Search moodle.org's
Developer Documentation

See Release Notes

  • Bug fixes for general core bugs in 4.2.x will end 22 April 2024 (12 months).
  • Bug fixes for security issues in 4.2.x will end 7 October 2024 (18 months).
  • PHP version: minimum PHP 8.0.0 Note: minimum PHP version has increased since Moodle 4.1. PHP 8.1.x is supported too.
<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**
 * Analysers base class.
 *
 * @package   core_analytics
 * @copyright 2016 David Monllao {@link http://www.davidmonllao.com}
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

namespace core_analytics\local\analyser;

defined('MOODLE_INTERNAL') || die();

/**
 * Analysers base class.
 *
 * @package   core_analytics
 * @copyright 2016 David Monllao {@link http://www.davidmonllao.com}
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
abstract class base {

    /**
     * @var int
     */
    protected $modelid;

    /**
     * The model target.
     *
     * @var \core_analytics\local\target\base
     */
    protected $target;

    /**
     * The model indicators.
     *
     * @var \core_analytics\local\indicator\base[]
     */
    protected $indicators;

    /**
     * Time splitting methods to use.
     *
     * Multiple time splitting methods during evaluation and 1 single
     * time splitting method once the model is enabled.
     *
     * @var \core_analytics\local\time_splitting\base[]
     */
    protected $timesplittings;

    /**
     * Execution options.
     *
     * @var array
     */
    protected $options;

    /**
     * Simple log array.
     *
     * @var string[]
     */
    protected $log;

    /**
     * Constructor method.
     *
     * @param int $modelid
     * @param \core_analytics\local\target\base $target
     * @param \core_analytics\local\indicator\base[] $indicators
     * @param \core_analytics\local\time_splitting\base[] $timesplittings
     * @param array $options
     * @return void
     */
    public function __construct($modelid, \core_analytics\local\target\base $target, $indicators, $timesplittings, $options) {
        $this->modelid = $modelid;
        $this->target = $target;
        $this->indicators = $indicators;
        $this->timesplittings = $timesplittings;

        if (empty($options['evaluation'])) {
            $options['evaluation'] = false;
        }
        $this->options = $options;

        // Checks if the analyser satisfies the indicators requirements.
        $this->check_indicators_requirements();

