lib/tablelib.php

   1 <?php // $Id$
   2
   3 define('TABLE_VAR_SORT',   1);
   4 define('TABLE_VAR_HIDE',   2);
   5 define('TABLE_VAR_SHOW',   3);
   6 define('TABLE_VAR_IFIRST', 4);
   7 define('TABLE_VAR_ILAST',  5);
   8 define('TABLE_VAR_PAGE',   6);
   9
  10 class flexible_table {
  11
  12     var $uniqueid        = NULL;
  13     var $attributes      = array();
  14     var $headers         = array();
  15     var $columns         = array();
  16     var $column_style    = array();
  17     var $column_class    = array();
  18     var $column_suppress = array();
  19     var $setup           = false;
  20     var $sess            = NULL;
  21     var $baseurl         = NULL;
  22     var $request         = array();
  23
  24     var $is_collapsible = false;
  25     var $is_sortable    = false;
  26     var $use_pages      = false;
  27     var $use_initials   = false;
  28
  29     var $maxsortkeys = 2;
  30     var $pagesize    = 30;
  31     var $currpage    = 0;
  32     var $totalrows   = 0;
  33     var $sort_default_column = NULL;
  34     var $sort_default_order  = SORT_ASC;
  35
  36     function flexible_table($uniqueid) {
  37         $this->uniqueid = $uniqueid;
  38         $this->request  = array(
  39             TABLE_VAR_SORT    => 'tsort',
  40             TABLE_VAR_HIDE    => 'thide',
  41             TABLE_VAR_SHOW    => 'tshow',
  42             TABLE_VAR_IFIRST  => 'tifirst',
  43             TABLE_VAR_ILAST   => 'tilast',
  44             TABLE_VAR_PAGE    => 'page'
  45         );
  46     }
  47
  48     function sortable($bool, $defaultcolumn = NULL, $defaultorder = SORT_ASC) {
  49         $this->is_sortable = $bool;
  50         $this->sort_default_column = $defaultcolumn;
  51         $this->sort_default_order  = $defaultorder;
  52     }
  53
  54     function collapsible($bool) {
  55         $this->is_collapsible = $bool;
  56     }
  57
  58     function pageable($bool) {
  59         $this->use_pages = $bool;
  60     }
  61
  62     function initialbars($bool) {
  63         $this->use_initials = $bool;
  64     }
  65
  66     function pagesize($perpage, $total) {
  67         $this->pagesize  = $perpage;
  68         $this->totalrows = $total;
  69         $this->use_pages = true;
  70     }
  71
  72     function set_control_variables($variables) {
  73         foreach($variables as $what => $variable) {
  74             if(isset($this->request[$what])) {
  75                 $this->request[$what] = $variable;
  76             }
  77         }
  78     }
  79
  80     function set_attribute($attribute, $value) {
  81         $this->attributes[$attribute] = $value;
  82     }
  83
  84     function column_suppress($column) {
  85         if(isset($this->column_suppress[$column])) {
  86             $this->column_suppress[$column] = true;
  87         }
  88     }
  89
  90     function column_class($column, $classname) {
  91         if(isset($this->column_class[$column])) {
  92             $this->column_class[$column] = ' '.$classname; // This space needed so that classnames don't run together in the HTML
  93         }
  94     }
  95
  96     function column_style($column, $property, $value) {
  97         if(isset($this->column_style[$column])) {
  98             $this->column_style[$column][$property] = $value;
  99         }
 100     }
 101
 102     function column_style_all($property, $value) {
 103         foreach(array_keys($this->columns) as $column) {
 104             $this->column_style[$column][$property] = $value;
 105         }
 106     }
 107
 108     function define_baseurl($url) {
 109         $this->reseturl = $url;
 110         if(!strpos($url, '?')) {
 111             $this->baseurl = $url.'?';
 112         }
 113         else {
 114             $this->baseurl = $url.'&amp;';
 115         }
 116     }
 117
 118     function define_columns($columns) {
