question/backuplib.php

   1 <?php // $Id$
   2 /**
   3  * Question bank backup code.
   4  *
   5  * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
   6  * @package questionbank
   7  *//** */
   8
   9 //This is the "graphical" structure of the question database:
  10     //To see, put your terminal to 160cc
  11
  12     // The following holds student-independent information about the questions
  13     //
  14     //          question_categories
  15     //             (CL,pk->id)
  16     //                  |
  17     //                  |
  18     //                  |.......................................
  19     //                  |                                      .
  20     //                  |                                      .
  21     //                  |    -------question_datasets------    .
  22     //                  |    |  (CL,pk->id,fk->question,  |    .
  23     //                  |    |   fk->dataset_definition)  |    .
  24     //                  |    |                            |    .
  25     //                  |    |                            |    .
  26     //                  |    |                            |    .
  27     //                  |    |                    question_dataset_definitions
  28     //                  |    |                      (CL,pk->id,fk->category)
  29     //              question                                   |
  30     //        (CL,pk->id,fk->category,files)                   |
  31     //                  |                             question_dataset_items
  32     //                  |                          (CL,pk->id,fk->definition)
  33     //                  |
  34     //                  |
  35     //                  |
  36     //             --------------------------------------------------------------------------------------------------------------
  37     //             |             |              |              |                       |                  |                     |
  38     //             |             |              |              |                       |                  |                     |
  39     //             |             |              |              |             question_calculated          |                     |
  40     //      question_truefalse   |     question_multichoice    |          (CL,pl->id,fk->question)        |                     |
  41     // (CL,pk->id,fk->question)  |   (CL,pk->id,fk->question)  |                       .                  |                     |  question_randomsamatch
  42     //             .             |              .              |                       .                  |                     |--(CL,pk->id,fk->question)
  43     //             .    question_shortanswer    .      question_numerical              .         question_multianswer.          |
  44     //             .  (CL,pk->id,fk->question)  .  (CL,pk->id,fk->question)            .        (CL,pk->id,fk->question)        |
  45     //             .             .              .              .                       .                  .                     |       question_match
  46     //             .             .              .              .                       .                  .                     |--(CL,pk->id,fk->question)
  47     //             .             .              .              .                       .                  .                     |             .
  48     //             .             .              .              .                       .                  .                     |             .
  49     //             .             .              .              .                       .                  .                     |             .
  50     //             .             .              .              .                       .                  .                     |    question_match_sub
  51     //             ........................................................................................                     |--(CL,pk->id,fk->question)
  52     //                                                   .                                                                      |
  53     //                                                   .                                                                      |
  54     //                                                   .                                                                      |  question_numerical_units
  55     //                                             question_answers                                                             |--(CL,pk->id,fk->question)
  56     //                                         (CL,pk->id,fk->question)----------------------------------------------------------
  57     //
  58     //
  59     // The following holds the information about student interaction with the questions
  60     //
  61     //             question_sessions
  62     //      (UL,pk->id,fk->attempt,question)
  63     //                    .
  64     //                    .
  65     //             question_states
  66     //       (UL,pk->id,fk->attempt,question)
  67     //
  68     // Meaning: pk->primary key field of the table
  69     //          fk->foreign key to link with parent
  70     //          nt->nested field (recursive data)
  71     //          SL->site level info
  72     //          CL->course level info
  73     //          UL->user level info
  74     //          files->table may have files
  75     //
