Dynamic JSON Deserialization with VB.NET [duplicate] - json

Question

This question already has answers here:
Deserializing JSON when sometimes array and sometimes object
(7 answers)
Closed 2 years ago.
I get an API response in JSON in following format
{
"stuffs": {
"prop1": "abcd",
"prop2": "efgh",
"prop3": [
{
"content": "123456",
"name": "abc def",
"id": "123"
},
{
"content": "789012",
"name": "def ghi",
"id": "456"
}
]
}
}
I have created my Class to deserialize this object as below
Public Class Prop3
Public Property content As String
Public Property name As String
Public Property id As String
End Class
Public Class Stuffs
Public Property prop1 As String
Public Property prop2 As String
Public Property prop3 As Prop3()
End Class
Public Class Example
Public Property stuffs As Stuffs
End Class
Now the issue is, sometime, the response is not an array for prop3 and looks like this
{
"stuffs": {
"prop1": "abcd",
"prop2": "efgh",
"prop3": {
"content": "123456",
"name": "abc def",
"id": "123"
}
}
}
This time I get error while deserializing as the prop3 is not array anymore bu the property declared inside my class stuffs is expecting an array of property prop3.
Is there any dynamic way to resolve this? Like if the JSON response is an array it will be treated as array
Public Property prop3 As Prop3()
and in case it is not an array then it will treated as single property
Public Property prop3 As Prop3
Please suggest how to overcome this as changing the response from the API is not feasible because it is being developed by client and I need to use it my application, so I need to find some dynamic way to resolve this.
After suggestion made by Craig, I have tried in the below way, but still it is not happening, please suggest if I am making any mistake.
Public Class SingleValueArrayConverter(Of T)
Inherits JsonConverter
Public Overrides Sub WriteJson(ByVal writer As JsonWriter, ByVal value As Object, ByVal serializer As JsonSerializer)
serializer.Serialize(writer, value)
End Sub
Public Overrides Function ReadJson(ByVal reader As JsonReader, ByVal objectType As Type, ByVal existingValue As Object, ByVal serializer As JsonSerializer) As Object
Dim retVal As Object = New Object()
If reader.TokenType = JsonToken.StartObject Then
Dim instance As T = CType(serializer.Deserialize(reader, GetType(T)), T)
retVal = New List(Of T)() From {
instance
}
ElseIf reader.TokenType = JsonToken.StartArray Then
retVal = serializer.Deserialize(reader, objectType)
End If
Return retVal
End Function
Public Overrides Function CanConvert(ByVal objectType As Type) As Boolean
Return True
End Function
End Class
Public Class myClass1
Public Class Prop3
Public Property content As String
Public Property name As String
Public Property id As String
End Class
Public Class Stuffs
Public Property prop1 As String
Public Property prop2 As String
<JsonProperty("prop3")>
<JsonConverter(GetType(SingleValueArrayConverter(Of Prop3)))>
Public Property prop3 As Prop3()
End Class
Public Class Example
Public Property stuffs As Stuffs
End Class
End Class
It gives error:
Unable to cast object of type 'SingleValueArrayConverter`1[myClass1.myClass+Prop3]' to type 'Newtonsoft.Json.JsonConverter'.'
Any highlight on what I am missing please.

Answer 1

It worked after changing
Public Property prop3 As Prop3()
to
Public Property prop3 As List(Of Prop3)