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("$CFG->libdir/questionlib.php");
  79
  80     function backup_question_categories($bf,$preferences) {
  81
  82         global $CFG;
  83
  84         $status = true;
  85
  86         //First, we get the used categories from backup_ids
  87         $categories = question_category_ids_by_backup ($preferences->backup_unique_code);
  88
  89         //If we've categories
  90         if ($categories) {
  91              //Write start tag
  92              $status = fwrite($bf,start_tag("QUESTION_CATEGORIES",2,true));
  93              //Iterate over each category
  94             foreach ($categories as $cat) {
  95                 //Start category
  96                 $status = fwrite ($bf,start_tag("QUESTION_CATEGORY",3,true));
  97                 //Get category data from question_categories
  98                 $category = get_record ("question_categories","id",$cat->old_id);
  99                 //Print category contents
 100                 fwrite($bf,full_tag("ID",4,false,$category->id));
 101                 fwrite($bf,full_tag("NAME",4,false,$category->name));
 102                 fwrite($bf,full_tag("INFO",4,false,$category->info));
 103                 fwrite($bf,full_tag("PUBLISH",4,false,$category->publish));
 104                 fwrite($bf,full_tag("STAMP",4,false,$category->stamp));
 105                 fwrite($bf,full_tag("PARENT",4,false,$category->parent));
 106                 fwrite($bf,full_tag("SORTORDER",4,false,$category->sortorder));
 107                 //Now, backup their questions
 108                 $status = backup_question($bf,$preferences,$category->id);
 109                 //End category
 110                 $status = fwrite ($bf,end_tag("QUESTION_CATEGORY",3,true));
 111             }
 112             //Write end tag
 113             $status = fwrite ($bf,end_tag("QUESTION_CATEGORIES",2,true));
 114         }
 115
 116         return $status;
 117     }
 118
 119     //This function backups all the questions in selected category and their
 120     //asociated data
 121     function backup_question($bf,$preferences,$category, $level = 4) {
 122
 123         global $CFG, $QTYPES;
 124
 125         $status = true;
 126
 127         // We'll fetch the questions sorted by parent so that questions with no parents
 128         // (these are the ones which could be parents themselves) are backed up first. This
 129         // is important for the recoding of the parent field during the restore process
 130         $questions = get_records("question","category",$category,"parent ASC, id");
 131         //If there are questions
 132         if ($questions) {
 133             //Write start tag
 134             $status = fwrite ($bf,start_tag("QUESTIONS",$level,true));
 135             $counter = 0;
 136             //Iterate over each question
 137             foreach ($questions as $question) {
 138                 //Start question
 139                 $status = fwrite ($bf,start_tag("QUESTION",$level + 1,true));
 140                 //Print question contents
 141                 fwrite ($bf,full_tag("ID",$level + 2,false,$question->id));
 142                 fwrite ($bf,full_tag("PARENT",$level + 2,false,$question->parent));
 143                 fwrite ($bf,full_tag("NAME",$level + 2,false,$question->name));
 144                 fwrite ($bf,full_tag("QUESTIONTEXT",$level + 2,false,$question->questiontext));
 145                 fwrite ($bf,full_tag("QUESTIONTEXTFORMAT",$level + 2,false,$question->questiontextformat));
 146                 fwrite ($bf,full_tag("IMAGE",$level + 2,false,$question->image));
 147                 fwrite ($bf,full_tag("GENERALFEEDBACK",$level + 2,false,$question->generalfeedback));
 148                 fwrite ($bf,full_tag("DEFAULTGRADE",$level + 2,false,$question->defaultgrade));
 149                 fwrite ($bf,full_tag("PENALTY",$level + 2,false,$question->penalty));
 150                 fwrite ($bf,full_tag("QTYPE",$level + 2,false,$question->qtype));
