CODEWITHSUNDEEP
.net-coreasp.net-core-mvcmodel-bindingasp.net-core-webapi
error_handler
error_handler

Reputation: 1201

Issue while passing null values to nullable properties in web api call in .netcore web api project

I am facing issue while passing null parameter values to properties of my model in HttpGet verb.

I am using .Net Core 2.1 for my web API project. Below is my action method in controller:

    [HttpGet("get")]
    public ActionResult GetData([FromQuery]MyTestModel model)
    {
        var result = new MyTestModel();
        return new JsonResult(result);
    }

And my MyTestModel.cs is like :

 [Serializable]
public class MyTestModel
{
    public MyTestModel()
    {
        PageNo = 1;
        PageSize = 10;
    }
    public int ClientId { get; set; }
    public int? CandidateId { get; set; }
    public DateTime? FromDate { get; set; }
    public DateTime? ToDate { get; set; }
    public int PageNo { get; set; }
    public int PageSize { get; set; }
}

When I call the API like :

api/controller/get?clientId=7583&candidateId=null&fromDate=null&toDate=null

I am getting 400 response. Below is the response message:

{"toDate":["The value 'null' is not valid for ToDate."],
 "fromDate":["The value 'null' is not valid for FromDate."],
 "candidateId":["The value 'null' is not valid for CandidateId."]
}

When I don't send nullable properties at all(candidateId, fromDate,toDate), this hits my action and uses default values as null.

What's the problem if I am trying to explicitly setting null values?

Do I need to set some configuration in my Startup.cs to handle null values for nullable properties?

Any help will be appreciated .

Thanks in advance.

Upvotes: 2

Views: 4286

Answers (1)

Chris Pratt
Chris Pratt

Reputation: 239290

Everything sent in the query string is just a string. So, when you do something like toDate=null, you're actually saying "set toDate to "null"", i.e. the string "null". The modelbinder attempts to convert all the strings to the actual types you're binding to, but there's no conversion available that can turn "null" into a null DateTime.

To set the value to null, you need to either pass no value toDate= or just omit the key entirely from the query string.

Upvotes: 7

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