admin/health.php

   1 <?php  // $Id$
   2
   3     ob_start(); //for whitespace test
   4     require_once('../config.php');
   5
   6     // extra whitespace test - intentionally breaks cookieless mode
   7     $extraws = '';
   8     while (true) {
   9         $extraws .= ob_get_contents();
  10         if (!@ob_end_clean()) {
  11             break;
  12         }
  13     }
  14
  15     require_once($CFG->libdir.'/adminlib.php');
  16
  17     admin_externalpage_setup('healthcenter');
  18
  19     define('SEVERITY_NOTICE',      'notice');
  20     define('SEVERITY_ANNOYANCE',   'annoyance');
  21     define('SEVERITY_SIGNIFICANT', 'significant');
  22     define('SEVERITY_CRITICAL',    'critical');
  23
  24     $solution = optional_param('solution', 0, PARAM_SAFEDIR); //in fact it is class name alhanumeric and _
  25
  26     require_login();
  27     require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
  28
  29     $site = get_site();
  30
  31     admin_externalpage_print_header();
  32
  33 echo <<<STYLES
  34 <style type="text/css">
  35 div#healthnoproblemsfound {
  36     width: 60%;
  37     margin: auto;
  38     padding: 1em;
  39     border: 1px black solid;
  40     -moz-border-radius: 6px;
  41 }
  42 dl.healthissues {
  43     width: 60%;
  44     margin: auto;
  45 }
  46 dl.critical dt, dl.critical dd {
  47     background-color: #a71501;
  48 }
  49 dl.significant dt, dl.significant dd {
  50     background-color: #d36707;
  51 }
  52 dl.annoyance dt, dl.annoyance dd {
  53     background-color: #dba707;
  54 }
  55 dl.notice dt, dl.notice dd {
  56     background-color: #e5db36;
  57 }
  58 dt.solution, dd.solution, div#healthnoproblemsfound {
  59     background-color: #5BB83E !important;
  60 }
  61 dl.healthissues dt, dl.healthissues dd {
  62     margin: 0px;
  63     padding: 1em;
  64     border: 1px black solid;
  65 }
  66 dl.healthissues dt {
  67     font-weight: bold;
  68     border-bottom: none;
  69     padding-bottom: 0.5em;
  70 }
  71 dl.healthissues dd {
  72     border-top: none;
  73     padding-top: 0.5em;
  74     margin-bottom: 10px;
  75 }
  76 dl.healthissues dd form {
  77     margin-top: 0.5em;
  78     text-align: right;
  79 }
  80 form#healthformreturn {
  81     text-align: center;
  82     margin: 2em;
  83 }
  84 dd.solution p {
  85     padding: 0px;
  86     margin: 1em 0px;
  87 }
  88 dd.solution li {
  89     margin-top: 1em;
  90 }
  91
  92 </style>
  93 STYLES;
  94
  95     if(strpos($solution, 'problem_') === 0 && class_exists($solution)) {
  96         health_print_solution($solution);
  97     }
  98     else {
  99         health_find_problems();
 100     }
 101
 102
 103     admin_externalpage_print_footer();
 104
 105
 106 function health_find_problems() {
 107
 108     print_heading(get_string('healthcenter'));
 109
 110     $issues   = array(
 111         SEVERITY_CRITICAL    => array(),
 112         SEVERITY_SIGNIFICANT => array(),
 113         SEVERITY_ANNOYANCE   => array(),
 114         SEVERITY_NOTICE      => array(),
 115     );
 116     $problems = 0;
 117
 118     for($i = 1; $i < 1000000; ++$i) {
 119         $classname = sprintf('problem_%06d', $i);
 120         if(!class_exists($classname)) {
 121             break;
 122         }
 123         $problem = new $classname;
 124         if($problem->exists()) {
 125             $severity = $problem->severity();
 126             $issues[$severity][$classname] = array(
 127                 'severity'    => $severity,
 128                 'description' => $problem->description(),
 129                 'title'       => $problem->title()
 130             );
 131             ++$problems;
 132         }
 133         unset($problem);
 134     }
 135
 136     if($problems == 0) {
 137         echo '<div id="healthnoproblemsfound">';
 138         echo get_string('healthnoproblemsfound');
 139         echo '</div>';
 140     }
 141     else {
 142         print_heading(get_string('healthproblemsdetected'));
 143         $severities = array(SEVERITY_CRITICAL, SEVERITY_SIGNIFICANT, SEVERITY_ANNOYANCE, SEVERITY_NOTICE);
 144         foreach($severities as $severity) {
 145             if(!empty($issues[$severity])) {
 146                 echo '<dl class="healthissues '.$severity.'">';
 147                 foreach($issues[$severity] as $classname => $data) {
 148                     echo '<dt id="'.$classname.'">'.$data['title'].'</dt>';
 149                     echo '<dd>'.$data['description'];
 150                     echo '<form action="health.php#solution" method="get">';
 151                     echo '<input type="hidden" name="solution" value="'.$classname.'" /><input type="submit" value="'.get_string('viewsolution').'" />';
 152                     echo '</form></dd>';
 153                 }
 154                 echo '</dl>';
 155             }
 156         }
 157     }
 158 }
 159
 160 function health_print_solution($classname) {
 161     $problem = new $classname;
 162     $data = array(
 163         'title'       => $problem->title(),
 164         'severity'    => $problem->severity(),
 165         'description' => $problem->description(),
 166         'solution'    => $problem->solution()
 167     );
 168
