MvvmCross: How to recall the current view model again using ICommand? - ios

I tried to do a basic form validation to require some fields on the form must filled in.
I tried to do the Validation check on the ViewModel, I have a ValidateForm function and will return a ValidationMessage, however, when the SaveCommand get call and it won't call back the current View again, so the error message Alert View won't popup. How can I recall the current View Model again after SaveCommand finished?
private string _ValidationMessage;
public string ValidationMessage
{
get { return _ValidationMessage; }
set
{
_ValidationMessage = value;
RaisePropertyChanged(() => ValidationMessage);
}
}
private string ValideForm()
{
if (string.IsNullOrEmpty(FirstName) || string.IsNullOrEmpty(LastName) || string.IsNullOrEmpty(Email) || string.IsNullOrEmpty(ZipCode))
return "Fields with * are required.";
return null;
}
private MvxCommand _saveCommand;
public ICommand SaveCommand
{
get
{
_saveCommand = _saveCommand ?? new MvxCommand(SaveCommandHandler);
return _saveCommand;
}
}
private void SaveCommandHandler()
{
var validationMessage = ValideForm();
if (!string.IsNullOrEmpty(validationMessage))
{
ValidationMessage = validationMessage;
return;
}
ShowViewModel<NextScreenViewModel>();
}

I think this is the same question as MvvmCross Dialog. The poster there suggests several ways to do this, and my answer covers one more 'architectural' way to do it too.
If you'd prefer a simpler way, then you can also just use a string property - eg ErrorMessage. The view can listen for changes in that string. When they happen,
then the view can display an error dialog. This is a bit like the approach taken for Progress Dialogs in this video and code - N=34 - http://slodge.blogspot.co.uk/2013/07/n34-showing-progress-isbusy-display-n1.html

Related

Outputcache 1 action, 2 views

So I have the following action which I am trying to add output caching to:
[OutputCache(CacheProfile = OutputCacheProfileNames.Hours24)]
public ActionResult ContactUs()
{
ContactUsModel model = _modelBuilder.BuildContactUsModel();
if (Request.IsAjaxRequest())
{
return Json(StringFromPartial(partialTemplate, model), JsonRequestBehavior.AllowGet);
}
else
{
return View(model);
}
}
But this seem to cache the first view that is requested - ie either the json OR the normal view.
Is there a way to get the output caching to work for both views, without having to split them out of the same action?
You beat me to the punch in answering your own question, but I thought this code may still be helpful. Since varying by user is such a common scenario, you should probably account for being able to do that and your AJAX vary. This code will allow you vary on any number of custom parameters, by appending to a single string to vary on.
public override string GetVaryByCustomString(System.Web.HttpContext context, string custom)
{
var args = custom.ToLower().Split(';');
var sb = new StringBuilder();
foreach (var arg in args)
{
switch (arg)
{
case "user":
sb.Append(User.Identity.Name);
break;
case "ajax":
if (context.Request.Headers["X-Requested-With"] != null)
{
// "XMLHttpRequest" will be appended if it's an AJAX request
sb.Append(context.Request.Headers["X-Requested-With"]);
}
break;
default:
continue;
}
}
return sb.ToString();
}
Then, you would just do something like the following if you need to vary by multiple custom params.
[OutputCache(CacheProfile = OutputCacheProfileNames.Hours24, VaryByCustom = "User;Ajax")]
Then, if you ever need additional custom vary params, you just keep adding case statements to cover those scenarios.
Thanks to the comments by REDEVI_ for pointing me in the right direction, I have been able to solve this.
I changed my output caching to:
[OutputCache(CacheProfile = OutputCacheProfileNames.Hours24, VaryByCustom = "IsAjax")]
And then in my global.asax file, I added the following override:
public override string GetVaryByCustomString(HttpContext context, string custom)
{
if (context != null)
{
switch (custom)
{
case "IsAjax":
return new HttpRequestWrapper(context.Request).IsAjaxRequest() ? "IsAjax" : "IsNotAjax";
}
}
return base.GetVaryByCustomString(context, custom);
}

