>>The problem now is that I can not directly use setFormControls as the above because my form is much more complex and I don't even expose Ids for controls.
>
>Don't see how the jscript can modify items if it has not way of identifying them - but javascript is *not* my specialist subject.
>Why not give them Id's ?
>
Sorry for drifting the thread in different direction. The reason I can not easily give id is that EditorFor is not a regular editor for, it is

<div class="editor-label">
    @Html.Label((ViewData.ModelMetadata.DisplayName??ViewData.ModelMetadata.PropertyName),
        new Dictionary<string, object>
            {                
                { "for", ViewData.ModelMetadata.PropertyName }
            })
</div>

<div class="editor-field">
   @if (ViewData.ModelMetadata.ModelType.IsNumeric())
   {
    @Html.TextBox("", ViewData.TemplateInfo.FormattedModelValue, new { type = "number", @class = "numericOnly"  })      
   }
    else
    {
     @Html.TextBox("", (object)Model,
        new Dictionary<string, object>
            {
                { "id", ViewData.ModelMetadata.PropertyName },
                { "name", ViewData.ModelMetadata.PropertyName },
                { "class", "text-box single-line"},
                { "data-bind", "value: " + ViewData.ModelMetadata.PropertyName },
            })
    }
   
     @Html.ValidationMessage(ViewData.ModelMetadata.PropertyName,
        new Dictionary<string, object>
            {
                { "data-valmsg-for", ViewData.ModelMetadata.PropertyName }
            })
</div>

And also there are many elements in that view so mapping each manually with returned data is a bit complex. I wish there can be some simple way of automatically setting Model = returned JSON data so I don't have to manually use setFormsControls.