question/category_class.php

   1 <?php // $Id$
   2 /**
   3  * Class representing question categories
   4  *
   5  * @author Martin Dougiamas and many others. {@link http://moodle.org}
   6  * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
   7  * @package questionbank
   8  */
   9
  10 // number of categories to display on page
  11 define( "PAGE_LENGTH",25 );
  12
  13 /**
  14  * Class representing question categories
  15  *
  16  * @package questionbank
  17  */
  18 class question_category_object {
  19
  20     var $str;
  21     var $pixpath;
  22     var $edittable;
  23     var $newtable;
  24     var $tab;
  25     var $tabsize = 3;
  26     var $categories;
  27     var $categorystrings;
  28     var $defaultcategory;
  29     var $course;
  30     var $topcount;
  31
  32     /**
  33      * Constructor
  34      *
  35      * Gets necessary strings and sets relevant path information
  36      */
  37     function question_category_object() {
  38         global $CFG;
  39
  40         $this->tab = str_repeat('&nbsp;', $this->tabsize);
  41
  42         $this->str->course         = get_string('course');
  43         $this->str->category       = get_string('category', 'quiz');
  44         $this->str->categoryinfo   = get_string('categoryinfo', 'quiz');
  45         $this->str->questions      = get_string('questions', 'quiz');
  46         $this->str->add            = get_string('add');
  47         $this->str->delete         = get_string('delete');
  48         $this->str->moveup         = get_string('moveup');
  49         $this->str->movedown       = get_string('movedown');
  50         $this->str->edit           = get_string('editthiscategory');
  51         $this->str->hide           = get_string('hide');
  52         $this->str->publish        = get_string('publish', 'quiz');
  53         $this->str->order          = get_string('order');
  54         $this->str->parent         = get_string('parent', 'quiz');
  55         $this->str->add            = get_string('add');
  56         $this->str->action         = get_string('action');
  57         $this->str->top            = get_string('top', 'quiz');
  58         $this->str->addcategory    = get_string('addcategory', 'quiz');
  59         $this->str->editcategory   = get_string('editcategory', 'quiz');
  60         $this->str->cancel         = get_string('cancel');
  61         $this->str->editcategories = get_string('editcategories', 'quiz');
  62         $this->str->page           = get_string('page');
  63         $this->pixpath = $CFG->pixpath;
  64
  65     }
  66
  67     /**
  68      * Sets the course for this object
  69      *
  70      * @param object course
  71      */
  72     function set_course($course) {
  73         $this->course = $course;
  74     }
  75
  76     /**
  77      * Displays the user interface
  78      *
  79      * @param object modform
  80      * @param int $page page number to display (0=don't paginate)
  81      */
  82     function display_user_interface($page=0) {
  83         $this->initialize();
  84
  85         /// Interface for adding a new category:
  86         print_heading_with_help($this->str->addcategory, 'categories_edit', 'quiz');
  87         $this->output_new_table();
  88         echo '<br />';
  89
  90         /// Interface for editing existing categories
  91         print_heading_with_help($this->str->editcategories, 'categories', 'quiz');
  92         $this->output_edit_table($page);
  93         if ($this->topcount>PAGE_LENGTH) {
  94             $this->display_page_numbers($page);
  95         }
  96         echo '<br />';
  97
  98     }
  99
 100
 101     /**
 102      * Initializes this classes general category-related variables
 103      */
 104     function initialize() {
 105
 106         /// Get the existing categories
 107         if (!$this->defaultcategory = get_default_question_category($this->course->id)) {
 108             error("Error: Could not find or make a category!");
 109         }
 110
 111         $this->categories = $this->get_question_categories(null, "parent, sortorder, name ASC");
 112
 113         $this->categories = $this->arrange_categories($this->categories);
 114
 115         // create the array of id=>full_name strings
 116         $this->categorystrings = $this->expanded_category_strings($this->categories);
 117
