c# mvc model binding nested lists

Question

I got a problem with my model binding. Got here following models:

public class RoomScan
{
    public RoomScan() { }

    public RoomScan(Guid id)
    {
        Room_ID = id;
        Assets = new List<AssetScanModel>();
    }
    //public Guid Soll_ID { get; set; }
    public Guid Room_ID { get; set; }
    public List<AssetScanModel> Assets { get; set; }

    [Display(Name = "Barcode", ResourceType = typeof(Dictionary))]
    public string Barcode { get; set; }

    [Display(Name = "RFID", ResourceType = typeof(Dictionary))]
    public string RFID { get; set; }
}

public class AssetScanModel
{
    public AssetScanModel(Asset asset)
    {
        Asset = asset;
        Scanned = false;
        CheckIn = false;
    }

    public Asset Asset { get; set; }

    [Display(Name = "Scanned", ResourceType = typeof(Dictionary))]
    public bool Scanned { get; set; }

    [Display(Name = "CheckIn", ResourceType = typeof(Dictionary))]
    public bool CheckIn { get; set; }
}

The View does list all the Assets:

using (Html.BeginForm("Scan", "Inventory", FormMethod.Post))
{
Html.HiddenFor(rs => rs.Room_ID);
Html.HiddenFor(rs => rs.Assets);

<div>
    <div class="editor-label">Barcode</div>
    <div class="editor-field"><input type="text" name="Barcode" value="@Model.Barcode" /></div>
</div>
<div>
    <div class="editor-label">RFID</div>
    <div class="editor-field"><input type="text" name="Barcode" value="@Model.RFID" /></div>
</div><br />

...

@for (int i = 0; i < Model.Assets.Count; i++)
{
    <tr>
        <td>@Html.DisplayFor(asm => asm.Assets[i].Asset.InventoryNumber)</td>
        <td>@Html.DisplayFor(asm => asm.Assets[i].Asset.Description)</td>
        <td>@Html.DisplayFor(asm => asm.Assets[i].Asset.Manufacturer)</td>
        <td>@Html.DisplayFor(asm => asm.Assets[i].Asset.Model)</td>
        <td>@Html.DisplayFor(asm => asm.Assets[i].Asset.SerialNumber)</td>
        <td>@Html.DisplayFor(asm => asm.Assets[i].Scanned)</td>
        <td>@Html.DisplayFor(asm => asm.Assets[i].CheckIn)</td>
    </tr>
}

I added the "Asset[i]" because I read somewhere it helps the default model binder to bind propperly (didn#t work)

My problem is: in my controller:

[HttpPost]
    public ActionResult Scan(RoomScan toVerify)

the List is empty (not null). I know this has to do with the model binder, but I am not familiar how to change it so it does work.

first change the DisplayFor to EditorFor ... then look at the generated html. Next make sure the input names look like toVerify.Assests[0].Assest.Inventory etc. — David Perlman
– David Perlman, Commented Feb 12, 2013 at 10:15
You should be using public ActionResult Scan(IEnumerable<RoomScan> toVerify){}. Please check this — Karthik Chintala
– Karthik Chintala, Commented Feb 12, 2013 at 10:46
@DavidPerlman I am just displaying the List, there should be no edit fields. the whole list is part of a form, in wich you can send a RFID or Barcode to the controller. Wich checks a scanned asset and sets "scanned" = true Also, the RoomScan Model is no List, it just contains one. — TheSamsa
– TheSamsa, Commented Feb 12, 2013 at 11:26

M.Ob · Accepted Answer · 2013-02-12 11:40:09Z

1

I have been using this for binding complex models with nested lists. I almost always replace the default model binder with this right off the bat...

A DefaultModelBinder that can update complex model graphs

I hope this helps you as much as it did me.

answered Feb 12, 2013 at 11:40

M.Ob

1,87717 silver badges29 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

TheSamsa Over a year ago

Looks like the right direction. I implemented it, but in the controller the AssetScanModel List is null.. I checked the new modelBinder, and he does not even get a AssetScanModel List from the view. Thats wierd, I think there is a big blunder i coded in

TheSamsa Over a year ago

found some mistakes on my side in the view (it seems html helper tend to be ignored if they are not wrapped around a html tag (div, etc)

M.Ob Over a year ago

Ah, yes. That'll get ya. Glad you were able to get it figured out.

Evgeny Popov · Accepted Answer · 2013-02-12 11:50:30Z

0

Try DisplayTemplates/EditorTemplates, create template for ur nested model type. In View write:

@Html.DisplayFor(asm => asm.Assets)

in DisplayTemplate (AssetScanModel.cshtml):

@model AssetScanModel

<tr>
    <td>@Html.DisplayFor(asm => asm.Asset.InventoryNumber)</td>
    <td>@Html.DisplayFor(asm => asm.Asset.Description)</td>
    <td>@Html.DisplayFor(asm => asm.Asset.Manufacturer)</td>
    <td>@Html.DisplayFor(asm => asm.Asset.Model)</td>
    <td>@Html.DisplayFor(asm => asm.Asset.SerialNumber)</td>
    <td>@Html.DisplayFor(asm => asm.Scanned)</td>
    <td>@Html.DisplayFor(asm => asm.CheckIn)</td>
</tr>

edited Feb 12, 2013 at 11:50

answered Feb 12, 2013 at 11:40

Evgeny Popov

831 silver badge8 bronze badges

Collectives™ on Stack Overflow

c# mvc model binding nested lists

2 Answers 2

3 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related