inc/RRule.php

   1 <?php
   2 /**
   3 * Class for parsing RRule and getting us the dates
   4 *
   5 * @package   awl
   6 * @subpackage   caldav
   7 * @author    Andrew McMillan <andrew@catalyst.net.nz>
   8 * @copyright Catalyst .Net Ltd
   9 * @license   http://gnu.org/copyleft/gpl.html GNU GPL v2
  10 */
  11
  12 $ical_weekdays = array( 'SU' => 0, 'MO' => 1, 'TU' => 2, 'WE' => 3, 'TH' => 4, 'FR' => 5, 'SA' => 6 );
  13
  14 /**
  15 * A Class for handling dates in iCalendar format.  We do make the simplifying assumption
  16 * that all date handling in here is normalised to GMT.  One day we might provide some
  17 * functions to do that, but for now it is done externally.
  18 *
  19 * @package awl
  20 */
  21 class iCalDate {
  22   /**#@+
  23   * @access private
  24   */
  25
  26   /** Text version */
  27   var $_text;
  28
  29   /** Epoch version */
  30   var $_epoch;
  31
  32   /** Fragmented parts */
  33   var $_yy;
  34   var $_mo;
  35   var $_dd;
  36   var $_hh;
  37   var $_mi;
  38   var $_ss;
  39   var $_tz;
  40
  41   /** Which day of the week does the week start on */
  42   var $_wkst;
  43
  44   /**#@-*/
  45
  46   /**
  47   * The constructor takes either an iCalendar date, a text string formatted as
  48   * an iCalendar date, or epoch seconds.
  49   */
  50   function iCalDate( $input ) {
  51     if ( gettype($input) == 'object' ) {
  52       $this->_text = $input->_text;
  53       $this->_epoch = $input->_epoch;
  54       $this->_yy = $input->_yy;
  55       $this->_mo = $input->_mo;
  56       $this->_dd = $input->_dd;
  57       $this->_hh = $input->_hh;
  58       $this->_mi = $input->_mi;
  59       $this->_ss = $input->_ss;
  60       $this->_tz = $input->_tz;
  61       return;
  62     }
  63
  64     $this->_wkst = 1; // Monday
  65     if ( preg_match( '/^\d{8}[T ]\d{6}$/', $input ) ) {
  66       $this->SetLocalDate($input);
  67     }
  68     else if ( preg_match( '/^\d{8}[T ]\d{6}Z$/', $input ) ) {
  69       $this->SetGMTDate($input);
  70     }
  71     else if ( intval($input) == 0 ) {
  72       $this->SetLocalDate(strtotime($input));
  73       return;
  74     }
  75     else {
  76       $this->SetEpochDate($input);
  77     }
  78   }
  79
  80
  81   /**
  82   * Set the date from a text string
  83   */
  84   function SetGMTDate( $input ) {
  85     $this->_text = $input;
  86     $this->_PartsFromText();
  87     $this->_GMTEpochFromParts();
  88   }
  89
  90
  91   /**
  92   * Set the date from a text string
  93   */
  94   function SetLocalDate( $input ) {
  95     $this->_text = $input;
  96     $this->_PartsFromText();
  97     $this->_EpochFromParts();
  98   }
  99
 100
 101   /**
 102   * Set the date from an epoch
 103   */
 104   function SetEpochDate( $input ) {
 105     $this->_epoch = intval($input);
 106     $this->_TextFromEpoch();
 107     $this->_PartsFromText();
 108   }
 109
 110
 111   /**
 112   * Given an epoch date, convert it to text
 113   */
 114   function _TextFromEpoch() {
 115     $this->_text = date('Ymd\THis', $this->_epoch );
 116 //    dbg_error_log( "RRule", " Text %s from epoch %d", $this->_text, $this->_epoch );
 117   }
 118
 119   /**
 120   * Given a GMT epoch date, convert it to text
 121   */
 122   function _GMTTextFromEpoch() {
 123     $this->_text = gmdate('Ymd\THis', $this->_epoch );
 124 //    dbg_error_log( "RRule", " Text %s from epoch %d", $this->_text, $this->_epoch );
 125   }
 126
 127   /**
 128   * Given a text date, convert it to parts
 129   */
 130   function _PartsFromText() {
 131     $this->_yy = intval(substr($this->_text,0,4));
 132     $this->_mo = intval(substr($this->_text,4,2));
 133     $this->_dd = intval(substr($this->_text,6,2));
 134     $this->_hh = intval(substr($this->_text,9,2));
 135     $this->_mi = intval(substr($this->_text,11,2));
 136     $this->_ss = intval(substr($this->_text,13,2));
 137   }
 138
 139
 140   /**
 141   * Given a GMT text date, convert it to an epoch
 142   */
 143   function _GMTEpochFromParts() {
 144     $this->_epoch = gmmktime ( $this->_hh, $this->_mi, $this->_ss, $this->_mo, $this->_dd, $this->_yy );
 145 //    dbg_error_log( "RRule", " Epoch %d from %04d-%02d-%02d %02d:%02d:%02d", $this->_epoch, $this->_yy, $this->_mo, $this->_dd, $this->_hh, $this->_mi, $this->_ss );
 146   }
 147
 148
 149   /**
 150   * Given a local text date, convert it to an epoch
 151   */
 152   function _EpochFromParts() {
 153     $this->_epoch = mktime ( $this->_hh, $this->_mi, $this->_ss, $this->_mo, $this->_dd, $this->_yy );
 154 //    dbg_error_log( "RRule", " Epoch %d from %04d-%02d-%02d %02d:%02d:%02d", $this->_epoch, $this->_yy, $this->_mo, $this->_dd, $this->_hh, $this->_mi, $this->_ss );
 155   }
 156
 157
 158   /**
 159   * Set the day of week used for calculation of week starts
 160   *
 161   * @param string $weekstart The day of the week which is the first business day.
