iddatetimestamp.pas

Indy控件的使用源代码

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{ $Log:  10119: IdDateTimeStamp.pas 
{
{   Rev 1.0    2002.11.12 10:34:48 PM  czhower
}
unit IdDateTimeStamp;

{
ToDo: Allow localisation date / time strings generated (i.e., to zone name).
ToDo: Rework SetFromRFC822 as it is (marginally) limited by it's   
  conversion to TDateTime.
ToDo: Conversion between Time Zones.
}

{
2002-Feb-07 Pete Mee
 - Modified interface: GetAsRFC882 is now GetAsRFC822. ;-)
 - Fixed GetAsTTimeStamp (was way out).
2001-Nov-10 Pete Mee
 - Added SetFromDOSDateTime.
2001-Mar-29 Pete Mee
 - Fixed bug in SetFromRFC822.  As luck would have it, my PC has changed
  to BST from GMT, so I caught the error.  Change use of GMTToLocalDateTime
  to StrInternetToDateTime.
2001-Mar-27 Pete Mee
 - Added GetTimeZoneHour, GetTimeZoneMinutes, GetTimeZoneAsString and
   corresponding properties, TimeZoneHour, TimeZoneMinutes and TimeZoneAsString.
 - Added SetFromRFC822 and SetFromISO8601.
2001-Mar-26 Pete Mee
 - Fixed bug in AddDays.  Was adding an extra day in the wrong centuary.
 - Fixed bug in AddDays.  Was not altering the year with large additions.
2001-Mar-23 Pete Mee
 - Fixed bug in SubtractMilliseconds.
 - GetBeatOfDay is more accurate (based on milliseconds instead of seconds).
2001-Mar-21 Pete Mee
 - Altered Day, Seond and Millisecond properties to use their respective
   Set methods.
 - Added SetTimeZone, Zero, ZeroTime and ZeroDate.
 - Altered SetYear and SetDay to cope with the value 0.
2000-Sep-16 Pete Mee
 - SetYear no longer accepts zero but instead simply exits.
2000-Aug-01 Pete Mee
 - Fix bugs in AddDays & SubtractDays.  Depending on the day of the year, the
   calculations could have been incorrect.  Now 'rounds off' to the nearest year   
   before any other calculation.
2000-Jul-28 Pete Mee
 - Fix bugs in AddDays & SubtractDays.  3 days in 400 years lost, 1 day in 100
   years lost.
2000-May-11 Pete Mee
 - Added GetAsRFC822, GetAsISO8601
2000-May-03 Pete Mee
 - Added detection of Day, Week and Month (various formats).
2000-May-02 Pete Mee
 - Started TIdDateTimeStamp
}

{
Development notes:

The Calendar used is the Gregorian Calendar (modern western society).  This
Calendar's use started somtime in the 1500s but wasn't adopted by some countries
until the early 1900s.  No attempt is made to cope with any other Calendars.

No attempt is made to cope with any Atomic time quantity less than a leap
year (i.e., an exact number of seconds per day and an exact number of days
per year / leap year - no leap seconds, no 1/4 days, etc).

The implementation revolves around the Milliseconds, Seconds, Days and Years.
The heirarchy is as follows:
Milliseconds modify seconds.  (0-999 Milliseconds)
Seconds modify days.  (0-59 Seconds)
Days modify years.  (1-365/366 Days)
Years modify years. (..., -2, -1, 1, ...)

All other time units are translated into necessary component parts.  I.e.,
a week is 7 days, and hour is 3600 seconds, a minute is 60 seconds, etc...

The implementation could be easily expanded to represent decades, centuries,
nanoseconds, and beyond in both directions.  Milliseconds are included to
provide easy conversion from TTimeStamp and back (and hence TDateTime).  The
current component is designed to give good functionality for the majority (if
not all) of Internet component requirements (including Swatch's Internet Time).
It is also not limited to the 2038 bug of many of today's OSs (32-bit signed
number of seconds from 1st Jan 1970 = 19th Jan 2038 03:14:07, or there abouts).

