MVC 3 when is the Controller.ViewData.ModelState is populated - asp.net-mvc-3

Currently I am reading the MVC 3 source code to try to find when is the Controller's ModelState is set.
From the code I can see from Controller.cs that ModelState property was delegated to its ViewData's ModelStata property, like the code below:
public ModelStateDictionary ModelState {
get {
return ViewData.ModelState;
}
}
However I can only see the ViewData.ModelState seems only populated through ValidateModel() method in Controller.cs, like the code below:
protected internal void ValidateModel(object model, string prefix) {
if (!TryValidateModel(model, prefix)) {
throw new InvalidOperationException(
String.Format(
CultureInfo.CurrentCulture,
MvcResources.Controller_Validate_ValidationFailed,
model.GetType().FullName
)
);
}
}
in above code TryValidateModel() method would indirectly populate the Controller.ModelState like code below:
foreach (ModelValidationResult validationResult in ModelValidator.GetModelValidator(metadata, ControllerContext).Validate(null)) {
ModelState.AddModelError(DefaultModelBinder.CreateSubPropertyName(prefix, validationResult.MemberName), validationResult.Message);
}
However I searched through all the source code and did not find any place that calls ValidateModel() method, and also from the access modifier, this method is protected, I wonder how this method is called by MVC 3 framework during the request processing, or ValidateModel() is only supposed to be called by user in the inherited controller class.

Related

Vibe.d basic form validation

I have a post create method:
void gönderiyiOluştur(HTTPServerRequest istek, HTTPServerResponse yanıt)
{
render!("gönderiler/oluştur.dt")(yanıt);
}
and a post store method like this:
void gönderiyiKaydet(HTTPServerRequest istek, HTTPServerResponse yanıt)
{
auto başlık = istek.form["baslik"];
auto içerik = istek.form["icerik"];
bool yayınla = false;
if (başlık.length > 0)
{
Gönderi gönderi = Gönderi(başlık, içerik);
gönderi.kaydet();
yanıt.redirect("/");
}
else
{
yanıt.redirect("/gönderiler/oluştur");
}
}
I'd like to make basic form validation. For example if input fields are empty it redirects to previous page.
I suppose I should pass some error message to the create method like baslik field should not be empty etc..
But since I am quite new to framework I shouldn't figure out. Are there any facilities does the framework offer for form validation.
Basic form validation is easy when you use the web framework from vibe.d. The basic steps are:
Create a class Gönderiyi and put your kaydet method inside this class:
class Shipment {
#method(HTTPMethod.POST)
void kaydet() { ... }
}
Define a method inside the class which should be called in case a validations fails. This method should display the error message:
void getError(string _error = null, HTTPServerResponse res) { ... }
Annotate the kaydet method with the #errorDisplay attribute to connect the method with the error function:
class Shipment {
#method(HTTPMethod.POST)
#errorDisplay!getError
void kaydet() { ... }
void getError(string _error = null, HTTPServerResponse res) { ... }
}
Now do the validation inside the kaydet method and throw an exception in case of an error. The getError method is then called automatically. You can take advantage of parameter binding and conversion, too. When the D parameter name is the same as the name of an HTML input value, then this value is bind to the D parameter. Automatic type conversion takes place (e.g. to int) and can lead to exceptions, which are then handled in the getError method, too.
As last step you need to register your class with the web framework:
auto router = new URLRouter;
router.registerWebInterface(new Gönderiyi);
You should have a look at the documentation of errorDisplay and at the web framework example from vibe.d, too.

How To Pass formdata parameters into ASP.NET WebAPI without creating a record structure

I have data coming into my form that looks like the image below (sessionsId: 1367,1368).
I've create c# in my webapi controller that works as below. when I've tried ot just make use SessionIds as the parameter (or sessionIds) by saying something like PostChargeForSessions(string SessionIds) either null gets passed in or I get a 404.
What is the proper way to catch a form parameter like in my request without declaring a structure.
(the code below works, but I'm not happy with it)
public class ChargeForSessionRec
{
public string SessionIds { get; set; }
}
[HttpPost]
[ActionName("ChargeForSessions")]
public HttpResponseMessage PostChargeForSessions(ChargeForSessionRec rec)
{
HttpResponseMessage response = Request.CreateResponse(HttpStatusCode.OK, new ShirtSizeReturn()
{
Success = true,
//Data = shirtSizeRecs
});
return response;
}
You can declare the action method like this.
public HttpResponseMessage Post(string[] sessionIds) { }
If you don't want to define a class, the above code is the way to go. Having said that, the above code will not work with the request body you have. It must be like this.
=1381&=1380

How do I get the MethodInfo of an action, given action, controller and area names?

