So I have these three lines:
<div style="background-color: lightgreen;">#Html.TextBoxFor(m => m.Id)</div>
<div style="background-color: green;">#Html.DisplayTextFor(m => m.Id)</div>
<div style="background-color: pink;">#Model.Id</div>
I've identified that the lightgreen value is not my Model.Id but the Id that is set by my route:
routes.MapRoute("Default", "{controller}/{action}/{id}", new { controller = "MyFunController", action = "Index", id = UrlParameter.Optional });
I've come accross some explanations here:
http://forums.asp.net/t/1792086.aspx/1
http://www.hanselman.com/blog/TheWeeklySourceCode38ASPNETMVCBetaObscurityModelStateIsValidIsFalseBecauseModelBinderPullsValuesFromRouteData.aspx
http://ayende.com/blog/3683/reproducing-a-bug
But they have all left me on my appetite. I'm looking for a smart way to work around this, I don't want to change my model's property names nor do I want to change the name of the route item. If I do it will represent a lot of work for me and is not ideal.
I'm sure I'm not the only one with this issue?
(This is MVC 4)
Thanks!
You could remove the problematic value from the ModelState (which is where the Html helpers are taking it from) in the controller action that is rendering the view:
public ActionResult SomeAction(int id)
{
ModelState.Remove("Id");
MyViewModel model = ...
return View(model);
}
Now it's the Id property of your view model that's gonna get used by the TextBox and not the one coming from the route.
Obviously that's only an ugly horrible workaround. The correct way is to of course properly define your view models so that you do not have such naming collisions.
Related
I am in the process of learning MVC 3 using the basic project template coupled with several examples I have. Things are going well, but now I am trying to implement my controllers and I am having a couple of issues.
So far I have modified the _Layout.cshtml file to have a new link with a specified route defined:
<header>
<div id="title">
<h1>My MVC Application</h1>
</div>
<div id="logindisplay">
#Html.Partial("_LogOnPartial")
</div>
<nav>
<ul id="menu">
<li>#Html.ActionLink("Home", "Index", "Home")</li>
<li>#Html.RouteLink("Contracts", "Contract")</li>
<li>#Html.ActionLink("About", "About", "Home")</li>
</ul>
</nav>
</header>
and my global.asax.cs file is as follows:
routes.MapRoute(
"Contract",
"Contract",
new { controller = "Contract", action = "List", id = UrlParameter.Optional }
);
routes.MapRoute(
"Default", // Route name
"{controller}/{action}/{id}", // URL with parameters
new { controller = "Home", action = "Index", id = UrlParameter.Optional } // Parameter defaults
);
This works fine as in it returns the expected action view from my Contract controller.
However I would like to modify this to accept an id into the List action. I know that I need to change the List method to accept a parameter, no problem there, but the issue it with the route and how to pass this paramter into the List method from the RouteLink in the _Layout.cshtml file. I have tried a few things, but this bit is really stumping me.
I intend to pass an id from the User that I logged in as through the AccountController, however I will ask another question about that to keep this more consise.
Thank you very much.
You don't actually need your Contract route, as your Default route will work for any controller and action that corresponds to the pattern controller/action/(optional id parameter here). See the comment in the template actually says Parameter defaults. This means, if there is no Controller, Action, or id passed in, it will default to those values. That's why you can just browse to the root of the website and the Home controller's Index action is the default call.
When using routes, you need to remember that the route parameter names need to match the parameter names in your actions.. for example, your Default route currently lets you do this:
[HttpGet]
public ActionResult MyAction(int id) {
}
But, if you changed your default route to be this:
routes.MapRoute(
"Default", // Route name
"{controller}/{action}/{myIDParameter}", // URL with parameters
new { controller = "Home", action = "Index", myIDParameter = UrlParameter.Optional } // Parameter defaults
);
..your Index action would no longer bind the integer parameter properly.. you would have to change the action to this:
[HttpGet]
public ActionResult MyAction(int myIDParameter) {
}
In answer to your question, it might make more sense to use an ActionLink, like the other two you already have:
#Html.ActionLink("Contracts", "Contract", "ActionMethodHere", new { id = UserIdHere }, null)
That assumes though, that you remove your Contract route and just use the default route.
