I have found so many questions about this, but none of them go over or seem to go over my scenario. I have a model:
public class CheckBoxModel
{
public int Id{ get; set; }
public bool IsSelected { get; set; }
}
In then try and bind my IsSelected bool to a checkbox like this:
<%= Html.CheckBox("IsSelectedCheck",Model.IsSelected)%>
I have lots of items on a page, they all have a checkbox next to them, all i am trying to do is pass back to the controller all the id's of the items and which ones have been selected.
At the moment, the value of IsSelected is always false. Should Html.CheckBox set the value of Model.IsSelected each time the user toggles the checkbox.
Thanks
Try like this:
<%= Html.CheckBoxFor(x => x.IsSelected) %>
Also if you want to pass along the id don't forget to do so:
<%= Html.HiddenFor(x => x.Id) %>
And if you had a collection of those:
public class MyViewModel
{
public CheckBoxModel[] CheckBoxes { get; set; }
}
you could:
<% for (var i = 0; i < Model.CheckBoxes.Length; i++) { %>
<div>
<%= Html.HiddenFor(x => x.CheckBoxes[i].Id) %>
<%= Html.CheckBoxFor(x => x.CheckBoxes[i].IsSelected) %>
</div>
<% } %>
which will successfully bind to:
[HttpPost]
public ActionResult MyAction(MyViewModel model)
{
// model.CheckBoxes will contain everything you need here
...
}
An alternative to Darin's fantastic answer
I definitely recommend following Darin's approach for returning classes which will be most of the time. This alternative is a 'quick' and dirty hack if all you need is the checked Ids:
<% foreach (var cb in Model.CheckBoxes) { %>
<div>
<input type="checkbox"
value="<%= cb.Id %>"
<%= cb.IsSelected ? "checked=\"checked\"" : "" %>
name="ids" />
</div>
<% } %>
Will bind to the int[] ids parameter in the following action:
[HttpPost]
public ActionResult MyAction(int[] ids)
{
// ids contains only those ids that were selected
...
}
The benefit is cleaner html as there is no hidden input.
The cost is writing more code in the view.
In MVC 4.0 (Razor 2.0) you can use the following syntax in your view:
<input type="checkbox" value="#cb.Id" checked="#cb.IsSelected" name="ids" />
I'm not even quite sure where to start explaining this problem. I've been working on this for about the past 10 hours without a clue as to what the root cause is. If any additional details are needed, I'd be happy to provide. I'm just guessing at what is relevant at this point.
I have an MVC2 site with routes set up by by Steve Hodgkiss' wonderful RestfulRouting package, using the default route setup with nested controllers (e.g. /customer/{custid}/location/{locid} and such).
In this, I have one particular model that is giving me issues. For some reason, when the create page post's the data back to my server, the ModelName property in the ModelBindingContext object passed to the DefaultModelBinder (well, my custom class inherited from DefaultModelBinder, to handle grabbing objects from a repository). This happens only for this one model. And I can't spot the differences at all.
The broken model
public class RemedialItem : Entity
{
public virtual int Id { get; set; }
....
A working model:
public class Customer : Entity
{
public virtual int Id { get; set; }
....
Entity is just an empty class used as a marker for Reflection use.
The broken controller method in RemedialItemController.cs
[HttpGet]
public ActionResult New(int? locationId, int? applianceId)
{
var model = ViewModelFactory.Create<CreateRemedialItemViewModel>();
model.Categories = (from c in repository.Query<RemedialItemCategory>()
orderby c.Name
select c).ToList();
model.RemedialItem = new RemedialItem();
return View(model);
}
A working controller method in CustomerController.cs
[HttpGet]
public ActionResult New()
{
var viewModel = ViewModelFactory.Create<SingleCustomerViewModel>();
viewModel.Customer = new Customer();
return View(viewModel);
}
ViewModelFactory is an injected class that handles setting up some basic properties common to all view models (mainly is the user logged in and user details right now)
A broken viewmodel:
public class CreateRemedialItemViewModel : ViewModelBase
{
public RemedialItem RemedialItem { get; set; }
public IList<Location> Locations { get; set; }
public IList<Appliance> Appliances { get; set; }
public IList<RemedialItemCategory> Categories { get; set; }
}
A working ViewModel:
public class SingleCustomerViewModel : ViewModelBase
{
public Customer Customer { get; set; }
}
ViewModelBase contains a handful of properties populated by the ViewModelFactory.
