lib/bennu/iCalendar_rfc2445.php

   1 <?php // $Id$
   2
   3 /**
   4  *  BENNU - PHP iCalendar library
   5  *  (c) 2005-2006 Ioannis Papaioannou (pj@moodle.org). All rights reserved.
   6  *
   7  *  Released under the LGPL.
   8  *
   9  *  See http://bennu.sourceforge.net/ for more information and downloads.
  10  *
  11  * @author Ioannis Papaioannou
  12  * @version $Id$
  13  * @license http://www.gnu.org/copyleft/lesser.html GNU Lesser General Public License
  14  */
  15
  16 /*
  17
  18    All names of properties, property parameters, enumerated property
  19    values and property parameter values are case-insensitive. However,
  20    all other property values are case-sensitive, unless otherwise
  21    stated.
  22
  23 */
  24
  25 define('RFC2445_CRLF',               "\r\n");
  26 define('RFC2445_WSP',                "\t ");
  27 define('RFC2445_WEEKDAYS',           'MO,TU,WE,TH,FR,SA,SU');
  28 define('RFC2445_FOLDED_LINE_LENGTH', 75);
  29
  30 define('RFC2445_REQUIRED', 0x01);
  31 define('RFC2445_OPTIONAL', 0x02);
  32 define('RFC2445_ONCE',     0x04);
  33
  34 define('RFC2445_PROP_FLAGS',       0);
  35 define('RFC2445_PROP_TYPE',        1);
  36 define('RFC2445_PROP_DEFAULT',     2);
  37
  38 define('RFC2445_XNAME', 'X-');
  39
  40 define('RFC2445_TYPE_BINARY',       0);
  41 define('RFC2445_TYPE_BOOLEAN',      1);
  42 define('RFC2445_TYPE_CAL_ADDRESS',  2);
  43 define('RFC2445_TYPE_DATE',         3);
  44 define('RFC2445_TYPE_DATE_TIME',    4);
  45 define('RFC2445_TYPE_DURATION',     5);
  46 define('RFC2445_TYPE_FLOAT',        6);
  47 define('RFC2445_TYPE_INTEGER',      7);
  48 define('RFC2445_TYPE_PERIOD',       8);
  49 define('RFC2445_TYPE_RECUR',        9);
  50 define('RFC2445_TYPE_TEXT',        10);
  51 define('RFC2445_TYPE_TIME',        11);
  52 define('RFC2445_TYPE_URI',         12); // CAL_ADDRESS === URI
  53 define('RFC2445_TYPE_UTC_OFFSET',  13);
  54
  55
  56 function rfc2445_fold($string) {
  57     if(strlen($string) <= RFC2445_FOLDED_LINE_LENGTH) {
  58         return $string;
  59     }
  60
  61     $retval = '';
  62
  63     while(strlen($string) > RFC2445_FOLDED_LINE_LENGTH) {
  64         $retval .= substr($string, 0, RFC2445_FOLDED_LINE_LENGTH - 1) . RFC2445_CRLF . ' ';
  65         $string  = substr($string, RFC2445_FOLDED_LINE_LENGTH - 1);
  66     }
  67
  68     $retval .= $string;
  69
  70     return $retval;
  71
  72 }
  73
  74 function rfc2445_unfold($string) {
  75     for($i = 0; $i < strlen(RFC2445_WSP); ++$i) {
  76         $string = str_replace(RFC2445_CRLF.substr(RFC2445_WSP, $i, 1), '', $string);
  77     }
  78
  79     return $string;
  80 }
  81
  82 function rfc2445_is_xname($name) {
  83
  84     // If it's less than 3 chars, it cannot be legal
  85     if(strlen($name) < 3) {
  86         return false;
  87     }
  88
  89     // If it contains an illegal char anywhere, reject it
  90     if(strspn($name, 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-') != strlen($name)) {
  91         return false;
  92     }
  93
  94     // To be legal, it must still start with "X-"
  95     return substr($name, 0, 2) === 'X-';
  96 }
  97
  98 function rfc2445_is_valid_value($value, $type) {
  99
 100     // This branch should only be taken with xname values
 101     if($type === NULL) {
 102         return true;
 103     }
 104
 105     switch($type) {
 106         case RFC2445_TYPE_CAL_ADDRESS:
 107         case RFC2445_TYPE_URI:
 108             if(!is_string($value)) {
 109                 return false;
 110             }
 111
 112             $valid_schemes = array('ftp', 'http', 'ldap', 'gopher', 'mailto', 'news', 'nntp', 'telnet', 'wais', 'file', 'prospero');
