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Differences Between: [Versions 39 and 401] [Versions 401 and 402] [Versions 401 and 403]

   1  <?php
   2  // This file is part of Moodle - http://moodle.org/
   3  //
   4  // Moodle is free software: you can redistribute it and/or modify
   5  // it under the terms of the GNU General Public License as published by
   6  // the Free Software Foundation, either version 3 of the License, or
   7  // (at your option) any later version.
   8  //
   9  // Moodle is distributed in the hope that it will be useful,
  10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  // GNU General Public License for more details.
  13  //
  14  // You should have received a copy of the GNU General Public License
  15  // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16  
  17  
  18  /**
  19   * Drop down form element to select the grade
  20   *
  21   * Contains HTML class for a drop down element to select the grade for an activity,
  22   * used in mod update form
  23   *
  24   * @package   core_form
  25   * @copyright 2006 Jamie Pratt <me@jamiep.org>
  26   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  27   */
  28  
  29  global $CFG;
  30  require_once "$CFG->libdir/form/select.php";
  31  require_once("HTML/QuickForm/element.php");
  32  require_once($CFG->dirroot.'/lib/form/group.php');
  33  require_once($CFG->dirroot.'/lib/grade/grade_scale.php');
  34  
  35  /**
  36   * Drop down form element to select the grade
  37   *
  38   * HTML class for a drop down element to select the grade for an activity,
  39   * used in mod update form
  40   *
  41   * @package   core_form
  42   * @category  form
  43   * @copyright 2006 Jamie Pratt <me@jamiep.org>
  44   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  45   */
  46  class MoodleQuickForm_modgrade extends MoodleQuickForm_group {
  47  
  48      /** @var boolean $isupdate Is this an add or an update ? */
  49      public $isupdate = false;
  50  
  51      /** @var float $currentgrade The current grademax for the grade_item */
  52      public $currentgrade = false;
  53  
  54      /** @var boolean $hasgrades Has this grade_item got any real grades (with values) */
  55      public $hasgrades = false;
  56  
  57      /** @var boolean $canrescale Does this activity support rescaling grades? */
  58      public $canrescale = false;
  59  
  60      /** @var int $currentscaleid The current scale id */
  61      public $currentscaleid = null;
  62  
  63      /** @var string $currentgradetype The current gradetype - can either be 'none', 'scale', or 'point' */
  64      public $currentgradetype = 'none';
  65  
  66      /** @var boolean $useratings Set to true if the activity is using ratings, false otherwise */
  67      public $useratings = false;
  68  
  69      /** @var MoodleQuickForm_select $gradetypeformelement */
  70      private $gradetypeformelement;
  71  
  72      /** @var MoodleQuickForm_select $scaleformelement */
  73      private $scaleformelement;
  74  
  75      /** @var MoodleQuickForm_text $maxgradeformelement */
  76      private $maxgradeformelement;
  77  
  78      /**
  79       * Constructor
  80       *
  81       * @param string $elementname Element's name
  82       * @param mixed $elementlabel Label(s) for an element
  83       * @param array $options Options to control the element's display. Required - must contain the following options:
  84       *              'isupdate' - is this a new module or are we editing an existing one?
  85       *              'currentgrade' - the current grademax in the database for this gradeitem
  86       *              'hasgrades' - whether or not the grade_item has existing grade_grades
  87       *              'canrescale' - whether or not the activity supports rescaling grades
  88       * @param mixed $attributes Either a typical HTML attribute string or an associative array
  89       */
  90      public function __construct($elementname = null, $elementlabel = null, $options = array(), $attributes = null) {
  91          // TODO MDL-52313 Replace with the call to parent::__construct().
  92          HTML_QuickForm_element::__construct($elementname, $elementlabel, $attributes);
  93          $this->_persistantFreeze = true;
  94          $this->_appendName = true;
  95          $this->_type = 'modgrade';
  96          $this->isupdate = !empty($options['isupdate']);
  97          if (isset($options['currentgrade'])) {
  98              $this->currentgrade = $options['currentgrade'];
  99          }
 100          if (isset($options['currentgradetype'])) {
 101              $gradetype = $options['currentgradetype'];
 102              switch ($gradetype) {
 103                  case GRADE_TYPE_NONE :
 104                      $this->currentgradetype = 'none';
 105                      break;
 106                  case GRADE_TYPE_SCALE :
 107                      $this->currentgradetype = 'scale';
 108                      break;
 109                  case GRADE_TYPE_VALUE :
 110                      $this->currentgradetype = 'point';
 111                      break;
 112              }
 113          }
 114          if (isset($options['currentscaleid'])) {
 115              $this->currentscaleid = $options['currentscaleid'];
 116          }
 117          $this->hasgrades = !empty($options['hasgrades']);
 118          $this->canrescale = !empty($options['canrescale']);
 119          $this->useratings = !empty($options['useratings']);
 120      }
 121  
 122      /**
 123       * Old syntax of class constructor. Deprecated in PHP7.