View/Model data isn't refreshing/changing after post/postback, even though I'm using the PRG pattern

Update I have saved my problem a long time ago. The problem was that I was trying to call the view model on the wrong view method! I was calling the base view method (Document), instead of one of it's derived method (like NewDocument, PDFDocument, etc.) Thus it was only giving me the Documents data, which didn't change. I was looking and using the wrong view method all the time... Stephen, when you asked me
"Why do you create derived classes in a method but then return only the base class"
I couldn't answer the question at the time because I didn't even know myself, until I remember that originally, the method wasn't returning the base class. I only changed it so that it can work with the base view method, which was wrong in the first place!
That's what I get for only getting 3-4 hours of sleep in 3 days. Everything works right now. Thanks.
I'm having a hard time trying to figure out why the data in my view isn't changing after I do a post. Originally I was doing it via return View() and it worked, but since it was a partial view, the page didn't look great, so I was reading up and saw that it was better to do it by Post-Redirect-Get pattern (PRG) and to use an id value to retrieve the values instead of sending the entire model via Tempdata. I even used ModelState.Clear() and that didn't even work. When I debugged the code, the model only has the values from when I first called it.
Here's part of my Get controller:
NewDocument Get Controller
[DocumentAuthenticationFilter]
public ActionResult NewDocument(int? id = null)
{
// This doesn't work. The view keeps on showing the data from View(Services.CreateNewDocument()).
if (id != null)
{
return View(Services.GetdocumentViewModelData(DocEnum.Section.NEW_DOC_INDEX, (int)id));
}
// This works fine
return View(Services.CreateNewDocument());
}
And here's the post that calls the redirect:
NewDocument Post controller
[HttpPost]
[ValidateAntiForgeryToken]
[MultipleButton(Name = "action", Argument = "AddDocuments")]
//[OutputCache(Duration = 30, VaryByParam = "*")]
public ActionResult AddDocumentViewModel(FormCollection frm, DocumentViewModel dvm)
{
try
{
if (ModelState.IsValid)
{
int? DocID = Services.AddingNewDocument(dvm);
// See, I even tried to clear it.
ModelState.Clear();
return base.RedirectToAction("NewDocument", new { id = DocID });
}
else
{
// Display errors in the modal
}
return base.RedirectToAction("NewDocument");
}
And here's the old way I did it:
NewDocument Post controller
[HttpPost]
[ValidateAntiForgeryToken]
[MultipleButton(Name = "action", Argument = "AddDocuments")]
//[OutputCache(Duration = 30, VaryByParam = "*")]
public ActionResult AddDocumentViewModel(FormCollection frm, DocumentViewModel dvm)
{
try
{
if (ModelState.IsValid)
{
Services.AddingNewDocument(ref dvm);
dvm.NewRecordMode = DocEnum.Action.UPDATE;
// It worked, but only the partial view showed, and not the entire view.
return PartialView("_NewDocument", dvm);
}
else
{
// Display errors in the model
}
return base.RedirectToAction("NewDocument");
}
Could it be because I'm using a custom model binding?
My Custom Model Binding
public class BaseClassModelBinder : DefaultModelBinder
{
public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
var modelType = bindingContext.ModelType;
var modelTypeValue = controllerContext.Controller.ValueProvider.GetValue("ViewModel");
if (modelTypeValue == null)
throw new Exception("View does not contain the needed derived model type name");
var modelTypeName = modelTypeValue.AttemptedValue;
var type = modelType.Assembly.GetTypes().SingleOrDefault(x => x.IsSubclassOf(modelType) && x.Name == modelTypeName);
if (type == null)
{
throw new Exception(String.Format("Derived model type {0} not found", modelTypeName));
}
var instance = bindingContext.Model ?? base.CreateModel(controllerContext, bindingContext, type);
