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NewGuid

Function NewGuid: TGuid

Example​

procedure ScriptEvent(var Value: variant);
var
  Identifier: TGuid;
begin
  Identifier := NewGuid;
  Value := GUIDToStringNoBraces(Identifier);
end;

Usage​

NewGuid requests a new Windows UUID as a TGuid but discards the operating-system status.

Returns

The TGuid record left in the output supplied to Velox CreateGUID.

Errors

The function has no explicit exception path for nonzero CreateGUID status because it ignores the result. Delayed DLL/runtime faults can still propagate. More importantly, a normal return is not a checked-success signal.

Usage notes

For ordinary identifiers, this is the standard Velox helper. If a flow needs auditable generation failure handling or a security-grade random value, use an API that returns/checks status and matches that requirement.

Additional Technical Info​

NewGuid asks the installed Windows Delphi runtime to create a UUID and returns the resulting 16-byte TGuid. The Velox wrapper ignores the status returned by Delphi CreateGUID, so scripts cannot distinguish full success, the Windows “local only” outcome or an actual generation problem.

The example is illustrative and source-reviewed only. The documentation workflow did not generate a GUID or execute the product runtime.

Implementation

The registered function is exactly:

function NewGuid: TGuid;
begin
  CreateGUID(Result);
end;

Installed Studio 37.0 implements Windows System.SysUtils.CreateGUID as HResultFromWin32(UuidCreate(Guid)), using delayed rpcrt4.dll function UuidCreate. Velox discards that HRESULT and performs no Succeeded check, retry, all-zero check or fallback.

The Embarcadero DocWiki page currently says Windows calls CoCreateGuid; that does not match the installed source governing this Velox build. Microsoft UuidCreate and installed Delphi source are authoritative here.

Windows status behavior

Microsoft documents these notable RPC statuses:

  • RPC_S_OK: the call succeeded.
  • RPC_S_UUID_LOCAL_ONLY: a UUID was produced but is guaranteed unique only on this computer.
  • RPC_S_UUID_NO_ADDRESS: Windows could not obtain an Ethernet or token-ring address.

Because Velox discards the mapped status, every case has the same script signature and apparent normal return. If an OS outcome does not leave a valid generated UUID, Velox neither detects nor replaces the output; callers should not infer checked success from the absence of an exception.

Edge cases and quirks

  • The function is nondeterministic and invokes operating-system UUID services.
  • A normal-looking GUID is an identifier, not a proof of authenticity, authorization or secrecy.
  • The wrapper does not guarantee a specific RFC version/variant in its own contract; it returns the Windows-generated value.
  • It does not enforce nonzero output or compare against EmptyGuid.
  • Collision risk follows the operating-system generator and reported status, but the status is unavailable to the script.
  • Generated values are not sequential and must not be assumed to sort by creation time.
  • Do not use the output as a password, API key, cryptographic nonce or unpredictable security boundary merely because it is unique-looking.

Side effects

Calls Windows UUID-generation services and writes the function result record. No Velox configuration or persistent data is changed by the helper itself.

Performance and concurrency

One operating-system call plus a fixed-size record return. Windows supplies concurrency behavior; Velox keeps no counter or shared state.

Related entries

External references

Created 2026-07-15