 162   */
 163   function SetWeekStart($weekstart) {
 164     global $ical_weekdays;
 165     $this->_wkst = $ical_weekdays[$weekstart];
 166   }
 167
 168
 169   /**
 170   * Set the day of week used for calculation of week starts
 171   */
 172   function Render( $fmt = 'Y-m-d H:i:s' ) {
 173     return date( $fmt, $this->_epoch );
 174   }
 175
 176
 177   /**
 178   * Render the date as GMT
 179   */
 180   function RenderGMT( $fmt = 'Ymd\THis\Z' ) {
 181     return gmdate( $fmt, $this->_epoch );
 182   }
 183
 184
 185   /**
 186   * No of days in a month 1(Jan) - 12(Dec)
 187   */
 188   function DaysInMonth( $mo=false, $yy=false ) {
 189     if ( $mo === false ) $mo = $this->_mo;
 190     switch( $mo ) {
 191       case  1: // January
 192       case  3: // March
 193       case  5: // May
 194       case  7: // July
 195       case  8: // August
 196       case 10: // October
 197       case 12: // December
 198         return 31;
 199         break;
 200
 201       case  4: // April
 202       case  6: // June
 203       case  9: // September
 204       case 11: // November
 205         return 30;
 206         break;
 207
 208       case  2: // February
 209         if ( $yy === false ) $yy = $this->_yy;
 210         if ( (($yy % 4) == 0) && ((($yy % 100) != 0) || (($yy % 400) == 0) ) ) return 29;
 211         return 28;
 212         break;
 213
 214       default:
 215         dbg_error_log( "ERROR"," Invalid month of '%s' passed to DaysInMonth", $mo );
 216         break;
 217
 218     }
 219   }
 220
 221
 222   /**
 223   * Set the day in the month to what we have been given
 224   */
 225   function SetMonthDay( $dd ) {
 226     if ( $dd == $this->_dd ) return; // Shortcut
 227     $dd = min($dd,$this->DaysInMonth());
 228     $this->_dd = $dd;
 229     $this->_EpochFromParts();
 230     $this->_TextFromEpoch();
 231   }
 232
 233
 234   /**
 235   * Add some number of months to a date
 236   */
 237   function AddMonths( $mo ) {
 238 //    dbg_error_log( "RRule", " Adding %d months to %s", $mo, $this->_text );
 239     $this->_mo += $mo;
 240     while ( $this->_mo < 1 ) {
 241       $this->_mo += 12;
 242       $this->_yy--;
 243     }
 244     while ( $this->_mo > 12 ) {
 245       $this->_mo -= 12;
 246       $this->_yy++;
 247     }
 248
 249     if ( ($this->_dd > 28 && $this->_mo == 2) || $this->_dd > 30 ) {
 250       // Ensure the day of month is still reasonable and coerce to last day of month if needed
 251       $dim = $this->DaysInMonth();
 252       if ( $this->_dd > $dim ) {
 253         $this->_dd = $dim;
 254       }
 255     }
 256     $this->_EpochFromParts();
 257     $this->_TextFromEpoch();
 258 //    dbg_error_log( "RRule", " Added %d months and got %s", $mo, $this->_text );
 259   }
 260
 261
 262   /**
 263   * Add some integer number of days to a date
 264   */
 265   function AddDays( $dd ) {
 266     $at_start = $this->_text;
 267     $this->_dd += $dd;
 268     while ( 1 > $this->_dd ) {
 269       $this->_mo--;
 270       if ( $this->_mo < 1 ) {
 271         $this->_mo += 12;
 272         $this->_yy--;
 273       }
 274       $this->_dd += $this->DaysInMonth();
 275     }
 276     while ( ($dim = $this->DaysInMonth($this->_mo)) < $this->_dd ) {
 277       $this->_dd -= $dim;
 278       $this->_mo++;
 279       if ( $this->_mo > 12 ) {
 280         $this->_mo -= 12;
 281         $this->_yy++;
 282       }
 283     }
 284     $this->_EpochFromParts();
 285     $this->_TextFromEpoch();
 286 //    dbg_error_log( "RRule", " Added %d days to %s and got %s", $dd, $at_start, $this->_text );
 287   }
 288
 289
 290   /**
 291   * Add duration
 292   */
 293   function AddDuration( $duration ) {