bindingContext.ModelMetadata = ModelMetadataProviders.Current.GetMetadataForType(() => instance, type);
return base.BindModel(controllerContext, bindingContext);
}
}
EDIT: And here's the GetDocumentViewModelData code:
GetDocumentFromViewModelData
public static DocumentViewModel GetDocumentViewModelData(DocEnum.Section docType, int id)
{
switch (docType)
{
case DocEnum.Section.NEW_DOCUMENT_INDEX:
// NewDocumentTypeViewModel is a child to DocumentTypeViewModel
DocumentTypeViewModel nd = NewDocumentService.GetViewModelByID(id);
return nd;
case DocEnum.Section.PDF_DOCUMENT:
DocumentTypeViewModel pdfvm = PDFDocumentService.GetViewModelByID(id);
return pdfvm;
case DocEnum.Section.XLS_DOCUMENT:
DocumentTypeViewModel xlsvm = XLSDocumentService.GetViewModelByID(id);
return xlsvm;
}
return null;
}
Edit: Also adding the GetViewModelByID function
GetViewModelByID
public static DocumentTypeViewModel GetViewModelByID(int id)
{
docEntities db = new docEntities();
NewDocumentTypeViewModel vm = new NewDocumentTypeViewModel();
// Calls a stored procedure called Select_Documents_ByID(id) to get the note entry
// that was submitted.
List<Select_Documents_ByID_Result> prevNotes = db.Select_Documents_ByID(id).ToList();
StringBuilder sNotes = new StringBuilder();
foreach (var note in prevNotes)
{
sNotes.AppendFormat("{0} - {1}: {2}\n\n", note.CreatedDate.ToString("yyyy-MM-dd HH:mm"), note.username, note.Entry);
}
vm.PreviousNotes = sNotes.ToString();
return vm;
}
Edit: I did a direct creation of the view model inside the Get controller, and it's the same result. when i debugged the view itself, the values from the new view model don't show up. Instead, the values from the initial view model, View(Services.CreateNewDocument()), shows.
[DocumentAuthenticationFilter]
public ActionResult NewDocument(int? id = null)
{
// Right here I created the view model to test thing, but I'm getting the same results. Nothing has changed.
if (id != null)
{
var d = new NewDocumentTypeViewModel(1, "Help!");
// This property is from the base class, DocumentTypeViewModel
d.DocumentTitle = "Testing!";
return View(d);
// Inside the view itself, none of the values in the view model, including the one
// belonging to the base class. It still shows the initial values.
}
// This works fine
// Or maybe not...
return View(Services.CreateNewDocument());
}
Edit: I wanted to see if it was also doing the same thing for the initial call to the view return View(Services.CreateNewDocument()), and decided to change the value for documentTitle in the base class from New Document to a randomly-generated number, after the object has been created.
Here's the code for DocumentTypeViewModel's default constructor:
public DocumentTypeViewModel()
{
DocumentTitle = "New Document";
NewRecordMode = DocEnum.Action.ADD;
DocumentID = 0;
}
And here's the Services.CreateNewDocument() code where I change the DocumentTitle after the View Model has been created.
public DocumentTypeViewModel CreateNewDocument()
{
DocumentTypeViewModel dtvm = new DocumentTypeViewModel();
Random r = new Random();
dtvm.DocumentTitle = r.Next(5, Int32.MaxValue).ToString();
return dtvm;
}
Now in the View, when I call DocumentTitle:
<div class="label-text-group">
#Html.LabelFor(model => model.DocumentTitle)
#Html.EditorFor(model => model.DocumentTitle)
</div>
You would expect to see a randomly-generated number every time the View gets called. Nope, what you would see is "New Document". Weird.
It's seems that Services.GetDocumentViewModelData() is not exactly working correctly. It only carries the values created by the base class' constructor when a view is created, not any values that have been added or changed within GetDocumentViewModelData() itself. Why is that? What's going on? Please help anybody!
I have solved it. Look at the Update section on top. Thanks Stephen.

