ASP.NET MVC: How to merge/add new item into RouteValueDictionary - asp.net-mvc-3

I'm going to simplify my route declaration around of my asp.net mvc project. So I have created several method to do this.
context.MapExtendedRoute("Home".MergeWithAreaName(context),
"www".MergeWithAppDomain(),
"123".MergeWithDefaultRouteKeys(),
new {Controller = "Home", Action = "Index"}.MergeWithDefaultRouteValues(),
new {}.MergeWithDefaultRouteConstraints());
There isn't any problem with first three methods. But method 4 and 5 returns invalid value. The initial signature of (for example MergeWithDefaultRouteValues) is something like this:
public static object MergeWithDefaultRouteValues(this object defaultValues) {
return new RouteValueDictionary(defaultValues) {{"Culture", "SomeValue"}};
}
Which returns output like this(from RouteDebugger):
Count = 3, Keys = System.Collections.Generic.Dictionary`2+KeyCollection[System.String,System.Object], Values = System.Collections.Generic.Dictionary`2+ValueCollection[System.String,System.Object]
You can see none of Keys/Values is correct! Can anybody tell me how i can figure it out?
Signature of MapExtendedRoute:
MapExtendedRoute(this AreaRegistrationContext context, string name, string domain, string url, object defaults, object constraints)
Thanks in advance ;)

I resolved this issue by adding new overload to MapExtendedRoute method and change signature to this:
MapExtendedRoute(this AreaRegistrationContext context, string name, string domain, string url, RouteValueDictionary defaults, RouteValueDictionary constraints)
The problem is from casting RouteValueDictionary to object, then casting back object to RouteValueDictionary! So Route Keys/Values come from first RouteValueDictionary Properties/Values.
var defaultValues = new {};
//this works fine
var x = new RouteValueDictionary(defaultValues) {{"Culture", null}};
//But when x casted to object
var obj = (object)x;
//And obj casted back to RouteValueDictionary
var x2 = new RouteValueDictionary(obj);
//Everything goes to be fail!

Related

Error in MVC view page displaying

I am getting an error in my MVC C# application. Although i am not getting following error in development environment, not even functionality is breaking, but when deploying it at IIS server, I am getting this error through elmah via emails with corresponding entry in the database
The parameters dictionary contains a null entry for parameter 'id' of non-nullable type 'System.Int32' for method 'System.Web.Mvc.ActionResult DetailSmallForeignWidget(System.String, Int32, System.String, System.Nullable`1[System.Int32], System.Nullable`1[System.DateTime], System.Nullable`1[System.Int32], System.String, System.String)' in 'BAR.Web.Controllers.ForeignRestaurantWidgetController'. An optional parameter must be a reference type, a nullable type, or be declared as an optional parameter.
After making id parameter nullable I got to know that the corresponding action method is getting called twice. Reviewing the code it looks fine but don't know why this is happening.
routes for the action method is as follows:
_routes.MapRoute(null, "widget/DetailWidget/{name}/{id}/{langID}/",
new { controller = "Widget", action = "DetailWidget" },
new[] { "BAR.Web.Controllers" });
Function signature is as follows:
public override ActionResult DetailWidget(
string name,
int id,
string refCode,
int? partySize,
DateTime? when,
int? sittingTimeId,
string time,
string langID)
<script type="text/javascript" src="http://localhost/widget/IncludeWidget/Street/205/iframe/ja-JP" ></script>
Corresponding route
_routes.MapRoute(null, "widget/IncludeWidget/{name}/{id}/{mode}/{langID}/",
new { controller = "Widget",
action = "IncludeWidget" },
new[] { "BAR.Web.Controllers" });
Inside Includewidget func. code is something like below:
ContentResult content = new ContentResult();
string url = Url.ToAbsoluteUrl(string.Format("widget/DetailWidget/{0}/{1}/{2}", name, id.Value, langID), true);
content.Content = #"document.write('<iframe src=""" + url + #""" width=""300"" height=""430"" style=""border: none;"" frameborder=""0""></iframe>')";
content.ContentType = "text/javascript";
return content
I tried to rename the route parameters and tried to script references from the view page, but still it is showing the same error based on new parameter name. How can I fix this issue?