 294     if ( strstr($duration,'T') === false ) $duration .= 'T';
 295     list( $sign, $days, $time ) = preg_split( '/[PT]/', $duration );
 296     $sign = ( $sign == "-" ? -1 : 1);
 297 //    dbg_error_log( "RRule", " Adding duration to '%s' of sign: %d,  days: %s,  time: %s", $this->_text, $sign, $days, $time );
 298     if ( preg_match( '/(\d+)(D|W)/', $days, $matches ) ) {
 299       $days = intval($matches[1]);
 300       if ( $matches[2] == 'W' ) $days *= 7;
 301       $this->AddDays( $days * $sign );
 302     }
 303     $hh = 0;    $mi = 0;    $ss = 0;
 304     if ( preg_match( '/(\d+)(H)/', $time, $matches ) )  $hh = $matches[1];
 305     if ( preg_match( '/(\d+)(M)/', $time, $matches ) )  $mi = $matches[1];
 306     if ( preg_match( '/(\d+)(S)/', $time, $matches ) )  $ss = $matches[1];
 307
 308 //    dbg_error_log( "RRule", " Adding %02d:%02d:%02d * %d to %02d:%02d:%02d", $hh, $mi, $ss, $sign, $this->_hh, $this->_mi, $this->_ss );
 309     $this->_hh += ($hh * $sign);
 310     $this->_mi += ($mi * $sign);
 311     $this->_ss += ($ss * $sign);
 312
 313     if ( $this->_ss < 0 ) {  $this->_mi -= (intval(abs($this->_ss/60))+1); $this->_ss += ((intval(abs($this->_mi/60))+1) * 60); }
 314     if ( $this->_ss > 59) {  $this->_mi += (intval(abs($this->_ss/60))+1); $this->_ss -= ((intval(abs($this->_mi/60))+1) * 60); }
 315     if ( $this->_mi < 0 ) {  $this->_hh -= (intval(abs($this->_mi/60))+1); $this->_mi += ((intval(abs($this->_mi/60))+1) * 60); }
 316     if ( $this->_mi > 59) {  $this->_hh += (intval(abs($this->_mi/60))+1); $this->_mi -= ((intval(abs($this->_mi/60))+1) * 60); }
 317     if ( $this->_hh < 0 ) {  $this->AddDays( -1 * (intval(abs($this->_hh/24))+1) );  $this->_hh += ((intval(abs($this->_hh/24))+1)*24);  }
 318     if ( $this->_hh > 23) {  $this->AddDays( (intval(abs($this->_hh/24))+1) );       $this->_hh -= ((intval(abs($this->_hh/24))+1)*24);  }
 319
 320     $this->_EpochFromParts();
 321     $this->_TextFromEpoch();
 322   }
 323
 324
 325   /**
 326   * Produce an iCalendar format DURATION for the difference between this an another iCalDate
 327   *
 328   * @param date $from The start of the period
 329   * @return string The date difference, as an iCalendar duration format
 330   */
 331   function DateDifference( $from ) {
 332     if ( !is_object($from) ) {
 333       $from = new iCalDate($from);
 334     }
 335     if ( $from->_epoch < $this->_epoch ) {
 336       /** One way to simplify is to always go for positive differences */
 337       return( "-". $from->DateDifference( $self ) );
 338     }
 339 //    if ( $from->_yy == $this->_yy && $from->_mo == $this->_mo ) {
 340       /** Also somewhat simpler if we can use seconds */
 341       $diff = $from->_epoch - $this->_epoch;
 342       $result = "";
 343       if ( $diff >= 86400) {
 344         $result = intval($diff / 86400);
 345         $diff = $diff % 86400;
 346         if ( $diff == 0 && (($result % 7) == 0) ) {
 347           // Duration is an integer number of weeks.
 348           $result .= intval($result / 7) . "W";
 349           return $result;
 350         }
 351         $result .= "D";
 352       }
 353       $result = "P".$result."T";
 354       if ( $diff >= 3600) {
 355         $result .= intval($diff / 3600) . "H";
 356         $diff = $diff % 3600;
 357       }
 358       if ( $diff >= 60) {
 359         $result .= intval($diff / 60) . "M";
 360         $diff = $diff % 60;
 361       }
 362       if ( $diff > 0) {
 363         $result .= intval($diff) . "S";
 364       }
 365       return $result;
 366 //    }
 367
 368 /**
 369 * From an intense reading of RFC2445 it appears that durations which are not expressible
 370 * in Weeks/Days/Hours/Minutes/Seconds are invalid.