Design Pattern To Refactor and Handle Non-Exceptional Errors in MVC Controller

In my MVC3 application, I have a "queries" class specific to each controller that performs conversions between domain entities and converts them to view models. I do this to keep my controllers clean and it's easier to unit test the controllers and queries seperately.
There are cases, though, when the query method needs to pass non-exceptional error messages to the view (e.g. the entity was not found). However, since my controller is only receiving a ViewModel from the query method and not any type of return code, the only two options that I have found to pass this error are as follows:
Throw an Exception from the query method and use a Try/Catch block to catch the exception in the controller.
Add a property to the View Model called "ErrorMessage" which is populated by the query method that the view uses to perform logic of what needs displayed.
Because these aren't exceptional cases, and I know I shouldn't use Try/Catch to control program flow, I have choosen to use the second method. Though this works for now, it feels "dirty" to me for the following reasons:
The controller has to receive a whole View Model when an error occurs just to get the ErrorMessage property.
The view has to have hard-coded logic and two sections to display either the error or the normal content
Though I could put the if (Model.ErrorMessage != null) logic in my controller to determine which view to pass, it's still not feeling like a "clean" solution.
Are there any design patterns that I could use that could help me refactor this code and make it cleaner?
Example View Model:
public class ApplicationViewModel
{
public string ErrorMessage { get; set; }
public int Id { get; set; }
public string Name { get; set; }
// Other properties here...
}
Example Controller Method:
public ActionResult Retrieve(Guid guid)
{
return View("Application", _applicationQueries.GetApplicationViewModel(guid));
}
Example ApplicationQueries Method:
public ApplicationViewModel GetApplicationViewModel(Guid guid)
{
var applicationViewModel = new applicationViewModel();
if (!_applicationServices.Exists(guid))
{
applicationViewModel.ErrorMessage = "The requested application does not exist.";
return applicationViewModel;
}
// More code here that checks things which might set the ErrorMessage property...
var application = _applicationServices.GetApplicationByGuid((Guid)guid);
Mapper.Map(grantApplication, grantApplicationViewModel);
return grantApplicationViewModel;
}
Snippit from Application.cshtml View for Error Handling:
#model MyApp.Web.Areas.Application.Models.ApplicationViewModel
if (Model.ErrorMessage != null)
{
<div>#Model.ErrorMessage</div>
}
else
{
<!-- Display "normal" content here //>
}
You could pass the ModelState instance to your queries layer and it will take care to add the error:
public ApplicationViewModel GetApplicationViewModel(Guid guid, ModelStateDictionary modelState)
{
var applicationViewModel = new applicationViewModel();
if (!_applicationServices.Exists(guid))
{
modelState.AddModelError("", "The requested application does not exist.");
return applicationViewModel;
}
// More code here that checks things which might set the ErrorMessage property...
var application = _applicationServices.GetApplicationByGuid((Guid)guid);
Mapper.Map(grantApplication, grantApplicationViewModel);
return grantApplicationViewModel;
}
and in your view:
#model MyApp.Web.Areas.Application.Models.ApplicationViewModel
#Html.ValidationSummary()
#if (ViewData.ModelState.IsValid)
{
<!-- Display "normal" content here //>
}