What I have is the following extension method:
public MyCustomAttribute[] GetActionAttributes(
this Controller #this,
string action,
string controller,
string area,
string method)
{
}
How does ASP.NET MVC 3 find the action method, given the area, controller, action names and the method (GET, POST)?
To this moment I have nothing... no clues on how to do this.
I am currently looking for the stack trace inside a controller action, to find out how MVC dicovered it.
Why I need these attributes
My attributes contain information about whether a given user can or not access it... but depending on whether they can or not access it, I wan't to show or hide some html fields, links, and other things that could call that action.
Other uses
I have thought of using this to place an attribute over an action, that tells the css class of the link that will be rendered to call it... and some other UI hints... and then build an HtmlHelper that will render that link, looking at these attributes.
Not a duplicate
Yes, some will say this is possibly a duplicate of this question...
that does not have the answer I want:
How can i get the MethodInfo of the controller action that will get called given a request?
That's why I have specified the circumstances of my question.
I have looked inside MVC 3 source code, and tested with MVC 4, and discovered how to do it.
I have tagged the question wrong... it is not for MVC 3, I am using MVC 4. Though, as I could find a solution looking at MVC 3 code, then it may work with MVC 3 too.
At the end... I hope this is worth 5 hours of exploration, with a lot trials and errors.
Works with
MVC 3 (I think)
MVC 4 (tested)
Drawbacks of my solution
Unfortunately, this solution is quite complex, and dependent on things that I don't like very much:
static object ControllerBuilder.Current (very bad for unit testing)
a lot of classes from MVC (high coupling is always bad)
not universal (it works with MVC 3 default objects, but may not work with other implementations derived from MVC... e.g. derived MvcHandler, custom IControllerFactory, and so on ...)
internals dependency (depends on specific aspects of MVC 3, (MVC 4 behaves like this too) may be MVC 5 is different... e.g. I know that RouteData object is not used to find the controller type, so I simply use stub RouteData objects)
mocks of complex objects to pass data (I needed to mock HttpContextWrapper and HttpRequestWrapper in order to set the http method to be POST or GET... these pretty simple values comes from complex objects (oh god! =\ ))
The code
public static Attribute[] GetAttributes(
this Controller #this,
string action = null,
string controller = null,
string method = "GET")
{
var actionName = action
?? #this.RouteData.GetRequiredString("action");
var controllerName = controller
?? #this.RouteData.GetRequiredString("controller");
var controllerFactory = ControllerBuilder.Current
.GetControllerFactory();
var controllerContext = #this.ControllerContext;
var otherController = (ControllerBase)controllerFactory
.CreateController(
new RequestContext(controllerContext.HttpContext, new RouteData()),
controllerName);
var controllerDescriptor = new ReflectedControllerDescriptor(
otherController.GetType());
var controllerContext2 = new ControllerContext(
new MockHttpContextWrapper(
controllerContext.HttpContext.ApplicationInstance.Context,
method),
new RouteData(),
otherController);
var actionDescriptor = controllerDescriptor
.FindAction(controllerContext2, actionName);
var attributes = actionDescriptor.GetCustomAttributes(true)
.Cast<Attribute>()
.ToArray();
return attributes;
}
EDIT
Forgot the mocked classes
class MockHttpContextWrapper : HttpContextWrapper
{
public MockHttpContextWrapper(HttpContext httpContext, string method)
: base(httpContext)
{
this.request = new MockHttpRequestWrapper(httpContext.Request, method);
}
private readonly HttpRequestBase request;
public override HttpRequestBase Request
{
get { return request; }
}
class MockHttpRequestWrapper : HttpRequestWrapper
{
public MockHttpRequestWrapper(HttpRequest httpRequest, string httpMethod)
: base(httpRequest)
{
this.httpMethod = httpMethod;
}
private readonly string httpMethod;
public override string HttpMethod
{
get { return httpMethod; }
}
}
}
Hope all of this helps someone...
Happy coding for everybody!
You can achieve this functionality by using the AuthorizeAttribute. You can get the Controller and Action name in OnAuthorization method. PLease find sample code below.
public sealed class AuthorizationFilterAttribute : AuthorizeAttribute
{
/// <summary>
/// Use for validate user permission and when it also validate user session is active.
/// </summary>
/// <param name="filterContext">Filter Context.</param>
public override void OnAuthorization(AuthorizationContext filterContext)
{
string actionName = filterContext.ActionDescriptor.ActionName;
string controller = filterContext.ActionDescriptor.ControllerDescriptor.ControllerName;
if (!IsUserHasPermission(controller, actionName))
{
// Do your required opeation
}
}
}
if you have a default route configured like
routes.MapRoute(
"Area",
"",
new { area = "MyArea", controller = "Home", action = "MyAction" }
);
you can get the route information inside the controller action like
ht tp://localhost/Admin
will give you
public ActionResult MyAction(string area, string controller, string action)
{
//area=Admin
//controller=Home
//action=MyAction
//also you can use RouteValues to get the route information
}
here is a great blog post and a utility by Phil Haack RouteDebugger 2.0
This is a short notice! Be sure to use filterContext.RouteData.DataTokens["area"]; instead of filterContext.RouteData.Values["area"];
Good Luck.