I have a strongly typed razor view for a model in my MVC 3 project. Basically its for editing the model.
The model contains an Id field for the database key and some other string fields (Its a viewModel and all but thats not the point of the question).
In the view I just have a form and a submit button and nothing else. When the View is posted to the controller the model in the controller has all fields empty EXCEPT for the Id field which seems to have been auto-magically filled up.
How and where does the Id field gets populated in the model without there being a corresponding 'input' element for it in the view.
This is probably a dumb question but I would appreciate even just a link to what I should read up on. Thanks.
I bet it comes from the url as route parameter.
For example you have the following controller:
public class HomeController: Controller
{
public ActionResult Index(int id)
{
vqr model = GetModel(id);
return View(model);
}
[HttpPost]
public ActionResult Index(MyViewModel model)
{
// the model.Id property will be automatically populated here
// because the request was POST /home/index/123
...
}
}
and the following view:
#model MyViewModel
#using (Html.BeginForm())
{
<button type="submit">OK</button>
}
Now you navigate to GET /home/index/123 and you get the following markup:
<form action="/home/index/123" method="post">
<button type="submit">OK</button>
</form>
Notice the action attribute of the form? That's where the id comes from. Basically the Html.BeginForm() helper uses the current url when generating the action attribute, and since the current url is /home/index/123 it is what gets used.
And because if you have left the default routes in your Global.asax, the {id} route token is used at the end of the url, the default model binder successfully binds it to the Id property of your view model.
You are probably hitting a URL similar to the following: /MyObject/Edit/15
This is then returning the page that you have your blank form on.
What happens next is you have an HTML.BeginForm() which is posting BACK to /MyObject/Edit/15
Now because of the post back having the same format your routing rules are picking up the '15' and binding it back to your id.
Have you added the ID field as a hidden field?
e.g.
#Html.HiddenFor(x=> x.ID)
It has been intriguing that my MVC3 razor form renders duplicated values inside a foreach code block in spite of correctly receiving the data from the server. Here is my simple form in MVC3 Razor...
-- sample of my .cshtml page
#model List<Category>
#using (#Html.BeginForm("Save", "Categories", FormMethod.Post))
{
foreach (Category cat in Model)
{
<span>Test: #cat.CategoryName</span>
<span>Actual: #Html.TextBoxFor(model => cat.CategoryName)</span>
#Html.HiddenFor(model => cat.ID)
<p>---</p>
}
<input type="submit" value="Save" name="btnSaveCategory" id="btnSaveCategory" />
}
My controller action looks something like this -
[HttpPost]
public ActionResult Save(ViewModel.CategoryForm cat)
{
... save the data based on posted "cat" values (I correctly receive them here)
List<Category> cL = ... populate category list here
return View(cL);
}
The save action above returns the model with correct data.
After submitting the form above, I expect to see values for categories similar to the following upon completing the action...
Test: Category1, Actual:Category1
Test: Category2, Actual:Category2
Test: Category3, Actual:Category3
Test: Category4, Actual:Category4
However #Html.TextBoxFor duplicates the first value from the list. After posting the form, I see the response something like below. The "Actual" values are repeated even though I get the correct data from the server.
Test: Category1, Actual:Category1
Test: Category2, Actual:Category1
Test: Category3, Actual:Category1
Test: Category4, Actual:Category1
What am I doing wrong? Any help will be appreciated.
The helper methods like TextBoxFor are meant to be used with a ViewModel that represent the single object, not a collection of objects.
A normal use would be:
#Html.TextBoxFor(c => c.Name)
Where c gets mapped, inside the method, to ViewData.Model.
You are doing something different:
#Html.TextBoxFor(c => iterationItem.Name)
The method internall will still try to use the ViewData.Model as base object for the rendering, but you intend to use it on the iteration item. That syntax, while valid for the compiler, nets you this problem.
A workaround is to make a partial view that operates on a single item: inside that view you can use html helpers with correct syntax (first sample), and then call it inside the foreach, passing the iteration item as parameter. That should work correctly.
A better way to do this would be to use EditorTemplates.