NB: This implementation is factors slower than those of the TDateTime and
TTimeStamp components of standard Delphi.  It's main use lies in the conversion
to / from ISO 8601 and RFC 822 formats as well as dates ranging beyond 2037 and
before 1970 (though TTimeStamp is capable here).  It's also the only date component
I'm aware of that complies with RFC 2550 "Y10K and Beyond"... one of those RFCs in   
the same category as RFC 1149, IP over Avian Carriers. ;-)

Pete Mee
}

interface

uses
  Classes,
  IdBaseComponent,
  SysConst {Import strings for days & months}, SysUtils ;

const
  // Some basic constants
  IdMilliSecondsInSecond = 1000;
  IdSecondsInMinute = 60;
  IdMinutesInHour = 60;
  IdHoursInDay = 24;

  IdDaysInWeek = 7;
  IdDaysInYear = 365;
  IdDaysInLeapYear = 366;
  IdYearsInShortLeapYearCycle = 4;
  IdDaysInShortLeapYearCycle = IdDaysInLeapYear + (IdDaysInYear * 3);
  IdDaysInShortNonLeapYearCycle = IdDaysInYear * IdYearsInShortLeapYearCycle;
  IdDaysInFourYears = IdDaysInShortLeapYearCycle;
  IdYearsInCentury = 100;
  IdDaysInCentury = (25 * IdDaysInFourYears) - 1;
  IdDaysInLeapCentury = IdDaysInCentury + 1;
  IdYearsInLeapYearCycle = 400;
  IdDaysInLeapYearCycle = IdDaysInCentury * 4 + 1;

  IdMonthsInYear = 12;

  // Beat time is Swatch's "Internet Time" http://www.swatch.com/    {Do not Localize}
  IdBeatsInDay = 1000;

  // Some compound constants
  IdHoursInHalfDay = IdHoursInDay div 2;

  IdSecondsInHour = IdSecondsInMinute * IdMinutesInHour;
  IdSecondsInDay = IdSecondsInHour * IdHoursInDay;
  IdSecondsInHalfDay = IdSecondsInHour * IdHoursInHalfDay;
  IdSecondsInWeek = IdDaysInWeek * IdSecondsInDay;
  IdSecondsInYear = IdSecondsInDay * IdDaysInYear;
  IdSecondsInLeapYear = IdSecondsInDay * IdDaysInLeapYear;

  IdMillisecondsInMinute = IdSecondsInMinute * IdMillisecondsInSecond;
  IdMillisecondsInHour = IdSecondsInHour * IdMillisecondsInSecond;
  IdMillisecondsInDay = IdSecondsInDay * IdMillisecondsInSecond;
  IdMillisecondsInWeek = IdSecondsInWeek * IdMillisecondsInSecond;

  IdDaysInMonth : array[1..IdMonthsInYear] of byte =
    (
      31, 28, 31, 30, 31, 30,
      31, 31, 30, 31, 30, 31
    );

  IdMonthNames : array[0..IdMonthsInYear] of string =
    ( '',    {Do not Localize}
      SLongMonthNameJan, SLongMonthNameFeb, SLongMonthNameMar,
      SLongMonthNameApr, SLongMonthNameMay, SLongMonthNameJun,
      SLongMonthNameJul, SLongMonthNameAug, SLongMonthNameSep,
      SLongMonthNameOct, SLongMonthNameNov, SLongMonthNameDec );


  IdMonthShortNames : array[0..IdMonthsInYear] of string =
    ( '', // Used for GetMonth    {Do not Localize}
      SShortMonthNameJan, SShortMonthNameFeb, SShortMonthNameMar,
      SShortMonthNameApr, SShortMonthNameMay, SShortMonthNameJun,
      SShortMonthNameJul, SShortMonthNameAug, SShortMonthNameSep,
      SShortMonthNameOct, SShortMonthNameNov, SShortMonthNameDec );

  IdDayNames : array[0..IdDaysInWeek] of string =
    ( '', SLongDayNameSun, SLongDayNameMon, SLongDayNameTue,    {Do not Localize}
      SLongDayNameWed, SLongDayNameThu, SLongDayNameFri,
      SLongDayNameSat );

  IdDayShortNames : array[0..IdDaysInWeek] of string =
    ( '', SShortDayNameSun, SShortDayNameMon, SShortDayNameTue,    {Do not Localize}
      SShortDayNameWed, SShortDayNameThu, SShortDayNameFri,
      SShortDayNameSat );