An ASP.NET MVC validator to make sure at least one checkbox is checked

I have an ASP.NET MVC 2 project in which I've created a data transfer object to receive data from a web page form. The form has two groups of checkboxes on it. I want to validate the object to make sure that at least one of the checkboxes in each group is checked.
I'm doing the validation on the server side so that a user won't be able to hack around any client-side validation. (I will add client-side validation with jQuery later; that's easy.)
My understanding is that I have to create my own custom ValidationAttribute for my data transfer object class, but I don't understand how to create and use one that can accept an arbitrary list of checkbox properties to make sure that at least one of them is true. I am guessing I will have to call the attributes like this:
[AtLeastOneCheckbox("set1check1", "set1check2", "set1check3",
ErrorMessage = "You must check at least one checkbox in set 1.")]
[AtLeastOneCheckbox("set2check1", "set2check2", "set2check3", "set2check4", "set2check5",
ErrorMessage = "You must check at least one checkbox in set 2.")]
public class MyFormDTO
{
...
}
What would the implementation of AtLeastOneCheckboxAttribute look like?
Or is there a different way that I should do this kind of validation?
if you have several checkbox groups, you just need to deine the attribute several times.
[AttributeUsage( AttributeTargets.Class)]
public class AtLeastOneCheckboxAttribute : ValidationAttribute
{
private string[] _checkboxNames;
public AtLeastOneCheckboxAttribute(params string[] checkboxNames)
{
_checkboxNames = checkboxNames;
}
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
var propertyInfos = value.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance)
.Where(x=>_checkboxNames.Contains(x.Name));
var values = propertyInfos.Select(x => x.GetGetMethod().Invoke(value, null));
if (values.Any(x => Convert.ToBoolean(x)))
return ValidationResult.Success;
else
{
ErrorMessage = "At least one checkbox must be selected";
return new ValidationResult(ErrorMessage);
}
}
}
UPDATE
as you have found out, class-level validation is called only after all properties pass. In order to get the error, just use empty string as the key.
Your DTO, which is I'm guessing your ViewModel can ihert IDataErrorInfo.
Then you can do your validation like this (note I didn't compile this)
//I'm guessing you have a list of checkboxes
IEnumerable<bool> checkBoxes1;
IEnumerable<bool> checkBoxes2;
public class MyFormDTO : IDataErrorInfo
{
public string this[string prop]
{
get
{
if(prop == "checkBoxes1")
{
if(checkBoxes1.Any(x => x == true))
{
return "Error: You need to select atleast one checkbox from set1";
}
}
else if(prop == "checkBoxes2")
{
if(checkBoxes2.Any(x => x == true))
{
return "Error: You need to select atleast one checkbox from set2";
}
}
return null;
}
}
public string Error { get { return null; } }
}

Is there a way to maintain IsAjaxRequest() across RedirectToAction?