  76     //-----------------------------------------------------------
  77
  78     require_once("$CFG->libdir/questionlib.php");
  79
  80     function backup_question_category_context($bf, $contextid, $course) {
  81         $status = true;
  82         $context = get_context_instance_by_id($contextid);
  83         $status = $status && fwrite($bf,start_tag("CONTEXT",4,true));
  84         switch ($context->contextlevel){
  85             case CONTEXT_MODULE:
  86                 $status = $status && fwrite($bf,full_tag("LEVEL",5,false, 'module'));
  87                 $status = $status && fwrite($bf,full_tag("INSTANCE",5,false, $context->instanceid));
  88                 break;
  89             case CONTEXT_COURSE:
  90                 $status = $status && fwrite($bf,full_tag("LEVEL",5,false, 'course'));
  91                 break;
  92             case CONTEXT_COURSECAT:
  93                 $thiscourse = get_record('course', 'id', $course);
  94                 $cat = $thiscourse->category;
  95                 $catno = 1;
  96                 while($context->instanceid != $cat){
  97                     $catno ++;
  98                     if ($cat ==0) {
  99                         return false;
 100                     }
 101                     $cat = get_field('course_categories', 'parent', 'id', $cat);
 102                 }
 103                 $status = $status && fwrite($bf,full_tag("LEVEL",5,false, 'coursecategory'));
 104                 $status = $status && fwrite($bf,full_tag("COURSECATEGORYLEVEL",5,false, $catno));
 105                break;
 106             case CONTEXT_SYSTEM:
 107                 $status = $status && fwrite($bf,full_tag("LEVEL",5,false, 'system'));
 108                 break;
 109             default :
 110                 return false;
 111         }
 112         $status = $status && fwrite($bf,end_tag("CONTEXT",4,true));
 113         return $status;
 114     }
 115
 116     function backup_question_categories($bf,$preferences) {
 117
 118         global $CFG;
 119
 120         $status = true;
 121
 122         //First, we get the used categories from backup_ids
 123         $categories = question_category_ids_by_backup ($preferences->backup_unique_code);
 124
 125         //If we've categories
 126         if ($categories) {
 127              //Write start tag
 128              $status = $status && fwrite($bf,start_tag("QUESTION_CATEGORIES",2,true));
 129              //Iterate over each category
 130             foreach ($categories as $cat) {
 131                 //Start category
 132                 $status = $status && fwrite ($bf,start_tag("QUESTION_CATEGORY",3,true));
 133                 //Get category data from question_categories
 134                 $category = get_record ("question_categories","id",$cat->old_id);
 135                 //Print category contents
 136                 $status = $status && fwrite($bf,full_tag("ID",4,false,$category->id));
 137                 $status = $status && fwrite($bf,full_tag("NAME",4,false,$category->name));
 138                 $status = $status && fwrite($bf,full_tag("INFO",4,false,$category->info));
 139                 $status = $status && backup_question_category_context($bf, $category->contextid, $preferences->backup_course);
 140                 $status = $status && fwrite($bf,full_tag("STAMP",4,false,$category->stamp));
 141                 $status = $status && fwrite($bf,full_tag("PARENT",4,false,$category->parent));
 142                 $status = $status && fwrite($bf,full_tag("SORTORDER",4,false,$category->sortorder));
 143                 //Now, backup their questions
 144                 $status = $status && backup_question($bf,$preferences,$category->id);
 145                 //End category
 146                 $status = $status && fwrite ($bf,end_tag("QUESTION_CATEGORY",3,true));
 147             }
 148             //Write end tag
 149             $status = $status && fwrite ($bf,end_tag("QUESTION_CATEGORIES",2,true));
 150         }
 151
 152         return $status;
 153     }
 154
 155     //This function backups all the questions in selected category and their
 156     //asociated data
 157     function backup_question($bf,$preferences,$category, $level = 4) {
 158
 159         global $CFG, $QTYPES;
 160
 161         $status = true;
 162
 163         // We'll fetch the questions sorted by parent so that questions with no parents
 164         // (these are the ones which could be parents themselves) are backed up first. This
 165         // is important for the recoding of the parent field during the restore process
 166         // Only select questions with ids in backup_ids table
 167         $questions = get_records_sql("SELECT q.* FROM {$CFG->prefix}backup_ids bk, {$CFG->prefix}question q ".
 168                                     "WHERE q.category= $category AND ".
 169                                     "bk.old_id=q.id AND ".
 170                                     "bk.backup_code = {$preferences->backup_unique_code} ".
 171                                     "ORDER BY parent ASC, q.id");
 172         //If there are questions
 173         if ($questions) {
 174             //Write start tag
 175             $status = $status && fwrite ($bf,start_tag("QUESTIONS",$level,true));
 176             $counter = 0;
 177             //Iterate over each question
 178             foreach ($questions as $question) {
 179                 // Deal with missing question types - they need to be included becuase
 180                 // user data or quizzes may refer to them.