  // Area Time Zones
  TZ_NZDT = 13;     // New Zealand Daylight Time
  TZ_IDLE = 12;     // International Date Line East
  TZ_NZST = TZ_IDLE;// New Zealand Standard Time
  TZ_NZT = TZ_IDLE; // New Zealand Time
  TZ_EADT = 11;     // Eastern Australian Daylight Time
  TZ_GST = 10;      // Guam Standard Time / Russia Zone 9
  TZ_JST = 9;       // Japan Standard Time / Russia Zone 8
  TZ_CCT = 8;       // China Coast Time / Russia Zone 7
  TZ_WADT = TZ_CCT; // West Australian Daylight Time
  TZ_WAST = 7;      // West Australian Standard Time / Russia Zone 6
  TZ_ZP6 = 6;       // Chesapeake Bay / Russia Zone 5
  TZ_ZP5 = 5;       // Chesapeake Bay / Russia Zone 4
  TZ_ZP4 = 4;       // Russia Zone 3
  TZ_BT = 3;        // Baghdad Time / Russia Zone 2
  TZ_EET = 2;       // Eastern European Time / Russia Zone 1
  TZ_MEST = TZ_EET; // Middle European Summer Time
  TZ_MESZ = TZ_EET; // Middle European Summer Zone
  TZ_SST = TZ_EET;  // Swedish Summer Time
  TZ_FST = TZ_EET;  // French Summer Time
  TZ_CET = 1;       // Central European Time
  TZ_FWT = TZ_CET;  // French Winter Time
  TZ_MET = TZ_CET;  // Middle European Time
  TZ_MEWT = TZ_CET; // Middle European Winter Time
  TZ_SWT = TZ_CET;  // Swedish Winter Time
  TZ_GMT = 0;       // Greenwich Meanttime
  TZ_UT = TZ_GMT;   // Universla Time
  TZ_UTC = TZ_GMT;  // Universal Time Co-ordinated
  TZ_WET = TZ_GMT;  // Western European Time
  TZ_WAT = -1;      // West Africa Time
  TZ_BST = TZ_WAT;  // British Summer Time
  TZ_AT = -2;       // Azores Time
  TZ_ADT = -3;      // Atlantic Daylight Time
  TZ_AST = -4;      // Atlantic Standard Time
  TZ_EDT = TZ_AST;  // Eastern Daylight Time
  TZ_EST = -5;      // Eastern Standard Time
  TZ_CDT = TZ_EST;  // Central Daylight Time
  TZ_CST = -6;      // Central Standard Time
  TZ_MDT = TZ_CST;  // Mountain Daylight Time
  TZ_MST = -7;      // Mountain Standard Time
  TZ_PDT = TZ_MST; // Pacific Daylight Time
  TZ_PST = -8;      // Pacific Standard Time
  TZ_YDT = TZ_PST;  // Yukon Daylight Time
  TZ_YST = -9;      // Yukon Standard Time
  TZ_HDT = TZ_YST;  // Hawaii Daylight Time
  TZ_AHST = -10;    // Alaska-Hawaii Standard Time
  TZ_CAT  = TZ_AHST;// Central Alaska Time
  TZ_HST = TZ_AHST; // Hawaii Standard Time
  TZ_EAST = TZ_AHST;// East Australian Standard Time
  TZ_NT = -11;      // -None-
  TZ_IDLW = -12;    // International Date Line West

  // Military Time Zones
  TZM_A = TZ_WAT;
  TZM_Alpha = TZM_A;
  TZM_B = TZ_AT;
  TZM_Bravo = TZM_B;
  TZM_C = TZ_ADT;
  TZM_Charlie = TZM_C;
  TZM_D = TZ_AST;
  TZM_Delta = TZM_D;
  TZM_E = TZ_EST;
  TZM_Echo = TZM_E;
  TZM_F = TZ_CST;
  TZM_Foxtrot = TZM_F;
  TZM_G = TZ_MST;
  TZM_Golf = TZM_G;
  TZM_H = TZ_PST;
  TZM_Hotel = TZM_H;
  TZM_J = TZ_YST;
  TZM_Juliet = TZM_J;
  TZM_K = TZ_AHST;
  TZM_Kilo = TZM_K;
  TZM_L = TZ_NT;
  TZM_Lima = TZM_L;
  TZM_M = TZ_IDLW;
  TZM_Mike = TZM_M;
  TZM_N = TZ_CET;
  TZM_November = TZM_N;
  TZM_O = TZ_EET;
  TZM_Oscar = TZM_O;
  TZM_P = TZ_BT;
  TZM_Papa = TZM_P;
  TZM_Q = TZ_ZP4;
  TZM_Quebec = TZM_Q;
  TZM_R = TZ_ZP5;
  TZM_Romeo = TZM_R;
  TZM_S = TZ_ZP6;
  TZM_Sierra = TZM_S;
  TZM_T = TZ_WAST;
  TZM_Tango = TZM_T;
  TZM_U = TZ_CCT;
  TZM_Uniform = TZM_U;
  TZM_V = TZ_JST;
  TZM_Victor = TZM_V;
  TZM_W = TZ_GST;
  TZM_Whiskey = TZM_W;
  TZM_X = TZ_NT;
  TZM_XRay = TZM_X;
  TZM_Y = TZ_IDLE;
  TZM_Yankee = TZM_Y;
  TZM_Z = TZ_GMT;
  TZM_Zulu = TZM_Z;