 124       *
 125       * @deprecated since Moodle 3.1
 126       */
 127      public function MoodleQuickForm_modgrade($elementname = null, $elementlabel = null, $options = array(), $attributes = null) {
 128          debugging('Use of class name as constructor is deprecated', DEBUG_DEVELOPER);
 129          self::__construct($elementname, $elementlabel, $options, $attributes);
 130      }
 131  
 132      /**
 133       * Create elements for this group.
 134       */
 135      public function _createElements() {
 136          global $COURSE, $CFG, $OUTPUT;
 137          $attributes = $this->getAttributes();
 138          if (is_null($attributes)) {
 139              $attributes = array();
 140          }
 141  
 142          $this->_elements = array();
 143  
 144          // Create main elements
 145          // We have to create the scale and point elements first, as we need their IDs.
 146  
 147          // Grade scale select box.
 148          $scales = get_scales_menu($COURSE->id);
 149          $langscale = get_string('modgradetypescale', 'grades');
 150          $this->scaleformelement = $this->createFormElement('select', 'modgrade_scale', $langscale,
 151              $scales, $attributes);
 152          $this->scaleformelement->setHiddenLabel(true);
 153          $scaleformelementid = $this->generate_modgrade_subelement_id('modgrade_scale');
 154          $this->scaleformelement->updateAttributes(array('id' => $scaleformelementid));
 155  
 156          // Maximum grade textbox.
 157          $langmaxgrade = get_string('modgrademaxgrade', 'grades');
 158          $this->maxgradeformelement = $this->createFormElement('text', 'modgrade_point', $langmaxgrade, array());
 159          $this->maxgradeformelement->setHiddenLabel(true);
 160          $maxgradeformelementid = $this->generate_modgrade_subelement_id('modgrade_point');
 161          $this->maxgradeformelement->updateAttributes(array('id' => $maxgradeformelementid));
 162  
 163          // Grade type select box.
 164          $gradetype = array(
 165              'none' => get_string('modgradetypenone', 'grades'),
 166              'scale' => get_string('modgradetypescale', 'grades'),
 167              'point' => get_string('modgradetypepoint', 'grades'),
 168          );
 169          $langtype = get_string('modgradetype', 'grades');
 170          $this->gradetypeformelement = $this->createFormElement('select', 'modgrade_type', $langtype, $gradetype,
 171              $attributes, true);
 172          $this->gradetypeformelement->setHiddenLabel(true);
 173          $gradetypeformelementid = $this->generate_modgrade_subelement_id('modgrade_type');
 174          $this->gradetypeformelement->updateAttributes(array('id' => $gradetypeformelementid));
 175  
 176          if ($this->isupdate && $this->hasgrades) {
 177              $this->gradetypeformelement->updateAttributes(array('disabled' => 'disabled'));
 178              $this->scaleformelement->updateAttributes(array('disabled' => 'disabled'));
 179  
 180              // Check box for options for processing existing grades.
 181              if ($this->canrescale) {
 182                  $langrescalegrades = get_string('modgraderescalegrades', 'grades');
 183                  $choices = array();
 184                  $choices[''] = get_string('choose');
 185                  $choices['no'] = get_string('no');
 186                  $choices['yes'] = get_string('yes');
 187                  $rescalegradesselect = $this->createFormElement('select',
 188                      'modgrade_rescalegrades',
 189                      $langrescalegrades,
 190                      $choices);
 191                  $rescalegradesselect->setHiddenLabel(true);
 192                  $rescalegradesselectid = $this->generate_modgrade_subelement_id('modgrade_rescalegrades');
 193                  $rescalegradesselect->updateAttributes(array('id' => $rescalegradesselectid));
 194              }
 195          }
 196  
 197          // Add elements.
 198          if ($this->isupdate && $this->hasgrades) {
 199              // Set a message so the user knows why they can not alter the grade type or scale.