        $this->log = array();
    }

    /**
< * Returns the list of analysable elements available on the site. < * < * \core_analytics\local\analyser\by_course and \core_analytics\local\analyser\sitewide are implementing < * this method returning site courses (by_course) and the whole system (sitewide) as analysables. < * < * @todo MDL-65284 This will be removed in Moodle 4.1 < * @deprecated < * @see get_analysables_iterator < * @throws \coding_exception < * @return \core_analytics\analysable[] Array of analysable elements using the analysable id as array key.
> * @deprecated since Moodle 3.7
*/ public function get_analysables() {
< // This function should only be called from get_analysables_iterator and we keep it here until Moodle 4.1 < // for backwards compatibility. < throw new \coding_exception('This method is deprecated in favour of get_analysables_iterator.');
> throw new \coding_exception('get_analysables() method has been removed and cannot be used any more.');
} /** * Returns the list of analysable elements available on the site. * * A relatively complex SQL query should be set so that we take into account which analysable elements * have already been processed and the order in which they have been processed. Helper methods are available * to ease to implementation of get_analysables_iterator: get_iterator_sql and order_sql. * * @param string|null $action 'prediction', 'training' or null if no specific action needed. * @param \context[] $contexts Only analysables that depend on the provided contexts. All analysables in the system if empty. * @return \Iterator */
< public function get_analysables_iterator(?string $action = null, array $contexts = []) { < < debugging('Please overwrite get_analysables_iterator with your own implementation, we only keep this default < implementation for backwards compatibility purposes with get_analysables(). note that $action param will < be ignored so the analysable elements will be processed using get_analysables order, regardless of the < last time they were processed.'); < < return new \ArrayIterator($this->get_analysables()); < }
> abstract public function get_analysables_iterator(?string $action = null, array $contexts = []);
/** * This function returns this analysable list of samples. * * @param \core_analytics\analysable $analysable * @return array array[0] = int[] (sampleids) and array[1] = array (samplesdata) */ abstract public function get_all_samples(\core_analytics\analysable $analysable); /** * This function returns the samples data from a list of sample ids. * * @param int[] $sampleids * @return array array[0] = int[] (sampleids) and array[1] = array (samplesdata) */ abstract public function get_samples($sampleids); /** * Returns the analysable of a sample. * * @param int $sampleid * @return \core_analytics\analysable */ abstract public function get_sample_analysable($sampleid); /** * Returns the sample's origin in moodle database. * * @return string */ abstract public function get_samples_origin(); /** * Returns the context of a sample. * * moodle/analytics:listinsights will be required at this level to access the sample predictions. * * @param int $sampleid * @return \context */ abstract public function sample_access_context($sampleid); /** * Describes a sample with a description summary and a \renderable (an image for example) * * @param int $sampleid * @param int $contextid * @param array $sampledata * @return array array(string, \renderable) */ abstract public function sample_description($sampleid, $contextid, $sampledata); /** * Model id getter. * @return int */ public function get_modelid(): int { return $this->modelid; } /** * Options getter. * @return array */ public function get_options(): array { return $this->options; } /** * Returns the analysed target. * * @return \core_analytics\local\target\base */ public function get_target(): \core_analytics\local\target\base { return $this->target; } /** * Getter for time splittings. * * @return \core_analytics\local\time_splitting\base */ public function get_timesplittings(): array { return $this->timesplittings; } /** * Getter for indicators. * * @return \core_analytics\local\indicator\base */ public function get_indicators(): array { return $this->indicators; } /** * Instantiate the indicators. * * @return \core_analytics\local\indicator\base[] */ public function instantiate_indicators() { foreach ($this->indicators as $key => $indicator) { $this->indicators[$key] = call_user_func(array($indicator, 'instance')); } // Free memory ASAP. gc_collect_cycles(); gc_mem_caches(); return $this->indicators; } /** * Samples data this analyser provides. * * @return string[] */ protected function provided_sample_data() { return array($this->get_samples_origin()); } /** * Returns labelled data (training and evaluation). * * @param \context[] $contexts Restrict the analysis to these contexts. No context restrictions if null. * @return \stored_file[] */ public function get_labelled_data(array $contexts = []) { // Delegates all processing to the analysis. $result = new \core_analytics\local\analysis\result_file($this->get_modelid(), true, $this->get_options()); $analysis = new \core_analytics\analysis($this, true, $result); $analysis->run($contexts); return $result->get(); } /** * Returns unlabelled data (prediction). * * @param \context[] $contexts Restrict the analysis to these contexts. No context restrictions if null. * @return \stored_file[] */ public function get_unlabelled_data(array $contexts = []) { // Delegates all processing to the analysis. $result = new \core_analytics\local\analysis\result_file($this->get_modelid(), false, $this->get_options()); $analysis = new \core_analytics\analysis($this, false, $result); $analysis->run($contexts); return $result->get(); } /** * Returns indicator calculations as an array. * * @param \context[] $contexts Restrict the analysis to these contexts. No context restrictions if null. * @return array */ public function get_static_data(array $contexts = []) { // Delegates all processing to the analysis. $result = new \core_analytics\local\analysis\result_array($this->get_modelid(), false, $this->get_options()); $analysis = new \core_analytics\analysis($this, false, $result); $analysis->run($contexts); return $result->get(); } /** * Checks if the analyser satisfies all the model indicators requirements. * * @throws \core_analytics\requirements_exception * @return void */ protected function check_indicators_requirements() { foreach ($this->indicators as $indicator) { $missingrequired = $this->check_indicator_requirements($indicator); if ($missingrequired !