 181                 if (!array_key_exists($question->qtype, $QTYPES)) {
 182                     $question->qtype = 'missingtype';
 183                     $question->questiontext = '<p>' . get_string('warningmissingtype', 'quiz') . '</p>' . $question->questiontext;
 184                 }
 185                 //Start question
 186                 $status = $status && fwrite ($bf,start_tag("QUESTION",$level + 1,true));
 187                 //Print question contents
 188                 fwrite ($bf,full_tag("ID",$level + 2,false,$question->id));
 189                 fwrite ($bf,full_tag("PARENT",$level + 2,false,$question->parent));
 190                 fwrite ($bf,full_tag("NAME",$level + 2,false,$question->name));
 191                 fwrite ($bf,full_tag("QUESTIONTEXT",$level + 2,false,$question->questiontext));
 192                 fwrite ($bf,full_tag("QUESTIONTEXTFORMAT",$level + 2,false,$question->questiontextformat));
 193                 fwrite ($bf,full_tag("IMAGE",$level + 2,false,$question->image));
 194                 fwrite ($bf,full_tag("GENERALFEEDBACK",$level + 2,false,$question->generalfeedback));
 195                 fwrite ($bf,full_tag("DEFAULTGRADE",$level + 2,false,$question->defaultgrade));
 196                 fwrite ($bf,full_tag("PENALTY",$level + 2,false,$question->penalty));
 197                 fwrite ($bf,full_tag("QTYPE",$level + 2,false,$question->qtype));
 198                 fwrite ($bf,full_tag("LENGTH",$level + 2,false,$question->length));
 199                 fwrite ($bf,full_tag("STAMP",$level + 2,false,$question->stamp));
 200                 fwrite ($bf,full_tag("VERSION",$level + 2,false,$question->version));
 201                 fwrite ($bf,full_tag("HIDDEN",$level + 2,false,$question->hidden));
 202                 fwrite ($bf,full_tag("TIMECREATED",$level + 2,false,$question->timecreated));
 203                 fwrite ($bf,full_tag("TIMEMODIFIED",$level + 2,false,$question->timemodified));
 204                 fwrite ($bf,full_tag("CREATEDBY",$level + 2,false,$question->createdby));
 205                 fwrite ($bf,full_tag("MODIFIEDBY",$level + 2,false,$question->modifiedby));
 206                 // Backup question type specific data
 207                 $status = $status && $QTYPES[$question->qtype]->backup($bf,$preferences,$question->id, $level + 2);
 208                 //End question
 209                 $status = $status && fwrite ($bf,end_tag("QUESTION",$level + 1,true));
 210                 //Do some output
 211                 $counter++;
 212                 if ($counter % 10 == 0) {
 213                     echo ".";
 214                     if ($counter % 200 == 0) {
 215                         echo "<br />";
 216                     }
 217                     backup_flush(300);
 218                 }
 219             }
 220             //Write end tag
 221             $status = $status && fwrite ($bf,end_tag("QUESTIONS",$level,true));
 222         }
 223         return $status;
 224     }
 225
 226     //This function backups the answers data in some question types
 227     //(truefalse, shortanswer,multichoice,numerical,calculated)
 228     function question_backup_answers($bf,$preferences,$question, $level = 6) {
 229
 230         global $CFG;
 231
 232         $status = true;
 233
 234         $answers = get_records("question_answers","question",$question,"id");
 235         //If there are answers
 236         if ($answers) {
 237             $status = $status && fwrite ($bf,start_tag("ANSWERS",$level,true));
 238             //Iterate over each answer
 239             foreach ($answers as $answer) {
 240                 $status = $status && fwrite ($bf,start_tag("ANSWER",$level + 1,true));
 241                 //Print answer contents
 242                 fwrite ($bf,full_tag("ID",$level + 2,false,$answer->id));
 243                 fwrite ($bf,full_tag("ANSWER_TEXT",$level + 2,false,$answer->answer));
 244                 fwrite ($bf,full_tag("FRACTION",$level + 2,false,$answer->fraction));
 245                 fwrite ($bf,full_tag("FEEDBACK",$level + 2,false,$answer->feedback));
 246                 $status = $status && fwrite ($bf,end_tag("ANSWER",$level + 1,true));
 247             }
 248             $status = $status && fwrite ($bf,end_tag("ANSWERS",$level,true));
 249         }
 250         return $status;
 251     }
 252
 253     //This function backups question_numerical_units from different question types
 254     function question_backup_numerical_units($bf,$preferences,$question,$level=7) {
 255
 256         global $CFG;
 257
 258         $status = true;
 259
 260         $numerical_units = get_records("question_numerical_units","question",$question,"id");