 118         // for pagination calculate number of 'top' categories and hence number of pages
 119         // (pagination only based on top categories)
 120         $count = 0;
 121         foreach( $this->categories as $category ) {
 122             if ($category->parent==0) {
 123                 ++$count;
 124             }
 125         }
 126         $this->topcount = $count;
 127         $this->pagecount = (integer) ceil( $count / PAGE_LENGTH );
 128     }
 129
 130     /**
 131      * display list of page numbers for navigation
 132      */
 133     function display_page_numbers( $page=0 ) {
 134         global $USER;
 135
 136         echo "<div class=\"paging\">{$this->str->page}:\n";
 137         foreach (range(1,$this->pagecount) as $currentpage) {
 138             if ($page == $currentpage) {
 139                 echo " $currentpage \n";
 140             }
 141             else {
 142                 echo "<a href=\"category.php?id={$this->course->id}&amp;page=$currentpage&amp;sesskey={$USER->sesskey}\">";
 143                 echo " $currentpage </a>\n";
 144             }
 145         }
 146         echo "</div>";
 147     }
 148
 149     /**
 150      * Outputs a table to allow entry of a new category
 151      */
 152     function output_new_table() {
 153         global $USER;
 154         $publishoptions[0] = get_string("no");
 155         $publishoptions[1] = get_string("yes");
 156
 157         $this->newtable->head  = array ($this->str->parent, $this->str->category, $this->str->categoryinfo, $this->str->publish, $this->str->action);
 158         $this->newtable->width = 200;
 159         $this->newtable->data[] = array();
 160         $this->newtable->tablealign = 'center';
 161
 162         /// Each section below adds a data cell to the table row
 163
 164
 165         $viableparents[0] = $this->str->top;
 166         $viableparents = $viableparents + $this->categorystrings;
 167         $this->newtable->align['parent'] =  "left";
 168         $this->newtable->wrap['parent'] = "nowrap";
 169         $row['parent'] = choose_from_menu ($viableparents, "newparent", $this->str->top, "", "", "", true);
 170
 171         $this->newtable->align['category'] =  "left";
 172         $this->newtable->wrap['category'] = "nowrap";
 173         $row['category'] = '<input type="text" name="newcategory" value="" size="15" />';
 174
 175         $this->newtable->align['info'] =  "left";
 176         $this->newtable->wrap['info'] = "nowrap";
 177         $row['info'] = '<input type="text" name="newinfo" value="" size="50" />';
 178
 179         $this->newtable->align['publish'] =  "left";
 180         $this->newtable->wrap['publish'] = "nowrap";
 181         $row['publish'] = choose_from_menu ($publishoptions, "newpublish", "", "", "", "", true);
 182
 183         $this->newtable->align['action'] =  "left";
 184         $this->newtable->wrap['action'] = "nowrap";
 185         $row['action'] = '<input type="submit" value="' . $this->str->add . '" />';
 186
 187
 188         $this->newtable->data[] = $row;
 189
 190         // wrap the table in a form and output it
 191         echo '<form action="category.php" method="post">';
 192         echo '<fieldset class="invisiblefieldset" style="display: block">';
 193         echo "<input type=\"hidden\" name=\"sesskey\" value=\"$USER->sesskey\" />";
 194         echo '<input type="hidden" name="id" value="'. $this->course->id . '" />';
 195         echo '<input type="hidden" name="addcategory" value="true" />';
 196         print_table($this->newtable);
 197         echo '</fieldset>';
 198         echo '</form>';
 199     }
 200
 201     /**
 202      * Outputs a table to allow editing/rearranging of existing categories
 203      *
 204      * $this->initialize() must have already been called
 205      *
 206      * @param object course
 207      * @param int $page page to display (0=do not paginate)
 208      */
 209     function output_edit_table($page=0) {
 210         $this->edittable->head  = array ($this->str->category, $this->str->categoryinfo, $this->str->questions, $this->str->publish,
 211                                     $this->str->delete, $this->str->order, $this->str->parent);
 212         $this->edittable->width = 200;
 213         $this->edittable->tablealign = 'center';
 214
 215         $courses = $this->course->shortname;
 216
 217         // if pagination required work out range
