The script engine can import procedure and functions from external DLL files. Thus, you can extend your publication by calling your own DLL functions.
How to import a DLL function in HEScript?
This is done thanks to the external keyword.
Syntax:
function functionName(arguments): resultType; [callingConvention]; external "libName.dll" [name 'ExternalFunctionName'];
For example, the following declaration:
function MyFunction(arg: integer): integer; external 'CustomLib.dll';
imports a function called MyFunction from CustomLib.dll. Default calling convention, if not specified, is
register.
HEScript allows to declare a different calling convention (stdcall, register, pascal, cdecl or safecall) and to use a different name for the DLL function, like the following declaration:
function MsgBox(hWnd: Pointer; lpText, lpCaption: String; uType: Cardinal): Integer; stdcall; external "user32.dll" name 'MessageBoxW';
This imports 'MessageBoxW' function from User32.dll (Windows API library), named 'MsgBox' to be used in script, like:
procedure TestDLL;
var
S: String;
begin
S := InputBox("What do you want to show?", "Query", "");
MsgBox(0, S, "You entered:", MB_OK+MB_ICONINFORMATION);
end;