 119         $this->columns = array();
 120         $this->column_style = array();
 121         $this->column_class = array();
 122         $colnum = 0;
 123
 124         foreach($columns as $column) {
 125             $this->columns[$column]         = $colnum++;
 126             $this->column_style[$column]    = array();
 127             $this->column_class[$column]    = '';
 128             $this->column_suppress[$column] = false;
 129         }
 130     }
 131
 132     function define_headers($headers) {
 133         $this->headers = $headers;
 134     }
 135
 136     function make_styles_string(&$styles) {
 137         if(empty($styles)) {
 138             return '';
 139         }
 140
 141         $string = ' style="';
 142         foreach($styles as $property => $value) {
 143             $string .= $property.':'.$value.';';
 144         }
 145         $string .= '"';
 146         return $string;
 147     }
 148
 149     function make_attributes_string(&$attributes) {
 150         if(empty($attributes)) {
 151             return '';
 152         }
 153
 154         $string = ' ';
 155         foreach($attributes as $attr => $value) {
 156             $string .= ($attr.'="'.$value.'" ');
 157         }
 158
 159         return $string;
 160     }
 161
 162     function setup() {
 163         global $SESSION, $CFG;
 164
 165         if(empty($this->columns) || empty($this->uniqueid)) {
 166             return false;
 167         }
 168
 169         if (!isset($SESSION->flextable)) {
 170             $SESSION->flextable = array();
 171         }
 172
 173         if(!isset($SESSION->flextable[$this->uniqueid])) {
 174             $SESSION->flextable[$this->uniqueid] = new stdClass;
 175             $SESSION->flextable[$this->uniqueid]->uniqueid = $this->uniqueid;
 176             $SESSION->flextable[$this->uniqueid]->collapse = array();
 177             $SESSION->flextable[$this->uniqueid]->sortby   = array();
 178             $SESSION->flextable[$this->uniqueid]->i_first  = '';
 179             $SESSION->flextable[$this->uniqueid]->i_last   = '';
 180         }
 181
 182         $this->sess = &$SESSION->flextable[$this->uniqueid];
 183
 184         if(!empty($_GET[$this->request[TABLE_VAR_SHOW]]) && isset($this->columns[$_GET[$this->request[TABLE_VAR_SHOW]]])) {
 185             // Show this column
 186             $this->sess->collapse[$_GET[$this->request[TABLE_VAR_SHOW]]] = false;
 187         }
 188         else if(!empty($_GET[$this->request[TABLE_VAR_HIDE]]) && isset($this->columns[$_GET[$this->request[TABLE_VAR_HIDE]]])) {
 189             // Hide this column
 190             $this->sess->collapse[$_GET[$this->request[TABLE_VAR_HIDE]]] = true;
 191             if(array_key_exists($_GET[$this->request[TABLE_VAR_HIDE]], $this->sess->sortby)) {
 192                 unset($this->sess->sortby[$_GET[$this->request[TABLE_VAR_HIDE]]]);
 193             }
 194         }
 195
 196         // Now, update the column attributes for collapsed columns
 197         foreach(array_keys($this->columns) as $column) {
 198             if(!empty($this->sess->collapse[$column])) {
 199                 $this->column_style[$column]['width'] = '10px';
 200             }
 201         }
 202
 203         if(
 204             !empty($_GET[$this->request[TABLE_VAR_SORT]]) &&
 205             (isset($this->columns[$_GET[$this->request[TABLE_VAR_SORT]]]) ||
 206                 (($_GET[$this->request[TABLE_VAR_SORT]] == 'firstname' || $_GET[$this->request[TABLE_VAR_SORT]] == 'lastname') && isset($this->columns['fullname']))
 207             ))
 208         {
 209             if(empty($this->sess->collapse[$_GET[$this->request[TABLE_VAR_SORT]]])) {
 210                 if(array_key_exists($_GET[$this->request[TABLE_VAR_SORT]], $this->sess->sortby)) {
 211                     // This key already exists somewhere. Change its sortorder and bring it to the top.