The broken form in thew New view for RemedialItem:
<% using(Html.BeginForm("Create","RemedialItem",FormMethod.Post))
{%>
<%: Html.AntiForgeryToken() %>
<fieldset>
<legend>General</legend>
<div>
<%: Html.LabelFor(m=>m.RemedialItem.Category) %>
<%:Html.DropDownListFor(m=>m.RemedialItem.Category.Id, new SelectList(Model.Categories,"Id","Name")) %>
</div>
<div>
<%: Html.LabelFor(m=>m.RemedialItem.Item) %>
<%: Html.TextAreaFor(m=>m.RemedialItem.Item) %>
</div>
<div>
<%: Html.LabelFor(m=>m.RemedialItem.Note) %>
<%: Html.TextAreaFor(m=>m.RemedialItem.Note) %>
</div>
<input type="submit" value="Create Item" />
</fieldset>
<%}%>
A working New view:
<% using (Html.BeginForm("Create","Customer",FormMethod.Post)) {%>
<%: Html.ValidationSummary(true) %>
<%:Html.AntiForgeryToken() %>
<fieldset>
<legend>Fields</legend>
<p>
<%: Html.LabelFor(m=>m.Customer.Name) %>
<%: Html.TextBoxFor(m=>m.Customer.Name) %>
</p>
<p>
<%: Html.LabelFor(m=>m.Customer.Street) %>
<%: Html.TextBoxFor(m=>m.Customer.Street) %>
</p>
[...tl;dr...]
<p>
<input type="submit" value="Create" />
</p>
</fieldset>
<% } %>
Both produce similar field names:
Broken:
<label for="RemedialItem_Item">Item</label>
<textarea cols="20" id="RemedialItem_Item" name="RemedialItem.Item" rows="2">
</textarea>
Working:
<label for="Customer_Name">Name</label>
<input id="Customer_Name" name="Customer.Name" type="text" value="" />
I apologize for the overly long code dump, in short:
The working set of stuff, when posted back on the create form, has the ModelName set to Customer. The broken stuff is an empty string
Is there something I'm missing? Has anyone encountered something like this before?
I found the issue. In the ViewModel the property that held the instance of RemedialItem to display was called RemedialItem. In the action it posted to, the parameter that took the RemedialItem instance was called item, and that broke everything.
In short, when using ViewModels, make sure the parameter name that takes an object from the ViewModel is the same as the property name in the viewmodel.
There went my day.
Using EditorFor( model lambda, "viewTemplateName"), my output is completely not as expected. This doesn't produce any errors, but it is rendering output without markup. What am I doing wrong?
The Output:
HarryTomRichard
The Expected Output (I need to figure out how to render the List [] indexes on id too but not to that problem yet):
<table>
<tr><td><span><input type="Text" id="Name[0]" value="Harry" /></span></td></tr>
<tr><td><span><input type="Text" id="Name[1]" value="Tom" /></span></td></tr>
<tr><td><span><input type="Text" id="Name[2]" value="Richard" /></span></td></tr>
</table>
My Classes:
namespace Marcs.Models {
public class Student { public string Name { get; set; } }
public class Classroom { public List<Student> Students { get; set; }
}
My Controller:
public ActionResult Index() {
var myStudents = new List<Student>();
myStudents.Add(new Student { Name = "Harry" });
myStudents.Add(new Student { Name = "Tom" });
myStudents.Add(new Student { Name = "Richard" });
var myClass = new Classroom {Students = myStudents};
return View(myClass);
}
My Index View:
Inherits="System.Web.Mvc.ViewPage<Marcs.Models.Classroom>" %>
<% using (Html.BeginForm()) { %>
<%= Html.EditorFor(m => m.Students, "Classroom") %>
<input type="submit" value="Save" />
<% } %>
My Classroom Template (notice the m => item so I can use the item, not the model):
Inherits="System.Web.Mvc.ViewUserControl<List<Marcs.Models.Student>>" %>
<table>
<% foreach (Marcs.Models.Student item in Model)
{ %><tr><td><%= Html.EditorFor(m => item, "Student")%></td></tr><%
} %>
</table>
My Student Template:
Inherits="System.Web.Mvc.ViewUserControl<Marcs.Models.Student>"
%><span><%= Html.Encode( Html.EditorFor( m => m.Name)) %></span>
jfar has the answer, and I will mark it appropriately when added. The solution was simply to ensure the files were located in Views->ControllerName->EditorTemplates and Views->ControllerName->DisplayTemplates. These can also be located in the Shared folder too.
