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, 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                 //Start question
 180                 $status = $status && fwrite ($bf,start_tag("QUESTION",$level + 1,true));
 181                 //Print question contents
 182                 fwrite ($bf,full_tag("ID",$level + 2,false,$question->id));
 183                 fwrite ($bf,full_tag("PARENT",$level + 2,false,$question->parent));
 184                 fwrite ($bf,full_tag("NAME",$level + 2,false,$question->name));
 185                 fwrite ($bf,full_tag("QUESTIONTEXT",$level + 2,false,$question->questiontext));
 186                 fwrite ($bf,full_tag("QUESTIONTEXTFORMAT",$level + 2,false,$question->questiontextformat));
 187                 fwrite ($bf,full_tag("IMAGE",$level + 2,false,$question->image));
 188                 fwrite ($bf,full_tag("GENERALFEEDBACK",$level + 2,false,$question->generalfeedback));
 189                 fwrite ($bf,full_tag("DEFAULTGRADE",$level + 2,false,$question->defaultgrade));
 190                 fwrite ($bf,full_tag("PENALTY",$level + 2,false,$question->penalty));
 191                 fwrite ($bf,full_tag("QTYPE",$level + 2,false,$question->qtype));
 192                 fwrite ($bf,full_tag("LENGTH",$level + 2,false,$question->length));
 193                 fwrite ($bf,full_tag("STAMP",$level + 2,false,$question->stamp));
 194                 fwrite ($bf,full_tag("VERSION",$level + 2,false,$question->version));
 195                 fwrite ($bf,full_tag("HIDDEN",$level + 2,false,$question->hidden));
 196                 fwrite ($bf,full_tag("TIMECREATED",$level + 2,false,$question->timecreated));
 197                 fwrite ($bf,full_tag("TIMEMODIFIED",$level + 2,false,$question->timemodified));
 198                 fwrite ($bf,full_tag("CREATEDBY",$level + 2,false,$question->createdby));
 199                 fwrite ($bf,full_tag("MODIFIEDBY",$level + 2,false,$question->modifiedby));
 200                 // Backup question type specific data
 201                 $status = $status && $QTYPES[$question->qtype]->backup($bf,$preferences,$question->id, $level + 2);
 202                 //End question
 203                 $status = $status && fwrite ($bf,end_tag("QUESTION",$level + 1,true));
 204                 //Do some output
 205                 $counter++;
 206                 if ($counter % 10 == 0) {
 207                     echo ".";
 208                     if ($counter % 200 == 0) {
 209                         echo "<br />";
 210                     }
 211                     backup_flush(300);
 212                 }
 213             }
 214             //Write end tag
 215             $status = $status && fwrite ($bf,end_tag("QUESTIONS",$level,true));
 216         }
 217         return $status;
 218     }
 219
 220     //This function backups the answers data in some question types
 221     //(truefalse, shortanswer,multichoice,numerical,calculated)
 222     function question_backup_answers($bf,$preferences,$question, $level = 6) {
 223
 224         global $CFG;
 225
 226         $status = true;
 227
 228         $answers = get_records("question_answers","question",$question,"id");
 229         //If there are answers
 230         if ($answers) {
 231             $status = $status && fwrite ($bf,start_tag("ANSWERS",$level,true));
 232             //Iterate over each answer
 233             foreach ($answers as $answer) {
 234                 $status = $status && fwrite ($bf,start_tag("ANSWER",$level + 1,true));
 235                 //Print answer contents
 236                 fwrite ($bf,full_tag("ID",$level + 2,false,$answer->id));
 237                 fwrite ($bf,full_tag("ANSWER_TEXT",$level + 2,false,$answer->answer));
 238                 fwrite ($bf,full_tag("FRACTION",$level + 2,false,$answer->fraction));
 239                 fwrite ($bf,full_tag("FEEDBACK",$level + 2,false,$answer->feedback));
 240                 $status = $status && fwrite ($bf,end_tag("ANSWER",$level + 1,true));
 241             }
 242             $status = $status && fwrite ($bf,end_tag("ANSWERS",$level,true));
 243         }
 244         return $status;
 245     }
 246
 247     //This function backups question_numerical_units from different question types
 248     function question_backup_numerical_units($bf,$preferences,$question,$level=7) {
 249
 250         global $CFG;
 251
 252         $status = true;
 253
 254         $numerical_units = get_records("question_numerical_units","question",$question,"id");
 255         //If there are numericals_units
 256         if ($numerical_units) {
 257             $status = $status && fwrite ($bf,start_tag("NUMERICAL_UNITS",$level,true));
 258             //Iterate over each numerical_unit
 259             foreach ($numerical_units as $numerical_unit) {
 260                 $status = $status && fwrite ($bf,start_tag("NUMERICAL_UNIT",$level+1,true));
 261                 //Print numerical_unit contents
 262                 fwrite ($bf,full_tag("MULTIPLIER",$level+2,false,$numerical_unit->multiplier));
