In EF/MVC, is it possible to edit virtual property?

Question

So I have the following 2 model:

[Table("Company")]
public class Company {
    public virtual List<UserAccount> Users {
        get {
            // I load my users here
        }
    }
}
[Table("UserAccount")]
public class UserAccount {
    public string email { get; set; }
}

In my view, I try to edit it:

@model MyXsite2013.Company
<table>
foreach (UserAccount ua in Model.Users) {
    <tr class="noRowHover">
        <td>
            @Html.TextBoxFor(modelItem => ua.email)
        </td>
    </tr>
}
</table>

And on postback, I try to save:

public ActionResult Edit(Company companyModel) {
    Company companyContext = database.Companies.Find(companyModel.ID);
    database.Entry(companyContext).CurrentValues.SetValues(companyModel);
    companyContext.IsActive = true;
    database.SaveChanges();
}

This of course, does not save the changes to the Users, in fact, it's not even seeing the changes coming in.

According to my understanding of your question. We cannot use in this passion because virtual keyword is used for foreign key purpose. if we use virtual keyword it means that collection will be lazy load. please correct me if I am wronge. — rishikesh tadaka, May 08 '13 at 15:17
PLease read [this](http://stackoverflow.com/questions/4949991/binding-collections-in-mvc) and [this](http://stackoverflow.com/questions/6852559/mvc3-modelbinding-to-a-collection-posted-back-with-index-gaps). After successful bind in the post action you read Company then update it's properties and collection (merge\removeAll+add). — lavrik, May 08 '13 at 15:20
You should wrap your form in `@using (Html.BeginForm()) { }`. — Henk Mollema, May 08 '13 at 19:32

Kirill Bestemyanov · Accepted Answer · 2013-05-08T18:14:07.233

1

Your problem is that you write your view in wrong way. If you want to bind model that contains list, you should set special names to them.

Something like:

@model MyXsite2013.Company
<table>
@{
   var i=0;
}
@foreach (UserAccount ua in Model.Users) {
    <tr class="noRowHover">
        <td>
            <input type="text" name="Model.Users[@i].email"/>
        </td>
    </tr>
    i++;
}
</table>

More information on this theme here

Update

You can use HtmlHelper methods:

@using(Html.BeginForm("Post", "Home", FormMethod.Post))
{
    int i = 0;
    foreach (var ua in Model.Users)
    {
        @Html.TextBox(string.Format("Model.Users[{0}].email", i), ua.email)
        i++;
    }
    <button type="submit">Submit</button>
}

And there should be public setter:

[Table("Company")]
public class Company {
    public virtual List<UserAccount> Users {
        get;
        set;
    }
}

edited May 08 '13 at 18:14

answered May 08 '13 at 15:19

Kirill Bestemyanov

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Can you clarify this section: , I do not believe it works. – Bill Software Engineer May 08 '13 at 15:57
of course it should be , – Kirill Bestemyanov May 08 '13 at 17:47
I add example of code that generate right markup with HtmlHelper methods. – Kirill Bestemyanov May 08 '13 at 18:14
Why do you use `Model.Users[@i].email` when you can use `ua.email`? This way you're using a foreach loop as for loop.. – Henk Mollema May 08 '13 at 19:44
If you want to bind it to list in model when submit, you should generate markup with names that contains indexes of current list item. So you should use variable that count list items. I recommend to read Hancelman's article by reference. – Kirill Bestemyanov May 08 '13 at 19:47
The foreach loop version can be done much shorter and allows the framework/HtmlHelpers to do their job better. Try: for (var i = 0; i < Model.Users.Count; i++) { @Html.TextBoxFor(x => x.Users[i].email) } – rossisdead May 08 '13 at 21:23

score 0 · Answer 2 · answered May 08 '13 at 15:25

Your Company model's Users property needs a public setter. Without it, the model binder will not be able to create a new List instance to populate.
You can't use a foreach loop in your view, because the html helpers won't render the correct tags needed for posting back properly. You need to use a regular for loop there instead.

score 0 · Answer 3 · answered May 08 '13 at 17:27

I followed the answer provided by Kirill Bestemyanov, but made some modifications:

[Table("Company")]
public class Company {
    public virtual List<UserAccount> Users {
        get;
        set;
    }
}

And the View:

@model MyXsite2013.Company
<table>
@{
   var i=0;
}
@foreach (UserAccount ua in Model.Users) {
    <tr class="noRowHover">
        <td>
            <input type="text" name="Users[@i].email" value="@ua.email"/>
        </td>
    </tr>
    i++;
}
</table>

And the postback:

foreach (UserAccount ua in companyModel.Users) {
    UserAccount UA_Context = database.UserAccounts.Find(ua.ID);
    database.Entry(UA_Context).CurrentValues.SetValues(ua);
}
database.SaveChanges();

In EF/MVC, is it possible to edit virtual property?

3 Answers3