 169     print_heading(get_string('healthcenter'));
 170     print_heading(get_string('healthproblemsolution'));
 171     echo '<dl class="healthissues '.$data['severity'].'">';
 172     echo '<dt>'.$data['title'].'</dt>';
 173     echo '<dd>'.$data['description'].'</dd>';
 174     echo '<dt id="solution" class="solution">'.get_string('healthsolution').'</dt>';
 175     echo '<dd class="solution">'.$data['solution'].'</dd></dl>';
 176     echo '<form id="healthformreturn" action="health.php#'.$classname.'" method="get">';
 177     echo '<input type="submit" value="'.get_string('healthreturntomain').'" />';
 178     echo '</form>';
 179 }
 180
 181 class problem_base {
 182     function exists() {
 183         return false;
 184     }
 185     function title() {
 186         return '???';
 187     }
 188     function severity() {
 189         return SEVERITY_NOTICE;
 190     }
 191     function description() {
 192         return '';
 193     }
 194     function solution() {
 195         return '';
 196     }
 197 }
 198
 199 class problem_000001 extends problem_base {
 200     function title() {
 201         return 'Invalid value for $CFG->dirroot';
 202     }
 203     function exists() {
 204         global $CFG;
 205         $dirroot = dirname(realpath('../index.php'));
 206         if (!empty($dirroot) && $dirroot != $CFG->dirroot) {
 207             return true;
 208         }
 209         return false;
 210     }
 211     function severity() {
 212         return SEVERITY_CRITICAL;
 213     }
 214     function description() {
 215         global $CFG;
 216         return 'Your <strong>config.php</strong> file contains the setting <strong>$CFG-&gt;dirroot = "'.$CFG->dirroot.'"</strong>, which is incorrect. Unless you correct this problem, Moodle will not function correctly, if at all.';
 217     }
 218     function solution() {
 219         global $CFG;
 220         $dirroot = dirname(realpath('../index.php'));
 221         return 'You need to edit your <strong>config.php</strong> file. Find the line which reads <pre>$CFG->dirroot = \''.$CFG->dirroot.'\';</pre> and change it to read <pre>$CFG->dirroot = \''.$dirroot.'\'</pre>';
 222     }
 223 }
 224
 225 class problem_000002 extends problem_base {
 226     function title() {
 227         return 'Extra characters at the end of config.php or other library function';
 228     }
 229     function exists() {
 230         global $extraws;
 231
 232         if($extraws === '') {
 233             return false;
 234         }
 235         return true;
 236     }
 237     function severity() {
 238         return SEVERITY_SIGNIFICANT;
 239     }
 240     function description() {
 241         return 'Your Moodle configuration file config.php or another library file, contains some characters after the closing PHP tag (?>). This causes Moodle to exhibit several kinds of problems (such as broken downloaded files) and must be fixed.';
 242     }
 243     function solution() {
 244         global $CFG;
 245         return 'You need to edit <strong>'.$CFG->dirroot.'/config.php</strong> and remove all characters (including spaces and returns) after the ending ?> tag. These two characters should be the very last in that file. The extra trailing whitespace may be also present in other PHP files that are included from lib/setup.php.';
 246     }
 247 }
 248
 249 class problem_000003 extends problem_base {
 250     function title() {
 251         return '$CFG->dataroot does not exist or does not have write permissions';
 252     }
 253     function exists() {
 254         global $CFG;
 255         if(!is_dir($CFG->dataroot) || !is_writable($CFG->dataroot)) {
 256             return true;
 257         }
 258         return false;
 259     }
 260     function severity() {
 261         return SEVERITY_SIGNIFICANT;
 262     }
 263     function description() {
 264         global $CFG;
 265         return 'Your <strong>config.php</strong> says that your "data root" directory is <strong>'.$CFG->dataroot.'</strong>. However, this directory either does not exist or cannot be written to by Moodle. This means that a variety of problems will be present, such as users not being able to log in and not being able to upload any files. It is imperative that you address this problem for Moodle to work correctly.';
 266     }
 267     function solution() {
 268         global $CFG;
 269         return 'First of all, make sure that the directory <strong>'.$CFG->dataroot.'</strong> exists. If the directory does exist, then you must make sure that Moodle is able to write to it. Contact your web server administrator and request that he gives write permissions for that directory to the user that the web server process is running as.';
 270     }
 271 }
 272
 273 class problem_000004 extends problem_base {
 274     function title() {
 275         return 'cron.php is not set up to run automatically';
 276     }
 277     function exists() {
 278         global $CFG;
 279         $lastcron = get_field_sql('SELECT max(lastcron) FROM '.$CFG->prefix.'modules');
 280         return (time() - $lastcron > 3600 * 24);
 281     }
 282     function severity() {
 283         return SEVERITY_SIGNIFICANT;
 284     }
 285     function description() {
