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program sample6;
uses
uPSCompiler,
uPSUtils,
uPSRuntime,
Dialogs
;
procedure MyOwnFunction(const Data: string);
begin
// Do something with Data
ShowMessage(Data);
end;
{$IFDEF UNICODE}
function ScriptOnExportCheck(Sender: TPSPascalCompiler; Proc: TPSInternalProcedure; const ProcDecl: AnsiString): Boolean;
{$ELSE}
function ScriptOnExportCheck(Sender: TPSPascalCompiler; Proc: TPSInternalProcedure; const ProcDecl: string): Boolean;
{$ENDIF}
{
The OnExportCheck callback function is called for each function in the script
(Also for the main proc, with '!MAIN' as a Proc^.Name). ProcDecl contains the
result type and parameter types of a function using this format:
ProcDecl: ResultType + ' ' + Parameter1 + ' ' + Parameter2 + ' '+Parameter3 + .....
Parameter: ParameterType+TypeName
ParameterType is @ for a normal parameter and ! for a var parameter.
A result type of 0 means no result.
}
begin
if Proc.Name = 'TEST' then // Check if the proc is the Test proc we want.
begin
if not ExportCheck(Sender, Proc, [0, {$IFDEF UNICODE}btUnicodeString{$ELSE}btString{$ENDIF}], [pmIn]) then // Check if the proc has the correct params.
begin
{ Something is wrong, so cause an error at the declaration position of the proc. }
Sender.MakeError('', ecTypeMismatch, '');
Result := False;
Exit;
end;
Result := True;
end else Result := True;
end;
{$IFDEF UNICODE}
function ScriptOnUses(Sender: TPSPascalCompiler; const Name: AnsiString): Boolean;
{$ELSE}
function ScriptOnUses(Sender: TPSPascalCompiler; const Name: string): Boolean;
{$ENDIF}
{ the OnUses callback function is called for each "uses" in the script.
It's always called with the parameter 'SYSTEM' at the top of the script.
For example: uses ii1, ii2;
This will call this function 3 times. First with 'SYSTEM' then 'II1' and then 'II2'.
}
begin
if Name = 'SYSTEM' then
begin
Sender.AddDelphiFunction('procedure MyOwnFunction(Data: string)');
{ This will register the function to the script engine. Now it can be used from within the script. }
Result := True;
end else
Result := False;
end;
procedure ExecuteScript(const Script: string);
var
Compiler: TPSPascalCompiler;
{ TPSPascalCompiler is the compiler part of the scriptengine. This will
translate a Pascal script into a compiled form the executer understands. }
Exec: TPSExec;
{ TPSExec is the executer part of the scriptengine. It uses the output of
the compiler to run a script. }
{$IFDEF UNICODE}Data: AnsiString;{$ELSE}Data: string;{$ENDIF}
N: PIfVariant;
{ The variant in which we are going to store the parameter }
ParamList: TIfList;
{ The parameter list}
begin
Compiler := TPSPascalCompiler.Create; // create an instance of the compiler.
Compiler.OnUses := ScriptOnUses; // assign the OnUses event.
Compiler.OnExportCheck := ScriptOnExportCheck; // Assign the onExportCheck event.
if not Compiler.Compile(Script) then // Compile the Pascal script into bytecode.
begin
Compiler.Free;
// You could raise an exception here.
Exit;
end;
Compiler.GetOutput(Data); // Save the output of the compiler in the string Data.
Compiler.Free; // After compiling the script, there is no need for the compiler anymore.
Exec := TPSExec.Create; // Create an instance of the executer.
Exec.RegisterDelphiFunction(@MyOwnFunction, 'MYOWNFUNCTION', cdRegister);
{ This will register the function to the executer. The first parameter is the executer. The second parameter is a
pointer to the function. The third parameter is the name of the function (in uppercase). And the last parameter is the
calling convention (usually Register). }
if not Exec.LoadData(Data) then // Load the data from the Data string.
begin
{ For some reason the script could not be loaded. This is usually the case when a
library that has been used at compile time isn't registered at runtime. }
Exec.Free;
// You could raise an exception here.
Exit;
end;
ParamList := TIfList.Create; // Create the parameter list
N := CreateHeapVariant(Exec.FindType2(btString));
{ Create a variant for the string parameter }
if n = nil then
begin
{ Something is wrong. Exit here }
ParamList.Free;
Exec.Free;
Exit;
end;
VSetString(n, 'Test Parameter!');
// Put something in the string parameter.
ParamList.Add(n); // Add it to the parameter list.
Exec.RunProc(ParamList, Exec.GetProc('TEST'));
{ This will call the test proc that was exported before }
FreePIFVariantList(ParamList); // Cleanup the parameters (This will also free N)
Exec.Free; // Free the executer.
end;
const
Script = 'procedure test(s: string); begin MyOwnFunction(''Test is called: ''+s);end; begin end.';
begin
ExecuteScript(Script);
end.
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