 218         if (!empty($page)) {
 219             $firstcat = ($page-1) * PAGE_LENGTH + 1;
 220             $lastcat = $firstcat + PAGE_LENGTH - 1;
 221         }
 222         else {
 223             $firstcat = 1;
 224             $lastcat = $this->topcount;
 225         }
 226 //echo "$firstcat $lastcat $page"; die;
 227         $this->build_edit_table_body($this->categories, $page, $firstcat, $lastcat);
 228         print_table($this->edittable);
 229     }
 230
 231     /**
 232      * Recursively builds up the edit-categories table body
 233      *
 234      * @param array categories contains category objects in  a tree representation
 235      * @param mixed courses String with shortname of course | array containing courseid=>shortname
 236      * @param int depth controls the indenting
 237      */
 238     function build_edit_table_body($categories, $page = 0, $firstcat = 1, $lastcat = 99999, $depth = 0) {
 239         $countcats = count($categories);
 240         $count = 0;
 241         $first = true;
 242         $last = false;
 243         $topcount = 0;
 244
 245         foreach ($categories as $category) {
 246             $count++;
 247             if ($count == $countcats) {
 248                 $last = true;
 249             }
 250             // check if this category is on the display page
 251             if ($depth==0) {
 252                 $topcount++;
 253                 if (($topcount<$firstcat) or ($topcount>$lastcat)) {
 254                     continue;
 255                 }
 256             }
 257             $up = $first ? false : true;
 258             $down = $last ? false : true;
 259             $first = false;
 260             $this->edit_question_category_row($category, $depth, $up, $down, $page);
 261             if (isset($category->children)) {
 262                 $this->build_edit_table_body($category->children, $page, $firstcat, $lastcat, $depth + 1);
 263             }
 264         }
 265     }
 266
 267     /**
 268      * gets all the courseids for the given categories
 269      *
 270      * @param array categories contains category objects in  a tree representation
 271      * @return array courseids flat array in form categoryid=>courseid
 272      */
 273     function get_course_ids($categories) {
 274         $courseids = array();
 275         foreach ($categories as $key=>$cat) {
 276             $courseids[$key] = $cat->course;
 277             if (!empty($cat->children)) {
 278                 $courseids = array_merge($courseids, $this->get_course_ids($cat->children));
 279             }
 280         }
 281         return $courseids;
 282     }
 283
 284     /**
 285      * Constructs each row of the edit-categories table
 286      *
 287      * @param object category
 288      * @param int depth controls the indenting
 289      * @param string shortname short name of the course
 290      * @param boolean up can it be moved up?
 291      * @param boolean down can it be moved down?
 292      * @param int page page number
 293      */
 294     function edit_question_category_row($category, $depth, $up = false, $down = false, $page = 0) {
 295         global $USER;
 296         $fill = str_repeat($this->tab, $depth);
 297
 298         $linkcss = $category->publish ? ' class="published" ' : ' class="unpublished" ';
 299
 300         if (!empty($page)) {
 301             $pagelink="&amp;page=$page";
 302         }
 303         else {
 304             $pagelink="";
 305         }
 306
 307         /// Each section below adds a data cell to this table row
 308
 309         $this->edittable->align["$category->id.name"] =  "left";
 310         $this->edittable->wrap["$category->id.name"] = "nowrap";
 311         $row["$category->id.name"] = '<a ' . $linkcss . ' title="' . $this->str->edit. '" href="category.php?id=' . $this->course->id .
 312             '&amp;edit=' . $category->id . '&amp;sesskey='.$USER->sesskey.$pagelink.'"><img src="' . $this->pixpath . '/t/edit.gif" class="iconsmall"
 313             alt="' .$this->str->edit. '" /> ' . $fill . $category->name . '</a>';
 314
 315         $this->edittable->align["$category->id.info"] =  "left";
 316         $this->edittable->wrap["$category->id.info"] = "nowrap";
 317         $row["$category->id.info"] = '<a ' . $linkcss . ' title="' . $this->str->edit .'" href="category.php?id=' . $this->course->id .