 371 *  ==> This code is not needed then :-)
 372     $yy = $from->_yy - $this->_yy;
 373     $mo = $from->_mo - $this->_mo;
 374     $dd = $from->_dd - $this->_dd;
 375     $hh = $from->_hh - $this->_hh;
 376     $mi = $from->_mi - $this->_mi;
 377     $ss = $from->_ss - $this->_ss;
 378
 379     if ( $ss < 0 ) {  $mi -= 1;   $ss += 60;  }
 380     if ( $mi < 0 ) {  $hh -= 1;   $mi += 60;  }
 381     if ( $hh < 0 ) {  $dd -= 1;   $hh += 24;  }
 382     if ( $dd < 0 ) {  $mo -= 1;   $dd += $this->DaysInMonth();  } // Which will use $this->_(mo|yy) - seemingly sensible
 383     if ( $mo < 0 ) {  $yy -= 1;   $mo += 12;  }
 384
 385     $result = "";
 386     if ( $yy > 0) {    $result .= $yy."Y";   }
 387     if ( $mo > 0) {    $result .= $mo."M";   }
 388     if ( $dd > 0) {    $result .= $dd."D";   }
 389     $result .= "T";
 390     if ( $hh > 0) {    $result .= $hh."H";   }
 391     if ( $mi > 0) {    $result .= $mi."M";   }
 392     if ( $ss > 0) {    $result .= $ss."S";   }
 393     return $result;
 394 */
 395   }
 396
 397   /**
 398   * Test to see if our _mo matches something in the list of months we have received.
 399   * @param string $monthlist A comma-separated list of months.
 400   * @return boolean Whether this date falls within one of those months.
 401   */
 402   function TestByMonth( $monthlist ) {
 403 //    dbg_error_log( "RRule", " Testing BYMONTH %s against month %d", (isset($monthlist) ? $monthlist : "no month list"), $this->_mo );
 404     if ( !isset($monthlist) ) return true;  // If BYMONTH is not specified any month is OK
 405     $months = array_flip(explode( ',',$monthlist ));
 406     return isset($months[$this->_mo]);
 407   }
 408
 409   /**
 410   * Applies any BYDAY to the month to return a set of days
 411   * @param string $byday The BYDAY rule
 412   * @return array An array of the day numbers for the month which meet the rule.
 413   */
 414   function GetMonthByDay($byday) {
 415 //    dbg_error_log( "RRule", " Applying BYDAY %s to month", $byday );
 416     $days_in_month = $this->DaysInMonth();
 417     $dayrules = explode(',',$byday);
 418     $set = array();
 419     $first_dow = (date('w',$this->_epoch) - $this->_dd + 36) % 7;
 420     foreach( $dayrules AS $k => $v ) {
 421       $days = $this->MonthDays($first_dow,$days_in_month,$v);
 422       foreach( $days AS $k2 => $v2 ) {
 423         $set[$v2] = $v2;
 424       }
 425     }
 426     asort( $set, SORT_NUMERIC );
 427     return $set;
 428   }
 429
 430   /**
 431   * Applies any BYMONTHDAY to the month to return a set of days
 432   * @param string $bymonthday The BYMONTHDAY rule
 433   * @return array An array of the day numbers for the month which meet the rule.
 434   */
 435   function GetMonthByMonthDay($bymonthday) {
 436 //    dbg_error_log( "RRule", " Applying BYMONTHDAY %s to month", $bymonthday );
 437     $days_in_month = $this->DaysInMonth();
 438     $dayrules = explode(',',$bymonthday);
 439     $set = array();
 440     foreach( $dayrules AS $k => $v ) {
 441       $v = intval($v);
 442       if ( $v > 0 && $v <= $days_in_month ) $set[$v] = $v;
 443     }
 444     asort( $set, SORT_NUMERIC );
 445     return $set;
 446   }
 447
 448
 449   /**
 450   * Applies any BYDAY to the week to return a set of days
 451   * @param string $byday The BYDAY rule
 452   * @param string $increasing When we are moving by months, we want any day of the week, but when by day we only want to increase. Default false.
 453   * @return array An array of the day numbers for the week which meet the rule.
 454   */
 455   function GetWeekByDay($byday, $increasing = false) {
 456     global $ical_weekdays;
 457 //    dbg_error_log( "RRule", " Applying BYDAY %s to week", $byday );
 458     $days = explode(',',$byday);
 459     $dow = date('w',$this->_epoch);
 460     $set = array();
 461     foreach( $days AS $k => $v ) {
 462       $daynum = $ical_weekdays[$v];
 463       $dd = $this->_dd - $dow + $daynum;
 464       if ( $daynum < $this->_wkst ) $dd += 7;
 465       if ( $dd > $this->_dd || !$increasing ) $set[$dd] = $dd;
 466     }
 467     asort( $set, SORT_NUMERIC );
 468
 469     return $set;
 470   }
 471
 472
 473   /**
 474   * Test if $this is greater than the date parameter
 475   * @param string $lesser The other date, as a local time string
 476   * @return boolean True if $this > $lesser
 477   */
 478   function GreaterThan($lesser) {
 479     if ( is_object($lesser) ) {
 480 //      dbg_error_log( "RRule", " Comparing %s with %s", $this->_text, $lesser->_text );
 481       return ( $this->_text > $lesser->_text );
 482     }
 483 //    dbg_error_log( "RRule", " Comparing %s with %s", $this->_text, $lesser );
 484     return ( $this->_text > $lesser );  // These sorts of dates are designed that way...