 212                     $sortorder = $this->sess->sortby[$_GET[$this->request[TABLE_VAR_SORT]]] == SORT_ASC ? SORT_DESC : SORT_ASC;
 213                     unset($this->sess->sortby[$_GET[$this->request[TABLE_VAR_SORT]]]);
 214                     $this->sess->sortby = array_merge(array($_GET[$this->request[TABLE_VAR_SORT]] => $sortorder), $this->sess->sortby);
 215                 }
 216                 else {
 217                     // Key doesn't exist, so just add it to the beginning of the array, ascending order
 218                     $this->sess->sortby = array_merge(array($_GET[$this->request[TABLE_VAR_SORT]] => SORT_ASC), $this->sess->sortby);
 219                 }
 220                 // Finally, make sure that no more than $this->maxsortkeys are present into the array
 221                 if(!empty($this->maxsortkeys) && ($sortkeys = count($this->sess->sortby)) > $this->maxsortkeys) {
 222                     while($sortkeys-- > $this->maxsortkeys) {
 223                         array_pop($this->sess->sortby);
 224                     }
 225                 }
 226             }
 227         }
 228
 229         // If we didn't sort just now, then use the default sort order if one is defined and the column exists
 230         if(empty($this->sess->sortby) && !empty($this->sort_default_column) && (isset($this->columns[$this->sort_default_column])
 231                                                                                 || (in_array('fullname',$this->columns)
 232                                                                                     && in_array($this->sort_default_column,
 233                                                                                                 array('firstname','lastname')))))  {
 234             $this->sess->sortby = array ($this->sort_default_column => ($this->sort_default_order == SORT_DESC ? SORT_DESC : SORT_ASC));
 235         }
 236
 237         if(isset($_GET[$this->request[TABLE_VAR_ILAST]])) {
 238             if(empty($_GET[$this->request[TABLE_VAR_ILAST]]) || is_numeric(strpos(get_string('alphabet'), $_GET[$this->request[TABLE_VAR_ILAST]]))) {
 239                 $this->sess->i_last = $_GET[$this->request[TABLE_VAR_ILAST]];
 240             }
 241         }
 242
 243         if(isset($_GET[$this->request[TABLE_VAR_IFIRST]])) {
 244             if(empty($_GET[$this->request[TABLE_VAR_IFIRST]]) || is_numeric(strpos(get_string('alphabet'), $_GET[$this->request[TABLE_VAR_IFIRST]]))) {
 245                 $this->sess->i_first = $_GET[$this->request[TABLE_VAR_IFIRST]];
 246             }
 247         }
 248
 249         if(empty($this->baseurl)) {
 250             $getcopy  = $_GET;
 251             unset($getcopy[$this->request[TABLE_VAR_SHOW]]);
 252             unset($getcopy[$this->request[TABLE_VAR_HIDE]]);
 253             unset($getcopy[$this->request[TABLE_VAR_SORT]]);
 254             unset($getcopy[$this->request[TABLE_VAR_IFIRST]]);
 255             unset($getcopy[$this->request[TABLE_VAR_ILAST]]);
 256             unset($getcopy[$this->request[TABLE_VAR_PAGE]]);
 257
 258             $strippedurl = strip_querystring(qualified_me());
 259
 260             if(!empty($getcopy)) {
 261                 $first = false;
 262                 $querystring = '';
 263                 foreach($getcopy as $var => $val) {
 264                     if(!$first) {
 265                         $first = true;
 266                         $querystring .= '?'.$var.'='.$val;
 267                     }
 268                     else {
 269                         $querystring .= '&amp;'.$var.'='.$val;
 270                     }
 271                 }
 272                 $this->reseturl =  $strippedurl.$querystring;
 273                 $querystring .= '&amp;';
 274             }
 275             else {
 276                 $this->reseturl =  $strippedurl.$querystring;
 277                 $querystring = '?';
 278             }
 279
 280             $this->baseurl = strip_querystring(qualified_me()) . $querystring;
 281         }
 282
 283         // If it's "the first time" we 've been here, forget the previous initials filters
 284         if(qualified_me() == $this->reseturl) {
 285             $this->sess->i_first = '';
 286             $this->sess->i_last  = '';
 287         }
 288
 289         $this->currpage = optional_param($this->request[TABLE_VAR_PAGE], 0);
 290         $this->setup = true;
 291
 292     /// Always introduce the "flexible" class for the table if not specified
 293     /// No attributes, add flexible class
 294         if (empty($this->attributes)) {
