Conditional Property Serialization Property To JSON - VB.net

Conditional Property Serialization

Json.NET has the ability to conditionally serialize properties by placing a ShouldSerialize method on a class. This functionality is similar to the 
XmlSerializer ShouldSerialize feature.

ShouldSerialize
To conditionally serialize a property, add a method that returns boolean with the same name as the property and then prefix the method name
with ShouldSerialize. The result of the method determines whether the property is serialized. If the method returns true then the property will be 
serialized, if it returns false then the property will be skipped.

Live Code
We need to exclude hsn and Doc_issue when they are nothing in runtime (Same is done Nothing when not to be Serialized)

Public Structure Json_Parent
        Public Property gstin As String
        Public Property fp As String
        Public Property version As String
        Public Property hash As String
        Public Property b2b As List(Of b2b)
        Public Property hsn As hsn
        Public Property doc_issue As doc_issue
        Public Property exp As List(Of exp)

' Make sure this is Function and WORD  [ShouldSerialize] Followed by Name of Property which is to be Excluded from serialization

        Public Function ShouldSerializehsn() As Boolean
            If IsNothing(hsn.data) = True Then
                Return False
            Else
                Return True
            End If
        End Function

        Public Function ShouldSerializedoc_issue() As Boolean
            If IsNothing(doc_issue.doc_det) = True Then
                Return False
            Else
                Return True
            End If
        End Function
    End Structure

While using the 
ParentJson.gstin = CompanyGSTinNo
ParentJson.fp = Format(FromDate, "MMyyyy")
ParentJson.version = "GST2.4"
ParentJson.hash = "hash" 
ParentJson.hsn = Nothing
ParentJson.doc_issue = Nothing




Employee class with a ShouldSerialize method

Copy
public class Employee
{
    public string Name { get; set; }
    public Employee Manager { get; set; }
    public bool ShouldSerializeManager()
    {
        // don't serialize the Manager property if an employee is their own manager
        return (Manager != this);
    }
}

ShouldSerialize output
Copy

Employee joe = new Employee();
joe.Name = "Joe Employee";

Employee mike = new Employee();
mike.Name = "Mike Manager";
joe.Manager = mike; // mike is his own manager

// ShouldSerialize will skip this property
mike.Manager = mike;

string json = JsonConvert.SerializeObject(new[] { joe, mike }, Formatting.Indented);
// [
//   {
//     "Name": "Joe Employee",
//     "Manager": {
//       "Name": "Mike Manager"
//     }
//   },
//   {
//     "Name": "Mike Manager"
//   }
// ]