VB6 JsonSerializer Class Module(.cls)

Easily serialize json using the TypeLib Information com library from Microsoft.

Setup

Copy the JsonSerializer class module into your project.

Add a project reference to TypeLib Information from tlbinf32.dll. Add a project reference to Microsoft Scripting Runtime

Install Missing DLL

Download the tlbinf32.dll Make sure you run command prompt as administrator and register the dll for com interop. C:\Windows\System32 regsvr32 tlbinf32.dll Requires a restart of VB6 to see.

Define a class module with the json properties you're expecting to use Initialize an instance of it or an array and pass it into the ConvertToJson method

Example:

Dim helper as new JsonSerializer
Dim testObj as Class1
Dim jsonStr as string

Set testObj = new Class1
jsonStr = helper.ConvertToJson(testObj)`

Result:

{ "name": "Test","test Spaced Name": null }

You can optionally enable(default) or disable null values from being in the json via the IgnoreNulls property

helper.IgnoreNulls = true

{ "name": "Test" }

Nested Object Handling

The serializer can handle nesting. There is no checks for infinite loops so be careful.

Dim a As New Class1

Dim b(1 To 2) As New Class1
Set b(1) = New Class1
Set b(2) = New Class1

Dim c As New Class1
Dim d As New Class1
    
c.nested = d
b(2).nested = c
a.nested = b

jsonStr = helper.ConvertToJson(a)

{"name": "Test","test Spaced Name": "","nested": [{"name": "Test","test Spaced Name": "","nested": null},{"name": "Test","test Spaced Name": "","nested": {"name": "Test","test Spaced Name": "","nested": {"name": "Test","test Spaced Name": "","nested": null}}}]}