B4J Question What's up with JSON?

[boten]

this is the code, a very simple map, each value is a type

Sub Process_Globals
   Dim mp As Map
   Type tp(a As String,z As String)
End Sub

Sub AppStart (Form1 As Form, Args() As String)
   mp.Initialize
   
   Dim t As tp
   t.Initialize
   t.a="aaa"
   t.z="AAA"
   mp.Put(1,t)
   
   Dim t As tp
   t.Initialize
   t.a="bbb"
   t.z="BBB"
   mp.Put(2,t)
   
   Dim t As tp
   t.Initialize
   t.a="ccc"
   t.z="CCC"
   mp.Put(3,t)
   
   Dim js As JSONGenerator
   Dim s As String
   js.Initialize(mp)
   s=js.ToPrettyString(3)
  Log(s)   
   Dim msg As Msgboxes
   msg.Show("done","")
End Sub

the log output is:

Program started.
{
  "1": "[IsInitialized=true, a=aaa, z=AAA\n]",
  "2": "[IsInitialized=true, a=bbb, z=BBB\n]",
  "3": "[IsInitialized=true, a=ccc, z=CCC\n]"
}

Why the Isinitialize appears, and how to get rid of it?
Why the "\n" and how to get rid of it?

 

[rwblinn]

Hi,

do not think JSON can handle types as it requires strings.

What output do you want?

You can test JSON formats by using the JSON Online Parser - it will provide example code and outputs.

 

[sorex]

that's normal behaviour I guess as the isInitialized is a property value just like the other tho.

you can always write your own json string builder to get rid of it if that jsongenerator doesn't have a way to add items one by one.

 

[Roycefer]

It is often convenient to write one's own ToJSONString() method for custom classes and types. This is especially easy for a simple type like yours:

Sub tpToJSONString(teepee as tp) As String
    Return "{a:" & teepee.a & ",z:" & teepee.z & "}"
End Sub

Then, while building your larger JSON String, call

mp.Put(1,tpToJSONString(t))
'instead of
'mp.Put(1,t)

 

[Erel]

If you want to serialize custom types with json then you should create a sub that converts the type to a Map:

Sub TpToMap(teepee As TP) As Map
 Return CreateMap("a": teepe.a, "b": teepe.b)
End Sub

Now you can convert the types to json with:

Dim t1, t2, t3 As TP
... fill the types
Dim jg As JsonGenerator
jg.Initialize(CreateMap(1: TpToMap(t1), 2: TpToMap(t2), 3: TpToMap(t3)))

 

[boten]

So essentially for the json at question - create map of maps

If you want to serialize custom types with json then you should create a sub that converts the type to a Map:

Sub TpToMap(teepee As TP) As Map
Return CreateMap("a": teepe.a, "b": teepe.b)
End Sub

Now you can convert the types to json with:

Dim t1, t2, t3 As TP
... fill the types
Dim jg As JsonGenerator
jg.Initialize(CreateMap(1: TpToMap(t1), 2: TpToMap(t2), 3: TpToMap(t3)))