Easy JSON Recursion in VB.NET with Nested Levels

Introduction

This is an easy short JSON recursion solution in VB.NET that handles full multilevel json response files to pull values from the name fields...

Background

I was looking and couldn't find what I needed so I put some time to this. It may not be the best solution yet. But I can continue to work on it. But it was better than most I found though searching on the web. So this is a great little solution to find a value that may be below a bunch on nodes below the root of a json string.

Using the Code

Make sure you have the Newtonsoft.Json installed via NuGet.

Create a new Class in your project "JsonHelper":

//
// vb.net Class Code.
//
Imports System.IO
Imports Newtonsoft.Json.Linq

Public Class JsonHelper

    Private Shared output As String

    Public Shared Function GetJson_
        (res As String, txt As String, Optional Top As Integer = 0) As String

        Dim ser As JObject = JObject.Parse(res)

        Dim data() As JToken
        Dim jT() As JToken
        If Top = 0 Then
            data = ser.Children().ToArray()
            jT = data(0).First.ToArray()
        Else
            jT = ser.Children().ToArray()
        End If

        For Each itm As JProperty In jT

            If itm.Name = txt Then
                output = itm.Value.ToString
            End If

            If itm.Value.Type = JTokenType.Array Then
                Dim str As String = itm.First.First.ToString
                GetJson(str, txt, 1)
            End If
            If itm.Value.Type = JTokenType.Object Then
                Dim str As String = itm.First.ToString
                GetJson(str, txt, 1)
            End If

        Next

        Return output

    End Function

End Class

Given the following response returned from json:

    Transaction complete
  {
  "transaction": {
    "product": "CRUMP!",
    "id": "1asdsadasdsadasdsadsada",
    "location_id": "dfsdfsdfsdfsdfs",
    "created_at": "2017-03-10T13:43:47Z",
    "tenders": [
      {
        "type": "WOW",
        "id": "sdfsdfsdfsdfsdfsdfsd",
        "location_id": "fhghfghfghfghfghfghfgh",
        "transaction_id": "sfsdfsdfsdfsdfsdfsdfsdf",
        "created_at": "2017-03-10T13:43:47Z",
        "something": {
          "money": "CAD",
          "value": 234324234
        },
        "card_details": {
          "status": "DONE",
          "entry_method": "ONLINE",
          "DC": {
            "card_brand": "THINKIT",
            "last_4": "3232"
          }
        }
      }
    ]
  }
}

The Json is multilevel and getting to the child of the child of the child would be a pain and nobody wants to hardcode levels in. So given the JsonHelper...

All you have to do in your VB.NET application:

    Dim trasid As String = JsonHelper.GetJson(response, "transaction_id")

Pass the Json to the helper in string format and request the feild name... and you will get the value returned no matter what level it's at.

History

• V1.0 - rbettinelli - 03-15-2017 - New post - 1^st version up