 113
 114             $pos = strpos($value, ':');
 115             if(!$pos) {
 116                 return false;
 117             }
 118
 119             $scheme = strtolower(substr($value, 0, $pos));
 120             $remain = substr($value, $pos + 1);
 121
 122             if(!in_array($scheme, $valid_schemes)) {
 123                 return false;
 124             }
 125
 126             if($scheme === 'mailto') {
 127                 $regexp = '^[a-zA-Z0-9]+[_a-zA-Z0-9\-]*(\.[_a-z0-9\-]+)*@(([0-9a-zA-Z\-]+\.)+[a-zA-Z][0-9a-zA-Z\-]+|([0-9]{1,3}\.){3}[0-9]{1,3})$';
 128             }
 129             else {
 130                 $regexp = '^//(.+(:.*)?@)?(([0-9a-zA-Z\-]+\.)+[a-zA-Z][0-9a-zA-Z\-]+|([0-9]{1,3}\.){3}[0-9]{1,3})(:[0-9]{1,5})?(/.*)?$';
 131             }
 132
 133             return ereg($regexp, $remain);
 134         break;
 135
 136         case RFC2445_TYPE_BINARY:
 137             if(!is_string($value)) {
 138                 return false;
 139             }
 140
 141             $len = strlen($value);
 142
 143             if($len % 4 != 0) {
 144                 return false;
 145             }
 146
 147             for($i = 0; $i < $len; ++$i) {
 148                 $ch = $value{$i};
 149                 if(!($ch >= 'a' && $ch <= 'z' || $ch >= 'A' && $ch <= 'Z' || $ch >= '0' && $ch <= '9' || $ch == '-' || $ch == '+')) {
 150                     if($ch == '=' && $len - $i <= 2) {
 151                         continue;
 152                     }
 153                     return false;
 154                 }
 155             }
 156             return true;
 157         break;
 158
 159         case RFC2445_TYPE_BOOLEAN:
 160             if(is_bool($value)) {
 161                 return true;
 162             }
 163             if(is_string($value)) {
 164                 $value = strtoupper($value);
 165                 return ($value == 'TRUE' || $value == 'FALSE');
 166             }
 167             return false;
 168         break;
 169
 170         case RFC2445_TYPE_DATE:
 171             if(is_int($value)) {
 172                 if($value < 0) {
 173                     return false;
 174                 }
 175                 $value = "$value";
 176             }
 177             else if(!is_string($value)) {
 178                 return false;
 179             }
 180
 181             if(strlen($value) != 8) {
 182                 return false;
 183             }
 184
 185             $y = intval(substr($value, 0, 4));
 186             $m = intval(substr($value, 4, 2));
 187             $d = intval(substr($value, 6, 2));
 188
 189             return checkdate($m, $d, $y);
 190         break;
 191
 192         case RFC2445_TYPE_DATE_TIME:
 193             if(!is_string($value) || strlen($value) < 15) {
 194                 return false;
 195             }
 196
 197             return($value{8} == 'T' &&
 198                    rfc2445_is_valid_value(substr($value, 0, 8), RFC2445_TYPE_DATE) &&
 199                    rfc2445_is_valid_value(substr($value, 9), RFC2445_TYPE_TIME));
 200         break;
 201
 202         case RFC2445_TYPE_DURATION:
 203             if(!is_string($value)) {
 204                 return false;
 205             }
 206
 207             $len = strlen($value);
 208
 209             if($len < 3) {
 210                 // Minimum conformant length: "P1W"
 211                 return false;
 212             }
 213
 214             if($value{0} == '+' || $value{0} == '-') {
 215                 $value = substr($value, 1);
 216                 --$len; // Don't forget to update this!