 151                 fwrite ($bf,full_tag("LENGTH",$level + 2,false,$question->length));
 152                 fwrite ($bf,full_tag("STAMP",$level + 2,false,$question->stamp));
 153                 fwrite ($bf,full_tag("VERSION",$level + 2,false,$question->version));
 154                 fwrite ($bf,full_tag("HIDDEN",$level + 2,false,$question->hidden));
 155                 // Backup question type specific data
 156                 $status = $QTYPES[$question->qtype]->backup($bf,$preferences,$question->id, $level + 2);
 157                 //End question
 158                 $status = fwrite ($bf,end_tag("QUESTION",$level + 1,true));
 159                 //Do some output
 160                 $counter++;
 161                 if ($counter % 10 == 0) {
 162                     echo ".";
 163                     if ($counter % 200 == 0) {
 164                         echo "<br />";
 165                     }
 166                     backup_flush(300);
 167                 }
 168             }
 169             //Write end tag
 170             $status = fwrite ($bf,end_tag("QUESTIONS",$level,true));
 171         }
 172         return $status;
 173     }
 174
 175     //This function backups the answers data in some question types
 176     //(truefalse, shortanswer,multichoice,numerical,calculated)
 177     function question_backup_answers($bf,$preferences,$question, $level = 6) {
 178
 179         global $CFG;
 180
 181         $status = true;
 182
 183         $answers = get_records("question_answers","question",$question,"id");
 184         //If there are answers
 185         if ($answers) {
 186             $status = fwrite ($bf,start_tag("ANSWERS",$level,true));
 187             //Iterate over each answer
 188             foreach ($answers as $answer) {
 189                 $status = fwrite ($bf,start_tag("ANSWER",$level + 1,true));
 190                 //Print answer contents
 191                 fwrite ($bf,full_tag("ID",$level + 2,false,$answer->id));
 192                 fwrite ($bf,full_tag("ANSWER_TEXT",$level + 2,false,$answer->answer));
 193                 fwrite ($bf,full_tag("FRACTION",$level + 2,false,$answer->fraction));
 194                 fwrite ($bf,full_tag("FEEDBACK",$level + 2,false,$answer->feedback));
 195                 $status = fwrite ($bf,end_tag("ANSWER",$level + 1,true));
 196             }
 197             $status = fwrite ($bf,end_tag("ANSWERS",$level,true));
 198         }
 199         return $status;
 200     }
 201
 202     //This function backups question_numerical_units from different question types
 203     function question_backup_numerical_units($bf,$preferences,$question,$level=7) {
 204
 205         global $CFG;
 206
 207         $status = true;
 208
 209         $numerical_units = get_records("question_numerical_units","question",$question,"id");
 210         //If there are numericals_units
 211         if ($numerical_units) {
 212             $status = fwrite ($bf,start_tag("NUMERICAL_UNITS",$level,true));
 213             //Iterate over each numerical_unit
 214             foreach ($numerical_units as $numerical_unit) {
 215                 $status = fwrite ($bf,start_tag("NUMERICAL_UNIT",$level+1,true));
 216                 //Print numerical_unit contents
 217                 fwrite ($bf,full_tag("MULTIPLIER",$level+2,false,$numerical_unit->multiplier));
 218                 fwrite ($bf,full_tag("UNIT",$level+2,false,$numerical_unit->unit));
 219                 //Now backup numerical_units
 220                 $status = fwrite ($bf,end_tag("NUMERICAL_UNIT",$level+1,true));
 221             }
 222             $status = fwrite ($bf,end_tag("NUMERICAL_UNITS",$level,true));
 223         }
 224
 225         return $status;
 226
 227     }
 228
 229     //This function backups dataset_definitions (via question_datasets) from different question types
 230     function question_backup_datasets($bf,$preferences,$question,$level=7) {
 231
 232         global $CFG;
 233
 234         $status = true;
 235
 236         //First, we get the used datasets for this question