 200              if ($this->currentgradetype == 'scale') {
 201                  $gradesexistmsg = get_string('modgradecantchangegradetyporscalemsg', 'grades');
 202              } else if ($this->canrescale) {
 203                  $gradesexistmsg = get_string('modgradecantchangegradetypemsg', 'grades');
 204              } else {
 205                  $gradesexistmsg = get_string('modgradecantchangegradetype', 'grades');
 206              }
 207  
 208              $gradesexisthtml = '<div class=\'alert alert-warning\'>' . $gradesexistmsg . '</div>';
 209              $this->_elements[] = $this->createFormElement('static', 'gradesexistmsg', '', $gradesexisthtml);
 210          }
 211  
 212          // Grade type select box.
 213          $label = html_writer::tag('label', $this->gradetypeformelement->getLabel(),
 214              array('for' => $this->gradetypeformelement->getAttribute('id')));
 215          $this->_elements[] = $this->createFormElement('static', 'gradetypelabel', '', '&nbsp;'.$label);
 216          $this->_elements[] = $this->gradetypeformelement;
 217          $this->_elements[] = $this->createFormElement('static', 'gradetypespacer', '', '<br />');
 218  
 219          // Only show the grade scale select box when applicable.
 220          if (!$this->isupdate || !$this->hasgrades || $this->currentgradetype == 'scale') {
 221              $label = html_writer::tag('label', $this->scaleformelement->getLabel(),
 222                  array('for' => $this->scaleformelement->getAttribute('id')));
 223              $this->_elements[] = $this->createFormElement('static', 'scalelabel', '', $label);
 224              $this->_elements[] = $this->scaleformelement;
 225              $this->_elements[] = $this->createFormElement('static', 'scalespacer', '', '<br />');
 226          }
 227  
 228          if ($this->isupdate && $this->hasgrades && $this->canrescale && $this->currentgradetype == 'point') {
 229              // We need to know how to apply any changes to maxgrade - ie to either update, or don't touch exising grades.
 230              $label = html_writer::tag('label', $rescalegradesselect->getLabel(),
 231                  array('for' => $rescalegradesselect->getAttribute('id')));
 232              $labelhelp = new help_icon('modgraderescalegrades', 'grades');
 233              $this->_elements[] = $this->createFormElement('static', 'scalelabel', '', $label . $OUTPUT->render($labelhelp));
 234              $this->_elements[] = $rescalegradesselect;
 235              $this->_elements[] = $this->createFormElement('static', 'scalespacer', '', '<br />');
 236          }
 237  
 238          // Only show the max points form element when applicable.
 239          if (!$this->isupdate || !$this->hasgrades || $this->currentgradetype == 'point') {
 240              $label = html_writer::tag('label', $this->maxgradeformelement->getLabel(),
 241                  array('for' => $this->maxgradeformelement->getAttribute('id')));
 242              $this->_elements[] = $this->createFormElement('static', 'pointlabel', '', $label);
 243  
 244              // Check if there are grades and if so then disable maxgradeformelement.
 245              if ($this->hasgrades) {
 246                  // If it has grades then disable it.
 247                  $this->maxgradeformelement->updateAttributes(['disabled' => 'disabled']);
 248              }
 249  
 250              $this->_elements[] = $this->maxgradeformelement;
 251              $this->_elements[] = $this->createFormElement('static', 'pointspacer', '', '<br />');
 252          }
 253      }
 254  
 255      /**
 256       * Calculate the output value for the element as a whole.
 257       *
 258       * @param array $submitvalues The incoming values from the form.
 259       * @param bool $notused Not used.
 260       * @return array Return value for the element, formatted like field name => value.
 261       */
 262      public function exportValue(&$submitvalues, $notused = false) {
 263          global $COURSE;
 264  
 265          // Get the values from all the child elements.
 266          $vals = array();
 267          foreach ($this->_elements as $element) {
 268              $thisexport = $element->exportValue($submitvalues[$this->getName()], true);
 269              if (!is_null($thisexport)) {
 270                  $vals += $thisexport;
 271              }
 272          }
 273  
 274          $type = (isset($vals['modgrade_type'])) ? $vals['modgrade_type'] : 'none';
 275          $point = (isset($vals['modgrade_point'])) ? $vals['modgrade_point'] : null;
 276          $scale = (isset($vals['modgrade_scale'])) ? $vals['modgrade_scale'] : null;
 277          $rescalegrades = (isset($vals['modgrade_rescalegrades'])) ? $vals['modgrade_rescalegrades'] : null;
 278  
 279          $return = $this->process_value($type, $scale, $point, $rescalegrades);
 280          return array($this->getName() => $return, $this->getName() . '_rescalegrades' => $rescalegrades);
 281      }
 282  
 283      /**
 284       * Process the value for the group based on the selected grade type, and the input for the scale and point elements.