 217             }
 218
 219             if($value{0} != 'P') {
 220                 return false;
 221             }
 222
 223             // OK, now break it up
 224             $num = '';
 225             $allowed = 'WDT';
 226
 227             for($i = 1; $i < $len; ++$i) {
 228                 $ch = $value{$i};
 229                 if($ch >= '0' && $ch <= '9') {
 230                     $num .= $ch;
 231                     continue;
 232                 }
 233                 if(strpos($allowed, $ch) === false) {
 234                     // Non-numeric character which shouldn't be here
 235                     return false;
 236                 }
 237                 if($num === '' && $ch != 'T') {
 238                     // Allowed non-numeric character, but no digits came before it
 239                     return false;
 240                 }
 241
 242                 // OK, $ch now holds a character which tells us what $num is
 243                 switch($ch) {
 244                     case 'W':
 245                         // If duration in weeks is specified, this must end the string
 246                         return ($i == $len - 1);
 247                     break;
 248
 249                     case 'D':
 250                         // Days specified, now if anything comes after it must be a 'T'
 251                         $allowed = 'T';
 252                     break;
 253
 254                     case 'T':
 255                         // Starting to specify time, H M S are now valid delimiters
 256                         $allowed = 'HMS';
 257                     break;
 258
 259                     case 'H':
 260                         $allowed = 'M';
 261                     break;
 262
 263                     case 'M':
 264                         $allowed = 'S';
 265                     break;
 266
 267                     case 'S':
 268                         return ($i == $len - 1);
 269                     break;
 270                 }
 271
 272                 // If we 're going to continue, reset $num
 273                 $num = '';
 274
 275             }
 276
 277             // $num is kept for this reason: if we 're here, we ran out of chars
 278             // therefore $num must be empty for the period to be legal
 279             return ($num === '' && $ch != 'T');
 280
 281         break;
 282
 283         case RFC2445_TYPE_FLOAT:
 284             if(is_float($value)) {
 285                 return true;
 286             }
 287             if(!is_string($value) || $value === '') {
 288                 return false;
 289             }
 290
 291             $dot = false;
 292             $int = false;
 293             $len = strlen($value);
 294             for($i = 0; $i < $len; ++$i) {
 295                 switch($value{$i}) {
 296                     case '-': case '+':
 297                         // A sign can only be seen at position 0 and cannot be the only char
 298                         if($i != 0 || $len == 1) {
 299                             return false;
 300                         }
 301                     break;
 302                     case '.':
 303                         // A second dot is an error
 304                         // Make sure we had at least one int before the dot
 305                         if($dot || !$int) {
 306                             return false;
 307                         }
 308                         $dot = true;
 309                         // Make also sure that the float doesn't end with a dot
 310                         if($i == $len - 1) {
 311                             return false;
 312                         }
 313                     break;
 314                     case '0': case '1': case '2': case '3': case '4':
 315                     case '5': case '6': case '7': case '8': case '9':
 316                         $int = true;
 317                     break;
 318                     default:
 319                         // Any other char is a no-no
 320                         return false;
 321                     break;
 322                 }
 323             }
 324             return true;
 325         break;
 326