 295             $this->attributes['class'] = 'flexible';
 296     /// No classes, add flexible class
 297         } else if (!isset($this->attributes['class'])) {
 298             $this->attributes['class'] = 'flexible';
 299     /// No flexible class in passed classes, add flexible class
 300         } else if (!in_array('flexible', explode(' ', $this->attributes['class']))) {
 301             $this->attributes['class'] = trim('flexible ' . $this->attributes['class']);
 302         }
 303
 304     }
 305
 306     function get_sql_sort($uniqueid = NULL) {
 307         if($uniqueid === NULL) {
 308             // "Non-static" function call
 309             if(!$this->setup) {
 310                return false;
 311             }
 312             $sess = &$this->sess;
 313         }
 314         else {
 315             // "Static" function call
 316             global $SESSION;
 317             if(empty($SESSION->flextable[$uniqueid])) {
 318                return '';
 319             }
 320             $sess = &$SESSION->flextable[$uniqueid];
 321         }
 322
 323         if(!empty($sess->sortby)) {
 324             $sortstring = '';
 325             foreach($sess->sortby as $column => $order) {
 326                 if(!empty($sortstring)) {
 327                     $sortstring .= ', ';
 328                 }
 329                 $sortstring .= $column.($order == SORT_ASC ? ' ASC' : ' DESC');
 330             }
 331             return $sortstring;
 332         }
 333         return '';
 334     }
 335
 336     function get_page_start() {
 337         if(!$this->use_pages) {
 338             return '';
 339         }
 340         return $this->currpage * $this->pagesize;
 341     }
 342
 343     function get_page_size() {
 344         if(!$this->use_pages) {
 345             return '';
 346         }
 347         return $this->pagesize;
 348     }
 349
 350     function get_sql_where() {
 351         if(!isset($this->columns['fullname'])) {
 352             return '';
 353         }
 354
 355         $LIKE = sql_ilike();
 356         if(!empty($this->sess->i_first) && !empty($this->sess->i_last)) {
 357             return 'firstname '.$LIKE.' \''.$this->sess->i_first.'%\' AND lastname '.$LIKE.' \''.$this->sess->i_last.'%\'';
 358         }
 359         else if(!empty($this->sess->i_first)) {
 360             return 'firstname '.$LIKE.' \''.$this->sess->i_first.'%\'';
 361         }
 362         else if(!empty($this->sess->i_last)) {
 363             return 'lastname '.$LIKE.' \''.$this->sess->i_last.'%\'';
 364         }
 365
 366         return '';
 367     }
 368
 369     function get_initial_first() {
 370         if(!$this->use_initials) {
 371             return NULL;
 372         }
 373
 374         return $this->sess->i_first;
 375     }
 376
 377     function get_initial_last() {
 378         if(!$this->use_initials) {
 379             return NULL;
 380         }
 381
 382         return $this->sess->i_last;
 383     }
 384
 385     function print_html() {
 386         global $CFG;
 387
 388         if(!$this->setup) {
 389             return false;
 390         }
 391
 392         $colcount = count($this->columns);
 393
 394         // Do we need to print initial bars?
 395
 396         if($this->use_initials && isset($this->columns['fullname'])) {
 397
 398             $strall = get_string('all');
 399             $alpha  = explode(',', get_string('alphabet'));
 400
 401             // Bar of first initials
 402
 403             echo '<div class="initialbar firstinitial">'.get_string('firstname').' : ';
 404             if(!empty($this->sess->i_first)) {
 405                 echo '<a href="'.$this->baseurl.$this->request[TABLE_VAR_IFIRST].'=">'.$strall.'</a>';
 406             } else {
 407                 echo '<strong>'.$strall.'</strong>';
 408             }
 409             foreach ($alpha as $letter) {
 410                 if ($letter == $this->sess->i_first) {
 411                     echo ' <strong>'.$letter.'</strong>';
 412                 } else {
 413                     echo ' <a href="'.$this->baseurl.$this->request[TABLE_VAR_IFIRST].'='.$letter.'">'.$letter.'</a>';
 414                 }
 415             }
 416             echo '</div>';
 417
 418             // Bar of last initials
 419
 420             echo '<div class="initialbar lastinitial">'.get_string('lastname').' : ';
 421             if(!empty($this->sess->i_last)) {
 422                 echo '<a href="'.$this->baseurl.$this->request[TABLE_VAR_ILAST].'=">'.$strall.'</a>';
 423             } else {