 286         return 'The cron.php mainenance script has not been run in the past 24 hours. This probably means that your server is not configured to automatically run this script in regular time intervals. If this is the case, then Moodle will mostly work as it should but some operations (notably sending email to users) will not be carried out at all.';
 287     }
 288     function solution() {
 289         global $CFG;
 290         return 'For detailed instructions on how to enable cron, see <a href="'.$CFG->wwwroot.'/doc/?file=install.html#cron">this section</a> of the installation manual.';
 291     }
 292 }
 293
 294 class problem_000005 extends problem_base {
 295     function title() {
 296         return 'PHP: session.auto_start is enabled';
 297     }
 298     function exists() {
 299         return ini_get_bool('session.auto_start');
 300     }
 301     function severity() {
 302         return SEVERITY_CRITICAL;
 303     }
 304     function description() {
 305         return 'Your PHP configuration includes an enabled setting, session.auto_start, that <strong>must be disabled</strong> in order for Moodle to work correctly. Notable symptoms arising from this misconfiguration include fatal errors and/or blank pages when trying to log in.';
 306     }
 307     function solution() {
 308         global $CFG;
 309         return '<p>There are two ways you can solve this problem:</p><ol><li>If you have access to your main <strong>php.ini</strong> file, then find the line that looks like this: <pre>session.auto_start = 1</pre> and change it to <pre>session.auto_start = 0</pre> and then restart your web server. Be warned that this, as any other PHP setting change, might affect other web applications running on the server.</li><li>Finally, you may be able to change this setting just for your site by creating or editing the file <strong>'.$CFG->dirroot.'/.htaccess</strong> to contain this line: <pre>php_value session.auto_start "0"</pre></li></ol>';
 310     }
 311 }
 312
 313 class problem_000006 extends problem_base {
 314     function title() {
 315         return 'PHP: magic_quotes_runtime is enabled';
 316     }
 317     function exists() {
 318         return (ini_get_bool('magic_quotes_runtime'));
 319     }
 320     function severity() {
 321         return SEVERITY_SIGNIFICANT;
 322     }
 323     function description() {
 324         return 'Your PHP configuration includes an enabled setting, magic_quotes_runtime, that <strong>must be disabled</strong> in order for Moodle to work correctly. Notable symptoms arising from this misconfiguration include strange display errors whenever a text field that includes single or double quotes is processed.';
 325     }
 326     function solution() {
 327         global $CFG;
 328         return '<p>There are two ways you can solve this problem:</p><ol><li>If you have access to your main <strong>php.ini</strong> file, then find the line that looks like this: <pre>magic_quotes_runtime = On</pre> and change it to <pre>magic_quotes_runtime = Off</pre> and then restart your web server. Be warned that this, as any other PHP setting change, might affect other web applications running on the server.</li><li>Finally, you may be able to change this setting just for your site by creating or editing the file <strong>'.$CFG->dirroot.'/.htaccess</strong> to contain this line: <pre>php_value magic_quotes_runtime "Off"</pre></li></ol>';
 329     }
 330 }
 331
 332 class problem_000007 extends problem_base {
 333     function title() {
 334         return 'PHP: file_uploads is disabled';
 335     }
 336     function exists() {
 337         return !ini_get_bool('file_uploads');
 338     }
 339     function severity() {
 340         return SEVERITY_SIGNIFICANT;
 341     }
 342     function description() {
 343         return 'Your PHP configuration includes a disabled setting, file_uploads, that <strong>must be enabled</strong> to let Moodle offer its full functionality. Until this setting is enabled, it will not be possible to upload any files into Moodle. This includes, for example, course content and user pictures.';
 344     }
 345     function solution() {
 346         global $CFG;
 347         return '<p>There are two ways you can solve this problem:</p><ol><li>If you have access to your main <strong>php.ini</strong> file, then find the line that looks like this: <pre>file_uploads = Off</pre> and change it to <pre>file_uploads = On</pre> and then restart your web server. Be warned that this, as any other PHP setting change, might affect other web applications running on the server.</li><li>Finally, you may be able to change this setting just for your site by creating or editing the file <strong>'.$CFG->dirroot.'/.htaccess</strong> to contain this line: <pre>php_value file_uploads "On"</pre></li></ol>';
 348     }
 349 }
 350
 351 class problem_000008 extends problem_base {
 352     function title() {
 353         return 'PHP: memory_limit cannot be controlled by Moodle';
 354     }
 355     function exists() {
 356         $oldmemlimit = @ini_get('memory_limit');
 357         if(empty($oldmemlimit)) {
 358             // PHP not compiled with memory limits, this means that it's
 359             // probably limited to 8M or in case of Windows not at all.
