用簡單的Tracer類來為應用寫入跟蹤 (1)

{***********************}
{                                             }
{       CodeMachine                 }
{                                              }
{       版權所有 (C) 2004 nil   }
{                                               }
{       2004-6-10                       }
{                                               }
{************************}

{
    通常將TTracer的實例存放於application級的Session中,在使用時,
    創建一個ITraceInfo,調用TTracer.Write(ITraceInfo)即可,
}

unit com.sunset.app.tracer;

interface

uses StrUtils,classes,SysUtils;

type

//==========================
// 接口聲明
//==========================

    //跟蹤信息的接口
    ITraceInfo = interface
        function ToString: string;
    end;
    //輸出目標的接口
    IOutput = interface
        procedure Write(const aInfo: ITraceInfo); //寫入跟蹤信息
    end;

//==========================
// 跟蹤信息類 ,實現 ITraceInfo
//==========================

    //string形式的跟蹤記錄
    TStringTI = class(TInterfacedObject, ITraceInfo)
    private
        FData: string;
    public
        constructor Create(data: string);
        function ToString: string;
    end;

//==========================
// 跟蹤信息輸出類,實現 IOutput
//==========================

    TFileLog = class(TInterfacedObject, IOutput)
    private
        FLogFile: string;
    public
        constructor Create(const FileName: string);
        procedure Write(const aInfo: ITraceInfo); //寫入跟蹤信息
    end;

    TProcStr = procedure(const value:string) of Object;
    TDatabaseLog = class(TInterfacedObject, IOutput)
    private
        FWriteProc :TProcStr;