Tips for new TMS Web Core developers and in particular for seasoned Delphi developers

WEB TMS WEB Core
21

Really catching ALL exceptions

In regular Delphi, catching a generic exception is done like this

Try
 ...
Except on E:Exception do
 Begin
 End
End

Well, in the JS environment, this does in fact not catch ALL errors. Errors created by the JS environment are NOT derived from class Exception and therefore On E:Exception does not catch these errors. As the Delphi ExceptObj is also not available, some JS helps again, like so:

Function GetMessageFromException(E : Exception) : String;
Var RMsg : String;
Begin
 RMsg := '';
 {$IFNDEF WIN32}
 ASM
  {if (!pas.SysUtils.Exception.isPrototypeOf(E)) {
   RMsg = E.message;
  } else {
   RMsg = E.fMessage;
  }}
 END;
 {$ENDIF}
 Result := RMsg;
End;

{---------------------------------------}

Procedure Foo;
Var e : Exception;
Begin
  Try
    ...
  Except
   {$IFNDEF WIN32} ASM e = $e; END; {$ENDIF}
   Console.error(GetMessageFromException(e));
  End
End;
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