 360             // We can ignore it for now - there is not much to test anyway
 361             // TODO: add manual test that fills memory??
 362             return false;
 363         }
 364         $oldmemlimit = get_real_size($oldmemlimit);
 365         //now lets change the memory limit to something unique below 128M==134217728
 366         if (empty($CFG->extramemorylimit)) {
 367             raise_memory_limit('128M');
 368         } else {
 369             raise_memory_limit($CFG->extramemorylimit);
 370         }
 371         $testmemlimit = get_real_size(@ini_get('memory_limit'));
 372         //verify the change had any effect at all
 373         if ($oldmemlimit == $testmemlimit) {
 374             //memory limit can not be changed - is it big enough then?
 375             if ($oldmemlimit < get_real_size('128M')) {
 376                 return true;
 377             } else {
 378                 return false;
 379             }
 380         }
 381         reduce_memory_limit($oldmemlimit);
 382         return false;
 383     }
 384     function severity() {
 385         return SEVERITY_NOTICE;
 386     }
 387     function description() {
 388         return 'The settings for PHP on your server do not allow a script to request more memory during its execution. '.
 389                'This means that there is a hard limit of '.@ini_get('memory_limit').' for each script. '.
 390                'It is possible that certain operations within Moodle will require more than this amount in order '.
 391                'to complete successfully, especially if there are lots of data to be processed.';
 392     }
 393     function solution() {
 394         return 'It is recommended that you contact your web server administrator to address this issue.';
 395     }
 396 }
 397
 398 class problem_000009 extends problem_base {
 399     function title() {
 400         return 'SQL: using account without password';
 401     }
 402     function exists() {
 403         global $CFG;
 404         return empty($CFG->dbpass);
 405     }
 406     function severity() {
 407         return SEVERITY_CRITICAL;
 408     }
 409     function description() {
 410         global $CFG;
 411         return 'The user account your are connecting to the database server with is set up without a password. This is a very big security risk and is only somewhat lessened if your database is configured to not accept connections from any hosts other than the server Moodle is running on. Unless you use a strong password to connect to the database, you risk unauthorized access to and manipulation of your data.'.($CFG->dbuser != 'root'?'':' <strong>This is especially alarming because such access to the database would be as the superuser (root)!</strong>');
 412     }
 413     function solution() {
 414         global $CFG;
 415         return 'You should change the password of the user <strong>'.$CFG->dbuser.'</strong> both in your database and in your Moodle <strong>config.php</strong> immediately!'.($CFG->dbuser != 'root'?'':' It would also be a good idea to change the user account from root to something else, because this would lessen the impact in the event that your database is compromised anyway.');
 416     }
 417 }
 418
 419 class problem_000010 extends problem_base {
 420     function title() {
 421         return 'Uploaded files: slasharguments disabled or not working';
 422     }
 423     function exists() {
 424         if (!$this->is_enabled()) {
 425             return true;
 426         }
 427         if ($this->status() < 1) {
 428             return true;
 429         }
 430         return false;
 431     }
 432     function severity() {
 433         if ($this->is_enabled() and $this->status() == 0) {
 434             return SEVERITY_SIGNIFICANT;
 435         } else {
 436             return SEVERITY_ANNOYANCE;
 437         }
 438     }
 439     function description() {
 440         global $CFG;
 441         $desc = 'Slasharguments are needed for relative linking in uploaded resources:<ul>';
 442         if (!$this->is_enabled()) {
 443             $desc .= '<li>slasharguments are <strong>disabled</strong> in Moodle configuration</li>';
 444         } else {
 445             $desc .= '<li>slasharguments are enabled in Moodle configuration</li>';
 446         }
 447         if ($this->status() == -1) {
 448             $desc .= '<li>can not run automatic test, you can verify it <a href="'.$CFG->wwwroot.'/file.php/testslasharguments" target="_blank">here</a> manually</li>';
