asp.net-mvcasp.net-mvc-3model-bindingdefaultmodelbinder

bind attribute include and exclude property with complex type nested objects


Ok, this is weird. I cannot use BindAttribute's Include and Exclude properties with complex type nested objects on ASP.NET MVC.

Here is what I did:

Model:

public class FooViewModel {

    public Enquiry Enquiry { get; set; }
}

public class Enquiry {

    public int EnquiryId { get; set; }
    public string Latitude { get; set; }
}

HTTP POST action:

[ActionName("Foo"), HttpPost]
public ActionResult Foo_post(
    [Bind(Include = "Enquiry.EnquiryId")]
    FooViewModel foo) {

    return View(foo);
}

View:

@using (Html.BeginForm()) {

    @Html.TextBoxFor(m => m.Enquiry.EnquiryId)
    @Html.TextBoxFor(m => m.Enquiry.Latitude)

    <input type="submit" value="push" />
}

Does not work at all. Can I only make this work if I define the BindAttribute for Enquiry class as it is stated here:

How do I use the [Bind(Include="")] attribute on complex nested objects?


Solution

  • Yes, you can make it work like that:

    [Bind(Include = "EnquiryId")]
    public class Enquiry 
    {
        public int EnquiryId { get; set; }
        public string Latitude { get; set; }
    }
    

    and your action:

    [ActionName("Foo"), HttpPost]
    public ActionResult Foo_post(FooViewModel foo) 
    {
        return View(foo);
    }
    

    This will include only the EnquiryId in the binding and leave the Latitude null.

    This being said, using the Bind attribute is not something that I would recommend you. My recommendation is to use view models. Inside those view models you include only the properties that make sense for this particular view.

    So simply readapt your view models:

    public class FooViewModel 
    {
        public EnquiryViewModel Enquiry { get; set; }
    }
    
    public class EnquiryViewModel 
    {
        public int EnquiryId { get; set; }
    }
    

    There you go. No longer need to worry about binding.