If you don't want any context or an example of why I need this, then skip to The question(s) at the bottom!
In a bid to keep things tidy I initially built my application without JavaScript. I am now attempting to add a layer of unobtrusive JavaScript on the top of it.
In the spirit of MVC I took advantage of the easy routing and re-routing you can do with things like RedirectToAction().
Suppose I have the following URL to kick off the sign up process:
http://www.mysite.com/signup
And suppose the sign up process is two steps long:
http://www.mysite.com/signup/1
http://www.mysite.com/signup/2
And suppose I want, if JavaScript is enabled, the sign up form to appear in a dialog box like ThickBox.
If the user leaves the sign up process at step 2, but later clicks the "sign up" button, I want this URL:
http://www.mysite.com/signup
To perform some business logic, checking the session. If they left a previous sign up effort half way through then I want to prompt them to resume that or start over.
I might end up with the following methods:
public ActionResult SignUp(int? step)
{
if(!step.HasValue)
{
if((bool)Session["SignUpInProgress"] == true)
{
return RedirectToAction("WouldYouLikeToResume");
}
else
{
step = 1;
}
}
...
}
public ActionResult WouldYouLikeToResume()
{
if(Request.IsAjaxRequest())
{
return View("WouldYouLikeToResumeControl");
}
return View();
}
The logic in WouldYouLikeToResume being:
If it's an AJAX request, only return the user control, or "partial", so that the modal popup box does not contain the master page.
Otherwise return the normal view
This fails, however, because once I redirect out of SignUp, IsAjaxRequest() becomes false.
Obviously there are very easy ways to fix this particular redirect, but I'd like to maintain the knowledge of the Ajax request globally to resolve this issue across my site.
The question(s):
ASP.NET MVC is very, very extensible.
Is it possible to intercept calls to RedirectToAction and inject something like "isAjaxRequest" in the parameters?
OR
Is there some other way I can detect, safely, that the originating call was an AJAX one?
OR
Am I going about this the completely wrong way?
As requested by #joshcomley, an automated answer using the TempData approach:
This assumes that you have a BaseController and your controllers are inheriting from it.
public class AjaxianController : /*Base?*/Controller
{
private const string AjaxTempKey = "__isAjax";
public bool IsAjax
{
get { return Request.IsAjaxRequest() || (TempData.ContainsKey(AjaxTempKey)); }
}
protected override RedirectResult Redirect(string url)
{
ensureAjaxFlag();
return base.Redirect(url);
}
protected override RedirectToRouteResult RedirectToAction(string actionName, string controllerName, System.Web.Routing.RouteValueDictionary routeValues)
{
ensureAjaxFlag();
return base.RedirectToAction(actionName, controllerName, routeValues);
}
protected override RedirectToRouteResult RedirectToRoute(string routeName, System.Web.Routing.RouteValueDictionary routeValues)
{
ensureAjaxFlag();
return base.RedirectToRoute(routeName, routeValues);
}
private void ensureAjaxFlag()
{
if (IsAjax)
TempData[AjaxTempKey] = true;
else if (TempData.ContainsKey(AjaxTempKey))
TempData.Remove(AjaxTempKey);
}
}
To use this, make your controller inherit from AjaxianController and use the "IsAjax" property instead of the IsAjaxRequest extension method, then all redirects on the controller will automatically maintain the ajax-or-not flag.
...
Havn't tested it though, so be wary of bugs :-)
...
Another generic approach that doesn't require using state that I can think of may requires you to modify your routes.
Specifically, you need to be able to add a generic word into your route, i.e.
{controller}/{action}/{format}.{ajax}.html
And then instead of checking for TempData, you'd check for RouteData["ajax"] instead.
And on the extension points, instead of setting the TempData key, you add "ajax" to your RouteData instead.
See this question on multiple format route for more info.
This worked for me.
Please note that this doesn't require any session state which is a potential concurrency issue:
protected override void OnActionExecuted(ActionExecutedContext filterContext)
{
base.OnActionExecuted(filterContext);
if (this.Request.IsAjaxRequest)
{
if (filterContext.Result is RedirectToRouteResult)
{
RedirectToRouteResult rrr = (RedirectToRouteResult)filterContext.Result;
rrr.RouteValues.Add("X-Requested-With",Request.Params["X-Requested-With"]);
}
}
}
}
Perhaps you can add a AjaxRedirected key in the TempData property before doing the redirection?
One way to transfer state is to add an extra route parameter i.e.
public ActionResult WouldYouLikeToResume(bool isAjax)
{
if(isAjax || Request.IsAjaxRequest())
{
return PartialView("WouldYouLikeToResumeControl");
