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Differences Between: [Versions 310 and 401] [Versions 39 and 401]

   1  <?php
   2  // This file is part of Moodle - http://moodle.org/
   3  //
   4  // Moodle is free software: you can redistribute it and/or modify
   5  // it under the terms of the GNU General Public License as published by
   6  // the Free Software Foundation, either version 3 of the License, or
   7  // (at your option) any later version.
   8  //
   9  // Moodle is distributed in the hope that it will be useful,
  10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  // GNU General Public License for more details.
  13  //
  14  // You should have received a copy of the GNU General Public License
  15  // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16  
  17  /**
  18   * Analysers base class.
  19   *
  20   * @package   core_analytics
  21   * @copyright 2016 David Monllao {@link http://www.davidmonllao.com}
  22   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23   */
  24  
  25  namespace core_analytics\local\analyser;
  26  
  27  defined('MOODLE_INTERNAL') || die();
  28  
  29  /**
  30   * Analysers base class.
  31   *
  32   * @package   core_analytics
  33   * @copyright 2016 David Monllao {@link http://www.davidmonllao.com}
  34   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  35   */
  36  abstract class base {
  37  
  38      /**
  39       * @var int
  40       */
  41      protected $modelid;
  42  
  43      /**
  44       * The model target.
  45       *
  46       * @var \core_analytics\local\target\base
  47       */
  48      protected $target;
  49  
  50      /**
  51       * The model indicators.
  52       *
  53       * @var \core_analytics\local\indicator\base[]
  54       */
  55      protected $indicators;
  56  
  57      /**
  58       * Time splitting methods to use.
  59       *
  60       * Multiple time splitting methods during evaluation and 1 single
  61       * time splitting method once the model is enabled.
  62       *
  63       * @var \core_analytics\local\time_splitting\base[]
  64       */
  65      protected $timesplittings;
  66  
  67      /**
  68       * Execution options.
  69       *
  70       * @var array
  71       */
  72      protected $options;
  73  
  74      /**
  75       * Simple log array.
  76       *
  77       * @var string[]
  78       */
  79      protected $log;
  80  
  81      /**
  82       * Constructor method.
  83       *
  84       * @param int $modelid
  85       * @param \core_analytics\local\target\base $target
  86       * @param \core_analytics\local\indicator\base[] $indicators
  87       * @param \core_analytics\local\time_splitting\base[] $timesplittings
  88       * @param array $options
  89       * @return void
  90       */
  91      public function __construct($modelid, \core_analytics\local\target\base $target, $indicators, $timesplittings, $options) {
  92          $this->modelid = $modelid;
  93          $this->target = $target;
  94          $this->indicators = $indicators;
  95          $this->timesplittings = $timesplittings;
  96  
  97          if (empty($options['evaluation'])) {
  98              $options['evaluation'] = false;
  99          }
 100          $this->options = $options;
 101  
 102          // Checks if the analyser satisfies the indicators requirements.
 103          $this->check_indicators_requirements();
 104  
 105          $this->log = array();
 106      }
 107  
 108      /**
 109       * @deprecated since Moodle 3.7
 110       */
 111      public function get_analysables() {
 112          throw new \coding_exception('get_analysables() method has been removed and cannot be used any more.');
 113      }
 114  
 115      /**
 116       * Returns the list of analysable elements available on the site.
 117       *
 118       * A relatively complex SQL query should be set so that we take into account which analysable elements
 119       * have already been processed and the order in which they have been processed. Helper methods are available
 120       * to ease to implementation of get_analysables_iterator: get_iterator_sql and order_sql.
 121       *
 122       * @param string|null $action 'prediction', 'training' or null if no specific action needed.
 123       * @param \context[] $contexts Only analysables that depend on the provided contexts. All analysables in the system if empty.
 124       * @return \Iterator
 125       */
 126      abstract public function get_analysables_iterator(?string $action = null, array $contexts = []);
 127  
 128      /**
 129       * This function returns this analysable list of samples.
 130       *
 131       * @param \core_analytics\analysable $analysable
 132       * @return array array[0] = int[] (sampleids) and array[1] = array (samplesdata)
 133       */
 134      abstract public function get_all_samples(\core_analytics\analysable $analysable);
 135  
 136      /**
 137       * This function returns the samples data from a list of sample ids.
 138       *
 139       * @param int[] $sampleids
 140       * @return array array[0] = int[] (sampleids) and array[1] = array (samplesdata)
 141       */
 142      abstract public function get_samples($sampleids);
 143  
 144      /**
 145       * Returns the analysable of a sample.
