JSON class creation help in VB.NET [duplicate] - json

Question

I am very new to json, JSON.net and all that. After reading similiar questions here I cannot get my code working.
What exactly is my error? What have I overseen?
Is it possible to skip the classes "links" and "meta" for testing purposes or do I have to define EVERY property?
I have got the following REST output:
{
"codes" : [
{
"href" : "https://www.someserver.com/form_definitions/OIlG4GxMyeh0sdrt3AYuaXbauGicW71M/field_definitions/zFEova6LiPM/codes/4Sxnr961xzM",
"rel" : "document_field_definition_code",
"title" : "TITLE 1"
},
{
"href" : "https://www.someserver.com/form_definitions/OIlG4GxMyeh0sdrt3AYuaXbauGicW71M/field_definitions/zFEova6LiPM/codes/buho0CsLc5k",
"rel" : "document_field_definition_code",
"title" : "TITLE 2"
},
{
"href" : "https://www.someserver.com/form_definitions/OIlG4GxMyeh0sdrt3AYuaXbauGicW71M/field_definitions/zFEova6LiPM/codes/RvQoykUM_Sk",
"rel" : "document_field_definition_code",
"title" : "TITLE 3"
}
],
"links" : [
{
"about" : "https://www.someserver.com/form_definitions/OIlG4GxMyeh0sdrt3AYuaXbauGicW71M/field_definitions/zFEova6LiPM/codes?about=1",
"href" : "https://www.someserver.com/form_definitions/OIlG4GxMyeh0sdrt3AYuaXbauGicW71M/field_definitions/zFEova6LiPM/codes",
"method" : "GET",
"rel" : "self",
"title" : null,
"type" : "codes"
},
{
"href" : "https://www.someserver.com/form_definitions/OIlG4GxMyeh0sdrt3AYuaXbauGicW71M/field_definitions/zFEova6LiPM/codes",
"method" : "POST",
"rel" : "codes",
"title" : "create new codes entity"
}
],
"meta" : {
"description" : null,
"last_page" : 1,
"page_offset" : 0,
"page_size" : 50,
"query-template" : "/codes{?query_search,page_offset,page_size,query_identification,embedded,properties,about}",
"total" : 6
}
}
As I unterstood I need three classes: e.g. codes, links and meta.
I created a class "clscodes":
Public Class clsCode
Private m_href As String
Private m_rel As String
Private m_title As String
Public Property Href As String
Get
Return m_href
End Get
Set(value As String)
m_href = value
End Set
End Property
Public Property Rel As String
Get
Return m_rel
End Get
Set(value As String)
m_rel = value
End Set
End Property
Public Property Title As String
Get
Return m_title
End Get
Set(value As String)
m_title = value
End Set
End Property
End Class
And I created a class clsValuelist:
Public Class clsWerteliste
Private m_code As IList(Of clsCode)
Public Property Code() As clsCode()
Get
Return m_code
End Get
Set(value As clsCode())
m_code = value
End Set
End Property
End Class
When I try to deserialize it I get "nothing" as in "CoolOutput"
Dim CoolOutput As New clsWerteliste
CoolOutput = JsonConvert.DeserializeObject(Of clsWerteliste)(jsonstring)

Answer 1

Your classes are pretty close, it looks like you possibly tried to pretty things up a bit such as changing codes to Codes but in so doing the properties no longer match. You can change class names but not property names (at least not that way):
Public Class CodeLinkContainer
<JsonProperty("codes")>
Public Property Codes As IList(Of Code)
<JsonProperty("links")>
Public Property Links As IList(Of Link)
<JsonProperty("meta")>
Public Property Meta As Meta
End Class
Public Class Meta
Public Property description As Object
Public Property last_page As Integer
Public Property page_offset As Integer
Public Property page_size As Integer
Public Property querytemplate As String
Public Property total As Integer
End Class
Public Class Code
Public Property href As String
Public Property rel As String
Public Property title As String
End Class
Public Class Link
Public Property about As String
Public Property href As String
Public Property method As String
Public Property rel As String
Public Property title As String
Public Property type As String
End Class
Using AutoImplement properties, available for some time now, means you can skip all the Get, Set boilerplate code. VS will create the classes for you also:
Edit Menu -> Paste Special -> Paste Json As Classes
You sometimes have to tweak the class if there is an array/list property. For instance, the robots may write:
Public Property elements() As Element
When it should be:
Public Property elements As Element()
The container class shows how to use <JsonProperty("pname")> to change the property name if you wish. This often needs to be done to create an alias for a property name which is a key word in VB (Return, Error etc). In this case, I changed codes and links to be Lists as you did.
Dim jstr = ... from whereever
Dim CodeLinks = JsonConvert.DeserializeObject(Of CodeLinkContainer)(jstr)
Console.WriteLine(CodeLinks.meta.total)
For Each Item In CodeLinks.codes
Console.WriteLine(Item.title)
Next
Result:
6
TITLE 1
TITLE 2
TITLE 3