 261         //If there are numericals_units
 262         if ($numerical_units) {
 263             $status = $status && fwrite ($bf,start_tag("NUMERICAL_UNITS",$level,true));
 264             //Iterate over each numerical_unit
 265             foreach ($numerical_units as $numerical_unit) {
 266                 $status = $status && fwrite ($bf,start_tag("NUMERICAL_UNIT",$level+1,true));
 267                 //Print numerical_unit contents
 268                 fwrite ($bf,full_tag("MULTIPLIER",$level+2,false,$numerical_unit->multiplier));
 269                 fwrite ($bf,full_tag("UNIT",$level+2,false,$numerical_unit->unit));
 270                 //Now backup numerical_units
 271                 $status = $status && fwrite ($bf,end_tag("NUMERICAL_UNIT",$level+1,true));
 272             }
 273             $status = $status && fwrite ($bf,end_tag("NUMERICAL_UNITS",$level,true));
 274         }
 275
 276         return $status;
 277
 278     }
 279
 280     //This function backups dataset_definitions (via question_datasets) from different question types
 281     function question_backup_datasets($bf,$preferences,$question,$level=7) {
 282
 283         global $CFG;
 284
 285         $status = true;
 286
 287         //First, we get the used datasets for this question
 288         $question_datasets = get_records("question_datasets","question",$question,"id");
 289         //If there are question_datasets
 290         if ($question_datasets) {
 291             $status = $status &&fwrite ($bf,start_tag("DATASET_DEFINITIONS",$level,true));
 292             //Iterate over each question_dataset
 293             foreach ($question_datasets as $question_dataset) {
 294                 $def = NULL;
 295                 //Get dataset_definition
 296                 if ($def = get_record("question_dataset_definitions","id",$question_dataset->datasetdefinition)) {;
 297                     $status = $status &&fwrite ($bf,start_tag("DATASET_DEFINITION",$level+1,true));
 298                     //Print question_dataset contents
 299                     fwrite ($bf,full_tag("CATEGORY",$level+2,false,$def->category));
 300                     fwrite ($bf,full_tag("NAME",$level+2,false,$def->name));
 301                     fwrite ($bf,full_tag("TYPE",$level+2,false,$def->type));
 302                     fwrite ($bf,full_tag("OPTIONS",$level+2,false,$def->options));
 303                     fwrite ($bf,full_tag("ITEMCOUNT",$level+2,false,$def->itemcount));
 304                     //Now backup dataset_entries
 305                     $status = $status && question_backup_dataset_items($bf,$preferences,$def->id,$level+2);
 306                     //End dataset definition
 307                     $status = $status &&fwrite ($bf,end_tag("DATASET_DEFINITION",$level+1,true));
 308                 }
 309             }
 310             $status = $status &&fwrite ($bf,end_tag("DATASET_DEFINITIONS",$level,true));
 311         }
 312
 313         return $status;
 314
 315     }
 316
 317     //This function backups datases_items from dataset_definitions
 318     function question_backup_dataset_items($bf,$preferences,$datasetdefinition,$level=9) {
 319
 320         global $CFG;
 321
 322         $status = true;
 323
 324         //First, we get the datasets_items for this dataset_definition
 325         $dataset_items = get_records("question_dataset_items","definition",$datasetdefinition,"id");
 326         //If there are dataset_items
 327         if ($dataset_items) {
 328             $status = $status &&fwrite ($bf,start_tag("DATASET_ITEMS",$level,true));
 329             //Iterate over each dataset_item
 330             foreach ($dataset_items as $dataset_item) {
 331                 $status = $status &&fwrite ($bf,start_tag("DATASET_ITEM",$level+1,true));
 332                 //Print question_dataset contents
 333                 fwrite ($bf,full_tag("NUMBER",$level+2,false,$dataset_item->itemnumber));
 334                 fwrite ($bf,full_tag("VALUE",$level+2,false,$dataset_item->value));
 335                 //End dataset definition
 336                 $status = $status &&fwrite ($bf,end_tag("DATASET_ITEM",$level+1,true));
 337             }
 338             $status = $status &&fwrite ($bf,end_tag("DATASET_ITEMS",$level,true));
 339         }
 340
 341         return $status;
 342
 343     }
 344
 345
 346     //Backup question_states contents (executed from backup_quiz_attempts)
 347     function backup_question_states ($bf,$preferences,$attempt, $level = 6) {
 348
 349         global $CFG;
 350
 351         $status = true;
 352
 353         $question_states = get_records("question_states","attempt",$attempt,"id");