 146       *
 147       * @param int $sampleid
 148       * @return \core_analytics\analysable
 149       */
 150      abstract public function get_sample_analysable($sampleid);
 151  
 152      /**
 153       * Returns the sample's origin in moodle database.
 154       *
 155       * @return string
 156       */
 157      abstract public function get_samples_origin();
 158  
 159      /**
 160       * Returns the context of a sample.
 161       *
 162       * moodle/analytics:listinsights will be required at this level to access the sample predictions.
 163       *
 164       * @param int $sampleid
 165       * @return \context
 166       */
 167      abstract public function sample_access_context($sampleid);
 168  
 169      /**
 170       * Describes a sample with a description summary and a \renderable (an image for example)
 171       *
 172       * @param int $sampleid
 173       * @param int $contextid
 174       * @param array $sampledata
 175       * @return array array(string, \renderable)
 176       */
 177      abstract public function sample_description($sampleid, $contextid, $sampledata);
 178  
 179      /**
 180       * Model id getter.
 181       * @return int
 182       */
 183      public function get_modelid(): int {
 184          return $this->modelid;
 185      }
 186  
 187      /**
 188       * Options getter.
 189       * @return array
 190       */
 191      public function get_options(): array {
 192          return $this->options;
 193      }
 194  
 195      /**
 196       * Returns the analysed target.
 197       *
 198       * @return \core_analytics\local\target\base
 199       */
 200      public function get_target(): \core_analytics\local\target\base {
 201          return $this->target;
 202      }
 203  
 204      /**
 205       * Getter for time splittings.
 206       *
 207       * @return \core_analytics\local\time_splitting\base
 208       */
 209      public function get_timesplittings(): array {
 210          return $this->timesplittings;
 211      }
 212  
 213      /**
 214       * Getter for indicators.
 215       *
 216       * @return \core_analytics\local\indicator\base
 217       */
 218      public function get_indicators(): array {
 219          return $this->indicators;
 220      }
 221  
 222      /**
 223       * Instantiate the indicators.
 224       *
 225       * @return \core_analytics\local\indicator\base[]
 226       */
 227      public function instantiate_indicators() {
 228          foreach ($this->indicators as $key => $indicator) {
 229              $this->indicators[$key] = call_user_func(array($indicator, 'instance'));
 230          }
 231  
 232          // Free memory ASAP.
 233          gc_collect_cycles();
 234          gc_mem_caches();
 235  
 236          return $this->indicators;
 237      }
 238  
 239      /**
 240       * Samples data this analyser provides.
 241       *
 242       * @return string[]
 243       */
 244      protected function provided_sample_data() {
 245          return array($this->get_samples_origin());
 246      }
 247  
 248      /**
 249       * Returns labelled data (training and evaluation).
 250       *
 251       * @param \context[] $contexts Restrict the analysis to these contexts. No context restrictions if null.
 252       * @return \stored_file[]
 253       */
 254      public function get_labelled_data(array $contexts = []) {
 255          // Delegates all processing to the analysis.
 256          $result = new \core_analytics\local\analysis\result_file($this->get_modelid(), true, $this->get_options());
 257          $analysis = new \core_analytics\analysis($this, true, $result);
 258          $analysis->run($contexts);
 259          return $result->get();
 260      }
 261  
 262      /**
 263       * Returns unlabelled data (prediction).
 264       *
 265       * @param \context[] $contexts Restrict the analysis to these contexts. No context restrictions if null.
 266       * @return \stored_file[]
 267       */
 268      public function get_unlabelled_data(array $contexts = []) {
 269          // Delegates all processing to the analysis.
 270          $result = new \core_analytics\local\analysis\result_file($this->get_modelid(), false, $this->get_options());
 271          $analysis = new \core_analytics\analysis($this, false, $result);
 272          $analysis->run($contexts);
 273          return $result->get();
 274      }
 275  
 276      /**
 277       * Returns indicator calculations as an array.
 278       *
 279       * @param \context[] $contexts Restrict the analysis to these contexts. No context restrictions if null.
 280       * @return array
 281       */
 282      public function get_static_data(array $contexts = []) {
 283          // Delegates all processing to the analysis.
 284          $result = new \core_analytics\local\analysis\result_array($this->get_modelid(), false, $this->get_options());
 285          $analysis = new \core_analytics\analysis($this, false, $result);
 286          $analysis->run($contexts);
 287          return $result->get();
 288      }
 289  
 290      /**
 291       * Checks if the analyser satisfies all the model indicators requirements.