How to update knockout model in mvc3 app

I've been playing with MVC3 with KnockoutJs for a few weeks and I've been wondering about something
say I have an mvc action which returns a simple list
public ActionResult AddFoos()
{
List<Foo> funds = new List<Foo>();
.. etc
return Json(funds.ToList(), JsonRequestBehavior.AllowGet);
}
which is then passed into the view model
var viewModel = {
fooChocies: ko.mapping.fromJS([]),
fooOptions: ko.mapping.fromJS([]),
loadInitialData: function () {
ko.mapping.fromJS(serverData, dataMappingOptions, viewModel.fooOptions);
},
};
In my type Foo I also have properties that show or hide ui elements
var Foo = function (data, preselect) {
var self = this;
self.id = ko.observable(data.id);
self.Name = ko.observable(data.Name);
self.number = ko.observable('');
self.showProducts = ko.observable(false); <---
self.displayBigPanel = ko.observable(false); <---
}
My approach so far as been to dynamically create elements of the form
which passes through the ModelBinder and creates a List< Foo > as a parameter for controller action.
Finally the question...
When the user navigates back to this page I need to restore the UI with the fooChoices the user made.
It seems I have 2 choices with rebuilding the user selections (both via extension methods)
Use raw json as seen by
ko.toJSON(viewModel.fooChoices))
which in addition to basic model properties also provides info on hiding and displaying UI elements,
sb.Append("viewModel.fooCghoices= ko.mapping.fromJS(" + json + ");");
sb.Append("ko.applyBindings(viewModel);");
return new HtmlString(sb.ToString());
thus sending client ui info to the server and back
or
Manipulate the ViewModel directly in effect simulating the user actions
sb.Append("viewModel.fooChoices.push(new Foo(1509));");
sb.Append("viewModel.fooChoices()[0].selectedSubFoo = new Foo(273);");
sb.Append("viewModel.fooChoices()[0].showProducts(true);");
In either case it feels a bit off and that a better pattern is out there. Would like to know if one way is better than the other or none of the above.
Many Thanks
Presently, your controller method returns a list of Foo. Consider creating a more complex object that holds both your Foos and your choices.
public class FooViewModel
{
public List<Foo> Foos { get; set; };
public UserChoices { get; set; }
}
Change your controller method so that it returns FooViewModel. This means user choices will be returned along with any Foos you are interested in.
public ActionResult AddFoos()
{
// Are there any choices stored in session?
// Use those first, otherwise create a new UserChoices object
UserChoices choices =
Session["User.Choices"] as UserChoices ?? new UserChoices();
List<Foo> funds = new List<Foo>();
.. etc
FooViewModel vm = new FooViewModel() { Foos = funds; UserChoices = choices };
// Return the whole object, containing Choices and Foos
return Json(vm, JsonRequestBehavior.AllowGet);
}
Also, consider some kind of action filter to allow you to pass complete objects easily. ObjectFilter is a good approach. It allows you to pass complex object structures easily without having to rely on specific markup.
http://www.c-sharpcorner.com/blogs/863/passing-json-into-an-asp-net-mvc-controller.aspx
ObjectFilter above a controller method. Pretty simple, just declaring that the controller should attempt to treat any incoming parameter called fooStuff as type FooViewModel.
[HttpPost,
ObjectFilter(Param = "fooStuff", RootType = typeof(FooViewModel)),
UnitOfWork]
public JsonResult ProcessFoos(FooViewModel fooStuff) {
By defining a corresponding JavaScript view model, you can just convert the whole thing to a json string and pass it to the controller method fully populated.
So, example of corresponding js vm would be:-
var fooViewModel = function(data) {
var self = this;
self.Foos = ko.observableArray(data.Foos);
self.UserChoices = ko.observable(data.UserChoices);
// Don't worry about properties or methods that don't exist
// on the C# end of things. They'll just be ignored.
self.usefulJSOnlyMethod = function() {
// behaviour
};
}
var userChoice = function(data) {
var self = this;
self.DinnerId = ko.observable(data.DinnerId);
}
Typical call to a controller method decorated by ObjectFilter would be something like this ( assuming self is a fooViewModel ):-
var queryData = ko.mapping.toJSON(self);
$.ajax(
//...
data: queryData,
Any matching ( same name, same type case-sensitive ) property from the js vm will automatically end up in the fooStuff parameter of your controller method. Time to save those choices:-
Also note that I'm persisting user choices in the session here. This'll allow them to be picked up by any other controller method which may need them ( example in AddFoos above ).
[HttpPost,
ObjectFilter(Param = "fooStuff", RootType = typeof(FooViewModel)),
UnitOfWork]
public JsonResult ProcessFoos(FooViewModel fooStuff)
{
// hey! I have a fully mapped FooViewModel right here!
// ( _fooServices.ProcessFoos will return updated version of viewmodel )
FooViewModel vm = _fooServices.ProcessFoos(fooStuff);
// What about those choices?
// Put them in the session at this point in case anyone else comes asking
// after them.
Session["User.Choices"] = vm.UserChoices;
return Json(vm);
}
Because we've:-
Defined a better C# view model
Defined a corresponding JS view model
Including UserChoices as part of that view model
....restoring the choice is simple at this point. Reference the part of the view model that contains the user's selected choice.
<select id="dinnerChoice"
data-bind="value: UserChoices.DinnerId"
>
</select>

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.