 354         //If there are states
 355         if ($question_states) {
 356             //Write start tag
 357             $status = $status && fwrite ($bf,start_tag("STATES",$level,true));
 358             //Iterate over each state
 359             foreach ($question_states as $state) {
 360                 //Start state
 361                 $status = $status && fwrite ($bf,start_tag("STATE",$level + 1,true));
 362                 //Print state contents
 363                 fwrite ($bf,full_tag("ID",$level + 2,false,$state->id));
 364                 fwrite ($bf,full_tag("QUESTION",$level + 2,false,$state->question));
 365                 fwrite ($bf,full_tag("ORIGINALQUESTION",$level + 2,false,$state->originalquestion));
 366                 fwrite ($bf,full_tag("SEQ_NUMBER",$level + 2,false,$state->seq_number));
 367                 fwrite ($bf,full_tag("ANSWER",$level + 2,false,$state->answer));
 368                 fwrite ($bf,full_tag("TIMESTAMP",$level + 2,false,$state->timestamp));
 369                 fwrite ($bf,full_tag("EVENT",$level + 2,false,$state->event));
 370                 fwrite ($bf,full_tag("GRADE",$level + 2,false,$state->grade));
 371                 fwrite ($bf,full_tag("RAW_GRADE",$level + 2,false,$state->raw_grade));
 372                 fwrite ($bf,full_tag("PENALTY",$level + 2,false,$state->penalty));
 373                 //End state
 374                 $status = $status && fwrite ($bf,end_tag("STATE",$level + 1,true));
 375             }
 376             //Write end tag
 377             $status = $status && fwrite ($bf,end_tag("STATES",$level,true));
 378         }
 379     }
 380
 381     //Backup question_sessions contents (executed from backup_quiz_attempts)
 382     function backup_question_sessions ($bf,$preferences,$attempt, $level = 6) {
 383         global $CFG;
 384
 385         $status = true;
 386
 387         $question_sessions = get_records("question_sessions","attemptid",$attempt,"id");
 388         //If there are sessions
 389         if ($question_sessions) {
 390             //Write start tag (the funny name 'newest states' has historical reasons)
 391             $status = $status && fwrite ($bf,start_tag("NEWEST_STATES",$level,true));
 392             //Iterate over each newest_state
 393             foreach ($question_sessions as $newest_state) {
 394                 //Start newest_state
 395                 $status = $status && fwrite ($bf,start_tag("NEWEST_STATE",$level + 1,true));
 396                 //Print newest_state contents
 397                 fwrite ($bf,full_tag("ID",$level + 2,false,$newest_state->id));
 398                 fwrite ($bf,full_tag("QUESTIONID",$level + 2,false,$newest_state->questionid));
 399                 fwrite ($bf,full_tag("NEWEST",$level + 2,false,$newest_state->newest));
 400                 fwrite ($bf,full_tag("NEWGRADED",$level + 2,false,$newest_state->newgraded));
 401                 fwrite ($bf,full_tag("SUMPENALTY",$level + 2,false,$newest_state->sumpenalty));
 402                 fwrite ($bf,full_tag("MANUALCOMMENT",$level + 2,false,$newest_state->manualcomment));
 403                 //End newest_state
 404                 $status = $status && fwrite ($bf,end_tag("NEWEST_STATE",$level + 1,true));
 405             }
 406             //Write end tag
 407             $status = $status && fwrite ($bf,end_tag("NEWEST_STATES",$level,true));
 408         }
 409         return $status;
 410     }
 411
 412     //Returns an array of categories id
 413     function question_category_ids_by_backup ($backup_unique_code) {
 414
 415         global $CFG;
 416
 417         return get_records_sql ("SELECT a.old_id, a.backup_code
 418                                  FROM {$CFG->prefix}backup_ids a
 419                                  WHERE a.backup_code = '$backup_unique_code' AND
 420                                        a.table_name = 'question_categories'");
 421     }
 422
 423     function question_ids_by_backup ($backup_unique_code) {
 424
 425         global $CFG;
 426
 427         return get_records_sql ("SELECT old_id, backup_code
 428                                  FROM {$CFG->prefix}backup_ids
 429                                  WHERE backup_code = '$backup_unique_code' AND
 430                                        table_name = 'question'");
 431     }
 432
 433     //Function for inserting question and category ids into db that are all called from
 434     // quiz_check_backup_mods during execution of backup_check.html
 435
 436
 437     function question_insert_c_and_q_ids_for_course($coursecontext, $backup_unique_code){
 438         global $CFG;
 439         // First, all categories from this course's context.