 292       *
 293       * @throws \core_analytics\requirements_exception
 294       * @return void
 295       */
 296      protected function check_indicators_requirements() {
 297  
 298          foreach ($this->indicators as $indicator) {
 299              $missingrequired = $this->check_indicator_requirements($indicator);
 300              if ($missingrequired !== true) {
 301                  throw new \core_analytics\requirements_exception(get_class($indicator) . ' indicator requires ' .
 302                      json_encode($missingrequired) . ' sample data which is not provided by ' . get_class($this));
 303              }
 304          }
 305      }
 306  
 307      /**
 308       * Checks that this analyser satisfies the provided indicator requirements.
 309       *
 310       * @param \core_analytics\local\indicator\base $indicator
 311       * @return true|string[] True if all good, missing requirements list otherwise
 312       */
 313      public function check_indicator_requirements(\core_analytics\local\indicator\base $indicator) {
 314  
 315          $providedsampledata = $this->provided_sample_data();
 316  
 317          $requiredsampledata = $indicator::required_sample_data();
 318          if (empty($requiredsampledata)) {
 319              // The indicator does not need any sample data.
 320              return true;
 321          }
 322          $missingrequired = array_diff($requiredsampledata, $providedsampledata);
 323  
 324          if (empty($missingrequired)) {
 325              return true;
 326          }
 327  
 328          return $missingrequired;
 329      }
 330  
 331      /**
 332       * Adds a register to the analysis log.
 333       *
 334       * @param string $string
 335       * @return void
 336       */
 337      public function add_log($string) {
 338          $this->log[] = $string;
 339      }
 340  
 341      /**
 342       * Returns the analysis logs.
 343       *
 344       * @return string[]
 345       */
 346      public function get_logs() {
 347          return $this->log;
 348      }
 349  
 350      /**
 351       * Whether the plugin needs user data clearing or not.
 352       *
 353       * This is related to privacy. Override this method if your analyser samples have any relation
 354       * to the 'user' database entity. We need to clean the site from all user-related data if a user
 355       * request their data to be deleted from the system. A static::provided_sample_data returning 'user'
 356       * is an indicator that you should be returning true.
 357       *
 358       * @return bool
 359       */
 360      public function processes_user_data() {
 361          return false;
 362      }
 363  
 364      /**
 365       * SQL JOIN from a sample to users table.
 366       *
 367       * This function should be defined if static::processes_user_data returns true and it is related to analytics API
 368       * privacy API implementation. It allows the analytics API to identify data associated to users that needs to be
 369       * deleted or exported.
 370       *
 371       * This function receives the alias of a table with a 'sampleid' field and it should return a SQL join
 372       * with static::get_samples_origin and with 'user' table. Note that:
 373       * - The function caller expects the returned 'user' table to be aliased as 'u' (defacto standard in moodle).
 374       * - You can join with other tables if your samples origin table does not contain a 'userid' field (if that would be
 375       *   a requirement this solution would be automated for you) you can't though use the following
 376       *   aliases: 'ap', 'apa', 'aic' and 'am'.
 377       *
 378       * Some examples:
 379       *
 380       * static::get_samples_origin() === 'user':
 381       *   JOIN {user} u ON {$sampletablealias}.sampleid = u.id
 382       *
 383       * static::get_samples_origin() === 'role_assignments':
 384       *   JOIN {role_assignments} ra ON {$sampletablealias}.sampleid = ra.userid JOIN {user} u ON u.id = ra.userid
 385       *
 386       * static::get_samples_origin() === 'user_enrolments':
 387       *   JOIN {user_enrolments} ue ON {$sampletablealias}.sampleid = ue.userid JOIN {user} u ON u.id = ue.userid
 388       *
 389       * @throws \coding_exception
 390       * @param string $sampletablealias The alias of the table with a sampleid field that will join with this SQL string
 391       * @return string
 392       */
 393      public function join_sample_user($sampletablealias) {
 394          throw new \coding_exception('This method should be implemented if static::processes_user_data returns true.');
 395      }
 396  
 397      /**
 398       * Do this analyser's analysables have 1 single sample each?
 399       *
 400       * Overwrite and return true if your analysables only have
 401       * one sample. The insights generated by models using this
 402       * analyser will then include the suggested actions in the
 403       * notification.
 404       *
 405       * @return bool
 406       */
 407      public static function one_sample_per_analysable() {
 408          return false;
 409      }
 410  
 411      /**
 412       * Returns an array of context levels that can be used to restrict the contexts used during analysis.
 413       *
 414       * The contexts provided to self::get_analysables_iterator will match these contextlevels.
 415       *
 416       * @return array Array of context levels or an empty array if context restriction is not supported.
 417       */
 418      public static function context_restriction_support(): array {
 419          return [];
 420      }
 421  
 422      /**
 423       * Returns the possible contexts used by the analyser.