I like this post. Now I need to learn how to use the MVC 2 template Html helpers that reference collections. It's in MVC 2 RC.
I have such a problem. I change my models fields in controller but doesn't see the changes.
Here are the parts of code :
this is view
Index.aspx
<%Html.BeginForm("Index", "First");%>
<p>
<%=Html.TextBox("Title") %>
</p>
<p>
<%=Html.TextBox("Price") %>
</p>
<input type="submit" value="Submit" />
<%Html.EndForm();%>
this is controller:
FirstController.cs
public class FirstController : Controller
{
[AcceptVerbs(HttpVerbs.Get)]
public ViewResult Index()
{
return View(new MyModel());
}
[AcceptVerbs(HttpVerbs.Post)]
public ViewResult Index(MyModel k)
{
k.Title = "Title";
return View(k);
}
and this is model:
MyModel.cs
public class MyModel
{
public String Title { get; set; }
public Decimal Price { get; set; }
}
when I change "Title" text box in controller I don't see changes in view
public ViewResult Index(MyModel k)
{
k.Title = "Title";
return View(k);
}
text box keep its value before submit.
Is there any mistake in my code.
This problem doesn't appear when I use html standart input tag instead of Html.TextBox:
input type="text" id="Title" name="Title" value="<%=Model.Title %>
Thank you in advance.
public ViewResult Index(MyModel k)
{
ModelState.Clear();
k.Title = "Title";
return View(k);
}
Have you tried to add ModelState.Clear() as in the above sample?
Hope this helps!
I have such a problem, but I think that we both don't understand MVC application lifecycle.
Let wait other answers
you should do it like this:
<%Html.BeginForm("Index", "First");%>
<p>
<%=Html.TextBox("Title",Model.Title) %>
</p>
<p>
<%=Html.TextBox("Price",Model.Price) %>
</p>
<input type="submit" value="Submit" />
<%Html.EndForm();%>
The Html.TextBox() have a overwrite version take object value arg to populate the text value!
Suppose I have ViewModel like
public class AnotherViewModel
{
public string Name { get; set; }
}
public class MyViewModel
{
public string Name { get; set; }
public AnotherViewModel Child { get; set; }
public AnotherViewModel Child2 { get; set; }
}
In the view I can render a partial with
<% Html.RenderPartial("AnotherViewModelControl", Model.Child) %>
In the partial I'll do
<%= Html.TextBox("Name", Model.Name) %>
or
<%= Html.TextBoxFor(x => x.Name) %>
However, the problem is that both will render name="Name" while I need to have name="Child.Name" in order for model binder to work properly. Or, name="Child2.Name" when I render the second property using the same partial view.
How do I make my partial view automatically recognize the required prefix? I can pass it as a parameter but this is too inconvenient. This is even worse when I want for example to render it recursively. Is there a way to render partial views with a prefix, or, even better, with automatic reconition of the calling lambda expression so that
<% Html.RenderPartial("AnotherViewModelControl", Model.Child) %>
will automatically add correct "Child." prefix to the generated name/id strings?
I can accept any solution, including 3-rd party view engines and libraries - I actually use Spark View Engine (I "solve" the problem using its macros) and MvcContrib, but did not find a solution there. XForms, InputBuilder, MVC v2 - any tool/insight that provide this functionality will be great.
Currently I think about coding this myself but it seems like a waste of time, I can't believe this trivial stuff is not implemented already.
A lot of manual solutions may exists, and all of them are welcome. For example, I can force my partials to be based off IPartialViewModel<T> { public string Prefix; T Model; }. But I'd rather prefer some existing/approved solution.
UPDATE: there's a similar question with no answer here.
