Creating nested JSON with new framework?

I need to build a nested JSON string as in the example below. I have it working with the old framework but as I am rewriting the corresponding program, I would like to make use of the new framework now.

As far as I see, there is no equivalent to JSONItem in the new framework and I wonder how I have to add a json to json?

Further I wonder how to add a list in square brackets, like the PaymentMethods you can see in the example below.

I have not found an example in the Dev Center ( Am I overlooking something or is it not documented?

Can anyone give me some example how to create such a nested string with the new framework?

{ "RequestHeader": { "SpecVersion": "1.3", "CustomerId": "123123", "RequestId": "33e8af17-35c1-4165-a343-c1c86a320f3b", "RetryIndicator": 0, "ClientInfo": { "ShopInfo": "My Shop", "ApplicationInfo": "ApplicationInfo", "OsInfo": "Windows Server 2013" } }, "TerminalId": "12345678", "Payment": { "Amount": { "Value": "100", "CurrencyCode": "CHF" }, "OrderId": "OrderId", "Description": "Description", "PayerNote": "Payernote" }, "PaymentMethods": [ "VISA", "MASTERCARD", "MASTERPASS" ], "Payer": { "IpAddress": "" }, "ReturnUrls": { "Success": "https://merchanthost/success", "Fail": "https://merchanthost/fail", "Abort": "https://merchanthost/abort" }, "Notification": { "MerchantEmail": "", "NotifyUrl": "https://merchanthost/notify.aspx?ID=ABC123" } }

Use Xojo.Core.Dictionary and Auto() (or other valid array types like Boolean() or Text()) to create your structure, then Xojo.Data.GenerateJSON to convert to a JSON string.

Part of your example:

dim parent as new Xojo.Core.Dictionary
dim child as new Xojo.Core.Dictionary

child.Value( "SpecVersion" ) = "1.3"
child.Value( "CustomerId" ) = "123123"

parent.Value( "RequestHeader" ) = child

dim payMethods() as text = array( "VISA", "MASTERCARD" )
parent.Value( "PaymentMethods" ) = payMethods

dim json as text = Xojo.Data.GenerateJSON( parent )

Note: with small structures it won’t matter, but for larger ones you’ll find the new framework significantly faster on the Mac and significantly slower on Windows.

Thanks a lot, Kem!

I got confused with the new way of naming things.
I would like to see this sample code of yours in the documentation.

Are there any known Json speed differences on Linux? My code will run on a Linux server…

I don’t recall if I tested, and don’t think so, but you can check it out using the project in this report:


One more note: if you need to add an array of object to your JSON, you might be tempted (as I once was) to do this:

dim arr() as Xojo.Core.Dictionary
arr.Append new Xojo.Core.Dictionary
parent.Value( "myObjects" ) = arr

This will generate an exception when you try to convert to JSON. Make your arrays one of these:

  • String()
  • Text()
  • Double()
  • Integer() // Any kind of int, I think
  • Boolean()
  • Auto()

Also, if you need case-sensitivity to start, create your initial dictionaries this way:

dim parent as Xojo.Core.Dictionary = Xojo.Data.ParseJSON( "{}" )

That’s an easy way to return a case-sensitive Dictionary.

[quote=303977:@Kem Tekinay]I don’t recall if I tested, and don’t think so, but you can check it out using the project in this report:


I recreated this test program as a webapp, 64-bit for Linux, and I am testing it on a Ubuntu Server 14.04 VPS
(12GB real memory, 6 GB virtual memory, Intel Xeon CPU E5520 @ 2.27GHz, 10 cores)

The results I’m getting:

51.061 seconds
50.129 seconds
51.376 seconds

(IMHO : This is freakin horrible. This takes about 0.7 seconds on a Mac and almost 9 seconds on Windows, desktop)

I added the test webapp to the feedback case