 318             '&amp;edit=' . $category->id . '&amp;sesskey='.$USER->sesskey.$pagelink.'">' . $category->info . '</a>';
 319
 320         $this->edittable->align["$category->id.qcount"] = "center";
 321         $row["$category->id.qcount"] = $category->questioncount;
 322
 323         $this->edittable->align["$category->id.publish"] =  "center";
 324         $this->edittable->wrap["$category->id.publish"] = "nowrap";
 325         if (!empty($category->publish)) {
 326               $row["$category->id.publish"] = '<a title="' . $this->str->hide . '" href="category.php?id=' . $this->course->id . '&amp;hide=' . $category->id .
 327               '&amp;sesskey='.$USER->sesskey.$pagelink.'"><img src="' . $this->pixpath . '/t/hide.gif" class="iconsmall" alt="' .$this->str->hide. '" /></a> ';
 328         } else {
 329             $row["$category->id.publish"] = '<a title="' . $this->str->publish . '" href="category.php?id=' . $this->course->id . '&amp;publish=' . $category->id .
 330                  '&amp;sesskey='.$USER->sesskey.$pagelink.'"><img src="' . $this->pixpath . '/t/show.gif" class="iconsmall" alt="' .$this->str->publish. '" /></a> ';
 331         }
 332
 333         if ($category->id != $this->defaultcategory->id) {
 334             $this->edittable->align["$category->id.delete"] =  "center";
 335             $this->edittable->wrap["$category->id.delete"] = "nowrap";
 336             $row["$category->id.delete"] =  '<a title="' . $this->str->delete . '" href="category.php?id=' . $this->course->id .
 337                     '&amp;delete=' . $category->id . '&amp;sesskey='.$USER->sesskey.$pagelink.'"><img src="' . $this->pixpath . '/t/delete.gif" class="iconsmall" alt="' .$this->str->delete. '" /></a> ';
 338         } else {
 339             $row["$category->id.delete"] = '';
 340         }
 341
 342         $this->edittable->align["$category->id.order"] =  "left";
 343         $this->edittable->wrap["$category->id.order"] = "nowrap";
 344         $icons = '';
 345         if ($up) {
 346             $icons .= '<a title="' . $this->str->moveup .'" href="category.php?id=' . $this->course->id . '&amp;moveup=' . $category->id . '&amp;sesskey='.$USER->sesskey.$pagelink.'">
 347                 <img src="' . $this->pixpath . '/t/up.gif" class="iconsmall" alt="' . $this->str->moveup. '" /></a> ';
 348         }
 349         if ($down) {
 350             $icons .= '<a title="' . $this->str->movedown .'" href="category.php?id=' . $this->course->id . '&amp;movedown=' . $category->id . '&amp;sesskey='.$USER->sesskey.$pagelink.'">
 351                  <img src="' . $this->pixpath . '/t/down.gif" class="iconsmall" alt="' .$this->str->movedown. '" /></a> ';
 352         }
 353         $row["$category->id.order"]= $icons;
 354
 355         $this->edittable->align["$category->id.moveto"] =  "left";
 356         $this->edittable->wrap["$category->id.moveto"] = "nowrap";
 357         if ($category->id != $this->defaultcategory->id) {
 358             $viableparents = $this->categorystrings;
 359             $this->set_viable_parents($viableparents, $category);
 360             $viableparents = array(0=>$this->str->top) + $viableparents;
 361
 362             $row["$category->id.moveto"] = popup_form ("category.php?id={$this->course->id}&amp;move={$category->id}&amp;sesskey=$USER->sesskey$pagelink&amp;moveto=",
 363                $viableparents, "moveform{$category->id}", "$category->parent", "", "", "", true);
 364         } else {
 365             $row["$category->id.moveto"]='---';
 366         }
 367
 368
 369         $this->edittable->data[$category->id] = $row;
 370     }
 371
 372
 373     function edit_single_category($categoryid,$page=1) {
 374     /// Interface for adding a new category
 375         global $USER;
 376         $this->initialize();
 377
 378         /// Interface for editing existing categories
 379         if ($category = get_record("question_categories", "id", $categoryid)) {
 380             echo '<h2 align="center">';
 381             echo $this->str->edit;
