[Gambas-user] Encode JSON form a collection within a collection?

[Admin]

Greetings!

I decided to make an SMS notifications for myself, chose a provider and 
read the API documentation. It's pretty straight-forward, they just want 
to recieve a JSON push like this:

{
     "destination": "phone",
     "originator": "alpha name",
     "body": "message text",
     "msisdn": "972000000",
     "reference": "ext_id_16",
     "validity": "1",
     "tariff": "0",
     "callback_url": "your_url"
}

So I wrote a code:

Public Sub SendSMS(sText As String, num As String)
Dim hClient As New HttpClient
Dim restapi As New Collection
Dim headers As New String[]

   headers.Add("X-API-KEY: whatevermykeyis")
   headers.Add("accept: application/json")

   restapi.Add("phone", "destination")
   restapi.Add("Me", "originator")
   restapi.Add(sText, "body")
   restapi.Add(num, "msisdn")
   restapi.Add("ext_id_" & Int(Rnd(1, 9)) & CInt(Now), "reference")

   hClient.URL = "https://api.myprovider.url/sms/create"
   hClient.Post("application/json", JSON.Encode(restapi), headers, 
"~/sms.log")
End

And it works, no problem. I was happy till I had to send the same SMS to 
more (a lot more) people. I can just pass 'num' for each number I want 
and send separate SMSes, which I do, but it's expensive. The prodiver 
can send up to 50 SMSes for the price of just one if I use another push 
request:

{
     "validity": "1",
     "tariff": "0",
     "destination": "phones",
     "originator": "alpha_name",
     "body": "message text",
     "phones":
     [
         {
             "msisdn": "972000000",
             "reference": "ext_id_17"
         },
         {
             "msisdn": "972000001",
             "reference": "ext_id_18"
         }
     ],
     "callback_url": "your_url"
}


And here I'm a bit stuck. How do I encode an array, a collection maybe, 
into a JSON which already is a collection?


Dmitry.