 485   }
 486
 487
 488   /**
 489   * Test if $this is less than the date parameter
 490   * @param string $greater The other date, as a local time string
 491   * @return boolean True if $this < $greater
 492   */
 493   function LessThan($greater) {
 494     if ( is_object($greater) ) {
 495 //      dbg_error_log( "RRule", " Comparing %s with %s", $this->_text, $greater->_text );
 496       return ( $this->_text < $greater->_text );
 497     }
 498 //    dbg_error_log( "RRule", " Comparing %s with %s", $this->_text, $greater );
 499     return ( $this->_text < $greater );  // These sorts of dates are designed that way...
 500   }
 501
 502
 503   /**
 504   * Given a MonthDays string like "1MO", "-2WE" return an integer day of the month.
 505   *
 506   * @param string $dow_first The day of week of the first of the month.
 507   * @param string $days_in_month The number of days in the month.
 508   * @param string $dayspec The specification for a month day (or days) which we parse.
 509   *
 510   * @return array An array of the day numbers for the month which meet the rule.
 511   */
 512   function &MonthDays($dow_first, $days_in_month, $dayspec) {
 513     global $ical_weekdays;
 514 //    dbg_error_log( "RRule", "MonthDays: Getting days for '%s'. %d days starting on a %d", $dayspec, $days_in_month, $dow_first );
 515     $set = array();
 516     preg_match( '/([0-9-]*)(MO|TU|WE|TH|FR|SA|SU)/', $dayspec, $matches);
 517     $numeric = intval($matches[1]);
 518     $dow = $ical_weekdays[$matches[2]];
 519
 520     $first_matching_day = 1 + ($dow - $dow_first);
 521     while ( $first_matching_day < 1 ) $first_matching_day += 7;
 522
 523 //    dbg_error_log( "RRule", " MonthDays: Looking at %d for first match on (%s/%s), %d for numeric", $first_matching_day, $matches[1], $matches[2], $numeric );
 524
 525     while( $first_matching_day <= $days_in_month ) {
 526       $set[] = $first_matching_day;
 527       $first_matching_day += 7;
 528     }
 529
 530     if ( $numeric != 0 ) {
 531       if ( $numeric < 0 ) {
 532         $numeric += count($set);
 533       }
 534       else {
 535         $numeric--;
 536       }
 537       $answer = $set[$numeric];
 538       $set = array( $answer => $answer );
 539     }
 540     else {
 541       $answers = $set;
 542       $set = array();
 543       foreach( $answers AS $k => $v ) {
 544         $set[$v] = $v;
 545       }
 546     }
 547
 548 //    dbg_log_array( "RRule", 'MonthDays', $set, false );
 549
 550     return $set;
 551   }
 552
 553
 554   /**
 555   * Given set position descriptions like '1', '3', '11', '-3' or '-1' and a set,
 556   * return the subset matching the list of set positions.
 557   *
 558   * @param string $bysplist  The list of set positions.
 559   * @param string $set The set of days that we will apply the positions to.
 560   *
 561   * @return array The subset which matches.
 562   */
 563   function &ApplyBySetPos($bysplist, $set) {
 564 //    dbg_error_log( "RRule", " ApplyBySetPos: Applying set position '%s' to set of %d days", $bysplist, count($set) );
 565     $subset = array();
 566     sort( $set, SORT_NUMERIC );
 567     $max = count($set);
 568     $positions = explode( '[^0-9-]', $bysplist );
 569     foreach( $positions AS $k => $v ) {
 570       if ( $v < 0 ) {
 571         $v += $max;
 572       }
 573       else {
 574         $v--;
 575       }
 576       $subset[$set[$v]] = $set[$v];
 577     }
 578     return $subset;
 579   }
 580 }
 581
 582
 583
 584 /**
 585 * A Class for handling Events on a calendar which repeat
 586 *
 587 * Here's the spec, from RFC2445:
 588 *
 589      recur      = "FREQ"=freq *(
 590
 591                 ; either UNTIL or COUNT may appear in a 'recur',
 592                 ; but UNTIL and COUNT MUST NOT occur in the same 'recur'
 593
 594                 ( ";" "UNTIL" "=" enddate ) /
 595                 ( ";" "COUNT" "=" 1*DIGIT ) /
 596
 597                 ; the rest of these keywords are optional,
