How do you bind data in a complex model in a controller post action in asp.net core 3.1 (or above) MVC?

Question

How do you bind data in a complex model in a controller post action in asp.net core 3.1 (or above) MVC ?

This is just an example model, but the takeaways are no flattening and no seperate viewmodel.

Given an example model like this:

public class Business
{
   public int Id {get; set;}
   public string Name {get; set;}
   public string WebAddress {get; set;}
   public ContactDetails ContactInfo {get; set;}
   public Address AddressInfo {get; set;}
}

public class ContactDetails
{
   public string TelNo {get; set;}
   public string Mobile {get; set;}
}

public class Address 
{
   public string BuildingNo {get; set;}
   public string Street {get; set;}
   public string City {get; set;}
   public string Postcode {get; set;}
}

All the individual properties appear in the in the view.

How would you specifically bind this to the post method on a controller?

How do you bind the complex properties?

[HttpPost]
[ValidateAntiForgeryToken]
public IActionResult Create([Bind("Name,WebAddress")] DeliCakeBiz deliCakeBiz) <--- ???
{

}

Answer 1

If you want to bind properties like "Id" , "Name" , "WebAddress",you can use [Bind("Id ,Name , WebAddress")] diretly , But If you want to bind Some specific nested Model's properties, you can add [Bind("")] in the class.

For example , If I want to bind Name and Street properties , I can use this code:

controller

        [HttpPost]
        public async Task<ActionResult> ComplexModel([Bind("AddressInfo,Name")] Business bus)
        {
            //.......
            return View();        
        }

Address model

    [Bind("Street")]
    public class Address
    {
        public string BuildingNo { get; set; }
        public string Street { get; set; }
        public string City { get; set; }
        public string Postcode { get; set; }
    }

view

<form asp-action="ComplexModel">
    <div class="form-group">
        <label asp-for="Id"></label>
        <input type="text" asp-for="Id" />
    </div>
    <div class="form-group">
        <label asp-for="Name "></label>
        <input type="text" asp-for="Name " />
    </div>
    <div class="form-group">
        <label asp-for="WebAddress "></label>
        <input type="text" asp-for="WebAddress " />
    </div>
    <div class="form-group">
        <label asp-for="ContactInfo.TelNo"></label>
        <input type="text" asp-for="ContactInfo.TelNo" />
    </div>
    <div class="form-group">
        <label asp-for="ContactInfo.Mobile "></label>
        <input type="text" asp-for="ContactInfo.Mobile " />
    </div>
    <div class="form-group">
        <label asp-for="AddressInfo.BuildingNo"></label>
        <input type="text" asp-for="AddressInfo.BuildingNo" />
    </div>
    <div class="form-group">
        <label asp-for="AddressInfo.Street"></label>
        <input type="text" asp-for="AddressInfo.Street" />
    </div>
    <div class="form-group">
        <label asp-for="AddressInfo.City"></label>
        <input type="text" asp-for="AddressInfo.City " />
    </div>
    <div class="form-group">
        <label asp-for="AddressInfo.Postcode"></label>
        <input type="text" asp-for="AddressInfo.Postcode" />
    </div>
    <button type="submit">submit</button>
</form>

When I submit the form , I just bind Street and Name properties