Checking to see if ViewBag has a property or not, to conditionally inject JavaScript

Consider this simple controller:
Porduct product = new Product(){
// Creating a product object;
};
try
{
productManager.SaveProduct(product);
return RedirectToAction("List");
}
catch (Exception ex)
{
ViewBag.ErrorMessage = ex.Message;
return View("Create", product);
}
Now, in my Create view, I want to check ViewBag object, to see if it has Error property or not. If it has the error property, I need to inject some JavaScript into the page, to show the error message to my user.
I created an extension method to check this:
public static bool Has (this object obj, string propertyName)
{
Type type = obj.GetType();
return type.GetProperty(propertyName) != null;
}
Then, in the Create view, I wrote this line of code:
#if (ViewBag.Has("Error"))
{
// Injecting JavaScript here
}
However, I get this error:
Cannot perform runtime binding on a null reference
Any idea?
#if (ViewBag.Error!=null)
{
// Injecting JavaScript here
}
Your code doesnt work because ViewBag is a dynamic object not a 'real' type.
the following code should work:
public static bool Has (this object obj, string propertyName)
{
var dynamic = obj as DynamicObject;
if(dynamic == null) return false;
return dynamic.GetDynamicMemberNames().Contains(propertyName);
}
Instead of using the ViewBag, use ViewData so you can check for the of the item you are storing. The ViewData object is used as Dictionary of objects that you can reference by key, it is not a dynamic as the ViewBag.
// Set the [ViewData][1] in the controller
ViewData["hideSearchForm"] = true;
// Use the condition in the view
if(Convert.ToBoolean(ViewData["hideSearchForm"])
hideSearchForm();
I would avoid ViewBag here completely.
See my thoughts here on this:
http://completedevelopment.blogspot.com/2011/12/stop-using-viewbag-in-most-places.html
The alternative would be to throw a custom error and catch it. how do you know if the database is down, or if its a business logic save error? in the example above you just catch a single exception, generally there is a better way to catch each exception type, and then a general exception handler for the truly unhandled exceptions such as the built in custom error pages or using ELMAH.
So above, I would instead
ModelState.AddModelError()
You can then look at these errors (assuming you arent jsut going to use the built in validation) via
How do I access the ModelState from within my View (aspx page)?
So please carefully consider displaying a message when you catch 'any' exception.
You can use ViewData.ContainsKey("yourkey").
In controller:
ViewBag.IsExist = true;
In view:
if(ViewData.ContainsKey("IsExist")) {...}
I need to test this but:
#if (ViewBag.ABoolParam ?? false)
{
//do stuff
}
I think will give you either the value of the ViewBag property, or return a default value if missing.

TryUpdateModel causing error from unit test cases (Asp.net mvc)

