Passing multiple checkbox values to deeper level of model .net mvc

Question

A few similar questions have been asked before but my use case is a bit different.

So this is my model:

  public class YourModel
  {
        public string[] Suburb { get; set; }
  }

And my view:

    <input name="Suburb" type="checkbox" value="sydney" /><span>sydney</span>
    <input name="Suburb" type="checkbox" value="melbourne" /><span>melbourne</span>

Controller:

 public ActionResult AdvancedSearch(YourModel s)
 {
      // logic
 }

So MVC is smart enough to retrieve the multiple checkbox values to put them in the Suburb array in YourModel model. I can inspect all values there. But my use case is that the YourModel is just the nested model inside another model MyModel:

  public class MyModel
  {
        //other properties
        public YourModel m { get; set; }
  }

So now how do I make MVC post the checkbox values to a deeper model MyModel.YourModel? I have tried @Html.CheckBoxFor and @Html.CheckBox but neither of them worked.

Right now my work around is to add a temporary array placeholder in the outside model and then assign all the data to the inside model when available, but that is definitely not ideal.

What your should be doing in that case is to use a view model(s) which will include a `bool IsSelected` property to bind to - refer [this answer](https://stackoverflow.com/questions/29542107/pass-list-of-checkboxes-into-view-and-pull-out-ienumerable/29554416#29554416) for an example — , Jan 31 '18 at 11:35
Even if you used `name="m.Suburb"` to bind in the POST method, you would lose all model binding in the view if you need to return the view because `ModelState` is invalid, or if you need to edit existing data (previous selections will be lost and you will not get any client side validation) — , Jan 31 '18 at 11:38

programtreasures · Answer 1 · 2018-01-31T11:54:31.360

3

You need to use add MyModel

<input name="m.Suburb" type="checkbox" value="sydney" /><span>sydney</span>
<input name="m.Suburb" type="checkbox" value="melbourne" /><span>melbourne</span>

edited Jan 31 '18 at 11:54

answered Jan 31 '18 at 11:32

programtreasures

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I think you mean `name="m.Suburb"` based on OP's code – Jan 31 '18 at 11:36
I tried that. But I used MyModel.m.Surburd (because MyModel does not have the Suburb property) and I get a System.NullReferenceException: which is expected, because when you get Suburb it is null. Do I miss something here? – Frostless Jan 31 '18 at 11:38
@Frostless It should be `name="m.Suburb"` as Stephen mentions. Your model doesn't contain a property named `MyModel` – Camilo Terevinto Jan 31 '18 at 11:40
@Camilo Terevinto that worked, you just saved my day. Actually what I used before was `@Model.m.Suburb` and it gave me the `NullReferenceException` error. A bit surprise that `name="m.Suburb" ` does not give me that. – Frostless Jan 31 '18 at 11:49
Not sure why people upvote this incorrect answer. Upvoters: try yourself, this answer is wrong. – Camilo Terevinto Jan 31 '18 at 11:53
@CamiloTerevinto, Your answer is exactly the same (and they are both awful solutions) – Jan 31 '18 at 11:56
@StephenMuecke Now, after over 20 minutes it was edited into a correct answer, it wasn't the same when I posted mine. Not sure why it would be awful, though – Camilo Terevinto Jan 31 '18 at 11:57
@CamiloTerevinto, Read my comments in the question – Jan 31 '18 at 11:58

score 0 · Accepted Answer · answered Jan 31 '18 at 11:51

In Razor, you don't have to define the name of the top-most Model, only the names of the properties of inner models:

<input name="m.Suburb" type="checkbox" value="sydney" /><span>sydney</span>
<input name="m.Suburb" type="checkbox" value="melbourne" /><span>melbourne</span>

However, I'd strongly suggest you to change that m name to something more significant.

Passing multiple checkbox values to deeper level of model .net mvc

2 Answers2