ASP.Net MVC: Passing a string parameter to an action using RedirectToAction()

I would like to know how to pass a string parameter using RedirectToAction().
Let's say I have this route:
routes.MapRoute(
"MyRoute",
"SomeController/SomeAction/{id}/{MyString}",
new { controller = "SomeController", action = "SomeAction", id = 0, MyString = UrlParameter.Optional }
);
And in SomeController, I have an action doing a redirection as follows:
return RedirectToAction( "SomeAction", new { id = 23, MyString = someString } );
I tried this redirection with someString = "!##$%?&* 1" and it always fails, no matter if I encode the string. I tried encoding it with HttpUtility.UrlEncode(someString), HttpUtility.UrlPathEncode(someString), and with Uri.EscapeUriString(someString) to no avail.
So I resorted to us TempData to pass someString, but still, I would be curious to know how to make the code above work, just to satisfy my curiosity.
I think the issue might be either in your route order, or in your controller. Here is some code that I got to work.
Route Definitions
routes.MapRoute(
"TestRoute",
"Home/Testing/{id}/{MyString}",
new { controller = "Home", action = "Testing", id = 0, MyString = UrlParameter.Optional }
);
routes.MapRoute(
"Default", // Route name
"{controller}/{action}/{id}", // URL with parameters
new { controller = "Home", action = "Index", id = UrlParameter.Optional } // Parameter defaults
);
// note how the TestRoute comes before the Default route
Controller Action Methods
public ActionResult MoreTesting()
{
return RedirectToAction("Testing", new { id = 23, MyString = "Hello" });
}
public string Testing(int id, string MyString)
{
return id.ToString() + MyString;
}
When I browse to /Home/MoreTesting I get the desired output of "23Hello" to output in my browser. Can you post your routes and your Controller code?
OK, I know this question is a few days old but I wasn't sure if you got this issue sorted or not so I had a look. I played around with this for a while now and this is what the problem is and how you could solve it.
The problem you are having is that the special characters causing issues are one of the many (I think 20) special characters, such as % and ".
In your example the problem is the % character.
As pointed out by Priyank here:
The route values are posted as part of the URL string.
The Url string (not query string parameter) can't handle %(%25), "(%22) and so on.
Further, as pointed out by Lee Gunn in the same post:
http://localhost:1423/Home/Testing/23/!%40%23%24%25%3f%26*%201 - (this will blow up)
One of the ways to fix this is to remove {MyString} from the route mapping. To make your root mapping look like this:
routes.MapRoute(
"TestRoute",
"Home/Testing/{id}",
new { controller = "Home", action = "Testing", id = 0, MyString = UrlParameter.Optional }
);
This will cause the post to generate this:
http://localhost:1423/Home/Testing/23?MyString=!%2540%2523%2524%2525%2B1
Now when you set MyString it will be turned into a query string parameter which works perfectly fine.
I did try that and it did work.
Priyank also mentioned in the SO post I linked above that you maybe could solve this with a custom ValueProvider but you would have to follow his linked article their to check if that is something that would apply to you.

