Skip to main content

AddGUID

function AddGUID(const aName: String;
  const aValue: TGUID): TJSONString;

Example​

procedure ScriptEvent(var Value: variant);
var
  Document: TJSONObject;
begin
  Document := TJSONObject.Create;
  try
    Document.AddGUID('id',
      StringToGUID('{11111111-2222-3333-4444-555555555555}'));
    Value := Document.AsString;
  finally
    Document.Free;
  end;
end;

Usage​

AddGUID adds a named braced GUID String or a null-marked String for the all-zero GUID, with container-dependent null output.

Additional Technical Info​

For a nonzero GUID, AddGUID creates a TJSONString, assigns aName, uses Delphi GUIDToString and transfers the node to the receiver. The serialized value includes braces and is quoted as JSON text; casing follows the RTL formatter.

The all-zero GUID is a sentinel. Instead of storing its textual form or constructing TJSONNull, the method creates an empty String node and sets IsNull=True. Objects emit null. Arrays reached through this ancestor emit "" in compact form because their compact serializer branches on String type, while display form tests null first and emits null.

The returned String is a borrowed, parent-owned child. It becomes invalid when removed, erased/replaced or when its parent is freed. The method compares all 16 GUID bytes, so only the exact zero structure receives null treatment.

No GUID parsing occurs here; the caller must already provide TGUID. Conversion errors in a preceding StringToGUID call happen before this method. Allocation or insertion errors propagate, with a possible leak if final owning-list insertion fails.

External references

Created 2026-07-15