 424       *
 425       * This method uses separate logic for each context level because to iterate through
 426       * the list of contexts calling get_context_name for each of them would be expensive
 427       * in performance terms.
 428       *
 429       * This generic implementation returns all the contexts in the site for the provided context level.
 430       * Overwrite it for specific restrictions in your analyser.
 431       *
 432       * @param  string|null $query Context name filter.
 433       * @return int[]
 434       */
 435      public static function potential_context_restrictions(string $query = null) {
 436          return \core_analytics\manager::get_potential_context_restrictions(static::context_restriction_support(), $query);
 437      }
 438  
 439      /**
 440       * Get the sql of a default implementation of the iterator.
 441       *
 442       * This method only works for analysers that return analysable elements which ids map to a context instance ids.
 443       *
 444       * @param  string      $tablename    The name of the table
 445       * @param  int         $contextlevel The context level of the analysable
 446       * @param  string|null $action
 447       * @param  string|null $tablealias   The table alias
 448       * @param  \context[]  $contexts     Only analysables that depend on the provided contexts. All analysables if empty.
 449       * @return array                     [0] => sql and [1] => params array
 450       */
 451      protected function get_iterator_sql(string $tablename, int $contextlevel, ?string $action = null, ?string $tablealias = null,
 452              array $contexts = []) {
 453          global $DB;
 454  
 455          if (!$tablealias) {
 456              $tablealias = 'analysable';
 457          }
 458  
 459          $params = ['contextlevel' => $contextlevel, 'modelid' => $this->get_modelid()];
 460          $select = $tablealias . '.*, ' . \context_helper::get_preload_record_columns_sql('ctx');
 461  
 462          // We add the action filter on ON instead of on WHERE because otherwise records are not returned if there are existing
 463          // records for another action or model.
 464          $usedanalysablesjoin = ' LEFT JOIN {analytics_used_analysables} aua ON ' . $tablealias . '.id = aua.analysableid AND ' .
 465              '(aua.modelid = :modelid OR aua.modelid IS NULL)';
 466  
 467          if ($action) {
 468              $usedanalysablesjoin .= " AND aua.action = :action";
 469              $params = $params + ['action' => $action];
 470          }
 471  
 472          $sql = 'SELECT ' . $select . '
 473                    FROM {' . $tablename . '} ' . $tablealias . '
 474                    ' . $usedanalysablesjoin . '
 475                    JOIN {context} ctx ON (ctx.contextlevel = :contextlevel AND ctx.instanceid = ' . $tablealias . '.id) ';
 476  
 477          if (!$contexts) {
 478              // Adding the 1 = 1 just to have the WHERE part so that all further conditions
 479              // added by callers can be appended to $sql with and ' AND'.
 480              $sql .= 'WHERE 1 = 1';
 481          } else {
 482  
 483              $contextsqls = [];
 484              foreach ($contexts as $context) {
 485                  $paramkey1 = 'paramctxlike' . $context->id;
 486                  $paramkey2 = 'paramctxeq' . $context->id;
 487                  $contextsqls[] = $DB->sql_like('ctx.path', ':' . $paramkey1);
 488                  $contextsqls[] = 'ctx.path = :' . $paramkey2;
 489  
 490                  // This includes the context itself.
 491                  $params[$paramkey1] = $context->path . '/%';
 492                  $params[$paramkey2] = $context->path;
 493              }
 494              $sql .= 'WHERE (' . implode(' OR ', $contextsqls) . ')';
 495          }
 496  
 497          return [$sql, $params];
 498      }
 499  
 500      /**
 501       * Returns the order by clause.
 502       *
 503       * @param  string|null $fieldname  The field name
 504       * @param  string      $order      'ASC' or 'DESC'
 505       * @param  string|null $tablealias The table alias of the field
 506       * @return string
 507       */
 508      protected function order_sql(?string $fieldname = null, string $order = 'ASC', ?string $tablealias = null) {
 509  
 510          if (!$tablealias) {
 511              $tablealias = 'analysable';
 512          }
 513  
 514          if ($order != 'ASC' && $order != 'DESC') {
 515              throw new \coding_exception('The order can only be ASC or DESC');
 516          }
 517  
 518          $ordersql = ' ORDER BY (CASE WHEN aua.timeanalysed IS NULL THEN 0 ELSE aua.timeanalysed END) ASC';
 519          if ($fieldname) {
 520              $ordersql .= ', ' . $tablealias . '.' . $fieldname .' ' . $order;
 521          }
 522  
 523          return $ordersql;
 524      }
 525  }