在delphi中嵌⼊脚本语⾔--（译）RemObjectsPascalScript使
⽤说明。。。
在delphi中嵌⼊脚本语⾔--(译)RemObjects Pascal Script使⽤说明(1)(译)
翻译这篇⽂章源于我的⼀个通⽤⼯资计算平台的想法，在⼯资的计算中，不可避免的需要使⽤到⾃定义公式，然⽽对于⾃定义公式的实现，我⾃⼰想了⼀些，也在⽹上搜索了很多，解决办法⼤致有以下⼏种：
1. ⾃⼰写代码去解析公式。这种⽅法的缺点是，解析的代码很难实现，如果公式的功能⽐较完整，如增加条件判断或⾃定义函数。不亚于实现了⼀个简单的语⾔编译嚣或解释嚣。所以，只能实现⼀些诸如加减乘除之类的简单公式。
2. 打包成SQL传给数据库去执⾏。这显然不是⼀种好办法。⽽且需要与特定的数据库和表结构进⾏适应。
3. 我想到在foxpro中有宏替换功能&，那不如就借⽤它的这个功能，即利⽤foxpro写⼀个dll，在这个dll中实现了将字符串转换成指令执⾏的功能，然后在delphi中加载这个dll，将公式传⼊dll中的函数执⾏。这应该是⼀个办法，但我还没有去实现它。
4. 内嵌脚本语⾔。
也只有第四种办法⽐较理想的，于是我就到了RemObjects Pascal Script，安装，并翻译了这篇使⽤说明。
再把应⽤范围扩⼤⼀点，其实在编译型程序中嵌⼊脚本语⾔可以解决很多应⽤程序⾃动化的问题，在了解并实际写了⼏个RemObjects Pascal Script的实从程序后。内⼼还是蛮兴奋的。
PS01 - Using the RemObjects Pascal Script
使⽤RemObjects Pascal Script
This article provides an overview of the new RemObjects Pascal Script and explains how to create some simple scripts.
这篇⽂章提供了RemObjects Pascal Script的⼀个概览，以及说明了如何去创建⼀些简单的脚本。
Pascal Script comprises two different parts:
Compiler (uPSCompiler.pas)
Runtime (uPSRuntime.pas)
Pascal Script由两个部分组成：
编译嚣(UPSCompiler.pas)
运⾏时(uPSRuntime.pas)
The two parts have no interdependencies on each other. You can use them directly, or you can use them in the TPSScript component, which can be found in the uPSComponent.pas unit, and wraps them both in one easy to use class.
这两部分之间是没有相互依赖的。你可以直接使⽤她们，或才你可以透过TPSSCript组件来使⽤她们，TPSSCript组件在uPSComponent.pas单元中，她对上述两个部分进⾏⼀些包装以便我们可以很容易的使⽤。
To use the component version of Pascal Script, you must first place it on your form or data module, set or assign the script property, call the Compile method, and call the Execute method. Compile errors, warnings or hints can be found in the CompilerMessages array property, while runtime errors can be found by reading the ExecErrorToString property.
要使⽤Pascal Script组件，你⾸先要将它从组件⾯板中拖置窗体或module中，然后设置它的script属性，
然后调⽤它的Compile⽅法进⾏编译，再然后调⽤它的Execute⽅法来执⾏脚本。编译的errors,hints,warnings可以通过其属性CompilerMessages取得，这个属性是⼀个数组。如果是运⾏时的错误，则可以通过属性ExecErrorToString取得。
The following example will compile and execute an empty script ("begin end."):
下⾯的例⼦将编译并执⾏⼀个空脚本("begin end."):
pascal语言还有人用吗var
Messages: string;
compiled: boolean;
begin
ce.Script.Text := 'begin end.';
Compiled := Ce.Compile;
for i := 0 to ce.CompilerMessageCount -1 do
Messages := Messages +
ce.CompilerMessages[i].MessageToString +
#13#10;
if Compiled then
Messages := Messages + 'Succesfully compiled'#13#10;
ShowMessage('Compiled Script: '#13#10+Messages);
if Compiled then begin
if Ce.Execute then
ShowMessage('Succesfully Executed')
else
ShowMessage('Error while executing script: '+
Ce.ExecErrorToString);
end;
end;
By default, the component only adds a few standard functions to the scripting engine (the exact list can be found at the top of uPSComponents.pas).
缺省情况下，组件只加⼊⼀少部分标淮的functions到脚本引擎中(具体可以在uPSComponents.pas单元头中到)
Besides the standard functions, there are a few libraries included with Pascal Script:
TPSDllPlugin Allow scripts to use dll functions, the syntax is like:
function FindWindow(C1, C2: PChar): Longint; external 'FindWindowA@user32.dll stdcall';
TPSImport_Classes Import library for TObject and the Classes unit.