 285       *
 286       * @param  string $type The value of the grade type select box. Can be 'none', 'scale', or 'point'
 287       * @param  string|int $scale The value of the scale select box.
 288       * @param  string|int $point The value of the point grade textbox.
 289       * @param  string $rescalegrades The value of the rescalegrades select.
 290       * @return int The resulting value
 291       */
 292      protected function process_value($type='none', $scale=null, $point=null, $rescalegrades=null) {
 293          global $COURSE;
 294          $val = 0;
 295  
 296          // If the maxgrade field is disabled with javascript, no value is sent with the form and mform assumes the default.
 297          if ($this->isupdate && $this->hasgrades && $this->currentgradetype == 'point') {
 298              // If the user cannot rescale, then return the original.
 299              $returnoriginal = !$this->canrescale;
 300  
 301              // If the user was forced to choose a rescale option - and they haven't - prevent any changes to the max grade.
 302              $returnoriginal = $returnoriginal || ($this->canrescale && empty($rescalegrades));
 303  
 304              if ($returnoriginal) {
 305                  return (string)unformat_float($this->currentgrade);
 306              }
 307          }
 308          switch ($type) {
 309              case 'point':
 310                  if ($this->validate_point($point) === true) {
 311                      $val = (int)$point;
 312                  }
 313                  break;
 314  
 315              case 'scale':
 316                  if ($this->validate_scale($scale)) {
 317                      $val = (int)(-$scale);
 318                  }
 319                  break;
 320          }
 321          return $val;
 322      }
 323  
 324      /**
 325       * Determines whether a given value is a valid scale selection.
 326       *
 327       * @param string|int $val The value to test.
 328       * @return bool Valid or invalid
 329       */
 330      protected function validate_scale($val) {
 331          global $COURSE;
 332          $scales = get_scales_menu($COURSE->id);
 333          return (!empty($val) && isset($scales[(int)$val])) ? true : false;
 334      }
 335  
 336      /**
 337       * Determines whether a given value is a valid point selection.
 338       *
 339       * @param string|int $val The value to test.
 340       * @return bool Valid or invalid
 341       */
 342      protected function validate_point($val) {
 343          if (empty($val)) {
 344              return false;
 345          }
 346          $maxgrade = (int)get_config('core', 'gradepointmax');
 347          $isintlike = ((string)(int)$val === $val) ? true : false;
 348          return ($isintlike === true && $val > 0 && $val <= $maxgrade) ? true : false;
 349      }
 350  
 351      /**
 352       * Called by HTML_QuickForm whenever form event is made on this element.
 353       *
 354       * @param string $event Name of event
 355       * @param mixed $arg event arguments
 356       * @param moodleform $caller calling object
 357       * @return mixed
 358       */
 359      public function onQuickFormEvent($event, $arg, &$caller) {
 360          $this->setMoodleForm($caller);
 361          switch ($event) {
 362              case 'createElement':
 363                  // The first argument is the name.
 364                  $name = $arg[0];
 365  
 366                  // Set disable actions.
 367                  $caller->hideIf($name.'[modgrade_scale]', $name.'[modgrade_type]', 'neq', 'scale');
 368                  $caller->hideIf($name.'[modgrade_point]', $name.'[modgrade_type]', 'neq', 'point');
 369                  $caller->hideIf($name.'[modgrade_rescalegrades]', $name.'[modgrade_type]', 'neq', 'point');
 370  
 371                  // Set validation rules for the sub-elements belonging to this element.
 372                  // A handy note: the parent scope of a closure is the function in which the closure was declared.
 373                  // Because of this using $this is safe despite the closures being called statically.
 374                  // A nasty magic hack!
 375                  $checkgradetypechange = function($val) {
 376                      // Nothing is affected by changes to the grade type if there are no grades yet.
 377                      if (!$this->hasgrades) {
 378                          return true;
 379                      }
 380                      // Check if we are changing the grade type when grades are present.