 598                 ; but MUST NOT occur more than once
 599
 600                 ( ";" "INTERVAL" "=" 1*DIGIT )          /
 601                 ( ";" "BYSECOND" "=" byseclist )        /
 602                 ( ";" "BYMINUTE" "=" byminlist )        /
 603                 ( ";" "BYHOUR" "=" byhrlist )           /
 604                 ( ";" "BYDAY" "=" bywdaylist )          /
 605                 ( ";" "BYMONTHDAY" "=" bymodaylist )    /
 606                 ( ";" "BYYEARDAY" "=" byyrdaylist )     /
 607                 ( ";" "BYWEEKNO" "=" bywknolist )       /
 608                 ( ";" "BYMONTH" "=" bymolist )          /
 609                 ( ";" "BYSETPOS" "=" bysplist )         /
 610                 ( ";" "WKST" "=" weekday )              /
 611                 ( ";" x-name "=" text )
 612                 )
 613
 614      freq       = "SECONDLY" / "MINUTELY" / "HOURLY" / "DAILY"
 615                 / "WEEKLY" / "MONTHLY" / "YEARLY"
 616
 617      enddate    = date
 618      enddate    =/ date-time            ;An UTC value
 619
 620      byseclist  = seconds / ( seconds *("," seconds) )
 621
 622      seconds    = 1DIGIT / 2DIGIT       ;0 to 59
 623
 624      byminlist  = minutes / ( minutes *("," minutes) )
 625
 626      minutes    = 1DIGIT / 2DIGIT       ;0 to 59
 627
 628      byhrlist   = hour / ( hour *("," hour) )
 629
 630      hour       = 1DIGIT / 2DIGIT       ;0 to 23
 631
 632      bywdaylist = weekdaynum / ( weekdaynum *("," weekdaynum) )
 633
 634      weekdaynum = [([plus] ordwk / minus ordwk)] weekday
 635
 636      plus       = "+"
 637
 638      minus      = "-"
 639
 640      ordwk      = 1DIGIT / 2DIGIT       ;1 to 53
 641
 642      weekday    = "SU" / "MO" / "TU" / "WE" / "TH" / "FR" / "SA"
 643      ;Corresponding to SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY,
 644      ;FRIDAY, SATURDAY and SUNDAY days of the week.
 645
 646      bymodaylist = monthdaynum / ( monthdaynum *("," monthdaynum) )
 647
 648      monthdaynum = ([plus] ordmoday) / (minus ordmoday)
 649
 650      ordmoday   = 1DIGIT / 2DIGIT       ;1 to 31
 651
 652      byyrdaylist = yeardaynum / ( yeardaynum *("," yeardaynum) )
 653
 654      yeardaynum = ([plus] ordyrday) / (minus ordyrday)
 655
 656      ordyrday   = 1DIGIT / 2DIGIT / 3DIGIT      ;1 to 366
 657
 658      bywknolist = weeknum / ( weeknum *("," weeknum) )
 659
 660      weeknum    = ([plus] ordwk) / (minus ordwk)
 661
 662      bymolist   = monthnum / ( monthnum *("," monthnum) )
 663
 664      monthnum   = 1DIGIT / 2DIGIT       ;1 to 12
 665
 666      bysplist   = setposday / ( setposday *("," setposday) )
 667
 668      setposday  = yeardaynum
 669 *
 670 * At this point we are going to restrict ourselves to parts of the RRULE specification
 671 * seen in the wild.  And by "in the wild" I don't include within people's timezone
 672 * definitions.  We always convert time zones to canonical names and assume the lower
 673 * level libraries can do a better job with them than we can.
 674 *
 675 * We will concentrate on:
 676 *  FREQ=(YEARLY|MONTHLY|WEEKLY|DAILY)
 677 *  UNTIL=
 678 *  COUNT=
 679 *  INTERVAL=
 680 *  BYDAY=
 681 *  BYMONTHDAY=
 682 *  BYSETPOS=
 683 *  WKST=
 684 *  BYYEARDAY=
 685 *  BYWEEKNO=
 686 *  BYMONTH=
 687 *
 688 *
 689 * @package awl
 690 */
 691 class RRule {
 692   /**#@+
 693   * @access private
 694   */
 695
 696   /** The first instance */
 697   var $_first;
 698
 699   /** The current instance pointer */
 700   var $_current;
 701
 702   /** An array of all the dates so far */
 703   var $_dates;
 704
 705   /** Whether we have calculated any of the dates */
 706   var $_started;
 707
 708   /** Whether we have calculated all of the dates */
 709   var $_finished;
 710
 711   /** The rule, in all it's glory */
 712   var $_rule;
 713
 714   /** The rule, in all it's parts */
 715   var $_part;
 716
 717   /**#@-*/
 718
 719   /**
 720   * The constructor takes a start date and an RRULE definition.  Both of these
 721   * follow the iCalendar standard.