== true) { throw new \core_analytics\requirements_exception(get_class($indicator) . ' indicator requires ' . json_encode($missingrequired) . ' sample data which is not provided by ' . get_class($this)); } } } /** * Checks that this analyser satisfies the provided indicator requirements. * * @param \core_analytics\local\indicator\base $indicator * @return true|string[] True if all good, missing requirements list otherwise */ public function check_indicator_requirements(\core_analytics\local\indicator\base $indicator) { $providedsampledata = $this->provided_sample_data(); $requiredsampledata = $indicator::required_sample_data(); if (empty($requiredsampledata)) { // The indicator does not need any sample data. return true; } $missingrequired = array_diff($requiredsampledata, $providedsampledata); if (empty($missingrequired)) { return true; } return $missingrequired; } /** * Adds a register to the analysis log. * * @param string $string * @return void */ public function add_log($string) { $this->log[] = $string; } /** * Returns the analysis logs. * * @return string[] */ public function get_logs() { return $this->log; } /** * Whether the plugin needs user data clearing or not. * * This is related to privacy. Override this method if your analyser samples have any relation * to the 'user' database entity. We need to clean the site from all user-related data if a user * request their data to be deleted from the system. A static::provided_sample_data returning 'user' * is an indicator that you should be returning true. * * @return bool */ public function processes_user_data() { return false; } /** * SQL JOIN from a sample to users table. * * This function should be defined if static::processes_user_data returns true and it is related to analytics API * privacy API implementation. It allows the analytics API to identify data associated to users that needs to be * deleted or exported. * * This function receives the alias of a table with a 'sampleid' field and it should return a SQL join * with static::get_samples_origin and with 'user' table. Note that: * - The function caller expects the returned 'user' table to be aliased as 'u' (defacto standard in moodle). * - You can join with other tables if your samples origin table does not contain a 'userid' field (if that would be * a requirement this solution would be automated for you) you can't though use the following * aliases: 'ap', 'apa', 'aic' and 'am'. * * Some examples: * * static::get_samples_origin() === 'user': * JOIN {user} u ON {$sampletablealias}.sampleid = u.id * * static::get_samples_origin() === 'role_assignments': * JOIN {role_assignments} ra ON {$sampletablealias}.sampleid = ra.userid JOIN {user} u ON u.id = ra.userid * * static::get_samples_origin() === 'user_enrolments': * JOIN {user_enrolments} ue ON {$sampletablealias}.sampleid = ue.userid JOIN {user} u ON u.id = ue.userid * * @throws \coding_exception * @param string $sampletablealias The alias of the table with a sampleid field that will join with this SQL string * @return string */ public function join_sample_user($sampletablealias) { throw new \coding_exception('This method should be implemented if static::processes_user_data returns true.'); } /** * Do this analyser's analysables have 1 single sample each? * * Overwrite and return true if your analysables only have * one sample. The insights generated by models using this * analyser will then include the suggested actions in the * notification. * * @return bool */ public static function one_sample_per_analysable() { return false; } /** * Returns an array of context levels that can be used to restrict the contexts used during analysis. * * The contexts provided to self::get_analysables_iterator will match these contextlevels. * * @return array Array of context levels or an empty array if context restriction is not supported. */ public static function context_restriction_support(): array { return []; } /** * Returns the possible contexts used by the analyser. * * This method uses separate logic for each context level because to iterate through * the list of contexts calling get_context_name for each of them would be expensive * in performance terms. * * This generic implementation returns all the contexts in the site for the provided context level. * Overwrite it for specific restrictions in your analyser. * * @param string|null $query Context name filter. * @return int[] */ public static function potential_context_restrictions(string $query = null) { return \core_analytics\manager::get_potential_context_restrictions(static::context_restriction_support(), $query); } /** * Get the sql of a default implementation of the iterator. * * This method only works for analysers that return analysable elements which ids map to a context instance ids. * * @param string $tablename The name of the table * @param int $contextlevel The context level of the analysable * @param string|null $action * @param string|null $tablealias The table alias * @param \context[] $contexts Only analysables that depend on the provided contexts. All analysables if empty. * @return array [0] => sql and [1] => params array */ protected function get_iterator_sql(string $tablename, int $contextlevel, ?string $action = null, ?string $tablealias = null, array $contexts = []) { global $DB; if (!$tablealias) { $tablealias = 'analysable'; } $params = ['contextlevel' => $contextlevel, 'modelid' => $this->get_modelid()]; $select = $tablealias . '.*, ' . \context_helper::get_preload_record_columns_sql('ctx'); // We add the action filter on ON instead of on WHERE because otherwise records are not returned if there are existing // records for another action or model. $usedanalysablesjoin = ' LEFT JOIN {analytics_used_analysables} aua ON ' . $tablealias . '.id = aua.analysableid AND ' . '(aua.modelid = :modelid OR aua.modelid IS NULL)'; if ($action) { $usedanalysablesjoin .= " AND aua.action = :action"; $params = $params + ['action' => $action]; } $sql = 'SELECT ' . $select . ' FROM {' . $tablename . '} ' . $tablealias . ' ' . $usedanalysablesjoin . ' JOIN {context} ctx ON (ctx.contextlevel = :contextlevel AND ctx.instanceid = ' . $tablealias . '.id) '; if (!$contexts) { // Adding the 1 = 1 just to have the WHERE part so that all further conditions // added by callers can be appended to $sql with and ' AND'. $sql .= 'WHERE 1 = 1'; } else { $contextsqls = []; foreach ($contexts as $context) { $paramkey1 = 'paramctxlike' . $context->id; $paramkey2 = 'paramctxeq' . $context->id; $contextsqls[] = $DB->sql_like('ctx.path', ':' . $paramkey1); $contextsqls[] = 'ctx.path = :' . $paramkey2; // This includes the context itself. $params[$paramkey1] = $context->path . '/%'; $params[$paramkey2] = $context->path; } $sql .= 'WHERE (' . implode(' OR ', $contextsqls) . ')'; } return [$sql, $params]; } /** * Returns the order by clause. * * @param string|null $fieldname The field name * @param string $order 'ASC' or 'DESC' * @param string|null $tablealias The table alias of the field * @return string */ protected function order_sql(?string $fieldname = null, string $order = 'ASC', ?string $tablealias = null) { if (!$tablealias) { $tablealias = 'analysable'; } if ($order != 'ASC' && $order != 'DESC') { throw new \coding_exception('The order can only be ASC or DESC'); } $ordersql = ' ORDER BY (CASE WHEN aua.timeanalysed IS NULL THEN 0 ELSE aua.timeanalysed END) ASC'; if ($fieldname) { $ordersql .= ', ' . $tablealias . '.' . $fieldname .' ' . $order; } return $ordersql; } }