You can extend Html helper class by this :
using System.Web.Mvc.Html
public static MvcHtmlString PartialFor<TModel, TProperty>(this HtmlHelper<TModel> helper, System.Linq.Expressions.Expression<Func<TModel, TProperty>> expression, string partialViewName)
{
string name = ExpressionHelper.GetExpressionText(expression);
object model = ModelMetadata.FromLambdaExpression(expression, helper.ViewData).Model;
var viewData = new ViewDataDictionary(helper.ViewData)
{
TemplateInfo = new System.Web.Mvc.TemplateInfo
{
HtmlFieldPrefix = name
}
};
return helper.Partial(partialViewName, model, viewData);
}
and simply use it in your views like this :
<%= Html.PartialFor(model => model.Child, "_AnotherViewModelControl") %>
and you will see everything is ok!
so far, i was searching for the same thing I have found this recent post:
http://davybrion.com/blog/2011/01/prefixing-input-elements-of-partial-views-with-asp-net-mvc/
<% Html.RenderPartial("AnotherViewModelControl", Model.Child, new ViewDataDictionary
{
TemplateInfo = new System.Web.Mvc.TemplateInfo { HtmlFieldPrefix = "Child1" }
})
%>
My answer, based on the answer of Mahmoud Moravej including the comment of Ivan Zlatev.
public static MvcHtmlString PartialFor<TModel, TProperty>(this HtmlHelper<TModel> helper, System.Linq.Expressions.Expression<Func<TModel, TProperty>> expression, string partialViewName)
{
string name = ExpressionHelper.GetExpressionText(expression);
object model = ModelMetadata.FromLambdaExpression(expression, helper.ViewData).Model;
StringBuilder htmlFieldPrefix = new StringBuilder();
if (helper.ViewData.TemplateInfo.HtmlFieldPrefix != "")
{
htmlFieldPrefix.Append(helper.ViewData.TemplateInfo.HtmlFieldPrefix);
htmlFieldPrefix.Append(name == "" ? "" : "." + name);
}
else
htmlFieldPrefix.Append(name);
var viewData = new ViewDataDictionary(helper.ViewData)
{
TemplateInfo = new System.Web.Mvc.TemplateInfo
{
HtmlFieldPrefix = htmlFieldPrefix.ToString()
}
};
return helper.Partial(partialViewName, model, viewData);
}
Edit:
The Mohamoud's answer is incorrect for nested partial rendering. You need to append the new prefix to the old prefix, only if it is necessary. This was not clear in the latest answers (:
Using MVC2 you can achieve this.
Here is the strongly typed view:
<%# Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<MvcLearner.Models.Person>" %>
<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
Create
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
<h2>Create</h2>
<% using (Html.BeginForm()) { %>
<%= Html.LabelFor(person => person.Name) %><br />
<%= Html.EditorFor(person => person.Name) %><br />
<%= Html.LabelFor(person => person.Age) %><br />
<%= Html.EditorFor(person => person.Age) %><br />
<% foreach (String FavoriteFoods in Model.FavoriteFoods) { %>
<%= Html.LabelFor(food => FavoriteFoods) %><br />
<%= Html.EditorFor(food => FavoriteFoods)%><br />
<% } %>
<%= Html.EditorFor(person => person.Birthday, "TwoPart") %>
<input type="submit" value="Submit" />
<% } %>
</asp:Content>
Here is the strongly typed view for the child class (which must be stored in a subfolder of the view directory called EditorTemplates):
<%# Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<MvcLearner.Models.TwoPart>" %>
<%= Html.LabelFor(birthday => birthday.Day) %><br />
<%= Html.EditorFor(birthday => birthday.Day) %><br />
<%= Html.LabelFor(birthday => birthday.Month) %><br />
<%= Html.EditorFor(birthday => birthday.Month) %><br />
Here is the controller:
public class PersonController : Controller
{
//
// GET: /Person/
[AcceptVerbs(HttpVerbs.Get)]
public ActionResult Index()
{
return View();
}
[AcceptVerbs(HttpVerbs.Get)]
public ActionResult Create()
{
Person person = new Person();
person.FavoriteFoods.Add("Sushi");
return View(person);
}
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Create(Person person)
{
return View(person);
}
}
Here are the custom classes:
public class Person
{
public String Name { get; set; }
public Int32 Age { get; set; }
public List<String> FavoriteFoods { get; set; }
public TwoPart Birthday { get; set; }
public Person()
{
this.FavoriteFoods = new List<String>();
this.Birthday = new TwoPart();
}
}
public class TwoPart
{
public Int32 Day { get; set; }
public Int32 Month { get; set; }
}
And the output source:
<form action="/Person/Create" method="post"><label for="Name">Name</label><br />
<input class="text-box single-line" id="Name" name="Name" type="text" value="" /><br />
<label for="Age">Age</label><br />
<input class="text-box single-line" id="Age" name="Age" type="text" value="0" /><br />
<label for="FavoriteFoods">FavoriteFoods</label><br />
<input class="text-box single-line" id="FavoriteFoods" name="FavoriteFoods" type="text" value="Sushi" /><br />
<label for="Birthday_Day">Day</label><br />
<input class="text-box single-line" id="Birthday_Day" name="Birthday.Day" type="text" value="0" /><br />
<label for="Birthday_Month">Month</label><br />
<input class="text-box single-line" id="Birthday_Month" name="Birthday.Month" type="text" value="0" /><br />
<input type="submit" value="Submit" />
</form>
Now this is complete. Set a breakpoint in the Create Post controller action to verify. Don't use this with lists however because it wont work. See my question on using EditorTemplates with IEnumerable for more on that.