type
  { TODO: I'm sure these are stored in a unit elsewhere... need to find out }    {Do not Localize}
  TDays = (TDaySun, TDayMon, TDayTue, TDayWed, TDayThu, TDayFri, TDaySat);
  TMonths = (TMthJan, TMthFeb, TMthMar, TMthApr, TMthMay, TMthJun,
             TMthJul, TMthAug, TMthSep, TMthOct, TMthNov, TMthDec);

  TIdDateTimeStamp = class(TIdBaseComponent)
  protected
    FDay : Integer;
    FIsLeapYear : Boolean;
    FMillisecond : Integer;
    FSecond : Integer;
    FTimeZone : Integer;  // Number of minutes + / - from GMT / UTC
    FYear : Integer;

    procedure CheckLeapYear;
    procedure SetDateFromISO8601(AString : String);
    procedure SetTimeFromISO8601(AString : String);
  public
    constructor Create(AOwner : TComponent); override;
    destructor Destroy; override;

    procedure AddDays(ANumber : Cardinal);
    procedure AddHours(ANumber : Cardinal);
    procedure AddMilliseconds(ANumber : Cardinal);
    procedure AddMinutes(ANumber : Cardinal);
    procedure AddMonths(ANumber : Cardinal);
    procedure AddSeconds(ANumber : Cardinal);
    procedure AddTDateTime(ADateTime : TDateTime);
    procedure AddTIdDateTimeStamp(AIdDateTime : TIdDateTimeStamp);
    procedure AddTTimeStamp(ATimeStamp : TTimeStamp);
    procedure AddWeeks(ANumber : Cardinal);
    procedure AddYears(ANumber : Cardinal);

    function GetAsISO8601Calendar : String;
    function GetAsISO8601Ordinal : String;
    function GetAsISO8601Week : String;
    function GetAsRFC822 : String;
{TODO :    function GetAsRFC977DateTime : String;}
    function GetAsTDateTime : TDateTime;
    function GetAsTTimeStamp : TTimeStamp;
    function GetAsTimeOfDay : String; // HH:MM:SS

    function GetBeatOfDay : Integer;
    function GetDaysInYear : Integer;
    function GetDayOfMonth : Integer;
    function GetDayOfWeek : Integer;
    function GetDayOfWeekName : String;
    function GetDayOfWeekShortName : String;
    function GetHourOf12Day : Integer;
    function GetHourOf24Day : Integer;
    function GetIsMorning : Boolean;
    function GetMinuteOfDay : Integer;
    function GetMinuteOfHour : Integer;
    function GetMonthOfYear : Integer;
    function GetMonthName : String;
    function GetMonthShortName : String;
    function GetSecondsInYear : Integer;
    function GetSecondOfMinute : Integer;
    function GetTimeZoneAsString: String;
    function GetTimeZoneHour: Integer;
    function GetTimeZoneMinutes: Integer;
    function GetWeekOfYear : Integer;

    procedure SetFromDOSDateTime(ADate, ATime : Word);
    procedure SetFromISO8601(AString : String);
    procedure SetFromRFC822(AString : String);
    procedure SetFromTDateTime(ADateTime : TDateTime);
    procedure SetFromTTimeStamp(ATimeStamp : TTimeStamp);

    procedure SetDay(ANumber : Integer);
    procedure SetMillisecond(ANumber : Integer);
    procedure SetSecond(ANumber : Integer);
    procedure SetTimeZone(const Value: Integer);
    procedure SetYear(ANumber : Integer);

    procedure SubtractDays(ANumber : Cardinal);
    procedure SubtractHours(ANumber : Cardinal);
    procedure SubtractMilliseconds(ANumber : Cardinal);
    procedure SubtractMinutes(ANumber : Cardinal);
    procedure SubtractMonths(ANumber : Cardinal);
    procedure SubtractSeconds(ANumber : Cardinal);
    procedure SubtractTDateTime(ADateTime : TDateTime);
    procedure SubtractTIdDateTimeStamp(AIdDateTime : TIdDateTimeStamp);
    procedure SubtractTTimeStamp(ATimeStamp : TTimeStamp);
    procedure SubtractWeeks(ANumber : Cardinal);
    procedure SubtractYears(ANumber : Cardinal);