 327         case RFC2445_TYPE_INTEGER:
 328             if(is_int($value)) {
 329                 return true;
 330             }
 331             if(!is_string($value) || $value === '') {
 332                 return false;
 333             }
 334
 335             if($value{0} == '+' || $value{0} == '-') {
 336                 if(strlen($value) == 1) {
 337                     return false;
 338                 }
 339                 $value = substr($value, 1);
 340             }
 341
 342             if(strspn($value, '0123456789') != strlen($value)) {
 343                 return false;
 344             }
 345
 346             return ($value >= -2147483648 && $value <= 2147483647);
 347         break;
 348
 349         case RFC2445_TYPE_PERIOD:
 350             if(!is_string($value) || empty($value)) {
 351                 return false;
 352             }
 353
 354             $parts = explode('/', $value);
 355             if(count($parts) != 2) {
 356                 return false;
 357             }
 358
 359             if(!rfc2445_is_valid_value($parts[0], RFC2445_TYPE_DATE_TIME)) {
 360                 return false;
 361             }
 362
 363             // Two legal cases for the second part:
 364             if(rfc2445_is_valid_value($parts[1], RFC2445_TYPE_DATE_TIME)) {
 365                 // It has to be after the start time, so
 366                 return ($parts[1] > $parts[0]);
 367             }
 368             else if(rfc2445_is_valid_value($parts[1], RFC2445_TYPE_DURATION)) {
 369                 // The period MUST NOT be negative
 370                 return ($parts[1]{0} != '-');
 371             }
 372
 373             // It seems to be illegal
 374             return false;
 375         break;
 376
 377         case RFC2445_TYPE_RECUR:
 378             if(!is_string($value)) {
 379                 return false;
 380             }
 381
 382             $parts = explode(';', strtoupper($value));
 383
 384             // First of all, we need at least a FREQ and a UNTIL or COUNT part, so...
 385             if(count($parts) < 2) {
 386                 return false;
 387             }
 388
 389             // Let's get that into a more easily comprehensible format
 390             $vars = array();
 391             foreach($parts as $part) {
 392
 393                 $pieces = explode('=', $part);
 394                 // There must be exactly 2 pieces, e.g. FREQ=WEEKLY
 395                 if(count($pieces) != 2) {
 396                     return false;
 397                 }
 398
 399                 // It's illegal for a variable to appear twice
 400                 if(isset($vars[$pieces[0]])) {
 401                     return false;
 402                 }
 403
 404                 // Sounds good
 405                 $vars[$pieces[0]] = $pieces[1];
 406             }
 407
 408             // OK... now to test everything else
 409
 410             // FREQ must be the first thing appearing
 411             reset($vars);
 412             if(key($vars) != 'FREQ') {
 413                 return false;
 414             }
 415
 416             // It's illegal to have both UNTIL and COUNT appear
 417             if(isset($vars['UNTIL']) && isset($vars['COUNT'])) {
 418                 return false;
 419             }
 420
 421             // Special case: BYWEEKNO is only valid for FREQ=YEARLY
 422             if(isset($vars['BYWEEKNO']) && $vars['FREQ'] != 'YEARLY') {
 423                 return false;
 424             }
 425
 426             // Special case: BYSETPOS is only valid if another BY option is specified
 427             if(isset($vars['BYSETPOS'])) {
 428                 $options = array('BYSECOND', 'BYMINUTE', 'BYHOUR', 'BYDAY', 'BYMONTHDAY', 'BYYEARDAY', 'BYWEEKNO', 'BYMONTH');
 429                 $defined = array_keys($vars);
 430                 $common  = array_intersect($options, $defined);
 431                 if(empty($common)) {
 432                     return false;
 433                 }
 434             }
 435
 436             // OK, now simply check if each element has a valid value,
 437             // unsetting them on the way. If at the end the array still
 438             // has some elements, they are illegal.