 440         $status = execute_sql("INSERT INTO {$CFG->prefix}backup_ids
 441                                    (backup_code, table_name, old_id, info)
 442                                SELECT '$backup_unique_code', 'question_categories', qc.id, 'course'
 443                                FROM {$CFG->prefix}question_categories qc
 444                                WHERE qc.contextid = {$coursecontext->id}", false);
 445         $status = $status && question_insert_q_ids($backup_unique_code, 'course');
 446         return $status;
 447     }
 448     /*
 449      * Insert all question ids for categories whose ids have already been inserted in the backup_ids table
 450      * Insert code to identify categories to later insert all question ids later eg. course, quiz or other module name.
 451      */
 452     function question_insert_q_ids($backup_unique_code, $info){
 453         global $CFG;
 454         //put the ids of the questions from all these categories into the db.
 455         $status = execute_sql("INSERT INTO {$CFG->prefix}backup_ids
 456                                        (backup_code, table_name, old_id, info)
 457                                        SELECT '$backup_unique_code', 'question', q.id, '" . sql_empty() . "'
 458                                        FROM {$CFG->prefix}question q, {$CFG->prefix}backup_ids bk
 459                                        WHERE q.category = bk.old_id AND bk.table_name = 'question_categories'
 460                                        AND " . sql_compare_text('bk.info') . " = '$info'
 461                                        AND bk.backup_code = '$backup_unique_code'", false);
 462         return $status;
 463     }
 464
 465     function question_insert_c_and_q_ids_for_module($backup_unique_code, $course, $modulename, $instances){
 466         global $CFG;
 467         $status = true;
 468         // using 'dummykeyname' in sql because otherwise get_records_sql_menu returns an error
 469         // if two key names are the same.
 470         $cmcontexts = array();
 471         if(!empty($instances)) {
 472             $cmcontexts = get_records_sql_menu("SELECT c.id, c.id AS dummykeyname FROM {$CFG->prefix}modules m,
 473                                                         {$CFG->prefix}course_modules cm,
 474                                                         {$CFG->prefix}context c
 475                                WHERE m.name = '$modulename' AND m.id = cm.module AND cm.id = c.instanceid
 476                                     AND c.contextlevel = ".CONTEXT_MODULE." AND cm.course = $course
 477                                     AND cm.instance IN (".implode(',',array_keys($instances)).")");
 478         }
 479
 480         if ($cmcontexts){
 481             $status = $status && execute_sql("INSERT INTO {$CFG->prefix}backup_ids
 482                                        (backup_code, table_name, old_id, info)
 483                                    SELECT '$backup_unique_code', 'question_categories', qc.id, '$modulename'
 484                                    FROM {$CFG->prefix}question_categories qc
 485                                    WHERE qc.contextid IN (".join(array_keys($cmcontexts), ', ').")", false);
 486         }
 487         $status = $status && question_insert_q_ids($backup_unique_code, $modulename);
 488         return $status;
 489     }
 490
 491     function question_insert_site_file_names($course, $backup_unique_code){
 492         global $QTYPES, $CFG;
 493         $status = true;
 494         $questionids = question_ids_by_backup ($backup_unique_code);
 495         $urls = array();
 496         if ($questionids){
 497             foreach ($questionids as $question_bk){
 498                 $question = get_record('question', 'id', $question_bk->old_id);
 499                 $QTYPES[$question->qtype]->get_question_options($question);
 500                 $urls = array_merge_recursive($urls, $QTYPES[$question->qtype]->find_file_links($question, SITEID));
 501             }
 502         }
 503         ksort($urls);
 504         foreach (array_keys($urls) as $url){
 505             if (file_exists($CFG->dataroot.'/'.SITEID.'/'.$url)){
 506                 $inserturl = new object();
 507                 $inserturl->backup_code = $backup_unique_code;
 508                 $inserturl->file_type = 'site';
 509                 $url = clean_param($url, PARAM_PATH);
 510                 $inserturl->path = addslashes($url);
 511                 $status = $status && insert_record('backup_files', $inserturl);
 512             } else {
 513                 notify(get_string('linkedfiledoesntexist', 'question', $url));
 514             }
 515         }
 516         return $status;
 517     }
 518 ?>