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MessageInfo

Procedure MessageInfo(
  const AMessage: string;
  HelpID: LongInt)

Example​

procedure ScriptEvent(var Value: variant);
begin
  // Foreground use can block on an OK dialog. HelpID is ignored.
  MessageInfo('The validation step has completed.', 0);
end;

Usage​

MessageInfo shows an information dialog on the foreground main thread or writes information to the system and Windows event logs in background execution.

Parameters

NameTypeDescription
AMessagestring, constText shown in the dialog or passed to system/Windows event logging. No redaction or formatting is applied.
HelpIDLongIntAccepted for legacy signature compatibility but ignored by Velox in both branches. Any value has the same behavior.

Additional Technical Info​

MessageInfo selects one of two destinations from process/thread context:

  • on the foreground main thread, it shows a modal information dialog titled Info; or
  • in background mode or on any non-main thread, it writes Information to the Velox system log and attempts a Windows Application event.

It does not add an ordinary item to the current action log through either branch. Use LogInfo for action-log information. The example can be interactive and was not executed.

Foreground main-thread path

When IsBackground=False and IsMainThread=True, Velox calls DialogInfo('Info', AMessage, ''). The dialog implementation uses a VCL TTaskDialog with an OK button on supported/themed Windows, otherwise a standard MessageDlg.

Both forms are modal: the script blocks until the user dismisses the message. This path does not write the action log, the Velox system log or Windows event log. It is unsuitable for unattended foreground automation and high-volume record loops.

Background/non-main-thread path

Velox calls gEventLogger.LogMessage(AMessage, EVENTLOG_INFORMATION_TYPE). Under an event-logger monitor lock, that method:

  1. adds the original message to gSystemLog at system information level 20 when the global system log exists;
  2. obtains/registers a Windows Application event source named from the executable filename;
  3. chooses the information event identifier expected by vxEventMessages.dll; and
  4. calls Win32 ReportEvent with the message.

This is system-level diagnostic logging, not the flow's TvxLog item list.

Failure and delay quirks

If the Windows event-source handle is zero, LogMessage makes up to three registration attempts and sleeps two seconds after each failure, including the final one. A call can therefore block the background thread for about six seconds before giving up. Calls are serialized by the same lock, so other event-log writers can wait behind it.

The Boolean result from Win32 ReportEvent is ignored, and the function returns no success status. Missing permissions, event-source/message-DLL problems, event-size limits or Windows event-log failures may leave only the Velox system-log copy (when available), with no indication to the script.

During application initialization Velox attempts to create/repair the Application event-source registry key under HKLM; permission failure is handled as a best-effort condition. HelpID is unrelated to this registration.

Status, privacy and limits

Neither branch changes current flow Warning/Issue/Error status. Background system logging can have its own persistence behavior. Foreground presentation alone is not durable evidence.

Messages can become visible to interactive users, Windows Event Viewer readers and system-log/support users. Do not include credentials, tokens or unnecessary personal data. Windows imposes event-message size constraints; Velox performs no preflight length check and ignores the final API result.

Related entries

  • LogInfo adds a user information item to the current action log without a dialog.
  • LogWarning and LogError add action-log status items and may show conditional foreground dialogs through a different path.
  • LogHighlight adds a prominent Note in the action log.

External references

Created 2026-07-15