In your form you would do this:
#model List<Category>
#using (#Html.BeginForm("Save", "Categories", FormMethod.Post))
{
#Html.EditorForModel()
<input type="submit" value="Save" name="btnSaveCategory" id="btnSaveCategory" />
}
Then, you would create a folder called EditorTemplates, either in the ~/Views/Shared folder or in your Controllers View folder (depending on whether you want to share the template with the whole app or just this controller), and in the EditorTemplates folder, create a Category.cshtml file which looks like this:
#model Category
<span>Test: #Model.CategoryName</span>
<span>Actual: #Html.TextBoxFor(model => model.CategoryName)</span>
#Html.HiddenFor(model => model.ID)
<p>---</p>
MVC will automatically iterate over the collection and call your template for each item in it.
I've noticed that using foreach loops within Views causes the name attributes of text boxes to be rendered the same for every item in the collection. For your example, every text box will be rendered with the following ID and Name attributes:
<input id="cat_CategoryName" name="cat.CategoryName" value="Category1" type="text">
When your controller receives the form data collection, it won't be able reconstruct the collection as different values.
The solution
A good pattern I've adopted is to bind your View to the same class you want to post back. In the example, model is being bound to List<Category> but the controller Save method receives a model ViewModel.CategoryForm. I would make them both the same.
Use a for loop instead of a foreach. The name/id attributes will be unique and the model binder will be able to distinguish the values.
My final code:
View
#model CategoryForm
#using TestMvc3.Models
#using (#Html.BeginForm("Save", "Categories", FormMethod.Post))
{
for (int i = 0; i < Model.Categories.Count; i++)
{
<span>Test: #Model.Categories[i].CategoryName</span>
<span>Actual: #Html.TextBoxFor(model => Model.Categories[i].CategoryName)</span>
#Html.HiddenFor(model => Model.Categories[i].ID)
<p>---</p>
}
<input type="submit" value="Save" name="btnSaveCategory" id="btnSaveCategory" />
}
Controller
public ActionResult Index()
{
// create the view model with some test data
CategoryForm form = new CategoryForm()
{
Categories = new List<Category>()
};
form.Categories.Add(new Category() { ID = 1, CategoryName = "Category1" });
form.Categories.Add(new Category() { ID = 2, CategoryName = "Category2" });
form.Categories.Add(new Category() { ID = 3, CategoryName = "Category3" });
form.Categories.Add(new Category() { ID = 4, CategoryName = "Category4" });
// pass the CategoryForm view model
return View(form);
}
[HttpPost]
public ActionResult Save(CategoryForm cat)
{
// the view model will now have the correct categories
List<Category> cl = new List<Category>(cat.Categories);
return View("Index", cat);
}
Im creating an application that allows me to record recipes. Im trying to create a view that allows me to add the basics of a recipe e.g. recipe name,date of recipe, temp cooked at & ingredients used.
I am creating a view that contains some jquery to load a partial view clientside.
On post im having a few troubles trying to get the values from the partial view that has been loaded using jquery.
A cut down version of my main view looks like (I initially want 1 partial view loaded)
<div id="ingredients">
#{ Html.RenderPartial("_AddIngredient", new IngredientViewModel()); }
</div>
<script type="text/javascript">
$(document).ready(function () {
var dest = $("#ingredients");
$("#add-ingredient").click(function () {
loadPartial();
});
function loadPartial() {
$.get("/Recipe/AddIngredient", {}, function (data) { $('#ingredients').append(data); }, "html");
};
});
</script>
My partial view looks like
<div class="ingredient-name">
#Html.LabelFor(x => Model.IngredientModel.IngredientName)
#Html.TextBoxFor(x => Model.IngredientModel.IngredientName)
</div>
<div class="ingredient-measurementamount">
#Html.LabelFor(x => Model.MeasurementAmount)
#Html.TextBoxFor(x => Model.MeasurementAmount)
</div>
<div class="ingredient-measurementtype">
#Html.LabelFor(x => Model.MeasurementType)
#Html.TextBoxFor(x => Model.MeasurementType)
</div>
Controller Post
[HttpPost]
public ActionResult Create(RecipeViewModel vm,IEnumerable<string>IngredientName, IEnumerable<string> MeasurementAmount, IEnumerable<string> MeasurementType)
{
Finally my viewmodel looks like
public class IngredientViewModel
{
public RecipeModel RecipeModel { get; set; }
public IEnumerable<IngredientModel> Ingredients { get; set; }
}
My controller is pretty ugly......im using Inumerble to get the values for MeasurementAmount & MeasurementType (IngredientName always returns null), Ideally I thought on the httppost Ingredients would be populated with all of the on I would be able Ingredients populated
What do I need to do to get the values from my partial view into my controller?
