{Required] Attribute is not working on Lists ASP.NET WebAPI

Question

Here's my model

 public class TaskForUpdateDTO
{
    [Required]
    public int Id { get; set; }
    [Required]
    public string Name { get; set; }
    [Required]
    public string Name { get; set; }
}

and my controller

    [HttpPut]
    public ActionResult<List<TaskDTO>> Put([FromBody] List<TaskForUpdateDTO> tasks )
    {
        List<TaskBO> tasksForUpdate = TaskForUpdateDTO.MapToBOList(tasks);
        tasksForUpdate = _serviceManager.TaskService.Update(tasksForUpdate);

        if (tasksForUpdate is null) return NotFound();

        return Ok(TaskDTO.MapToDTOList(tasksForUpdate));
    }

and body of my request

    [{
    "Name":"Do Laundry",
    "UserId":1
     },
     {
    "Name":"Wash Dishes",
    "UserId":1
    }]

when sending a PUT request, I'm not getting a 400 error , which I should because I'm not sending the Id of the item.

how can I fix this?

Answer 1

The Required Attribute only check for null. The Default value of an int is simply "0"(zero). So, it is not null when Required attribute check it.

If you Prefer to use the Required attribute then replace your int to int? (Nullable int. The Default Value of Nullable int is null And can double-Check with it's static .HasValue() method)

Or if you need to check that not pass the value when value is Zero or Less then you can use Range Attribute

Usage of Range Attribute :

[Range(1, Int32.MaxValue)]
public int Id {get;set;}

Simply you can change the Int32.MaxValue to your Maximum acceptable integer of your needs.

Hope this helps.