 382             helpbutton("categories_edit", $this->str->editcategory, "quiz");
 383             echo '</h2>';
 384             echo '<table width="100%"><tr><td>';
 385             $this->output_edit_single_table($category,$page);
 386             echo '</td></tr></table>';
 387             echo '<p><div align="center"><form action="category.php" method="get">
 388                 <div>
 389                 <input type="hidden" name="sesskey" value="'.$USER->sesskey.'" />
 390                 <input type="hidden" name="id" value="' . $this->course->id . '" />
 391                 <input type="submit" value="' . $this->str->cancel . '" />
 392                 </div>
 393                 </form>
 394                 </div></p>';
 395             print_footer($this->course);
 396             exit;
 397         } else {
 398             error("Category $categoryid not found", "category.php?id={$this->course->id}");
 399         }
 400     }
 401
 402     /**
 403      * Outputs a table to allow editing of an existing category
 404      *
 405      * @param object category
 406      * @param int page current page
 407      */
 408     function output_edit_single_table($category, $page=1) {
 409         global $USER;
 410         $publishoptions[0] = get_string("no");
 411         $publishoptions[1] = get_string("yes");
 412         $strupdate = get_string('update');
 413
 414         $edittable = new stdClass;
 415
 416         $edittable->head  = array ($this->str->parent, $this->str->category, $this->str->categoryinfo, $this->str->publish, $this->str->action);
 417         $edittable->width = 200;
 418         $edittable->data[] = array();
 419         $edittable->tablealign = 'center';
 420
 421         /// Each section below adds a data cell to the table row
 422
 423         $viableparents = $this->categorystrings;
 424         $this->set_viable_parents($viableparents, $category);
 425         $viableparents = array(0=>$this->str->top) + $viableparents;
 426         $edittable->align['parent'] =  "left";
 427         $edittable->wrap['parent'] = "nowrap";
 428         $row['parent'] = choose_from_menu ($viableparents, "updateparent", "{$category->parent}", "", "", "", true);
 429
 430         $edittable->align['category'] =  "left";
 431         $edittable->wrap['category'] = "nowrap";
 432         $row['category'] = '<input type="text" name="updatename" value="' . format_string($category->name) . '" size="15" />';
 433
 434         $edittable->align['info'] =  "left";
 435         $edittable->wrap['info'] = "nowrap";
 436         $row['info'] = '<input type="text" name="updateinfo" value="' . $category->info . '" size="50" />';
 437
 438         $edittable->align['publish'] =  "left";
 439         $edittable->wrap['publish'] = "nowrap";
 440         $selected = (boolean)$category->publish ? 1 : 0;
 441         $row['publish'] = choose_from_menu ($publishoptions, "updatepublish", $selected, "", "", "", true);
 442
 443         $edittable->align['action'] =  "left";
 444         $edittable->wrap['action'] = "nowrap";
 445         $row['action'] = '<input type="submit" value="' . $strupdate . '" />';
 446
 447         $edittable->data[] = $row;
 448
 449         // wrap the table in a form and output it
 450         echo '<p><form action="category.php" method="post">';
 451         echo '<fieldset class="invisiblefieldset">';
 452         echo "<input type=\"hidden\" name=\"sesskey\" value=\"$USER->sesskey\" />";
 453         echo '<input type="hidden" name="id" value="'. $this->course->id . '" />';
 454         echo '<input type="hidden" name="updateid" value="' . $category->id . '" />';
 455         echo "<input type=\"hidden\" name=\"page\" value=\"$page\" />";
 456         print_table($edittable);
 457         echo '</fieldset>';
 458         echo '</form></p>';
 459     }
 460
 461     /**
 462      * Creates an array of "full-path" category strings
 463      * Structure:
 464      *    key => string
 465      *    where key is the category id, and string contains the name of all ancestors as well as the particular category name