Why don't you take a look at the MVC Controlstoolkit
I think they would do what you want.
Without getting in too much detail. Can you change the public ActionResult Create to use FormCollection instead of a view model? This will allow you to see what data is coming through if any. It would help if you could post it then.
Your view model gets populated by using Binding - if you haven't read about it, it might be a good idea to do that. Finally I would consider wrapping your lists or enums into a single view model.
Possible Problem
The problem could lay with the fact that the new Partial you just rendered isn't correctly binded with your ViewModel that you post later on.
If you inspect the elements with firebug then the elements in the Partial should be named/Id'ed something like this: Ingredients[x].Property1,Ingredients[x].Property2 etc.
In your situation when you add a partial they are probably just called Property1,Property2.
Possible Solution
Give your properties in your partial the correct name that corresponds with your List of Ingredients. Something like this:
#Html.TextBox("Ingredients[x].Property1","")
Of, after rendering your partial just change all the names en ID's with jquery to the correct value.
It happens because fields' names from partial view do not fit in default ModelBinder convention. You should analyze what names fields have in your partial view.
Also you should implement correct way of binding collections to MVC controller. You could find example in Phil's Haack post
Assuming RecipeViewModel is the model being supplied to the partial view, try just accepting that back in your POST controller like this:
[HttpPost]
public ActionResult Create(RecipeViewModel vm)
{
//
}
You should get the model populated with all the values supplied in the form.
I'm working on an application where a system is being built where multiple "customers" will use the system and 99.9% of the controllers/actions will be the same, just pulling different data, but there are times and places where a custom controller action, or view might be needed.
Right now I'm using a default route similar to the following to get the company name with requests.
routes.MapRoute(
"Default", // Route name
"{company}/{controller}/{action}/{id}",
new {company = "Unknown", controller = "Home",
action = "Index", id = UrlParameter.Optional}
);
This works great as I can have my individual controller actions defined like this
public ActionResult ShowReport(string company)
{
//Actual code goes here..
}
I have a system in place that will get the data segment for this specific company and return the proper view. SO for my 99.9% situation this looks great. What I'm looking for is a solution for when I need to render a different view, or have additional actions that are specific to one company.
I could add in switch or other logic within my action, but that feels overly dirty...
For a specific company you can use something like this and put it before the default action, in this case url has to contain Company1/somethingcontroller/etc/etc.
routes.MapRoute(
"Company1Default", // Route name
"Company1/{controller}/{action}/{id}",
new {company = "Company1", controller = "DefaultControllerForCompany1",
action = "Index", id = UrlParameter.Optional}
);
While I actually lean to Jay's answer pertaining to the use of data within models, I think that there is another option. Be warned that I haven't played this all the way out and don't have a full understanding of your application...
Why would you want to hardcode a company name within your global.asax? I don't think that it would be very scalable. If you want to add support for an additional 10 companies, you'd have to create 10 new entries. Also, what if you want to change the name of a company because of a buyout or something? More maintenance.
Why not add a route to send every company to the same controller like...
routes.MapRoute(
"CompanyRouting", // Route name
"{companyname}/{action}",
new { controller = "MySingleCompanyControllerName", action = "Index", companyname = UrlParameter.Optional }
);
MySingleCompanyController.cs
Once in your controller you can just get whatever the companyname value is whenever you want it.
public ActionResult Index()
{
ViewData["companynamevalue"] = RouteData.Values["companyname"];
return View();
}
Index.aspx
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Index</title>
</head>
<body>
<div>
Requested Company Name = <%: ViewData["companynamevalue"] %>
</div>
</body>
</html>
NOTE: One more thing to look into for routing help is Phil Haack's routing debugger.
Defining which view is return from an action is easy:
return View("Index");
This will return the view named "Index" no matter which action is invoked.
On the other hand, both views and actions must be defined at compile time, so you cannot dynamically create them (from what i know of).
I might suggest implementing the Command Pattern in your action to get exactly what you would want for individual companies from a single action.