Styjun

Using "disabled" attribute on inputs on form does not post them, which is expected and wanted. However, if you prepare a form of 3 objects in a list, disable the first and third, and submit, the 2nd object appears in post header, but does not bind to the list correctly, because it has an index [1] instead of [0].

I understand how model binding works and why it does not bind the posted object that I want, but I don't know how else to describe the problem to get specific results that would lead me to my solution. Anything I search for leads to basic post and binding examples.

List inside the model I'm using:

public IList<_Result> Results get; set; 

Class _Result has one of the properties:

public string Value get; set; 

I fill up the list and use it in view like so:

@for (int i = 0; i < Model.Results.Count; i++)

 ...
 <td>
 <input asp-for="Results[i].Value" disabled />
 </td>
 ...

I have checkboxes on form, which remove (with javascript) the "disabled" attribute from the inputs and thus allow them to be posted.

When I fill up the said list with 3 _Result objects, they are shown on form and all have the "disabled" attribute. If I remove the "disabled" attribute from the first two objects and click on submit button, I receive the Results list with first 2 _Result objects, which is as expected.

However, if I remove the "disabled" attribute only from the second _Result object (the first _Result object still has "disabled" attribute), the Results list comes back empty in my Controller method.
In my Form Data Header, I see this: "Results[1].Value: Value that I want posted", which means that post occurs, but list does not bind the object due to the index.

Any idea on how I can achieve that proper binding? Also, the reason I'm using "disabled" attribute is because I'm showing many results on a single page and want to only post those that are selected.

For getting selected items, you could try checkbox with View Model instead of using jquery to control the disable property.

1. 
   

   Change ViewModel

   
   
   

   public class ModelBindVM
   
    public IList<_ResultVM> Results get; set; 
   
   public class _ResultVM
   
    public bool IsSelected get; set; 
    public string Value get; set; 
   
   

   
   


2. 
   

   Controller

   
   
   

   [HttpGet]
   public IActionResult ModelBindTest()
   
    ModelBindVM model = new ModelBindVM
    
    Results = new List<_ResultVM>() 
    new _ResultVM Value = "T1" ,
    new _ResultVM Value = "T2" ,
    new _ResultVM Value = "T3" 
    
    ;
    return View(model);
   
   [HttpPost]
   public IActionResult ModelBindTest(ModelBindVM modelBind)
   
    return View();
   
   

   
   


3. 
   

   View

   
   
   

   <div class="row">
    <div class="col-md-4">
    <form asp-action="ModelBindTest">
    @for (int i = 0; i < Model.Results.Count; i++)
    
    <input type="checkbox" asp-for="Results[i].IsSelected" />
    <label asp-for="@Model.Results[i].IsSelected">@Model.Results[i].Value</label>
    <input type="hidden" asp-for="@Model.Results[i].Value" />
    
    <div asp-validation-summary="ModelOnly" class="text-danger"></div>
    <div class="form-group">
    <input type="submit" value="Save" class="btn btn-primary" />
    </div>
    </form>
    </div>
   </div>