 439
 440             if($vars['FREQ'] != 'SECONDLY' && $vars['FREQ'] != 'MINUTELY' && $vars['FREQ'] != 'HOURLY' &&
 441                $vars['FREQ'] != 'DAILY'    && $vars['FREQ'] != 'WEEKLY' &&
 442                $vars['FREQ'] != 'MONTHLY'  && $vars['FREQ'] != 'YEARLY') {
 443                 return false;
 444             }
 445             unset($vars['FREQ']);
 446
 447             // Set this, we may need it later
 448             $weekdays = explode(',', RFC2445_WEEKDAYS);
 449
 450             if(isset($vars['UNTIL'])) {
 451                 if(rfc2445_is_valid_value($vars['UNTIL'], RFC2445_TYPE_DATE_TIME)) {
 452                     // The time MUST be in UTC format
 453                     if(!(substr($vars['UNTIL'], -1) == 'Z')) {
 454                         return false;
 455                     }
 456                 }
 457                 else if(!rfc2445_is_valid_value($vars['UNTIL'], RFC2445_TYPE_DATE_TIME)) {
 458                     return false;
 459                 }
 460             }
 461             unset($vars['UNTIL']);
 462
 463
 464             if(isset($vars['COUNT'])) {
 465                 if(empty($vars['COUNT'])) {
 466                     // This also catches the string '0', which makes no sense
 467                     return false;
 468                 }
 469                 if(strspn($vars['COUNT'], '0123456789') != strlen($vars['COUNT'])) {
 470                     return false;
 471                 }
 472             }
 473             unset($vars['COUNT']);
 474
 475
 476             if(isset($vars['INTERVAL'])) {
 477                 if(empty($vars['INTERVAL'])) {
 478                     // This also catches the string '0', which makes no sense
 479                     return false;
 480                 }
 481                 if(strspn($vars['INTERVAL'], '0123456789') != strlen($vars['INTERVAL'])) {
 482                     return false;
 483                 }
 484             }
 485             unset($vars['INTERVAL']);
 486
 487
 488             if(isset($vars['BYSECOND'])) {
 489                 if($vars['BYSECOND'] == '') {
 490                     return false;
 491                 }
 492                 // Comma also allowed
 493                 if(strspn($vars['BYSECOND'], '0123456789,') != strlen($vars['BYSECOND'])) {
 494                     return false;
 495                 }
 496                 $secs = explode(',', $vars['BYSECOND']);
 497                 foreach($secs as $sec) {
 498                     if($sec == '' || $sec < 0 || $sec > 59) {
 499                         return false;
 500                     }
 501                 }
 502             }
 503             unset($vars['BYSECOND']);
 504
 505
 506             if(isset($vars['BYMINUTE'])) {
 507                 if($vars['BYMINUTE'] == '') {
 508                     return false;
 509                 }
 510                 // Comma also allowed
 511                 if(strspn($vars['BYMINUTE'], '0123456789,') != strlen($vars['BYMINUTE'])) {
 512                     return false;
 513                 }
 514                 $mins = explode(',', $vars['BYMINUTE']);
 515                 foreach($mins as $min) {
 516                     if($min == '' || $min < 0 || $min > 59) {
 517                         return false;
 518                     }
 519                 }
 520             }
 521             unset($vars['BYMINUTE']);
 522
 523
 524             if(isset($vars['BYHOUR'])) {
 525                 if($vars['BYHOUR'] == '') {
 526                     return false;
 527                 }
 528                 // Comma also allowed
 529                 if(strspn($vars['BYHOUR'], '0123456789,') != strlen($vars['BYHOUR'])) {
 530                     return false;
 531                 }
 532                 $hours = explode(',', $vars['BYHOUR']);
 533                 foreach($hours as $hour) {
 534                     if($hour == '' || $hour < 0 || $hour > 23) {
 535                         return false;
 536                     }
 537                 }
 538             }
 539             unset($vars['BYHOUR']);
 540
 541
 542             if(isset($vars['BYDAY'])) {
 543                 if(empty($vars['BYDAY'])) {
 544                     return false;
 545                 }
 546
 547                 // First off, split up all values we may have
 548                 $days = explode(',', $vars['BYDAY']);
 549
 550                 foreach($days as $day) {
 551                     $daypart = substr($day, -2);
 552                     if(!in_array($daypart, $weekdays)) {
 553                         return false;
 554                     }
 555
 556                     if(strlen($day) > 2) {
