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AsGUID

property AsGUID: TGUID read write;

Example​

procedure ScriptEvent(var Value: variant);
var
  Text: TJSONString;
  Item: TJSONValue;
begin
  Text := TJSONString.Create;
  try
    Item := Text;
    Item.AsGUID := StringToGUID(
      '{12345678-1234-1234-1234-1234567890AB}');
    Value := Item.AsString;
  finally
    Text.Free;
  end;
end;

Usage​

AsGUID parses strict braced GUID text or writes Velox's braced GUID representation through the value setter.

Additional Technical Info​

The reader returns the all-zero NULLGUID when IsNull is true. Otherwise it passes AsString to Delphi StringToGUID. The parser expects the canonical braced, hyphenated hexadecimal shape and raises EConvertError for malformed, blank or incompatible text. JSON itself has no GUID type; this is a Velox/Deltics String convention.

The writer calls Delphi GUIDToString and sends its 38-character braced representation through the concrete virtual String setter. A TJSONString stores that form. Other scalar classes can reject it after changing null state, and a container attempts to parse it as replacement JSON. Assigning an all-zero GUID does not make this property null; it stores the all-zero textual GUID. Some AddGUID helpers instead treat all-zero as a null sentinel, so those paths are not equivalent.

Reading null and reading a stored all-zero GUID both produce the same binary record. Check IsNull when the distinction matters. The conversion is synchronous, constant-space apart from the returned String, and locale-independent.

External references

Created 2026-07-15