 466      *   E.g. '123'=>'Language / English / Grammar / Modal Verbs"
 467      *
 468      * @param array $categories an array containing categories arranged in a tree structure
 469      */
 470     function expanded_category_strings($categories, $parent=null) {
 471         $prefix = is_null($parent) ? '' : "$parent / ";
 472         $categorystrings = array();
 473         foreach ($categories as $key => $category) {
 474             $expandedname = "$prefix$category->name";
 475             $categorystrings[$key] = $expandedname;
 476             if (isset($category->children)) {
 477                 $categorystrings = $categorystrings + $this->expanded_category_strings($category->children, $expandedname);
 478             }
 479         }
 480         return $categorystrings;
 481     }
 482
 483     /**
 484      * Arranges the categories into a hierarchical tree
 485      *
 486      * If a category has children, it's "children" property holds an array of children
 487      * The questioncount for each category is also calculated
 488      *
 489      * @param    array records a flat list of the categories
 490      * @return   array categorytree a hierarchical list of the categories
 491      */
 492     function arrange_categories($records) {
 493     //TODO: get the question count for all records with one sql statement: select category, count(*) from question group by category
 494         $levels = array();
 495
 496         // build a levels array, which places each record according to it's depth from the top level
 497         $parents = array(0);
 498         while (!empty($parents)) {
 499             $children = array();
 500             foreach ($records as $record) {
 501                 if (in_array($record->parent, $parents)) {
 502                     $children[] = $record->id;
 503                 }
 504             }
 505             if (!empty($children)) {
 506                 $levels[] = $children;
 507             }
 508             $parents = $children;
 509         }
 510         // if there is no hierarchy (e.g., if all records have parent == 0), set level[0] to these keys
 511         if (empty($levels)) {
 512             $levels[0] = array_keys($records);
 513         }
 514
 515         // build a hierarchical array that depicts the parent-child relationships of the categories
 516         $categorytree = array();
 517         for ($index = count($levels) - 1; $index >= 0; $index--) {
 518             foreach($levels[$index] as $key) {
 519                 $parentkey = $records[$key]->parent;
 520                 if (!($records[$key]->questioncount = count_records('question', 'category', $records[$key]->id, 'hidden', 0, 'parent', '0'))) {
 521                     $records[$key]->questioncount = 0;
 522                 }
 523                 if ($parentkey == 0) {
 524                     $categorytree[$key] = $records[$key];
 525                 } else {
 526                     $records[$parentkey]->children[$key] = $records[$key];
 527                 }
 528             }
 529         }
 530         return $categorytree;
 531     }
 532
 533     /**
 534      * Sets the viable parents
 535      *
 536      *  Viable parents are any except for the category itself, or any of it's descendants
 537      *  The parentstrings parameter is passed by reference and changed by this function.
 538      *
 539      * @param    array parentstrings a list of parentstrings
 540      * @param   object category
 541      */
 542     function set_viable_parents(&$parentstrings, $category) {
 543
 544         unset($parentstrings[$category->id]);
 545         if (isset($category->children)) {
 546             foreach ($category->children as $child) {
 547                 $this->set_viable_parents($parentstrings, $child);
 548             }
 549         }
 550     }
 551
 552     /**
 553      * Gets question categories
 554      *
 555      * @param    int parent - if given, restrict records to those with this parent id.