 424                 echo '<strong>'.$strall.'</strong>';
 425             }
 426             foreach ($alpha as $letter) {
 427                 if ($letter == $this->sess->i_last) {
 428                     echo ' <strong>'.$letter.'</strong>';
 429                 } else {
 430                     echo ' <a href="'.$this->baseurl.$this->request[TABLE_VAR_ILAST].'='.$letter.'">'.$letter.'</a>';
 431                 }
 432             }
 433             echo '</div>';
 434
 435         }
 436
 437         // End of initial bars code
 438
 439         // Paging bar
 440         if($this->use_pages) {
 441             print_paging_bar($this->totalrows, $this->currpage, $this->pagesize, $this->baseurl, $this->request[TABLE_VAR_PAGE]);
 442         }
 443
 444         if (empty($this->data)) {
 445             print_heading(get_string('nothingtodisplay'));
 446             return true;
 447         }
 448
 449
 450         $suppress_enabled = array_sum($this->column_suppress);
 451         $suppress_lastrow = NULL;
 452         // Start of main data table
 453
 454         echo '<table'.$this->make_attributes_string($this->attributes).'>';
 455
 456         echo '<tr>';
 457         foreach($this->columns as $column => $index) {
 458             $icon_hide = '';
 459             $icon_sort = '';
 460
 461             if($this->is_collapsible) {
 462                 if(!empty($this->sess->collapse[$column])) {
 463                     // some headers contain < br/> tags, do not include in title
 464                     $icon_hide = ' <a href="'.$this->baseurl.$this->request[TABLE_VAR_SHOW].'='.$column.'"><img src="'.$CFG->pixpath.'/t/switch_plus.gif" title="'.get_string('show').' '.strip_tags($this->headers[$index]).'" alt="'.get_string('show').'" /></a>';
 465                 }
 466                 else if($this->headers[$index] !== NULL) {
 467                     // some headers contain < br/> tags, do not include in title
 468                     $icon_hide = ' <a href="'.$this->baseurl.$this->request[TABLE_VAR_HIDE].'='.$column.'"><img src="'.$CFG->pixpath.'/t/switch_minus.gif" title="'.get_string('hide').' '.strip_tags($this->headers[$index]).'" alt="'.get_string('hide').'" /></a>';
 469                 }
 470             }
 471
 472             $primary_sort_column = '';
 473             $primary_sort_order  = '';
 474             if(reset($this->sess->sortby)) {
 475                 $primary_sort_column = key($this->sess->sortby);
 476                 $primary_sort_order  = current($this->sess->sortby);
 477             }
 478
 479             switch($column) {
 480
 481                 case 'fullname':
 482                 if($this->is_sortable) {
 483                     $icon_sort_first = $icon_sort_last = '';
 484                     if($primary_sort_column == 'firstname') {
 485                         $lsortorder = get_string('asc');
 486                         if($primary_sort_order == SORT_ASC) {
 487                             $icon_sort_first = ' <img src="'.$CFG->pixpath.'/t/down.gif" alt="'.get_string('asc').'" />';
 488                             $fsortorder = get_string('asc');
 489                         }
 490                         else {
 491                             $icon_sort_first = ' <img src="'.$CFG->pixpath.'/t/up.gif" alt="'.get_string('desc').'" />';
 492                             $fsortorder = get_string('desc');
 493                         }
 494                     }
 495                     else if($primary_sort_column == 'lastname') {
 496                         $fsortorder = get_string('asc');
 497                         if($primary_sort_order == SORT_ASC) {
 498                             $icon_sort_last = ' <img src="'.$CFG->pixpath.'/t/down.gif" alt="'.get_string('asc').'" />';
 499                             $lsortorder = get_string('asc');
 500                         }
 501                         else {
 502                             $icon_sort_last = ' <img src="'.$CFG->pixpath.'/t/up.gif" alt="'.get_string('desc').'" />';
 503                             $lsortorder = get_string('desc');
 504                         }
 505                     } else {
 506                         $fsortorder = get_string('asc');
 507                         $lsortorder = get_string('asc');
 508                     }
 509                     $this->headers[$index] = '<a href="'.$this->baseurl.$this->request[TABLE_VAR_SORT].'=firstname">'.get_string('firstname').'<span class="accesshide">'.get_string('sortby').' '.get_string('firstname').' '.$fsortorder.'</span></a> '.$icon_sort_first.' / '.