 449         } else if ($this->status() == 0) {
 450             $desc .= '<li>slashargument test <strong>failed</strong>, please check server configuration</li>';
 451         } else {
 452             $desc .= '<li>slashargument test passed</li>';
 453         }
 454         $desc .= '</ul>';
 455         return $desc;
 456     }
 457     function solution() {
 458         global $CFG;
 459         $enabled = $this->is_enabled();
 460         $status = $this->status();
 461         $solution = '';
 462         if ($enabled and ($status == 0)) {
 463             $solution .= 'Slasharguments are enabled, but the test failed. Please disable slasharguments in Moodle configuration or fix the server configuration.<hr />';
 464         } else if ((!$enabled) and ($status == 0)) {
 465             $solution .= 'Slasharguments are disabled and the test failed. You may try to fix the server configuration.<hr />';
 466         } else if ($enabled and ($status == -1)) {
 467             $solution .= 'Slasharguments are enabled, <a href="'.$CFG->wwwroot.'/file.php/testslasharguments">automatic testing</a> not possible.<hr />';
 468         } else if ((!$enabled) and ($status == -1)) {
 469             $solution .= 'Slasharguments are disabled, <a href="'.$CFG->wwwroot.'/file.php/testslasharguments">automatic testing</a> not possible.<hr />';
 470         } else if ((!$enabled) and ($status > 0)) {
 471             $solution .= 'Slasharguments are disabled though the iternal test is OK. You should enable slasharguments in Moodle configuration.';
 472         } else if ($enabled and ($status > 0)) {
 473             $solution .= 'Congratulations - everything seems OK now :-D';
 474         }
 475         if ($status < 1) {
 476             $solution .= '<p>IIS:<ul><li>try to add <code>cgi.fix_pathinfo=1</code> to php.ini</li><li>do NOT enable AllowPathInfoForScriptMappings !!!</li><li>slasharguments may not work when using ISAPI and PHP 4.3.10 and older</li></ul></p>';
 477             $solution .= '<p>Apache 1:<ul><li>try to add <code>cgi.fix_pathinfo=1</code> to php.ini</li></ul></p>';
 478             $solution .= '<p>Apache 2:<ul><li>you must add <code>AcceptPathInfo on</code> to php.ini or .htaccess</li><li>try to add <code>cgi.fix_pathinfo=1</code> to php.ini</li></ul></p>';
 479         }
 480         return $solution;
 481     }
 482     function is_enabled() {
 483         global $CFG;
 484         return !empty($CFG->slasharguments);
 485     }
 486     function status() {
 487         global $CFG;
 488         $handle = @fopen($CFG->wwwroot.'/file.php?file=/testslasharguments', "r");
 489         $contents = @trim(fread($handle, 10));
 490         @fclose($handle);
 491         if ($contents != 'test -1') {
 492             return -1;
 493         }
 494         $handle = @fopen($CFG->wwwroot.'/file.php/testslasharguments', "r");
 495         $contents = trim(@fread($handle, 10));
 496         @fclose($handle);
 497         switch ($contents) {
 498             case 'test 1': return 1;
 499             case 'test 2': return 2;
 500             default:  return 0;
 501         }
 502     }
 503 }
 504
 505 class problem_000011 extends problem_base {
 506     function title() {
 507         return 'Session errors detected';
 508     }
 509     function exists() {
 510         global $CFG;
 511         return isset($CFG->session_error_counter);
 512     }
 513     function severity() {
 514         return SEVERITY_ANNOYANCE;
 515     }
 516     function description() {
 517         global $CFG;
 518         if (isset($CFG->session_error_counter)) {
 519             return 'Session problems were detected. Total count: '.$CFG->session_error_counter;
 520         } else {
 521             return 'No session errors detected.';
 522         }
 523     }
 524     function solution() {
 525         global $CFG;
 526         if (optional_param('resetsesserrorcounter', 0, PARAM_BOOL)) {
 527             if (get_field('config', 'name', 'name', 'session_error_counter')) {
 528                 delete_records('config', 'name', 'session_error_counter');
 529             }
 530             return 'Error counter was cleared.';
 531         } else {
 532             return '<p>Session errors can be caused by:</p><ul>' .
 533             '<li>unresolved problem in server software (aka random switching of users),</li>' .
 534             '<li>blocked or modified cookies,</li>' .