I have on post action in controller. Code is as given below
[HttpPost]
public ActionResult Create(Int64 id, FormCollection collection)
{
var data = Helper.CreateEmptyApplicationsModel();
if (TryUpdateModel(data))
{
// TODO: Save data
return RedirectToAction("Edit", "Applications", new { area = "Applications", id = id });
}
else
{
// TODO: update of the model has failed, look at the error and pass back to the view
if (!ModelState.IsValid)
{
if (id != 0) Helper.ShowLeftColumn(data, id);
return View("Create", data);
}
}
return RedirectToAction("Details", "Info", new { area = "Deals", InfoId= id });
}
I wrote test case for this as below
[TestMethod]
public void CreateTest_for_post_data()
{
var collection = GetApplicantDataOnly();
_controller.ValueProvider = collection.ToValueProvider();
var actual = _controller.Create(0, collection);
Assert.IsInstanceOfType(actual, typeof(RedirectToRouteResult));
}
When I debug this single test case, test case passed because condition
if (TryUpdateModel(data)) return true and its goes to if condition.
But when I debug test cases from entire solution this test case failed because it goes to else condition of " if (TryUpdateModel(data))".
I dont know why..
Please help...
Thanks
I've experienced a similar problem which will solve your issue provided you don't need to use a FormCollection.
I haven't used TryUpdateModel ever since the day I learned of the Auto-Binding feature. Auto-binding, in a nutshell pretty much does the work TryUpdateModel would do for you, that is, it'll set a model object according to the values found in the FormCollection as well as attempting to validate the model. And it does this automatically. All you'll have to do is place a parameter in the ActionMethod and it will automatically have it's properties filled with the values found in the FormCollection. Your Action signature will then turn into this:
public ActionResult Create(Int64 id, SomeModel data)
Now you don't need to call TryUpdateModel at all. You still need to check if the ModelState is valid to decide whether or not to redirect or return a view.
[HttpPost]
public ActionResult Create(Int64 id, SomeModel data)
{
if (ModelState.IsValid)
{
// TODO: Save data
return RedirectToAction("Edit", "Applications", new { area = "Applications", id = id });
}
else
{
if (id != 0) Helper.ShowLeftColumn(data, id);
return View("Create", data);
}
}
This won't throw an exception in your unit tests so that's one problem solved. However, there's another problem now. If you run your application using the above code, it'll work just fine. You model will be validated upon entering the Action and the correct ActionResult, either a redirect or a view, will be returned. However, when you try to unit test both paths, you'll find the model will always return the redirect, even when the model is invalid.
The problem is that when unit testing, the model isn't being validated at all. And since the ModelState is by default valid, ModelState.IsValid will always return true in your unit tests and thus will always return a redirect even when the model is invalid.
The solution: call TryValidateModel instead of ModelState.IsValid. This will force your unit test to validate the model. One problem with this approach is that means the model will be validated once in your unit tests and twice in your application. Which means any errors discovered will be recorded twice in your application. Which means if you use the ValidationSummary helper method in your view, your gonna see some duplicated messages listed.
If this is too much to bear, you can clear the ModelState before calling TryValidateModel. There are some problems with doing so because your gonna lose some useful data, such as the attempted value if you clear the ModelState so you could instead just clear the errors recorded in the ModelState. You can do so by digging deep into the ModelState and clearing every error stored in every item like so:
protected void ClearModelStateErrors()
{
foreach (var modelState in ModelState.Values)
modelState.Errors.Clear();
}
I've placed the code in a method so it can be reused by all Actions. I also added the protected keyword to hint that this might be a useful method to place in a BaseController that all your controllers derive from so that they all have access to this method.
Final Solution:
[HttpPost]
public ActionResult Create(Int64 id, SomeModel data)
{
ClearModelStateErrors();
if (ModelState.IsValid)
{
// TODO: Save data
return RedirectToAction("Edit", "Applications", new { area = "Applications", id = id });
}
else
{
if (id != 0) Helper.ShowLeftColumn(data, id);
return View("Create", data);
}
}
NOTE: I realize I didn't shed any light on the root issue. That's because I don't completely understand the root issue. If you notice the failing unit test, it fails because a ArgumentNullException was thrown because the ControllerContext is null and it is passed to a method which throws an exception if the ControllerContext is null. (Curse the MVC team with their damned defensive programming).
If you attempt to mock the ControllerContext, you'll still get an exception, this time a NullReferenceException. Funnily enough, the stack trace for the exception shows that both exceptions occur at the same method, or should I say constructor, located at System.Web.Mvc.ChildActionValueProvider. I don't have a copy of the source code handy so I have no idea what is causing the exception and I've yet to find a better solution than the one I offered above. I personally don't like my solution because I'm changing the way I code my application for the benefit of my unit tests but there doesn't seem to be a better alternative. I bet the real solution will involve mocking some other object but I just don't know what.
Also, before anyone gets any smart ideas, mocking the ValueProvider is not a solution. It'll stop exceptions but your unit tests won't be validating your model and your ModelState will always report that the model is valid even when it isn't.
You might want to clean up your code a bit:
[HttpPost]
public ActionResult Create(int id, FormCollection collection)
{
var data = Helper.CreateEmptyApplicationsModel();
if (!ModelState.IsValid)
{
if (id != 0)
{
Helper.ShowLeftColumn(data, id);
}
return View("Create", data);
}
if (TryUpdateModel(data))
{
return RedirectToAction("Edit", "Applications", new { area = "Applications", id = id });
}
return RedirectToAction("Details", "Info", new { area = "Deals", InfoId= id });
}
Don't use Int64, just use int.
As for your failing test, I would expect your test to fail all the time since TryUpdateModel will return false. As your running the code from a unit test, the controller context for a controller is not available, thus TryUpdateModel will fail.
You need to somehow fake/mock TryUpdateModel so that it does not actually run properly. Instead you "fake" it to return true. Here's some links to help:
How do I Unit Test Actions without Mocking that use UpdateModel?
The above SO answer shows an example using RhinoMocks which is a free mocking framework.
Or this:
http://www.codecapers.com/post/ASPNET-MVC-Unit-Testing-UpdateModel-and-TryUpdateModel.aspx
Debug your tests and check the modelstate errors collection, all the errors that the tryupdatemodel encountered should be there.

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