id == 0)
{
return Json(new {url = ""});
}
else
{
return Json(new { url = Url.Action("EditPage", new { id = id }) });
}
}

An answer is to redirect to the view action - and maybe give some feed back why they failed.
public ActionResult Edit(int id)
{
if (ShouldAllowEdit(id))
{
return this.View("Edit", ...edit stuff...)
}
ModelState.AddModelError("id", "Not allowed to edit this item");
return RedirectToAction(Edit(id));
}

If the user clicks a link they will be taken away. They might be sent back right to the same page, but the page will unload, be requested from the server again, and then re-rendered in the browser. If you don't want that to happen, you don't give the user the link in the first place. In other words, conditionally render the link or not based on the user's roles or whatever.
#if (userCanEdit)
{
#Html.ActionLink(...)
}
Where userCanEdit is whatever logic you need to make that determination.
If the user fails whatever check you determine, then they don't get the link. Simple.
However, since there's malicious people in the world, you can't just leave it entirely there. There's potential for the user to figure out the link to edit something and go there manually. So, to prevent that you check for the edit permission in your action (like you've already got in your code sample), but if the user is not allowed, then you just return a forbidden status code:
return new HttpStatusCodeResult(HttpStatusCode.Forbidden);
Or
return new HttpStatusCodeResult(403);
They both do the same thing.
UPDATE
Based on your comment above, it appears that the user is normally allowed to edit but can't in a particular instance because another user is editing. A 403 Forbidden is not appropriate in that case, so really all you've got is a simple redirect back to the page they were on, perhaps with a message explaining why they're back there.
TempData["EditErrorMessage"] = "Sorry another user is editing that right now.";
return RedirectToAction("Index");

ValidationSummary not appearing with Partial Views

I have this problem:
I go to a page such as:
/Auction/Details/37
and this calls this action method:
public ActionResult Details(int id)
A particular line in this method is:
return View("DetailsLub", auction);
This view contains this line:
#Html.Action("BidOnAuction", new { auctionId = Model.Id })
Which calls this action method:
public PartialViewResult BidOnAuction(int auctionId)
So far so good?
Now, I have a form in the BidOnAuction view, whcih has a button. When I click on this button, this action method is invloked:
[HttpPost]
public ActionResult BidOnAuction(BidOnAuctionViewModel model)
This action method has a catch statement with the following lines:
ModelState.AddModelError(string.Empty, operation + #" Failure: " + message);
return RedirectToAction("Details", new { id = model.AuctionId });
Now, both the DetailsLUB view and the BidOnAction view contain this line:
#Html.ValidationSummary(true)
But, the issue is that nothing ever gets printed to the screen. What am I doing wrong?

InOrder to get the validation Message on the page you need to return view with Model, as model has the Model State within it, something like this:
return View(Model);
This will return the model BidOnAuction with Validation Summary.

This line of code
return RedirectToAction("Details", new { id = model.AuctionId });
Returns instance of RedirectResult class. That is generally used for redirections and does not render view. If you want to render child action into parent view using #Html.Action, you need to return view from that child action, not RedirectResult. And that RedirectResult will not work even when there's no child action. Returning RedirectResult causes browser to issue fresh, all new request to that action. And model state is lost anyways. You should do something like
try
{
//some actions
return RedirectResult("Details", new { id = model.AuctionId });
}
catch
{
ModelState.AddModelError(string.Empty, operation + #" Failure: " + message);
return View("Details", new { id = model.AuctionId });
}

You can't redirect to a new action and expect the modelstate to be there.
If the modelState is invalid just return (with View(model))
else
redirect to details.
If you need the error information in the details view you will have add it to TempData or pass it in as an optional parameter.

ASP MVC Redirect without changing URL(routing)

Goal:
I want to be able to type URL: www.mysite.com/NewYork OR www.mysite.com/name-of-business
Depending on the string I want to route to different actions without changing the URL.
So far I have:
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute(
"UrlRouter", // Route name
"{query}", // URL with parameters
new { controller = "Routing", action = "TestRouting" } // Parameter defaults
);
}
In the controller I have:
public ActionResult TestRouting(string query)
{
if (query == "NewYork")
return RedirectToAction("Index", "Availability"); // <--------- not sure
else if (query == "name-of-business")
return Redirect("nameofbusines.aspx?id=2731"); // <--------- not sure
else
return RedirectToAction("TestTabs", "Test"); // <--------- not sure
}
I have pretty much tried everything to redirect/transfer to the page without
changing the URL, but everything I've tried changes the URL or gives me an error.
Basically I'm looking for the equivalent of server.transfer where I can keep the URL but send info to the action and have it display its result.

I'm with Nick on this one, though I think you could just use regular views instead of having to do partials. You may need to implement them as shared views if they are not in the views corresponding to the controller (since it will only look in the associated and shared views).
public ActionResult TestRouting(string query)
{
if (query == "NewYork")
{
var model = ...somehow get "New York" model
return View("Index", model );
}
else if (query == "name-of-business")
{
var model = ...get "nameofbusiness" model
return View("Details", model );
}
else
{
return View("TestTabs");
}
}
Each view would then take a particular instance of the model and render it's contents using the model. The URL will not change.
Anytime that you use a RedirectResult, you will actually be sending an HTTP redirect to the browser and that will force a URL change.

Im not sure if you tried this way or if this way has any drawbacks..
Add a global.asax file to your project. In that add the following method:
void Application_BeginRequest(object sender, EventArgs e)
{
// Handles all incoming requests
string strURLrequested = Context.Request.Url.ToString();
GetURLToRedirect objUrlToRedirect = new GetURLToRedirect(strURLrequested);
Context.RewritePath(objUrlToRedirect.RedirectURL);
}
GetURLToRedirect can be a class that has the logic to find the actual URL based on the URL typed in. The [RedirectURL] property will be set with the url to redirect to beneath the sheets.
Hope that helps...

You can change your controller like this:
public ActionResult TestRouting(string query)
{
string controller,action;
if (query == "NewYork")
{
controller = "Availability";
action = "Index";
}
else
{
controller = "Test";
action = "TestTabs";
}
ViewBag.controller = controller;
ViewBag.action = action;
return View();
}
Then you can use these ViewBags in your view like this:
#{
Layout = null;
Html.RenderAction(ViewBag.action, ViewBag.controller);
}
That's it. And you can improve this example with use a class and some functions.

Are you saying you want to go to "www.mysite.com/NewYork" and then "really" go "somewhere else" but leave the url alone? Perhaps what you would want to do then is use partial views to implement this? That way, your base page would be what gets routed to, and then inside of that page you do your condition testing to bring up different partial views? I've done that in my application for viewing either a read-only version of a grid or an editable grid. It worked very nicely.

I'm not sure what you can do about the redirect to the .aspx page, but you should be able to replace the RedirectToAction(...)s with something like this:
public ActionResult TestRouting(string query)
{
if (query == "NewYork")
{
var controller = new AvailabilityController();
return controller.Index();
}
else if (query == "name-of-business")
return Redirect("nameofbusines.aspx?id=2731"); <--------- not sure
else
{
var controller = new TestController();
return controller.TestTabs();
}
}