TPSImport_DateUtils    Import library for date/time related functions.
TPSImport_ComObj Access COM Objects from your scripts.
TPSImport_DB Import library for db.pas.
TPSImport_Forms  Import library for the Forms & Menus units.
TPSImport_Controls    Import library to Controls.pas and Graphics.pas.
TPSImport_StdCtrls    Import library for ExtCtrls and Buttons.
除了这些标淮的functions之外，Pascal Script还包含了⼀少部分程式库：
TPSDllPlugin      允许脚本可以使⽤外部DLL函数，其调⽤语法类似下例：
function FindWindow(C1, C2: PChar): Longint; external 'FindWindowA@user32.dll stdcall';
TPSImport_Classes 导⼊对应于TObject和Classes单元的libraries；
TPSImport_DateUtils    导⼊⽇期时间相关的libraries；
TPSImport_ComObj 在脚本中访问COM对象；
TPSImport_DB      导⼊对应于db.pas单元的libraries；
TPSImport_Forms  导⼊对应于Forms和Menus单元的libraries；
TPSImport_Controls 导⼊对应于Controls.pas和Graphics.pas单元的libraries；
TPSImport_StdCtrls 导⼊对应于ExtCtrls和Buttons的libraries.
To use these libraries, add them to your form or data module, select the [...] button next to the plugins property of the TPSCompiler component, add a new item and set the Plugin property to the plugin component.
要使⽤这些libraries，将它们从组件⾯板中拖⾄窗体数据data module中，然后设置TPSCompiler的plugins属性，在其中增加条⽬，并将条⽬指向这些plugin组件。
Besides the standard libraries, you can easily add new functions to the scripting engine. In order to do that, create a new method you would like to expose to the scripting engine, for example:
除了这些标淮的libraries之外，你还可以很⽅便地向脚本引擎中添加新的函数。要做到这⼀点，创建⼀个你要加⼊到脚本中的method，如下例：
procedure TForm1.ShowNewMessage(const Message: string);
begin
ShowMessage('ShowNewMessage invoked:'#13#10+Message);
end;
Then, assign an event handler to the OnCompile event and use the AddMethod method of TPSCompiler to add the actual method:
然后，在TPSCompiler 的OnCompile事件中将该⽅法添加⼊脚本中：
procedure TForm1.CECompile(Sender: TPSScript);
begin
Sender.AddMethod(Self, @TForm1.ShowNewMessage,
'procedure ShowNewMessage
(const Message: string);');
end;
A sample script that uses this function could look like this:
这样， 你就可以在脚本中使⽤这个函数，如下：
begin
ShowNewMessage('Show This !');
end.
Advanced Features
⾼级功能
Pascal Script includes a preprocessor that allows you to use defines ({$IFDEF}, {$ELSE}, {$ENDIF}) and include other files in your script ({$I filename.inc}). To enable these features, you must set the UsePreprocessor property to true and the MainFileName property to match the name of the script in the Script property. The Defines property specifies which defines are set by default, and the OnNeedFile event is called when an include file is needed.
Pascal Script包含了⼀个预处理程序，以便你可以在脚本中使⽤编译预定义(defines)({$IFDEF}, {$ELSE}, {$ENDIF}) 以及在脚本中包含其它脚本 ({$I filename.inc})。要达到这个功能，你需要设置UsePreprocessor属性为true，and the MainFileName property to match the name of the script in the Script property. 。Defines属性指定要缺省时定义哪些defines；OnNeedFile事件代码在需要包含的⽂件时被执⾏。
NeedFile(Sender: TObject;
const OrginFileName: String;
var FileName, Output: String): Boolean;
var
path: string;
f: TFileStream;
begin
Path := ExtractFilePath(ParamStr(0)) + FileName;
try
F := TFileStream.Create(Path, fmOpenRead or fmShareDenyWrite);
except
Result := false;
exit;
end;
try
SetLength(Output, f.Size);
f.Read(Output[1], Length(Output));
finally
f.Free;
end;
Result := True;
end;
When these properties are set, the CompilerMessages array property will include the file name these messages occur in.
当这些属性被设置以后，CompilerMessages属性可就将可能包含这些⽂件名。
Additionally, you can call scripted functions from Delphi. The following sample will be used as a script:
另外，你可以在Delphi中调⽤脚本裡的函数。如下函数被定义在脚本中，后⾯将会在delphi中被调⽤：
function TestFunction(Param1: Double; Data: String): Longint;
begin
ShowNewMessage('Param1: '+FloatToString(param1)
+#13#10+'Data: '+Data);
Result := 1234567;
end;
begin
end.