 556      * @param    string sort - [[sortfield [,sortfield]] {ASC|DESC}]
 557      * @return   array categories
 558      */
 559     function get_question_categories($parent=null, $sort="sortorder ASC") {
 560
 561         if (is_null($parent)) {
 562             $categories = get_records('question_categories', 'course', "{$this->course->id}", $sort);
 563         } else {
 564             $select = "parent = '$parent' AND course = '{$this->course->id}'";
 565             $categories = get_records_select('question_categories', $select, $sort);
 566         }
 567         return $categories;
 568     }
 569
 570     /**
 571      * Deletes an existing question category
 572      *
 573      * @param    int deletecat  id of category to delete
 574      * @param    int destcategoryid id of category which will inherit the orphans of deletecat
 575      */
 576     function delete_category($deletecat, $destcategoryid = null) {
 577         global $USER;
 578
 579         if (!$category = get_record("question_categories", "id", $deletecat)) {  // security
 580             error("No such category $deletecat!", "category.php?id={$this->course->id}");
 581         }
 582
 583         if (!is_null($destcategoryid)) { // Need to move some questions before deleting the category
 584             if (!$category2 = get_record("question_categories", "id", $destcategoryid)) {  // security
 585                 error("No such category $destcategoryid!", "category.php?id={$this->course->id}");
 586             }
 587             if (! set_field('question', 'category', $destcategoryid, 'category', $deletecat)) {
 588                 error("Error while moving questions from category '" . format_string($category->name) . "' to '$category2->name'", "category.php?id={$this->course->id}");
 589             }
 590
 591         } else {
 592             // todo: delete any hidden questions that are not actually in use any more
 593             if ($count = count_records("question", "category", $category->id)) {
 594                 $vars = new stdClass;
 595                 $vars->name = $category->name;
 596                 $vars->count = $count;
 597                 print_simple_box(get_string("categorymove", "quiz", $vars), "center");
 598                 $this->initialize();
 599                 $categorystrings = $this->categorystrings;
 600                 unset ($categorystrings[$category->id]);
 601                 echo "<p><div align=\"center\"><form action=\"category.php\" method=\"get\">";
 602                 echo '<fieldset class="invisiblefieldset">';
 603                 echo "<input type=\"hidden\" name=\"sesskey\" value=\"$USER->sesskey\" />";
 604                 echo "<input type=\"hidden\" name=\"id\" value=\"{$this->course->id}\" />";
 605                 echo "<input type=\"hidden\" name=\"delete\" value=\"$category->id\" />";
 606                 choose_from_menu($categorystrings, "confirm", "", "");
 607                 echo "<input type=\"submit\" value=\"". get_string("categorymoveto", "quiz") . "\" />";
 608                 echo "<input type=\"submit\" name=\"cancel\" value=\"{$this->str->cancel}\" />";
 609                 echo '</fieldset>';
 610                 echo "</form></div></p>";
 611                 print_footer($this->course);
 612                 exit;
 613             }
 614         }
 615
 616         /// Send the children categories to live with their grandparent
 617         if ($childcats = get_records("question_categories", "parent", $category->id)) {
 618             foreach ($childcats as $childcat) {
 619                 if (! set_field("question_categories", "parent", $category->parent, "id", $childcat->id)) {
 620                     error("Could not update a child category!", "category.php?id={$this->course->id}");
 621                 }
 622             }
 623         }
 624
 625         /// Finally delete the category itself
 626         if (delete_records("question_categories", "id", $category->id)) {
 627             notify(get_string("categorydeleted", "quiz", format_string($category->name)), 'notifysuccess');
 628         }
 629     }
 630
 631     /**
 632      * Moves a category up or down in the display order
 633      *
 634      * @param    string direction  up|down
 635      * @param    int categoryid id of category to move
 636      */
 637     function move_category_up_down ($direction, $categoryid) {
 638     /// Move a category up or down
 639         $swapcategory = NULL;
 640         $movecategory = NULL;
 641
 642         if ($direction == 'up') {
 643             if ($movecategory = get_record("question_categories", "id", $categoryid)) {
 644                 $categories = $this->get_question_categories("$movecategory->parent", 'parent, sortorder, name');
 645
 646                 foreach ($categories as $category) {
 647                     if ($category->id == $movecategory->id) {
 648                         break;
 649                     }
 650                     $swapcategory = $category;
 651                 }
 652             }
 653         }
 654         if ($direction == 'down') {
 655             if ($movecategory = get_record("question_categories", "id", $categoryid)) {
 656                 $categories = $this->get_question_categories("$movecategory->parent", 'parent, sortorder, name');
