RemObjects PascalScript How to get the value of the variable after compilation? - pascalscript

Question

RemObjects PascalScript.
How to get the value of the variable after compilation?
var a,b,c: integer;
begin
a := 5;
b := 6;
c := a+b;
end;
cc := IntTostr(????c????);

Answer 1

You have two options:
You can register a function with
Sender.AddDelphiFunction('procedure MyOwnFunction(Data: string)');
and
Exec := TPSExec.Create; // Create an instance of the executer.
Exec.RegisterDelphiFunction(#MyOwnFunction, 'MYOWNFUNCTION', cdRegister);
and then call it from within your script.
Alternatively, you can define your script as a function and set the Result. Then you can retrieve it with
TestFunc := TTestFunction(Exec.GetProcAsMethodN('Test'));
Both methods are demonstrated in this example:
program sample8;
uses
uPSCompiler,
uPSRuntime,
uPSUtils,
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;
{$ENDIF}
{
The OnExportCheck callback function is called for each function in the script
(Also for the main proc, with '!MAIN' as a Proc^.Name). ProcDecl contains the
result type and parameter types of a function using this format:
ProcDecl: ResultType + ' ' + Parameter1 + ' ' + Parameter2 + ' '+Parameter3 + .....
Parameter: ParameterType+TypeName
ParameterType is # for a normal parameter and ! for a var parameter.
A result type of 0 means no result.
}
begin
if Proc.Name = 'TEST' then // Check if the proc is the Test proc we want.
begin
if not ExportCheck(Sender, Proc, {$IFDEF UNICODE}[btUnicodeString, btUnicodeString]{$ELSE}[btString, btString]{$ENDIF}, [pmIn]) then // Check if the proc has the correct params.
begin
{ Something is wrong, so cause an error. }
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;
{$ENDIF}
{ the OnUses callback function is called for each "uses" in the script.
It's always called with the parameter 'SYSTEM' at the top of the script.
For example: uses ii1, ii2;
This will call this function 3 times. First with 'SYSTEM' then 'II1' and then 'II2'.
}
begin
if Name = 'SYSTEM' then
begin
Sender.AddDelphiFunction('procedure MyOwnFunction(Data: string)');
{ This will register the function to the script engine. Now it can be used from within the script. }
Result := True;
end else
Result := False;
end;
type
TTestFunction = function (const s: string): string of object;
// Header of the test function, added of object.
procedure ExecuteScript(const Script: string);
var
Compiler: TPSPascalCompiler;
{ TPSPascalCompiler is the compiler part of the scriptengine. This will
translate a Pascal script into a compiled form the executer understands. }
Exec: TPSExec;
{ TPSExec is the executer part of the scriptengine. It uses the output of
the compiler to run a script. }
{$IFDEF UNICODE}Data: AnsiString;{$ELSE}Data: string;{$ENDIF}
TestFunc: TTestFunction;
begin
Compiler := TPSPascalCompiler.Create; // create an instance of the compiler.
Compiler.OnUses := ScriptOnUses; // assign the OnUses event.
Compiler.OnExportCheck := ScriptOnExportCheck; // Assign the onExportCheck event.
Compiler.AllowNoBegin := True;
Compiler.AllowNoEnd := True; // AllowNoBegin and AllowNoEnd allows it that begin and end are not required in a script.
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);
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;
TestFunc := TTestFunction(Exec.GetProcAsMethodN('Test'));
if #TestFunc <> nil then
ShowMessage('Result from TestFunc(''test indata''): '+TestFunc('test indata'));
Exec.Free; // Free the executer.
end;
const
Script = 'function test(s: string): string; begin MyOwnFunction(''Test Called with param: ''+s); Result := ''Test Result: ''+s; end;';
begin
ExecuteScript(Script);
end.