This is an old question, but for anyone arriving here looking for a solution, consider using EditorFor, as suggested in a comment in https://stackoverflow.com/a/29809907/456456. To move from a partial view to an editor template, follow these steps.
Verify that your partial view is bound to ComplexType.
Move your partial view to a subfolder EditorTemplates of the current view folder, or to the folder Shared. Now, it is an editor template.
Change #Html.Partial("_PartialViewName", Model.ComplexType) to #Html.EditorFor(m => m.ComplexType, "_EditorTemplateName"). The editor template is optional if it's the only template for the complex type.
Html Input elements will automatically be named ComplexType.Fieldname.
PartailFor for asp.net Core 2 in case someone needs it.
public static ModelExplorer GetModelExplorer<TModel, TResult>(this IHtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TResult>> expression)
{
if (expression == null)
throw new ArgumentNullException(nameof(expression));
return ExpressionMetadataProvider.FromLambdaExpression(expression, htmlHelper.ViewData, htmlHelper.MetadataProvider);
}
public static IHtmlContent PartialFor<TModel, TResult>(this IHtmlHelper<TModel> helper, Expression<Func<TModel, TResult>> expression, string partialViewName, string prefix = "")
{
var modelExplorer = helper.GetModelExplorer(expression);
var viewData = new ViewDataDictionary(helper.ViewData);
viewData.TemplateInfo.HtmlFieldPrefix += prefix;
return helper.Partial(partialViewName, modelExplorer.Model, viewData);
}
As stated here: https://stackoverflow.com/a/58943378/3901618 - for ASP.NET Core - you can use the partial tag helper.
<partial name="AnotherViewModelControl" for="Child" />
<partial name="AnotherViewModelControl" for="Child2" />
It generates all required name prefixes.
I came across this issue also and after much pain i found it was easier to redesign my interfaces such that i didn't need to post back nested model objects. This forced me to change my interface workflows: sure i now require the user to do in two steps what i dreamed of doing on one, but the usability and code maintainability of the new approach is of greater value to me now.
Hope this helps some.
You could add a helper for the RenderPartial which takes the prefix and pops it in the ViewData.
public static void RenderPartial(this HtmlHelper helper,string partialViewName, object model, string prefix)
{
helper.ViewData["__prefix"] = prefix;
helper.RenderPartial(partialViewName, model);
}
Then a further helper which concatenates the ViewData value
public static void GetName(this HtmlHelper helper, string name)
{
return string.Concat(helper.ViewData["__prefix"], name);
}
and so in the view ...
<% Html.RenderPartial("AnotherViewModelControl", Model.Child, "Child.") %>
in the partial ...
<%= Html.TextBox(Html.GetName("Name"), Model.Name) %>
Like you, I add Prefix property (a string) to my ViewModels which I append before my model bound input names. (YAGNI preventing the below)
A more elegant solution might be a base view model that has this property and some HtmlHelpers that check if the view model derives from this base and if so append the prefix to the input name.
Hope that helps,
Dan
How about just before you call RenderPartial you do
<% ViewData["Prefix"] = "Child."; %>
<% Html.RenderPartial("AnotherViewModelControl", Model.Child) %>
Then in your partial you have
<%= Html.TextBox(ViewData["Prefix"] + "Name", Model.Name) %>