 237         $question_datasets = get_records("question_datasets","question",$question,"id");
 238         //If there are question_datasets
 239         if ($question_datasets) {
 240             $status = $status &&fwrite ($bf,start_tag("DATASET_DEFINITIONS",$level,true));
 241             //Iterate over each question_dataset
 242             foreach ($question_datasets as $question_dataset) {
 243                 $def = NULL;
 244                 //Get dataset_definition
 245                 if ($def = get_record("question_dataset_definitions","id",$question_dataset->datasetdefinition)) {;
 246                     $status = $status &&fwrite ($bf,start_tag("DATASET_DEFINITION",$level+1,true));
 247                     //Print question_dataset contents
 248                     fwrite ($bf,full_tag("CATEGORY",$level+2,false,$def->category));
 249                     fwrite ($bf,full_tag("NAME",$level+2,false,$def->name));
 250                     fwrite ($bf,full_tag("TYPE",$level+2,false,$def->type));
 251                     fwrite ($bf,full_tag("OPTIONS",$level+2,false,$def->options));
 252                     fwrite ($bf,full_tag("ITEMCOUNT",$level+2,false,$def->itemcount));
 253                     //Now backup dataset_entries
 254                     $status = question_backup_dataset_items($bf,$preferences,$def->id,$level+2);
 255                     //End dataset definition
 256                     $status = $status &&fwrite ($bf,end_tag("DATASET_DEFINITION",$level+1,true));
 257                 }
 258             }
 259             $status = $status &&fwrite ($bf,end_tag("DATASET_DEFINITIONS",$level,true));
 260         }
 261
 262         return $status;
 263
 264     }
 265
 266     //This function backups datases_items from dataset_definitions
 267     function question_backup_dataset_items($bf,$preferences,$datasetdefinition,$level=9) {
 268
 269         global $CFG;
 270
 271         $status = true;
 272
 273         //First, we get the datasets_items for this dataset_definition
 274         $dataset_items = get_records("question_dataset_items","definition",$datasetdefinition,"id");
 275         //If there are dataset_items
 276         if ($dataset_items) {
 277             $status = $status &&fwrite ($bf,start_tag("DATASET_ITEMS",$level,true));
 278             //Iterate over each dataset_item
 279             foreach ($dataset_items as $dataset_item) {
 280                 $status = $status &&fwrite ($bf,start_tag("DATASET_ITEM",$level+1,true));
 281                 //Print question_dataset contents
 282                 fwrite ($bf,full_tag("NUMBER",$level+2,false,$dataset_item->itemnumber));
 283                 fwrite ($bf,full_tag("VALUE",$level+2,false,$dataset_item->value));
 284                 //End dataset definition
 285                 $status = $status &&fwrite ($bf,end_tag("DATASET_ITEM",$level+1,true));
 286             }
 287             $status = $status &&fwrite ($bf,end_tag("DATASET_ITEMS",$level,true));
 288         }
 289
 290         return $status;
 291
 292     }
 293
 294
 295     //Backup question_states contents (executed from backup_quiz_attempts)
 296     function backup_question_states ($bf,$preferences,$attempt, $level = 6) {
 297
 298         global $CFG;
 299
 300         $status = true;
 301
 302         $question_states = get_records("question_states","attempt",$attempt,"id");
 303         //If there are states
 304         if ($question_states) {
 305             //Write start tag
 306             $status = fwrite ($bf,start_tag("STATES",$level,true));
 307             //Iterate over each state
 308             foreach ($question_states as $state) {
 309                 //Start state
 310                 $status = fwrite ($bf,start_tag("STATE",$level + 1,true));
 311                 //Print state contents
 312                 fwrite ($bf,full_tag("ID",$level + 2,false,$state->id));
 313                 fwrite ($bf,full_tag("QUESTION",$level + 2,false,$state->question));
 314                 fwrite ($bf,full_tag("ORIGINALQUESTION",$level + 2,false,$state->originalquestion));