    procedure Zero;
    procedure ZeroDate;
    procedure ZeroTime;

    property AsISO8601Calendar : String read GetAsISO8601Calendar;
    property AsISO8601Ordinal : String read GetAsISO8601Ordinal;
    property AsISO8601Week : String read GetAsISO8601Week;
    property AsRFC822 : String read GetAsRFC822;
    property AsTDateTime : TDateTime read GetAsTDateTime;
    property AsTTimeStamp : TTimeStamp read GetAsTTimeStamp;
    property AsTimeOfDay : String read GetAsTimeOfDay;
    property BeatOfDay : Integer read GetBeatOfDay;
    property Day : Integer read FDay write SetDay;
    property DaysInYear : Integer read GetDaysInYear;
    property DayOfMonth : Integer read GetDayOfMonth;
    property DayOfWeek : Integer read GetDayOfWeek;
    property DayOfWeekName : String read GetDayOfWeekName;
    property DayOfWeekShortName : String read GetDayOfWeekShortName;
    property HourOf12Day : Integer read GetHourOf12Day;
    property HourOf24Day : Integer read GetHourOf24Day;
    property IsLeapYear : Boolean read FIsLeapYear;
    property IsMorning : Boolean read GetIsMorning;
    property Millisecond : Integer read FMillisecond write SetMillisecond;
    property MinuteOfDay : Integer read GetMinuteOfDay;
    property MinuteOfHour : Integer read GetMinuteOfHour;
    property MonthOfYear : Integer read GetMonthOfYear;
    property MonthName : String read GetMonthName;
    property MonthShortName : String read GetMonthShortName;
    property Second : Integer read FSecond write SetSecond;
    property SecondsInYear : Integer read GetSecondsInYear;
    property SecondOfMinute : Integer read GetSecondOfMinute;
    property TimeZone : Integer read FTimeZone write SetTimeZone;
    property TimeZoneHour : Integer read GetTimeZoneHour;
    property TimeZoneMinutes : Integer read GetTimeZoneMinutes;
    property TimeZoneAsString : String read GetTimeZoneAsString;
    property Year : Integer read FYear write SetYear;
    property WeekOfYear : Integer read GetWeekOfYear;
  end;

implementation

uses
  IdGlobal,
  IdStrings;

const
  MaxWeekAdd : Cardinal = $FFFFFFFF div IdDaysInWeek;
  MaxMinutesAdd : Cardinal = $FFFFFFFF div IdSecondsInMinute;
  DIGITS : String = '0123456789'; {Do not Localize}


/////////////
// IdDateTime
/////////////

constructor TIdDateTimeStamp.Create;
begin
  inherited Create(AOwner);
  Zero;
  FTimeZone := 0;
end;

destructor TIdDateTimeStamp.Destroy;
begin
  inherited;
end;

procedure TIdDateTimeStamp.AddDays;
var
  i : Integer;
begin
  // First 'round off' the current day of the year.  This is done to prevent    {Do not Localize}
  // miscalculations in leap years and also as an optimisation for small
  // increments.
  if (ANumber > Cardinal(DaysInYear - FDay)) and (not (FDay = 1)) then begin
    ANumber := ANumber - Cardinal(DaysInYear - FDay);
    FDay := 0;
    AddYears(1);
  end else begin
    // The number of days added is contained within this year.
    FDay := FDay + Integer(ANumber);
    if (FDay > DaysInYear) then
    begin
      ANumber := FDay;
      FDay := 0;
      AddDays(ANumber);
    end;
    Exit;
  end;

  if ANumber >= IdDaysInLeapYearCycle then begin
    i := ANumber div IdDaysInLeapYearCycle;
    AddYears(i * IdYearsInLeapYearCycle);
    ANumber := ANumber - Cardinal(i * IdDaysInLeapYearCycle);
  end;

  if ANumber >= IdDaysInLeapCentury then begin
    while ANumber >= IDDaysInLeapCentury do begin
      i := FYear div 100;

      if i mod 4 = 3 then begin
        // Going forward through a 'leap' century    {Do not Localize}
        AddYears(IdYearsInCentury);
        ANumber := ANumber - Cardinal(IdDaysInLeapCentury);
      end else begin