 535             '<li>deleting of active session files.</li>' .
 536             '</ul><p><a href="'.me().'&amp;resetsesserrorcounter=1">Reset counter</a></p>';
 537         }
 538     }
 539 }
 540
 541 class problem_000012 extends problem_base {
 542     function title() {
 543         return 'Random questions data consistency';
 544     }
 545     function exists() {
 546         return record_exists_select('question', "qtype = 'random' AND parent <> id");
 547     }
 548     function severity() {
 549         return SEVERITY_ANNOYANCE;
 550     }
 551     function description() {
 552         return '<p>For random questions, question.parent should equal question.id. ' .
 553         'There are some questions in your database for which this is not true. ' .
 554         'One way that this could have happened is for random questions restored from backup before ' .
 555         '<a href="http://tracker.moodle.org/browse/MDL-5482">MDL-5482</a> was fixed.</p>';
 556     }
 557     function solution() {
 558         global $CFG;
 559         return '<p>Upgrade to Moodle 1.9.1 or later, or manually execute the SQL</p>' .
 560         '<pre>UPDATE ' . $CFG->prefix . 'question SET parent = id WHERE qtype = \'random\' and parent &lt;> id;</pre>';
 561     }
 562 }
 563
 564 class problem_000013 extends problem_base {
 565     function title() {
 566         return 'Multi-answer questions data consistency';
 567     }
 568     function exists() {
 569         global $CFG;
 570         $positionexpr = sql_position(sql_concat("','", "q.id", "','"),
 571                 sql_concat("','", "qma.sequence", "','"));
 572         return record_exists_sql("
 573                 SELECT * FROM {$CFG->prefix}question q
 574                     JOIN {$CFG->prefix}question_multianswer qma ON $positionexpr > 0
 575                 WHERE qma.question <> q.parent") ||
 576             record_exists_sql("
 577                 SELECT * FROM {$CFG->prefix}question q
 578                     JOIN {$CFG->prefix}question parent_q ON parent_q.id = q.parent
 579                 WHERE q.category <> parent_q.category");
 580     }
 581     function severity() {
 582         return SEVERITY_ANNOYANCE;
 583     }
 584     function description() {
 585         return '<p>For each sub-question whose id is listed in ' .
 586         'question_multianswer.sequence, its question.parent field should equal ' .
 587         'question_multianswer.question; and each sub-question should be in the same ' .
 588         'category as its parent. There are questions in your database for ' .
 589         'which this is not the case. One way that this could have happened is ' .
 590         'for multi-answer questions restored from backup before ' .
 591         '<a href="http://tracker.moodle.org/browse/MDL-14750">MDL-14750</a> was fixed.</p>';
 592     }
 593     function solution() {
 594         return '<p>Upgrade to Moodle 1.9.1 or later, or manually execute the ' .
 595         'code in question_multianswer_fix_subquestion_parents_and_categories in ' .
 596         '<a href="http://cvs.moodle.org/moodle/question/type/multianswer/db/upgrade.php?revision=1.1.10.2&amp;view=markup">/question/type/multianswer/db/upgrade.php' .
 597         'from the 1.9 stable branch</a>.</p>';
 598     }
 599 }
 600
 601 class problem_000014 extends problem_base {
 602     function title() {
 603         return 'Only multianswer and random questions should be the parent of another question';
 604     }
 605     function exists() {
 606         global $CFG;
 607         return record_exists_sql("
 608                 SELECT * FROM {$CFG->prefix}question q
 609                     JOIN {$CFG->prefix}question parent_q ON parent_q.id = q.parent
 610                 WHERE parent_q.qtype NOT IN ('random', 'multianswer')");
 611     }
 612     function severity() {
 613         return SEVERITY_ANNOYANCE;
 614     }
 615     function description() {
 616         return '<p>You have questions that violate this in your databse. ' .
 617         'You will need to investigate to determine how this happened.</p>';
 618     }
 619     function solution() {
 620         return '<p>It is impossible to give a solution without knowing more about ' .
 621         ' how the problem was caused. You may be able to get help from the ' .