Before this scripted function can be used, it has to be checked to match its parameter and result types, which can be done in the OnVerifyProc event.
在使⽤调⽤这个函数之前，必须对其进⾏⼀个校验，校验其参数和返回值类型，在OnVerifyProc执⾏这个校验。
procedure TForm1.CEVerifyProc(Sender: TPSScript;
Proc: TPSInternalProcedure;
const Decl: String;
var Error: Boolean);
begin
if Proc.Name = 'TESTFUNCTION' then begin
if not ExportCheck(Sender.Comp, Proc,
[btS32, btDouble, btString], [pmIn, pmIn]) then begin
Sender.Comp.MakeError('', ecCustomError, 'Function header for
TestFunction does not match.');
Error := True;
end
else begin
Error := False;
end;
end
else
Error := False;
end;
The ExportCheck function checks if the parameters match. In this case, btu8 is a boolean (the result type), btdouble is the first parameter, and btString the second parameter. [pmIn, pmIn] specifies that both parameters are IN parameters. To call this scripted function, you have to create an event declaration for this function and call that.
ExportCheck函数检查参数的匹配情况。在这个例⼦中，btu8是⼀个布尔型(返回值类型)，btdouble是第⼀个参数，btString是第⼆个参数。[pmIn, pmIn]表⽰两个参数都是输⼊参数。要调⽤这个脚本函数，你需要为它创建⼀个函数类型声明。
type
TTestFunction = function (Param1: Double;
Data: String): Longint of object;
//...
var
Meth: TTestFunction;
Meth := TTestFunction(ce.GetProcMethod('TESTFUNCTION'));
if @Meth = nil then
raise Exception.Create('Unable to call TestFunction');
ShowMessage('Result: '+IntToStr(Meth(pi, DateTimeToStr(Now))));
It's also possible to add variables to the script engine, which can be used from within the script. To do this, you have to use the AddRegisteredVariable function. You can set this in the OnExecute event :
还可以向脚本引擎中添加变量，然后就可以在脚本中使⽤这些变量 。要做到这⼀点，你需要使⽤AddRegisteredVariable函数。可以在OnExecute设置它：
Execute(Sender: TPSScript);
begin
CE.SetVarToInstance('SELF', Self);
// ^^^ For class variables
VSetInt(CE.GetVariable('MYVAR'), 1234567);
end;
To read this variable back, after the script has finished executing, you can use the OnAfterExecute event:
若要再去读取这个变量的值，在脚本执⾏完成后，在OnAfterExecute事件中访问：
VGetInt(CE.GetVariable('MYVAR')).
Registering external variables to the script engine is also possible. It's a two step process, first, in the OnCompile event, add the types to the script using the AddRegisteredPTRVariable function.
注册⼀个外部变量到脚本引擎中也是可以的。这需要两个步骤，⾸先在OnCompile事件中使⽤AddRegisteredPTRVariable函数将变量类型添加到脚本中。
procedure TMyForm.PSScriptCompile(Sender: TPSScript);
begin
Sender.AddRegisteredPTRVariable('MyClass', 'TButton');
Sender.AddRegisteredPTRVariable('MyVar', 'Longint');
end;
This will register the external MyClass and MyVar variables. Second, attach a pointer to these variables in the OnExecute event:
这样就注册了MyClass 和 MyVar这两个变量。第⼆步，在OnExecute中通过将变量值的地址指针传给变量来实现给变量赋值：
procedure TMyForm.PSScriptExecute(Sender: TPSScript);
begin
PSScript.SetPointerToData('MyVar', @MyVar, PSScript.FindBaseType(bts32));
PSScript.SetPointerToData('Memo1', @Memo1, PSScript.FindNamedType('TMemo'));
end;
There are two types of variables in Pascal Script, base types, which are simple types (see the table below), and class types. Base types are registered in the uPSUtils.pas unit and can be located using the FindBaseType function. Class types have to be located by name, using the FindNamedType. Changes to these variables have a direct effect on the actual variable.
在Pascal Script中有两种类型的变量，⼀种是基本类型，包含⼀些简单的类型，下⾯会列出；另⼀种是类类型。基本类型是在
uPSUtils.pas被注册进去的，可以通过FindBaseType函数到。类类型需要使⽤FindNamedType函数通过名称到。改变这些变量将直接地影响到实际的变量。
Base types:
btU8    Byte
btS8    Shortint
btU16    Word
btS16    Smallint
btU32    Longword
btS32    Longint
btS64    Int64
btSingle      Single
btDouble      Double
btExtended    Extended
btVariant    Variant
btString      String
btWideString WideString
btChar  Char
btWideChar    WideChar
The component version of Pascal Script also supports execution of scripted functions. This works by using the ExecuteFunction method.

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