 381                      if (isset($val['modgrade_type']) && $val['modgrade_type'] !== $this->currentgradetype) {
 382                          return false;
 383                      }
 384                      return true;
 385                  };
 386                  $checkscalechange = function($val) {
 387                      // Nothing is affected by changes to the scale if there are no grades yet.
 388                      if (!$this->hasgrades) {
 389                          return true;
 390                      }
 391                      // Check if we are changing the scale type when grades are present.
 392                      // If modgrade_type is empty then use currentgradetype.
 393                      $gradetype = isset($val['modgrade_type']) ? $val['modgrade_type'] : $this->currentgradetype;
 394                      if ($gradetype === 'scale') {
 395                          if (isset($val['modgrade_scale']) && ($val['modgrade_scale'] !== $this->currentscaleid)) {
 396                              return false;
 397                          }
 398                      }
 399                      return true;
 400                  };
 401                  $checkmaxgradechange = function($val) {
 402                      // Nothing is affected by changes to the max grade if there are no grades yet.
 403                      if (!$this->hasgrades) {
 404                          return true;
 405                      }
 406                      // If we are not using ratings we can change the max grade.
 407                      if (!$this->useratings) {
 408                          return true;
 409                      }
 410                      // Check if we are changing the max grade if we are using ratings and there is a grade.
 411                      // If modgrade_type is empty then use currentgradetype.
 412                      $gradetype = isset($val['modgrade_type']) ? $val['modgrade_type'] : $this->currentgradetype;
 413                      if ($gradetype === 'point') {
 414                          if (isset($val['modgrade_point']) &&
 415                              grade_floats_different($this->currentgrade, $val['modgrade_point'])) {
 416                              return false;
 417                          }
 418                      }
 419                      return true;
 420                  };
 421                  $checkmaxgrade = function($val) {
 422                      // Closure to validate a max points value. See the note above about scope if this confuses you.
 423                      // If modgrade_type is empty then use currentgradetype.
 424                      $gradetype = isset($val['modgrade_type']) ? $val['modgrade_type'] : $this->currentgradetype;
 425                      if ($gradetype === 'point') {
 426                          if (isset($val['modgrade_point'])) {
 427                              return $this->validate_point($val['modgrade_point']);
 428                          }
 429                      }
 430                      return true;
 431                  };
 432                  $checkvalidscale = function($val) {
 433                      // Closure to validate a scale value. See the note above about scope if this confuses you.
 434                      // If modgrade_type is empty then use currentgradetype.
 435                      $gradetype = isset($val['modgrade_type']) ? $val['modgrade_type'] : $this->currentgradetype;
 436                      if ($gradetype === 'scale') {
 437                          if (isset($val['modgrade_scale'])) {
 438                              return $this->validate_scale($val['modgrade_scale']);
 439                          }
 440                      }
 441                      return true;
 442                  };
 443  
 444                  $checkrescale = function($val) {
 445                      // Nothing is affected by changes to grademax if there are no grades yet.
 446                      if (!$this->isupdate || !$this->hasgrades || !$this->canrescale) {
 447                          return true;
 448                      }
 449                      // Closure to validate a scale value. See the note above about scope if this confuses you.
 450                      // If modgrade_type is empty then use currentgradetype.
 451                      $gradetype = isset($val['modgrade_type']) ? $val['modgrade_type'] : $this->currentgradetype;
 452                      if ($gradetype === 'point' && isset($val['modgrade_point'])) {
 453                          // Work out if the value was actually changed in the form.
 454                          if (grade_floats_different($this->currentgrade, $val['modgrade_point'])) {
 455                              if (empty($val['modgrade_rescalegrades'])) {
 456                                  // This was an "edit", the grademax was changed and the process existing setting was not set.
 457                                  return false;
 458                              }
 459                          }
 460                      }
 461                      return true;
 462                  };
 463  
 464                  $cantchangegradetype = get_string('modgradecantchangegradetype', 'grades');
 465                  $cantchangemaxgrade = get_string('modgradecantchangeratingmaxgrade', 'grades');
 466                  $maxgradeexceeded = get_string('modgradeerrorbadpoint', 'grades', get_config('core', 'gradepointmax'));
 467                  $invalidscale = get_string('modgradeerrorbadscale', 'grades');
 468                  $cantchangescale = get_string('modgradecantchangescale', 'grades');
 469                  $mustchooserescale = get_string('mustchooserescaleyesorno', 'grades');
 470                  // When creating the rules the sixth arg is $force, we set it to true because otherwise the form
 471                  // will attempt to validate the existence of the element, we don't want this because the element
 472                  // is being created right now and doesn't actually exist as a registered element yet.