 657                 $choosenext = false;
 658                 foreach ($categories as $category) {
 659                     if ($choosenext) {
 660                         $swapcategory = $category;
 661                         break;
 662                     }
 663                     if ($category->id == $movecategory->id) {
 664                         $choosenext = true;
 665                     }
 666                 }
 667             }
 668         }
 669         if ($swapcategory and $movecategory) {        // Renumber everything for robustness
 670             $count=0;
 671             foreach ($categories as $category) {
 672                 $count++;
 673                 if ($category->id == $swapcategory->id) {
 674                     $category = $movecategory;
 675                 } else if ($category->id == $movecategory->id) {
 676                     $category = $swapcategory;
 677                 }
 678                 if (! set_field("question_categories", "sortorder", $count, "id", $category->id)) {
 679                     notify("Could not update that category!");
 680                 }
 681             }
 682         }
 683     }
 684
 685     /**
 686      * Changes the parent of a category
 687      *
 688      * @param    int categoryid
 689      * @param    int parentid
 690      */
 691     function move_category($categoryid, $parentid) {
 692     /// Move a category to a new parent
 693
 694         if ($tempcat = get_record("question_categories", "id", $categoryid)) {
 695             if ($tempcat->parent != $parentid) {
 696                 if (! set_field("question_categories", "parent", $parentid, "id", $tempcat->id)) {
 697                     notify("Could not update that category!");
 698                 }
 699             }
 700         }
 701     }
 702
 703     /**
 704      * Changes the published status of a category
 705      *
 706      * @param    boolean publish
 707      * @param    int categoryid
 708      */
 709     function publish_category($publish, $categoryid) {
 710     /// Hide or publish a category
 711
 712         $publish = ($publish == false) ? 0 : 1;
 713         $tempcat = get_record("question_categories", "id", $categoryid);
 714         if ($tempcat) {
 715             if (! set_field("question_categories", "publish", $publish, "id", $tempcat->id)) {
 716                 notify("Could not update that category!");
 717             }
 718         }
 719     }
 720
 721     /**
 722      * Creates a new category with given params
 723      *
 724      * @param int $newparent       id of the parent category
 725      * @param string $newcategory  the name for the new category
 726      * @param string $newinfo      the info field for the new category
 727      * @param int $newpublish      whether to publish the category
 728      * @param int $newcourse       the id of the associated course
 729      */
 730     function add_category($newparent, $newcategory, $newinfo, $newpublish, $newcourse) {
 731         if (empty($newcategory)) {
 732             notify(get_string('categorynamecantbeblank', 'quiz'), 'notifyproblem');
 733             return false;
 734         }
 735
 736         if ($newparent) {
 737             // first check that the parent category is in the correct course
 738             if(!(get_field('question_categories', 'course', 'id', $newparent) == $newcourse)) {
 739                 return false;
 740             }
 741         }
 742
 743         $cat = NULL;
 744         $cat->parent = $newparent;
 745         $cat->name = $newcategory;
 746         $cat->info = $newinfo;
 747         $cat->publish = $newpublish;
 748         $cat->course = $newcourse;
 749         $cat->sortorder = 999;
 750         $cat->stamp = make_unique_id_code();
 751         if (!insert_record("question_categories", $cat)) {
 752             error("Could not insert the new question category '$newcategory'", "category.php?id={$newcourse}");
 753         } else {
 754             notify(get_string("categoryadded", "quiz", $newcategory), 'notifysuccess');
 755         }
 756     }
 757
 758     /**
 759      * Updates an existing category with given params
 760      *
 761      * @param    int updateid
 762      * @param    int updateparent
 763      * @param    string updatename
 764      * @param    string updateinfo
 765      * @param    int updatepublish
 766      * @param    int courseid the id of the associated course
 767      */
 768     function update_category($updateid, $updateparent, $updatename, $updateinfo, $updatepublish, $courseid) {
 769         if (empty($updatename)) {
 770             notify(get_string('categorynamecantbeblank', 'quiz'), 'notifyproblem');
 771             return false;
 772         }
 773
 774         $cat = NULL;
 775         $cat->id = $updateid;
 776         $cat->parent = $updateparent;
 777         $cat->name = $updatename;
 778         $cat->info = $updateinfo;
 779         $cat->publish = $updatepublish;
 780         if (!update_record("question_categories", $cat)) {
 781             error("Could not update the category '$updatename'", "category.php?id={$courseid}");
 782         } else {
 783             notify(get_string("categoryupdated", 'quiz'), 'notifysuccess');
 784         }
 785     }
 786 }
 787
 788 ?>