Skip to main content

erCustomError

erCustomError = 24

Example​

procedure RequireFictionalValue(const Candidate: string);
begin
  if Candidate = '' then
    RaiseException(erCustomError, 'Fictional value is required');
end;

Usage​

erCustomError represents deliberate script-defined failures and several Velox scripting errors preserved as direct custom message text.

Formatting and exception state​

ExceptionToString returns Param verbatim after Velox scripting's string conversion. It adds no label, punctuation or fallback; an empty parameter formats as an empty string. When RaiseException is used, characters outside the active Windows code page can change.

Additional Technical Info​

erCustomError is member ordinal 24 of TIFException, the script-visible declaration that is kept in exact ordinal alignment with PascalScript's runtime TPSError. Its sidebar position 20 is alphabetical navigation metadata and is not its enumeration value.

erCustomError is the normal category for a deliberate script-defined validation or business-rule failure. It is also used internally when PascalScript catches a nested EPSException, detects selected string-index failures, or reports object/interface cast failures through a prepared resource message. When a nested EPSException is translated, the runtime retains that exception's procedure number and bytecode position but stores its display message as the custom parameter. The script-visible category is therefore not a Delphi exception class and does not preserve a distinct subclass identity.

Behavior, recovery and quirks​

  • Because the parameter becomes the entire display message, keep it actionable and safe for logs or user-visible channels. Do not include credentials, tokens or unnecessary customer data.
  • Use this member for failures your script intentionally owns. Do not use VM-corruption categories merely to make a message appear more severe.
  • Raising it transfers control through finally/except frames and can fail the current event or Flow action. It does not undo side effects completed before the raise.
  • Exception transfer is not a database, dataset, filesystem or external-system transaction. Any earlier side effect remains unless the called API or surrounding Flow provides an explicit rollback contract.
  • Do not persist the numeric ordinal as an integration contract. Store the member name, formatted message, parameter and relevant procedure/position with the Velox version.

Related Code Library entries

External references

Created 2026-07-15