 722   */
 723   function RRule( $start, $rrule ) {
 724     $this->_first = new iCalDate($start);
 725     $this->_finished = false;
 726     $this->_started = false;
 727     $this->_dates = array();
 728     $this->_current = -1;
 729
 730     $this->_rule = preg_replace( '/\s/m', '', $rrule);
 731     if ( substr($this->_rule, 0, 6) == 'RRULE:' ) {
 732       $this->_rule = substr($this->_rule, 6);
 733     }
 734
 735     dbg_error_log( "RRule", " new RRule: Start: %s, RRULE: %s", $start->Render(), $this->_rule );
 736
 737     $parts = explode(';',$this->_rule);
 738     $this->_part = array( 'INTERVAL' => 1 );
 739     foreach( $parts AS $k => $v ) {
 740       list( $type, $value ) = explode( '=', $v, 2);
 741 //      dbg_error_log( "RRule", " Parts of %s explode into %s and %s", $v, $type, $value );
 742       $this->_part[$type] = $value;
 743     }
 744
 745     // A little bit of validation
 746     if ( !isset($this->_part['FREQ']) ) {
 747       dbg_error_log( "ERROR", " RRULE MUST have FREQ=value (%s)", $rrule );
 748     }
 749     if ( isset($this->_part['COUNT']) && isset($this->_part['UNTIL'])  ) {
 750       dbg_error_log( "ERROR", " RRULE MUST NOT have both COUNT=value and UNTIL=value (%s)", $rrule );
 751     }
 752     if ( isset($this->_part['COUNT']) && intval($this->_part['COUNT']) < 1 ) {
 753       dbg_error_log( "ERROR", " RRULE MUST NOT have both COUNT=value and UNTIL=value (%s)", $rrule );
 754     }
 755     if ( !preg_match( '/(YEAR|MONTH|WEEK|DAI)LY/', $this->_part['FREQ']) ) {
 756       dbg_error_log( "ERROR", " RRULE Only FREQ=(YEARLY|MONTHLY|WEEKLY|DAILY) are supported at present (%s)", $rrule );
 757     }
 758     if ( $this->_part['FREQ'] == "YEARLY" ) {
 759       $this->_part['INTERVAL'] *= 12;
 760       $this->_part['FREQ'] = "MONTHLY";
 761     }
 762   }
 763
 764
 765   /**
 766   * Processes the array of $relative_days to $base and removes any
 767   * which are not within the scope of our rule.
 768   */
 769   function WithinScope( $base, $relative_days ) {
 770
 771     $ok_days = array();
 772
 773     $ptr = $this->_current;
 774
 775 //    dbg_error_log( "RRule", " WithinScope: Processing list of %d days relative to %s", count($relative_days), $base->Render() );
 776     foreach( $relative_days AS $day => $v ) {
 777
 778       $test = new iCalDate($base);
 779       $days_in_month = $test->DaysInMonth();
 780
 781 //      dbg_error_log( "RRule", " WithinScope: Testing for day %d based on %s, with %d days in month", $day, $test->Render(), $days_in_month );
 782       if ( $day > $days_in_month ) {
 783         $test->SetMonthDay($days_in_month);
 784         $test->AddDays(1);
 785         $day -= $days_in_month;
 786         $test->SetMonthDay($day);
 787       }
 788       else if ( $day < 1 ) {
 789         $test->SetMonthDay(1);
 790         $test->AddDays(-1);
 791         $days_in_month = $test->DaysInMonth();
 792         $day += $days_in_month;
 793         $test->SetMonthDay($day);
 794       }
 795       else {
 796         $test->SetMonthDay($day);
 797       }
 798
 799 //      dbg_error_log( "RRule", " WithinScope: Testing if %s is within scope", count($relative_days), $test->Render() );
 800
 801       if ( isset($this->_part['UNTIL']) && $test->GreaterThan($this->_part['UNTIL']) ) {
 802         $this->_finished = true;
 803         return $ok_days;
 804       }
 805
 806       // if ( $this->_current >= 0 && $test->LessThan($this->_dates[$this->_current]) ) continue;
 807
 808       if ( !$test->LessThan($this->_first) ) {
 809 //        dbg_error_log( "RRule", " WithinScope: Looks like %s is within scope", $test->Render() );
 810         $ok_days[$day] = $test;
 811         $ptr++;
 812       }
 813
 814       if ( isset($this->_part['COUNT']) && $ptr >= $this->_part['COUNT'] ) {
 815         $this->_finished = true;
 816         return $ok_days;
 817       }
 818
 819     }
 820
 821     return $ok_days;
 822   }
 823
 824
 825   /**
 826   * This is most of the meat of the RRULE processing, where we find the next date.
 827   * We maintain an
 828   */
 829   function &GetNext( ) {
 830
 831     if ( $this->_current < 0 ) {
 832       $next = new iCalDate($this->_first);
 833       $this->_current++;
 834     }
 835     else {
 836       $next = new iCalDate($this->_dates[$this->_current]);
 837       $this->_current++;
 838
 839       /**
 840       * If we have already found some dates we may just be able to return one of those.