MVC Model Binding a Complex Type to a Simple Type and Vice Versa

Here's a scenario:
I have an autocomplete plugin (custom) that keeps a hidden field of JSON objects (using a specific struct).
I've created an Html helper that helps me easily bind to a specific custom model (basically, it has a JSON property that is for two-way binding and a property that lets me deserialize the JSON into the appropriate struct):
public class AutoCompleteModel {
public string JSON { get; set; }
public IEnumerable<Person> People {
get {
return new JavaScriptSerializer().Deserialize<Person>(this.JSON);
}
set {
this.JSON = new JavaScriptSerializer().Serialize(value);
}
}
}
This works great and I can model bind using the default binder #Html.Autocomplete(viewModel => viewModel.AutoCompleteModelTest). The HTML helper generates HTML like:
<input type="text" id="AutoCompleteModelTest_ac" name="AutoCompleteModelTest_ac" value="" />
<input type="hidden" id="AutoCompleteModelTest_JSON" name="AutoCompleteModelTest.JSON" value="{JSON}" />
The problem is this is not the best way for consumers. They have to manually set the People property to an array of Person structs. In my data layer, my domain objects probably will not be storing the full struct, only the person's ID (a corporate ID). The autocomplete will take care of looking up the person itself if only given an ID.
The best scenario will be to call it like this:
#Html.Autocomplete(domainObject => domainObject.PersonID) or
#Html.Autocomplete(domainObject => domainObject.ListOfPersonIDs
I would like it to work against the string property AND against the custom AutoCompleteModel. The autocompleter only updates a single hidden field, and that field name is passed back on postback (the value looks like: [{ "Id":"12345", "FullName":"A Name"},{ "Id":"12347", "FullName":"Another Name" }]).
The problem is, of course, that those domain object properties only have an ID or array of IDs, not a full Person struct (so cannot be directly serialized into JSON). In the HTML helper, I can transform those property values into a struct, but I don't know how to transform it back into a simple type on POST. The solution I need would transform an ID into a new Person struct on page load, serializing it into the hidden field. On POST, it would deserialize the generated JSON back into a simple array of IDs.
Is a custom model binder the solution I need? How can I tell it to work both with a custom model AND simple types (because I don't want it applied to EVERY string property, just need it to deal with the values given by the HTML helper).
I figured it out, it's possible!
To clarify, I needed to: transform a string or string array (of IDs) into a JSON structure for my hidden field value, then on post back, deserialize the JSON in the hidden field and transform the struct back into a simple string or string array (of IDs) for my domain object's property.
Step 1: Create a HTML helper
I had done this already, but only for accepting my custom AutoCompleteModel type. I needed one for a string and an Enumerable of string type.
All I did was generate my Person struct(s) from the value of the property and serialize them into JSON for the hidden field the Autocompleter uses (this is an example of the string helper, I also have a nearly identical one for IEnumerable<string>):
public static MvcHtmlString AutoComplete<TModel>(
this HtmlHelper<TModel> htmlHelper,
Expression<Func<TModel, string>> idProp)
where TModel : class
{
TModel model = htmlHelper.ViewData.Model;
string id = idProp.Compile().Invoke(model);
string propertyName = idProp.GetPropertyName();
Person[] people = new Person[] {
new Person() { ID = id }
};
// Don't name the textbox the same name as the property,
// otherwise the value will be whatever the textbox is,
// if you care.
MvcHtmlString textBox = htmlHelper.TextBox(propertyName + "_ac", string.Empty);
// For me, the JSON is the value I want to postback
MvcHtmlString hidden = htmlHelper.Hidden(propertyName, new JavaScriptSerializer().Serialize(people));
return MvcHtmlString.Create(
"<span class=\"AutoComplete\">" +
textBox.ToHtmlString() +
hidden.ToHtmlString() +
"</span>");
}
Usage: #Html.AutoComplete(model => model.ID)
Step 2: Create a custom model binder
The crux of my issue was that I needed this binder to only apply to certain properties, and they were strings or string arrays.
I was inspired by this article because it used Generics. I decided, hey, we can just ask people what property they want to apply the binder for.
public class AutoCompleteBinder<T> : DefaultModelBinder
where T : class
{
private IEnumerable<string> PropertyNames { get; set; }
public AutoCompleteBinder(params Expression<Func<T, object>>[] idProperties)
{
this.PropertyNames = idProperties.Select(x => x.GetPropertyName());
}
protected override object GetPropertyValue(
ControllerContext controllerContext,
ModelBindingContext bindingContext,
PropertyDescriptor propertyDescriptor,
IModelBinder propertyBinder)
{
var submittedValue = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
if (submittedValue != null && this.PropertyNames.Contains(propertyDescriptor.Name))
{
string json = submittedValue.AttemptedValue;
Person[] people = new JavaScriptSerializer().Deserialize<Person[]>(json);
if (people != null && people.Any())
{
string[] IDs = people.Where(x => !string.IsNullOrEmpty(x.ID)).Select(x => x.ID).ToArray();
bool isArray = bindingContext.ModelType != typeof(string) &&
(bindingContext.ModelType == typeof(string[]) ||
bindingContext.ModelType.HasInterface<IEnumerable>());
if (IDs.Count() == 1 && !isArray)
return IDs.First(); // return string
else if (IDs.Count() > 0 && isArray)
return IDs.ToArray(); // return string[]
else
return null;
}
else
{
return null;
}
}
return base.GetPropertyValue(controllerContext, bindingContext, propertyDescriptor, propertyBinder);
}
}
GetPropertyName() (translate LINQ expression into a string, i.e. m => m.ID = ID) and HasInterface() are just two utility methods I have.
Step 3: Register
Register the binder on your domain objects and their properties in Application_Start:
ModelBinders.Binders.Add(typeof(Employee), new AutoCompleteBinder<Employee>(e => e.ID, e => e.TeamIDs));
It's only a little bit annoying to have to register the binder for specific properties, but it's not the end of the world and provides a nice, smooth experience working with my autocompleter.
Any comments are welcome.

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