 557                         $intpart = substr($day, 0, strlen($day) - 2);
 558                         if(!rfc2445_is_valid_value($intpart, RFC2445_TYPE_INTEGER)) {
 559                             return false;
 560                         }
 561                         if(intval($intpart) == 0) {
 562                             return false;
 563                         }
 564                     }
 565                 }
 566             }
 567             unset($vars['BYDAY']);
 568
 569
 570             if(isset($vars['BYMONTHDAY'])) {
 571                 if(empty($vars['BYMONTHDAY'])) {
 572                     return false;
 573                 }
 574                 $mdays = explode(',', $vars['BYMONTHDAY']);
 575                 foreach($mdays as $mday) {
 576                     if(!rfc2445_is_valid_value($mday, RFC2445_TYPE_INTEGER)) {
 577                         return false;
 578                     }
 579                     $mday = abs(intval($mday));
 580                     if($mday == 0 || $mday > 31) {
 581                         return false;
 582                     }
 583                 }
 584             }
 585             unset($vars['BYMONTHDAY']);
 586
 587
 588             if(isset($vars['BYYEARDAY'])) {
 589                 if(empty($vars['BYYEARDAY'])) {
 590                     return false;
 591                 }
 592                 $ydays = explode(',', $vars['BYYEARDAY']);
 593                 foreach($ydays as $yday) {
 594                     if(!rfc2445_is_valid_value($yday, RFC2445_TYPE_INTEGER)) {
 595                         return false;
 596                     }
 597                     $yday = abs(intval($yday));
 598                     if($yday == 0 || $yday > 366) {
 599                         return false;
 600                     }
 601                 }
 602             }
 603             unset($vars['BYYEARDAY']);
 604
 605
 606             if(isset($vars['BYWEEKNO'])) {
 607                 if(empty($vars['BYWEEKNO'])) {
 608                     return false;
 609                 }
 610                 $weeknos = explode(',', $vars['BYWEEKNO']);
 611                 foreach($weeknos as $weekno) {
 612                     if(!rfc2445_is_valid_value($weekno, RFC2445_TYPE_INTEGER)) {
 613                         return false;
 614                     }
 615                     $weekno = abs(intval($weekno));
 616                     if($weekno == 0 || $weekno > 53) {
 617                         return false;
 618                     }
 619                 }
 620             }
 621             unset($vars['BYWEEKNO']);
 622
 623
 624             if(isset($vars['BYMONTH'])) {
 625                 if(empty($vars['BYMONTH'])) {
 626                     return false;
 627                 }
 628                 // Comma also allowed
 629                 if(strspn($vars['BYMONTH'], '0123456789,') != strlen($vars['BYMONTH'])) {
 630                     return false;
 631                 }
 632                 $months = explode(',', $vars['BYMONTH']);
 633                 foreach($months as $month) {
 634                     if($month == '' || $month < 1 || $month > 12) {
 635                         return false;
 636                     }
 637                 }
 638             }
 639             unset($vars['BYMONTH']);
 640
 641
 642             if(isset($vars['BYSETPOS'])) {
 643                 if(empty($vars['BYSETPOS'])) {
 644                     return false;
 645                 }
 646                 $sets = explode(',', $vars['BYSETPOS']);
 647                 foreach($sets as $set) {
 648                     if(!rfc2445_is_valid_value($set, RFC2445_TYPE_INTEGER)) {
 649                         return false;
 650                     }
 651                     $set = abs(intval($set));
 652                     if($set == 0 || $set > 366) {
 653                         return false;
 654                     }
 655                 }
 656             }
 657             unset($vars['BYSETPOS']);
 658
 659
 660             if(isset($vars['WKST'])) {
 661                 if(!in_array($vars['WKST'], $weekdays)) {
 662                     return false;
 663                 }
 664             }
 665             unset($vars['WKST']);
 666
 667
 668             // Any remaining vars must be x-names
 669             if(empty($vars)) {
 670                 return true;
 671             }
 672
 673             foreach($vars as $name => $var) {
 674                 if(!rfc2445_is_xname($name)) {
 675                     return false;
 676                 }
 677             }
 678
 679             // At last, all is OK!