 315                 fwrite ($bf,full_tag("SEQ_NUMBER",$level + 2,false,$state->seq_number));
 316                 fwrite ($bf,full_tag("ANSWER",$level + 2,false,$state->answer));
 317                 fwrite ($bf,full_tag("TIMESTAMP",$level + 2,false,$state->timestamp));
 318                 fwrite ($bf,full_tag("EVENT",$level + 2,false,$state->event));
 319                 fwrite ($bf,full_tag("GRADE",$level + 2,false,$state->grade));
 320                 fwrite ($bf,full_tag("RAW_GRADE",$level + 2,false,$state->raw_grade));
 321                 fwrite ($bf,full_tag("PENALTY",$level + 2,false,$state->penalty));
 322                 //End state
 323                 $status = fwrite ($bf,end_tag("STATE",$level + 1,true));
 324             }
 325             //Write end tag
 326             $status = fwrite ($bf,end_tag("STATES",$level,true));
 327         }
 328     }
 329
 330     //Backup question_sessions contents (executed from backup_quiz_attempts)
 331     function backup_question_sessions ($bf,$preferences,$attempt, $level = 6) {
 332         global $CFG;
 333
 334         $status = true;
 335
 336         $question_sessions = get_records("question_sessions","attemptid",$attempt,"id");
 337         //If there are sessions
 338         if ($question_sessions) {
 339             //Write start tag (the funny name 'newest states' has historical reasons)
 340             $status = fwrite ($bf,start_tag("NEWEST_STATES",$level,true));
 341             //Iterate over each newest_state
 342             foreach ($question_sessions as $newest_state) {
 343                 //Start newest_state
 344                 $status = fwrite ($bf,start_tag("NEWEST_STATE",$level + 1,true));
 345                 //Print newest_state contents
 346                 fwrite ($bf,full_tag("ID",$level + 2,false,$newest_state->id));
 347                 fwrite ($bf,full_tag("QUESTIONID",$level + 2,false,$newest_state->questionid));
 348                 fwrite ($bf,full_tag("NEWEST",$level + 2,false,$newest_state->newest));
 349                 fwrite ($bf,full_tag("NEWGRADED",$level + 2,false,$newest_state->newgraded));
 350                 fwrite ($bf,full_tag("SUMPENALTY",$level + 2,false,$newest_state->sumpenalty));
 351                 fwrite ($bf,full_tag("MANUALCOMMENT",$level + 2,false,$newest_state->manualcomment));
 352                 //End newest_state
 353                 $status = fwrite ($bf,end_tag("NEWEST_STATE",$level + 1,true));
 354             }
 355             //Write end tag
 356             $status = fwrite ($bf,end_tag("NEWEST_STATES",$level,true));
 357         }
 358         return $status;
 359     }
 360
 361     //Returns an array of categories id
 362     function question_category_ids_by_backup ($backup_unique_code) {
 363
 364         global $CFG;
 365
 366         return get_records_sql ("SELECT a.old_id, a.backup_code
 367                                  FROM {$CFG->prefix}backup_ids a
 368                                  WHERE a.backup_code = '$backup_unique_code' AND
 369                                        a.table_name = 'question_categories'");
 370     }
 371
 372     function question_ids_by_backup ($backup_unique_code) {
 373
 374         global $CFG;
 375
 376         return get_records_sql ("SELECT q.id, q.category
 377                                  FROM {$CFG->prefix}backup_ids a,
 378                                       {$CFG->prefix}question q
 379                                  WHERE a.backup_code = '$backup_unique_code' AND
 380                                        q.category = a.old_id AND
 381                                        a.table_name = 'question_categories'");
 382     }
 383
 384     //Delete category ids from backup_ids table
 385     function delete_category_ids ($backup_unique_code) {
 386         global $CFG;
 387         $status = true;
 388         $status = execute_sql("DELETE FROM {$CFG->prefix}backup_ids
 389                                WHERE backup_code = '$backup_unique_code'",false);
 390         return $status;
 391     }
 392
 393 ?>