 510                                           '<a href="'.$this->baseurl.$this->request[TABLE_VAR_SORT].'=lastname">'.get_string('lastname').'<span class="accesshide">'.get_string('sortby').' '.get_string('lastname').' '.$lsortorder.'</span></a> '.$icon_sort_last;
 511                 }
 512                 break;
 513
 514                 case 'userpic':
 515                     // do nothing, do not display sortable links
 516                 break;
 517
 518                 default:
 519                 if($this->is_sortable) {
 520                     if($primary_sort_column == $column) {
 521                         if($primary_sort_order == SORT_ASC) {
 522                             $icon_sort = ' <img src="'.$CFG->pixpath.'/t/down.gif" alt="'.get_string('asc').'" />';
 523                             $localsortorder = get_string('asc');
 524                         }
 525                         else {
 526                             $icon_sort = ' <img src="'.$CFG->pixpath.'/t/up.gif" alt="'.get_string('desc').'" />';
 527                             $localsortorder = get_string('desc');
 528                         }
 529                     } else {
 530                         $localsortorder = get_string('asc');
 531                     }
 532                     $this->headers[$index] = '<a href="'.$this->baseurl.$this->request[TABLE_VAR_SORT].'='.$column.'">'.$this->headers[$index].'<span class="accesshide">'.get_string('sortby').' '.$this->headers[$index].' '.$localsortorder.'</span></a>';
 533                 }
 534             }
 535
 536             if($this->headers[$index] === NULL) {
 537                 echo '<th class="header c'.$index.$this->column_class[$column].'" scope="col">&nbsp;</th>';
 538             }
 539             else if(!empty($this->sess->collapse[$column])) {
 540                 echo '<th class="header c'.$index.$this->column_class[$column].'" scope="col">'.$icon_hide.'</th>';
 541             }
 542             else {
 543                 // took out nowrap for accessibility, might need replacement
 544                 if (!is_array($this->column_style[$column])) {
 545                     // $usestyles = array('white-space:nowrap');
 546                     $usestyles = '';
 547                  } else {
 548                     // $usestyles = $this->column_style[$column]+array('white-space'=>'nowrap');
 549                     $usestyles = $this->column_style[$column];
 550                  }
 551                 echo '<th class="header c'.$index.$this->column_class[$column].'" '.$this->make_styles_string($usestyles).' scope="col">'.$this->headers[$index].$icon_sort.'<div class="commands">'.$icon_hide.'</div></th>';
 552             }
 553
 554         }
 555         echo '</tr>';
 556
 557         if(!empty($this->data)) {
 558             $oddeven = 1;
 559             $colbyindex = array_flip($this->columns);
 560             foreach($this->data as $row) {
 561                 $oddeven = $oddeven ? 0 : 1;
 562                 echo '<tr class="r'.$oddeven.'">';
 563
 564                 // If we have a separator, print it
 565                 if($row === NULL && $colcount) {
 566                     echo '<td colspan="'.$colcount.'"><div class="tabledivider"></div></td>';
 567                 }
 568                 else {
 569                     foreach($row as $index => $data) {
 570                         if($index >= $colcount) {
 571                             break;
 572                         }
 573                         $column = $colbyindex[$index];
 574                         echo '<td class="cell c'.$index.$this->column_class[$column].'"'.$this->make_styles_string($this->column_style[$column]).'>';
 575                         if(empty($this->sess->collapse[$column])) {
 576                             if($this->column_suppress[$column] && $suppress_lastrow !== NULL && $suppress_lastrow[$index] === $data) {
 577                                 echo '&nbsp;';
 578                             }
 579                             else {
 580                                 echo $data;
 581                             }
 582                         }
 583                         else {
 584                             echo '&nbsp;';
 585                         }
 586                         echo '</td>';
 587                     }
 588                 }
 589                 echo '</tr>';
 590                 if($suppress_enabled) {
 591                     $suppress_lastrow = $row;
 592                 }
 593             }
 594         }
 595
 596         echo '</table>';
 597
 598         // Paging bar
 599         if($this->use_pages) {
 600             print_paging_bar($this->totalrows, $this->currpage, $this->pagesize, $this->baseurl, $this->request[TABLE_VAR_PAGE]);
 601         }
 602     }
 603
 604     function add_data($row) {
 605         if(!$this->setup) {
 606             return false;
 607         }
 608         $this->data[] = $row;
 609     }
 610
 611     function add_separator() {
 612         if(!$this->setup) {
 613             return false;
 614         }
 615         $this->data[] = NULL;
 616     }
 617
 618 }
 619
 620 ?>