Nullable in Model Binding - asp.net

Question

I am using ASP.NET Core with VS 2017. I want to allow the users to create an employee record where they can leave the address input field empty i.e. as optional field input.
Using [Bind("Name","Address")] always validates the inputs and the request will always fail when the address field is empty.
Here is the data model.
public class Employee
{
public int ID { get; set; }
public string Name { get; set; }
public string Address { get; set; }
}
and the Create method reading the parameters from Post request has a model binding as follows
public async Task<IActionResult> Create([Bind("Name,Address")] Employee emp)
and the view has a default asp form using Employee Model.
<div class="col-md-10">
<input asp-for="Address" class="form-control" />
<span asp-validation-for="Address" class="text-danger"></span>
</div>
Is there any way to make the address input field as an optional input for Model Binding?

Answer 1

I'm very new to Asp.net core, but from what I've learned so far, this is how I would do it:
<form method="post" asp-controller="YourController" asp-action="Create">
<div>
<input asp-for="Name" placeholder="Name"/>
<div class="stylized-error">
<span asp-validation-for="Name"></span>
</div>
<input asp-for="Address" placeholder="Address"/>
<div class="stylized-error">
<span asp-validation-for="Address"></span>
</div>
<input type="submit" value="Submit" />
<div class="error-list" asp-validation-summary="ModelOnly"></div>
</div>
</form>
You want Address to be optional which is by default true, so you actually want to make Name required:
public class Employee
{
public int ID { get; set; }
[Required]
public string Name { get; set; }
public string Address { get; set; }
}
And your controller:
public async Task<IActionResult> Create(Employee emp)
{
if (ModelState.IsValid)
{
// Do whatever you want here...
}
}
A property is considered optional if it is valid for it to contain
null. If null is not a valid value to be assigned to a property then
it is considered to be a required property.
Later
You can use Data Annotations to indicate that a property is required.
From docs.microsoft