 622         '<a href="http://moodle.org/mod/forum/view.php?f=121">Quiz forum</a>.</p>';
 623     }
 624 }
 625
 626 class problem_000015 extends problem_base {
 627     function title() {
 628         return 'Question categories should belong to a valid context';
 629     }
 630     function exists() {
 631         global $CFG;
 632         return record_exists_sql("
 633             SELECT qc.*, (SELECT COUNT(1) FROM {$CFG->prefix}question q WHERE q.category = qc.id) AS numquestions
 634             FROM {$CFG->prefix}question_categories qc
 635                 LEFT JOIN {$CFG->prefix}context con ON qc.contextid = con.id
 636             WHERE con.id IS NULL");
 637     }
 638     function severity() {
 639         return SEVERITY_ANNOYANCE;
 640     }
 641     function description() {
 642         global $CFG;
 643         $problemcategories = get_records_sql("
 644             SELECT qc.id, qc.name, qc.contextid, (SELECT COUNT(1) FROM {$CFG->prefix}question q WHERE q.category = qc.id) AS numquestions
 645             FROM {$CFG->prefix}question_categories qc
 646                 LEFT JOIN {$CFG->prefix}context con ON qc.contextid = con.id
 647             WHERE con.id IS NULL
 648             ORDER BY numquestions DESC, qc.name");
 649         $table = '<table><thead><tr><th>Cat id</th><th>Category name</th>' .
 650         "<th>Context id</th><th>Num Questions</th></tr></thead><tbody>\n";
 651         if ($problemcategories) {
 652             foreach ($problemcategories as $cat) {
 653                 $table .= "<tr><td>$cat->id</td><td>" . s($cat->name) . "</td><td>" .
 654                 $cat->contextid ."</td><td>$cat->numquestions</td></tr>\n";
 655             }
 656         }
 657         $table .= '</tbody></table>';
 658         return '<p>All question categories are linked to a context id, and, ' .
 659         'the context they are linked to must exist. The following categories ' .
 660         'belong to a non-existant category:</p>' . $table . '<p>Any of these ' .
 661         'categories that contain no questions can just be deleted form the database. ' .
 662         'Other categories will require more thought.</p>';
 663     }
 664     function solution() {
 665         global $CFG;
 666         return '<p>You can delete the empty categories by executing the following SQL:</p><pre>
 667 DELETE FROM ' . $CFG->prefix . 'question_categories
 668 WHERE
 669     NOT EXISTS (SELECT * FROM ' . $CFG->prefix . 'question q WHERE q.category = ' . $CFG->prefix . 'question_categories.id)
 670 AND NOT EXISTS (SELECT * FROM ' . $CFG->prefix . 'context con WHERE contextid = con.id)
 671         </pre><p>Any remaining categories that contain questions will require more thought. ' .
 672         'People in the <a href="http://moodle.org/mod/forum/view.php?f=121">Quiz forum</a> may be able to help.</p>';
 673     }
 674 }
 675
 676 class problem_000016 extends problem_base {
 677     function title() {
 678         return 'Question categories should belong to the same context as their parent';
 679     }
 680     function exists() {
 681         global $CFG;
 682         return record_exists_sql("
 683             SELECT parent_qc.id AS parent, child_qc.id AS child, child_qc.contextid
 684             FROM {$CFG->prefix}question_categories child_qc
 685                 JOIN {$CFG->prefix}question_categories parent_qc ON child_qc.parent = parent_qc.id
 686             WHERE child_qc.contextid <> parent_qc.contextid");
 687     }
 688     function severity() {
 689         return SEVERITY_ANNOYANCE;
 690     }
 691     function description() {
 692         global $CFG;
 693         $problemcategories = get_records_sql("
 694             SELECT
 695                 parent_qc.id AS parentid, parent_qc.name AS parentname, parent_qc.contextid AS parentcon,
 696                 child_qc.id AS childid, child_qc.name AS childname, child_qc.contextid AS childcon
 697             FROM {$CFG->prefix}question_categories child_qc
 698                 JOIN {$CFG->prefix}question_categories parent_qc ON child_qc.parent = parent_qc.id
 699             WHERE child_qc.contextid <> parent_qc.contextid");
 700         $table = '<table><thead><tr><th colspan="3">Child category</th><th colspan="3">Parent category</th></tr><tr>' .
 701         '<th>Id</th><th>Name</th><th>Context id</th>' .
 702         '<th>Id</th><th>Name</th><th>Context id</th>' .
 703         "</tr></thead><tbody>\n";
 704         if ($problemcategories) {
 705             foreach ($problemcategories as $cat) {
 706                 $table .= "<tr><td>$cat->childid</td><td>" . s($cat->childname) .
 707                 "</td><td>$cat->childcon</td><td>$cat->parentid</td><td>" . s($cat->parentname) .
 708                 "</td><td>$cat->parentcon</td></tr>\n";
 709             }
 710         }
 711         $table .= '</tbody></table>';
 712         return '<p>When one question category is the parent of another, then they ' .
 713         'should both belong to the same context. This is not true for the following categories:</p>' .
 714         $table;
 715     }
 716     function solution() {
 717         return '<p>An automated solution is difficult. It depends whether the ' .