 680             return true;
 681
 682         break;
 683
 684         case RFC2445_TYPE_TEXT:
 685             return true;
 686         break;
 687
 688         case RFC2445_TYPE_TIME:
 689             if(is_int($value)) {
 690                 if($value < 0) {
 691                     return false;
 692                 }
 693                 $value = "$value";
 694             }
 695             else if(!is_string($value)) {
 696                 return false;
 697             }
 698
 699             if(strlen($value) == 7) {
 700                 if(strtoupper(substr($value, -1)) != 'Z') {
 701                     return false;
 702                 }
 703                 $value = substr($value, 0, 6);
 704             }
 705             if(strlen($value) != 6) {
 706                 return false;
 707             }
 708
 709             $h = intval(substr($value, 0, 2));
 710             $m = intval(substr($value, 2, 2));
 711             $s = intval(substr($value, 4, 2));
 712
 713             return ($h <= 23 && $m <= 59 && $s <= 60);
 714         break;
 715
 716         case RFC2445_TYPE_UTC_OFFSET:
 717             if(is_int($value)) {
 718                 if($value >= 0) {
 719                     $value = "+$value";
 720                 }
 721                 else {
 722                     $value = "$value";
 723                 }
 724             }
 725             else if(!is_string($value)) {
 726                 return false;
 727             }
 728
 729             if(strlen($value) == 7) {
 730                 $s = intval(substr($value, 5, 2));
 731                 $value = substr($value, 0, 5);
 732             }
 733             if(strlen($value) != 5 || $value == "-0000") {
 734                 return false;
 735             }
 736
 737             if($value{0} != '+' && $value{0} != '-') {
 738                 return false;
 739             }
 740
 741             $h = intval(substr($value, 1, 2));
 742             $m = intval(substr($value, 3, 2));
 743
 744             return ($h <= 23 && $m <= 59 && $s <= 59);
 745         break;
 746     }
 747
 748     // TODO: remove this assertion
 749     trigger_error('bad code path', E_USER_WARNING);
 750     var_dump($type);
 751     return false;
 752 }
 753
 754 function rfc2445_do_value_formatting($value, $type) {
 755     // Note: this does not only do formatting; it also does conversion to string!
 756     switch($type) {
 757         case RFC2445_TYPE_CAL_ADDRESS:
 758         case RFC2445_TYPE_URI:
 759             // Enclose in double quotes
 760             $value = '"'.$value.'"';
 761         break;
 762         case RFC2445_TYPE_TEXT:
 763             // Escape entities
 764             $value = strtr($value, array("\r\n" => '\\n', "\n" => '\\n', '\\' => '\\\\', ',' => '\\,', ';' => '\\;'));
 765         break;
 766     }
 767     return $value;
 768 }
 769
 770 function rfc2445_undo_value_formatting($value, $type) {
 771     switch($type) {
 772         case RFC2445_TYPE_CAL_ADDRESS:
 773         case RFC2445_TYPE_URI:
 774             // Trim beginning and end double quote
 775             $value = substr($value, 1, strlen($value) - 2);
 776         break;
 777         case RFC2445_TYPE_TEXT:
 778             // Unescape entities
 779             $value = strtr($value, array('\\n' => "\n", '\\N' => "\n", '\\\\' => '\\', '\\,' => ',', '\\;' => ';'));
 780         break;
 781     }
 782     return $value;
 783 }
 784
 785 ?>