 263                 fwrite ($bf,full_tag("UNIT",$level+2,false,$numerical_unit->unit));
 264                 //Now backup numerical_units
 265                 $status = $status && fwrite ($bf,end_tag("NUMERICAL_UNIT",$level+1,true));
 266             }
 267             $status = $status && fwrite ($bf,end_tag("NUMERICAL_UNITS",$level,true));
 268         }
 269
 270         return $status;
 271
 272     }
 273
 274     //This function backups dataset_definitions (via question_datasets) from different question types
 275     function question_backup_datasets($bf,$preferences,$question,$level=7) {
 276
 277         global $CFG;
 278
 279         $status = true;
 280
 281         //First, we get the used datasets for this question
 282         $question_datasets = get_records("question_datasets","question",$question,"id");
 283         //If there are question_datasets
 284         if ($question_datasets) {
 285             $status = $status &&fwrite ($bf,start_tag("DATASET_DEFINITIONS",$level,true));
 286             //Iterate over each question_dataset
 287             foreach ($question_datasets as $question_dataset) {
 288                 $def = NULL;
 289                 //Get dataset_definition
 290                 if ($def = get_record("question_dataset_definitions","id",$question_dataset->datasetdefinition)) {;
 291                     $status = $status &&fwrite ($bf,start_tag("DATASET_DEFINITION",$level+1,true));
 292                     //Print question_dataset contents
 293                     fwrite ($bf,full_tag("CATEGORY",$level+2,false,$def->category));
 294                     fwrite ($bf,full_tag("NAME",$level+2,false,$def->name));
 295                     fwrite ($bf,full_tag("TYPE",$level+2,false,$def->type));
 296                     fwrite ($bf,full_tag("OPTIONS",$level+2,false,$def->options));
 297                     fwrite ($bf,full_tag("ITEMCOUNT",$level+2,false,$def->itemcount));
 298                     //Now backup dataset_entries
 299                     $status = $status && question_backup_dataset_items($bf,$preferences,$def->id,$level+2);
 300                     //End dataset definition
 301                     $status = $status &&fwrite ($bf,end_tag("DATASET_DEFINITION",$level+1,true));
 302                 }
 303             }
 304             $status = $status &&fwrite ($bf,end_tag("DATASET_DEFINITIONS",$level,true));
 305         }
 306
 307         return $status;
 308
 309     }
 310
 311     //This function backups datases_items from dataset_definitions
 312     function question_backup_dataset_items($bf,$preferences,$datasetdefinition,$level=9) {
 313
 314         global $CFG;
 315
 316         $status = true;
 317
 318         //First, we get the datasets_items for this dataset_definition
 319         $dataset_items = get_records("question_dataset_items","definition",$datasetdefinition,"id");
 320         //If there are dataset_items
 321         if ($dataset_items) {
 322             $status = $status &&fwrite ($bf,start_tag("DATASET_ITEMS",$level,true));
 323             //Iterate over each dataset_item
 324             foreach ($dataset_items as $dataset_item) {
 325                 $status = $status &&fwrite ($bf,start_tag("DATASET_ITEM",$level+1,true));
 326                 //Print question_dataset contents
 327                 fwrite ($bf,full_tag("NUMBER",$level+2,false,$dataset_item->itemnumber));
 328                 fwrite ($bf,full_tag("VALUE",$level+2,false,$dataset_item->value));
 329                 //End dataset definition
 330                 $status = $status &&fwrite ($bf,end_tag("DATASET_ITEM",$level+1,true));
 331             }
 332             $status = $status &&fwrite ($bf,end_tag("DATASET_ITEMS",$level,true));
 333         }
 334
 335         return $status;
 336
 337     }
 338
 339
 340     //Backup question_states contents (executed from backup_quiz_attempts)
 341     function backup_question_states ($bf,$preferences,$attempt, $level = 6) {
 342
 343         global $CFG;
 344
 345         $status = true;
 346
 347         $question_states = get_records("question_states","attempt",$attempt,"id");
 348         //If there are states
 349         if ($question_states) {
 350             //Write start tag
 351             $status = $status && fwrite ($bf,start_tag("STATES",$level,true));
 352             //Iterate over each state
 353             foreach ($question_states as $state) {
 354                 //Start state
 355                 $status = $status && fwrite ($bf,start_tag("STATE",$level + 1,true));
 356                 //Print state contents
 357                 fwrite ($bf,full_tag("ID",$level + 2,false,$state->id));
 358                 fwrite ($bf,full_tag("QUESTION",$level + 2,false,$state->question));
 359                 fwrite ($bf,full_tag("ORIGINALQUESTION",$level + 2,false,$state->originalquestion));
 360                 fwrite ($bf,full_tag("SEQ_NUMBER",$level + 2,false,$state->seq_number));
 361                 fwrite ($bf,full_tag("ANSWER",$level + 2,false,$state->answer));
 362                 fwrite ($bf,full_tag("TIMESTAMP",$level + 2,false,$state->timestamp));