}
return View();
}
and then in the Signup method:
return RedirectToAction("WouldYouLikeToResume", new { isAjax = Request.IsAjaxRequest() });
// Don't forget to also set the "ajax" parameter to false in your RouteTable
// So normal views is not considered Ajax
Then in your RouteTable, default the "ajax" parameter to false.
Or another way to go would be override extension points in your BaseController (you do have one, right?) to always pass along the IsAjaxRequest state.
..
The TempData approaches are valid too, but I'm a little allergic of states when doing anything that looks RESTful :-)
Havn't tested/prettify the route though but you should get the idea.
I would just like to offer what I believe is a MUCH better answer than the current accepted one.
Use this:
public class BaseController : Controller
{
private string _headerValue = "X-Requested-With";
protected override void OnActionExecuting(ActionExecutingContext filterContext)
{
var ajaxHeader = TempData[_headerValue] as string;
if (!Request.IsAjaxRequest() && ajaxHeader != null)
Request.Headers.Add(_headerValue, ajaxHeader);
}
protected override void OnActionExecuted(ActionExecutedContext filterContext)
{
base.OnActionExecuted(filterContext);
if (Request.IsAjaxRequest() && IsRedirectResult(filterContext.Result))
TempData[_headerValue] = Request.Headers[_headerValue];
}
private bool IsRedirectResult(ActionResult result)
{
return result.GetType().Name.ToLower().Contains("redirect");
}
}
Then make all your controllers inherit from this.
What it does:
Before an action executes this checks to see if there is a value in TempData. If there is then it manually adds its value to the Request object's header collection.
After an action executes it checks if the result was a redirect. If it was a redirect and the request was an Ajax Request before this action was hit then it reads the value of the custom ajax header that was sent and stores it in temp data.
This is better because of two things.
It is shorter and cleaner.
It adds the request header to the Request object after reading the temp data. This allows Request.IsAjaxRequest() to work normally. No calling a custom IsAjax property.
Credit to: queen3 for his question containing this solution. I did modify it to clean it up a bit but it is his solution originally.
The Problem is in the Client-Cache.
To overcome this, just add a cachebreaker
like "?_=XXXXXX" to Location Url in the 302 Response.
Here is my working Filter. Regisiter it in the GlobalFilter Collection.
I added the Location Header to the Redirected Response, so the client script can get the destination url, in the ajax call. (for Google-Analytics)
public class PNetAjaxFilterAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
var request = filterContext.HttpContext.Request;
if(request.QueryString["_"] == "ajax")
{
filterContext.HttpContext.Request.Headers["X-Requested-With"] = "XMLHttpRequest";
request.QueryString.Remove("_");
}
}
public override void OnResultExecuted(ResultExecutedContext filterContext)
//public override void OnResultExecuting(ResultExecutingContext filterContext)
{
var context = filterContext.HttpContext;
if (!context.Request.IsAjaxRequest())
return;
var request = context.Request;
String noCacheQuery = String.Empty;
if (request.HttpMethod == "GET")
{
noCacheQuery = request.QueryString["_"];
}
else if (context.Response.IsRequestBeingRedirected)
{
var pragma = request.Headers["Pragma"] ?? String.Empty;
if (pragma.StartsWith("no-cache", StringComparison.OrdinalIgnoreCase))
{
noCacheQuery = DateTime.Now.ToUnixTimestamp().ToString();
}
else
{
//mode switch: one spezial cache For AjaxResponse
noCacheQuery = "ajax";
}
}
if (!String.IsNullOrEmpty(noCacheQuery))
{
if (context.Response.IsRequestBeingRedirected)
{
var location = context.Response.RedirectLocation;
if (location.Contains('?'))
location += "&_=" + noCacheQuery;
else
location += "?_=" + noCacheQuery;
context.Response.RedirectLocation = location;
}
else
{
var url = new UriBuilder(request.Url);
if (url.Port == 80 && url.Scheme == Uri.UriSchemeHttp)
url.Port = -1;
else if(url.Port == 443 && url.Scheme == Uri.UriSchemeHttps)
url.Port = -1;
if(!String.IsNullOrEmpty(url.Query))
url.Query = String.Join("&", url.Query.Substring(1).Split('&').Where(s => !s.StartsWith("_=")));
context.Response.AppendHeader("Location", url.ToString());
}
}
}
}
And here the jQuery:
var $form = $("form");
var action = $form.attr("action");
var $item = $("body");
$.ajax({
type: "POST",
url: action,
data: $form.serialize(),
success: function (data, status, xhr) {
$item.html(data);
var source = xhr.getResponseHeader('Location');
if (source == null) //if no redirect
source = action;
$(document).trigger("partialLoaded", { source: source, item: $item });
}
});

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