 841       */
 842       if ( isset($this->_dates[$this->_current]) ) {
 843 //        dbg_error_log( "RRule", " GetNext: Returning %s, (%d'th)", $this->_dates[$this->_current]->Render(), $this->_current );
 844         return $this->_dates[$this->_current];
 845       }
 846       else {
 847         if ( isset($this->_part['COUNT']) && $this->_current >= $this->_part['COUNT'] ) // >= since _current is 0-based and COUNT is 1-based
 848           $this->_finished = true;
 849       }
 850     }
 851
 852     if ( $this->_finished ) {
 853       $next = null;
 854       return $next;
 855     }
 856
 857     $days = array();
 858     if ( isset($this->_part['WKST']) ) $next->SetWeekStart($this->_part['WKST']);
 859     if ( $this->_part['FREQ'] == "MONTHLY" ) {
 860 //      dbg_error_log( "RRule", " GetNext: Calculating more dates for MONTHLY rule" );
 861       $limit = 200;
 862       do {
 863         $limit--;
 864         do {
 865           $limit--;
 866           if ( $this->_started ) {
 867             $next->AddMonths($this->_part['INTERVAL']);
 868           }
 869           else {
 870             $this->_started = true;
 871           }
 872         }
 873         while ( isset($this->_part['BYMONTH']) && $limit > 0 && ! $next->TestByMonth($this->_part['BYMONTH']) );
 874
 875         if ( isset($this->_part['BYDAY']) ) {
 876           $days = $next->GetMonthByDay($this->_part['BYDAY']);
 877         }
 878         else if ( isset($this->_part['BYMONTHDAY']) ) {
 879           $days = $next->GetMonthByMonthDay($this->_part['BYMONTHDAY']);
 880         }
 881         else
 882           $days[$next->_dd] = $next->_dd;
 883
 884         if ( isset($this->_part['BYSETPOS']) ) {
 885           $days = $next->ApplyBySetpos($this->_part['BYSETPOS'], $days);
 886         }
 887
 888         $days = $this->WithinScope( $next, $days);
 889       }
 890       while( $limit && count($days) < 1 && ! $this->_finished );
 891 //      dbg_error_log( "RRule", " GetNext: Found %d days for MONTHLY rule", count($days) );
 892
 893     }
 894     else if ( $this->_part['FREQ'] == "WEEKLY" ) {
 895 //      dbg_error_log( "RRule", " GetNext: Calculating more dates for WEEKLY rule" );
 896       $limit = 200;
 897       do {
 898         $limit--;
 899         if ( $this->_started ) {
 900           $next->AddDays($this->_part['INTERVAL'] * 7);
 901         }
 902         else {
 903           $this->_started = true;
 904         }
 905
 906         if ( isset($this->_part['BYDAY']) ) {
 907           $days = $next->GetWeekByDay($this->_part['BYDAY'], false );
 908         }
 909         else
 910           $days[$next->_dd] = $next->_dd;
 911
 912         if ( isset($this->_part['BYSETPOS']) ) {
 913           $days = $next->ApplyBySetpos($this->_part['BYSETPOS'], $days);
 914         }
 915
 916         $days = $this->WithinScope( $next, $days);
 917       }
 918       while( $limit && count($days) < 1 && ! $this->_finished );
 919
 920 //      dbg_error_log( "RRule", " GetNext: Found %d days for WEEKLY rule", count($days) );
 921     }
 922     else if ( $this->_part['FREQ'] == "DAILY" ) {
 923 //      dbg_error_log( "RRule", " GetNext: Calculating more dates for DAILY rule" );
 924       $limit = 100;
 925       do {
 926         $limit--;
 927         if ( $this->_started ) {
 928           $next->AddDays($this->_part['INTERVAL']);
 929         }
 930
 931         if ( isset($this->_part['BYDAY']) ) {
 932           $days = $next->GetWeekByDay($this->_part['BYDAY'], $this->_started );
 933         }
 934         else
 935           $days[$next->_dd] = $next->_dd;
 936
 937         if ( isset($this->_part['BYSETPOS']) ) {
 938           $days = $next->ApplyBySetpos($this->_part['BYSETPOS'], $days);
 939         }
 940
 941         $days = $this->WithinScope( $next, $days);
 942         $this->_started = true;
 943       }
 944       while( $limit && count($days) < 1 && ! $this->_finished );
 945
 946 //      dbg_error_log( "RRule", " GetNext: Found %d days for DAILY rule", count($days) );
 947     }
 948
 949     $ptr = $this->_current;
 950     foreach( $days AS $k => $v ) {
 951       $this->_dates[$ptr++] = $v;
 952     }
 953
 954     if ( isset($this->_dates[$this->_current]) ) {
 955 //      dbg_error_log( "RRule", " GetNext: Returning %s, (%d'th)", $this->_dates[$this->_current]->Render(), $this->_current );
 956       return $this->_dates[$this->_current];
 957     }
 958     else {
 959 //      dbg_error_log( "RRule", " GetNext: Returning null date" );
 960       $next = null;
 961       return $next;
 962     }
 963   }
 964
 965 }
 966