 363                 fwrite ($bf,full_tag("EVENT",$level + 2,false,$state->event));
 364                 fwrite ($bf,full_tag("GRADE",$level + 2,false,$state->grade));
 365                 fwrite ($bf,full_tag("RAW_GRADE",$level + 2,false,$state->raw_grade));
 366                 fwrite ($bf,full_tag("PENALTY",$level + 2,false,$state->penalty));
 367                 //End state
 368                 $status = $status && fwrite ($bf,end_tag("STATE",$level + 1,true));
 369             }
 370             //Write end tag
 371             $status = $status && fwrite ($bf,end_tag("STATES",$level,true));
 372         }
 373     }
 374
 375     //Backup question_sessions contents (executed from backup_quiz_attempts)
 376     function backup_question_sessions ($bf,$preferences,$attempt, $level = 6) {
 377         global $CFG;
 378
 379         $status = true;
 380
 381         $question_sessions = get_records("question_sessions","attemptid",$attempt,"id");
 382         //If there are sessions
 383         if ($question_sessions) {
 384             //Write start tag (the funny name 'newest states' has historical reasons)
 385             $status = $status && fwrite ($bf,start_tag("NEWEST_STATES",$level,true));
 386             //Iterate over each newest_state
 387             foreach ($question_sessions as $newest_state) {
 388                 //Start newest_state
 389                 $status = $status && fwrite ($bf,start_tag("NEWEST_STATE",$level + 1,true));
 390                 //Print newest_state contents
 391                 fwrite ($bf,full_tag("ID",$level + 2,false,$newest_state->id));
 392                 fwrite ($bf,full_tag("QUESTIONID",$level + 2,false,$newest_state->questionid));
 393                 fwrite ($bf,full_tag("NEWEST",$level + 2,false,$newest_state->newest));
 394                 fwrite ($bf,full_tag("NEWGRADED",$level + 2,false,$newest_state->newgraded));
 395                 fwrite ($bf,full_tag("SUMPENALTY",$level + 2,false,$newest_state->sumpenalty));
 396                 fwrite ($bf,full_tag("MANUALCOMMENT",$level + 2,false,$newest_state->manualcomment));
 397                 //End newest_state
 398                 $status = $status && fwrite ($bf,end_tag("NEWEST_STATE",$level + 1,true));
 399             }
 400             //Write end tag
 401             $status = $status && fwrite ($bf,end_tag("NEWEST_STATES",$level,true));
 402         }
 403         return $status;
 404     }
 405
 406     //Returns an array of categories id
 407     function question_category_ids_by_backup ($backup_unique_code) {
 408
 409         global $CFG;
 410
 411         return get_records_sql ("SELECT a.old_id, a.backup_code
 412                                  FROM {$CFG->prefix}backup_ids a
 413                                  WHERE a.backup_code = '$backup_unique_code' AND
 414                                        a.table_name = 'question_categories'");
 415     }
 416
 417     function question_ids_by_backup ($backup_unique_code) {
 418
 419         global $CFG;
 420
 421         return get_records_sql ("SELECT old_id, backup_code
 422                                  FROM {$CFG->prefix}backup_ids
 423                                  WHERE backup_code = '$backup_unique_code' AND
 424                                        table_name = 'question'");
 425     }
 426
 427     //Delete category ids from backup_ids table
 428     function delete_ids ($backup_unique_code, $tablename) {
 429         global $CFG;
 430         $status = execute_sql("DELETE FROM {$CFG->prefix}backup_ids
 431                                WHERE backup_code = '$backup_unique_code' AND table_name = '$tablename'",false);
 432         return $status;
 433     }
 434     function question_insert_site_file_names($course, $backup_unique_code){
 435         global $QTYPES, $CFG;
 436         $status = true;
 437         $questionids = question_ids_by_backup ($backup_unique_code);
 438         $urls = array();
 439         if ($questionids){
 440             foreach ($questionids as $question_bk){
 441                 $question = get_record('question', 'id', $question_bk->old_id);
 442                 $QTYPES[$question->qtype]->get_question_options(&$question);
 443                 $urls = array_merge_recursive($urls, $QTYPES[$question->qtype]->find_file_links($question, SITEID));
 444             }
 445         }
 446         ksort($urls);
 447         foreach (array_keys($urls) as $url){
 448             if (file_exists($CFG->dataroot.'/'.SITEID.'/'.$url)){
 449                 $inserturl = new object();
 450                 $inserturl->backup_code = $backup_unique_code;
 451                 $inserturl->file_type = 'site';
 452                 $url = clean_param($url, PARAM_PATH);
 453                 $inserturl->path = addslashes($url);
 454                 $status = $status && insert_record('backup_files', $inserturl);
 455             } else {
 456                 notify(get_string('linkedfiledoesntexist', 'question', $url));
 457             }
 458         }
 459         return $status;
 460     }
 461 ?>