 473                  $caller->addRule($name, $cantchangegradetype, 'callback', $checkgradetypechange, 'server', false, true);
 474                  $caller->addRule($name, $cantchangemaxgrade, 'callback', $checkmaxgradechange, 'server', false, true);
 475                  $caller->addRule($name, $maxgradeexceeded, 'callback', $checkmaxgrade, 'server', false, true);
 476                  $caller->addRule($name, $invalidscale, 'callback', $checkvalidscale, 'server', false, true);
 477                  $caller->addRule($name, $cantchangescale, 'callback', $checkscalechange, 'server', false, true);
 478                  $caller->addRule($name, $mustchooserescale, 'callback', $checkrescale, 'server', false, true);
 479  
 480                  break;
 481  
 482              case 'updateValue':
 483                  // As this is a group element with no value of its own we are only interested in situations where the
 484                  // default value or a constant value are being provided to the actual element.
 485                  // In this case we expect an int that is going to translate to a scale if negative, or to max points
 486                  // if positive.
 487  
 488                  // Set the maximum points field to disabled if the rescale option has not been chosen and there are grades.
 489                  $caller->disabledIf($this->getName() . '[modgrade_point]', $this->getName() .
 490                          '[modgrade_rescalegrades]', 'eq', '');
 491  
 492                  // A constant value should be given as an int.
 493                  // The default value should be an int and be either $CFG->gradepointdefault or whatever was set in set_data().
 494                  $value = $this->_findValue($caller->_constantValues);
 495                  if (null === $value) {
 496                      if ($caller->isSubmitted() && $this->_findValue($caller->_submitValues) !== null) {
 497                          // Submitted values are array, one value for each individual element in this group.
 498                          // When there is submitted data let parent::onQuickFormEvent() process it.
 499                          break;
 500                      }
 501                      $value = $this->_findValue($caller->_defaultValues);
 502                  }
 503  
 504                  if (!is_null($value) && !is_scalar($value)) {
 505                      // Something unexpected (likely an array of subelement values) has been given - this will be dealt
 506                      // with somewhere else - where exactly... likely the subelements.
 507                      debugging('An invalid value (type '.gettype($value).') has arrived at '.__METHOD__, DEBUG_DEVELOPER);
 508                      break;
 509                  }
 510  
 511                  // Set element state for existing data.
 512                  // This is really a pretty hacky thing to do, when data is being set the group element is called
 513                  // with the data first and the subelements called afterwards.
 514                  // This means that the subelements data (inc const and default values) can be overridden by form code.
 515                  // So - when we call this code really we can't be sure that will be the end value for the element.
 516                  if (!empty($this->_elements)) {
 517                      if (!empty($value)) {
 518                          if ($value < 0) {
 519                              $this->gradetypeformelement->setValue('scale');
 520                              $this->scaleformelement->setValue(($value * -1));
 521                          } else if ($value > 0) {
 522                              $this->gradetypeformelement->setValue('point');
 523                              $maxvalue = !empty($this->currentgrade) ? (string)unformat_float($this->currentgrade) : $value;
 524                              $this->maxgradeformelement->setValue($maxvalue);
 525                          }
 526                      } else {
 527                          $this->gradetypeformelement->setValue('none');
 528                          $this->maxgradeformelement->setValue(100);
 529                      }
 530                  }
 531                  break;
 532          }
 533  
 534          // Always let the parent do its thing!
 535          return parent::onQuickFormEvent($event, $arg, $caller);
 536      }
 537  
 538      /**
 539       * Generates the id attribute for the subelement of the modgrade group.
 540       *
 541       * Uses algorithm similar to what {@link HTML_QuickForm_element::_generateId()}
 542       * does but takes the name of the wrapping modgrade group into account.
 543       *
 544       * @param string $subname the name of the HTML_QuickForm_element in this modgrade group
 545       * @return string
 546       */
 547      protected function generate_modgrade_subelement_id($subname) {
 548          $gid = str_replace(array('[', ']'), array('_', ''), $this->getName());
 549          return clean_param('id_'.$gid.'_'.$subname, PARAM_ALPHANUMEXT);
 550      }
 551  }