 718         'parent or child category is in the wrong pace.' .
 719         'People in the <a href="http://moodle.org/mod/forum/view.php?f=121">Quiz forum</a> may be able to help.</p>';
 720     }
 721 }
 722
 723 class problem_000017 extends problem_base {
 724     function title() {
 725         return 'Question categories tree structure';
 726     }
 727     function find_problems() {
 728         static $answer = null;
 729
 730         if (is_null($answer)) {
 731             $categories = get_records('question_categories', '', '', 'id');
 732
 733             // Look for missing parents.
 734             $missingparent = array();
 735             foreach ($categories as $category) {
 736                 if ($category->parent != 0 && !array_key_exists($category->parent, $categories)) {
 737                     $missingparent[$category->id] = $category;
 738                 }
 739             }
 740
 741             // Look for loops.
 742             $loops = array();
 743             while (!empty($categories)) {
 744                 $current = array_pop($categories);
 745                 $thisloop = array($current->id => $current);
 746                 while (true) {
 747                     if (isset($thisloop[$current->parent])) {
 748                         // Loop detected
 749                         $loops[$current->id] = $thisloop;
 750                         break;
 751                     } else if (!isset($categories[$current->parent])) {
 752                         // Got to the top level, or a category we already know is OK.
 753                         break;
 754                     } else {
 755                         // Continue following the path.
 756                         $current = $categories[$current->parent];
 757                         $thisloop[$current->id] = $current;
 758                         unset($categories[$current->id]);
 759                     }
 760                 }
 761             }
 762
 763             $answer = array($missingparent, $loops);
 764         }
 765
 766         return $answer;
 767     }
 768     function exists() {
 769         list($missingparent, $loops) = $this->find_problems();
 770         return !empty($missingparent) || !empty($loops);
 771     }
 772     function severity() {
 773         return SEVERITY_ANNOYANCE;
 774     }
 775     function description() {
 776         list($missingparent, $loops) = $this->find_problems();
 777
 778         $description = '<p>The question categories should be arranged into tree ' .
 779                 ' structures by the question_categories.parent field. Sometimes ' .
 780                 ' this tree structure gets messed up.</p>';
 781
 782         if (!empty($missingparent)) {
 783             $description .= '<p>The following categories are missing their parents:</p><ul>';
 784             foreach ($missingparent as $cat) {
 785                 $description .= "<li>Category $cat->id: " . s($cat->name) . "</li>\n";
 786             }
 787             $description .= "</ul>\n";
 788         }
 789
 790         if (!empty($loops)) {
 791             $description .= '<p>The following categories form a loop of parents:</p><ul>';
 792             foreach ($loops as $loop) {
 793                 $description .= "<li><ul>\n";
 794                 foreach ($loop as $cat) {
 795                     $description .= "<li>Category $cat->id: " . s($cat->name) . " has parent $cat->parent</li>\n";
 796                 }
 797                 $description .= "</ul></li>\n";
 798             }
 799             $description .= "</ul>\n";
 800         }
 801
 802         return $description;
 803     }
 804     function solution() {
 805         global $CFG;
 806         list($missingparent, $loops) = $this->find_problems();
 807
 808         $solution = '<p>Consider executing the following SQL queries. These fix ' .
 809                 'the problem by moving some categories to the top level.</p>';
 810
 811         if (!empty($missingparent)) {
 812             $solution .= "<pre>UPDATE " . $CFG->prefix . "question_categories\n" .
 813                     "        SET parent = 0\n" .
 814                     "        WHERE id IN (" . implode(',', array_keys($missingparent)) . ");</pre>\n";
 815         }
 816
 817         if (!empty($loops)) {
 818             $solution .= "<pre>UPDATE " . $CFG->prefix . "question_categories\n" .
 819                     "        SET parent = 0\n" .
 820                     "        WHERE id IN (" . implode(',', array_keys($loops)) . ");</pre>\n";
 821         }
 822
 823         return $solution;
 824     }
 825 }
 826
 827 class problem_00000x extends problem_base {
 828     function title() {
 829         return '';
 830     }
 831     function exists() {
 832         return false;
 833     }
 834     function severity() {
 835         return SEVERITY_SIGNIFICANT;
 836     }
 837     function description() {
 838         return '';
 839     }
 840     function solution() {
 841         global $CFG;
 842         return '';
 843     }
 844 }
 845
 846 /*
 847
 848 TODO:
 849
 850     session.save_path -- it doesn't really matter because we are already IN a session, right?
 851     detect unsupported characters in $CFG->wwwroot - see bug Bug #6091 - relative vs absolute path during backup/restore process
 852
 853 */
 854
 855 ?>