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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/>.

/**
 * This file contains the code to analyse all the responses to a particular question.
 *
 * @package    core_question
 * @copyright  2014 Open University
 * @author     Jamie Pratt <me@jamiep.org>
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

namespace core_question\statistics\responses;
defined('MOODLE_INTERNAL') || die();

/**
 * This class can compute, store and cache the analysis of the responses to a particular question.
 *
 * @package    core_question
 * @copyright  2014 The Open University
 * @author     James Pratt me@jamiep.org
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class analyser {
    /**
     * @var int When analysing responses and breaking down the count of responses per try, how many columns should we break down
     * tries into? This is set to 5 columns, any response in a try more than try 5 will be counted in the fifth column.
     */
    const MAX_TRY_COUNTED = 5;

< /** @var int Time after which responses are automatically reanalysed. */
> /** @var int No longer used. Previously the time after which statistics are automatically recomputed. */
const TIME_TO_CACHE = 900; // 15 minutes. /** @var object full question data from db. */ protected $questiondata; /** * @var analysis_for_question|analysis_for_question_all_tries */ public $analysis; /**
> * @var int used during calculations, so all results are stored with the same timestamp. * @var array Two index array first index is unique string for each sub question part, the second string index is the 'class' > */ * that sub-question part can be classified into. > protected $calculationtime; * > * This is the return value from {@link \question_type::get_possible_responses()} see that method for fuller documentation. > /**
*/ public $responseclasses = array(); /** * @var bool whether to break down response analysis by variant. This only applies to questions that have variants and is * used to suppress the break down of analysis by variant when there are going to be very many variants. */ protected $breakdownbyvariant; /** * Create a new instance of this class for holding/computing the statistics * for a particular question. * * @param object $questiondata the full question data from the database defining this question. * @param string $whichtries which tries to analyse. */ public function __construct($questiondata, $whichtries = \question_attempt::LAST_TRY) { $this->questiondata = $questiondata; $qtypeobj = \question_bank::get_qtype($this->questiondata->qtype); if ($whichtries != \question_attempt::ALL_TRIES) { $this->analysis = new analysis_for_question($qtypeobj->get_possible_responses($this->questiondata)); } else { $this->analysis = new analysis_for_question_all_tries($qtypeobj->get_possible_responses($this->questiondata)); } $this->breakdownbyvariant = $qtypeobj->break_down_stats_and_response_analysis_by_variant($this->questiondata); } /** * Does the computed analysis have sub parts? * * @return bool whether this analysis has more than one subpart. */ public function has_subparts() { return count($this->responseclasses) > 1; } /** * Does the computed analysis's sub parts have classes? * * @return bool whether this analysis has (a subpart with) more than one response class. */ public function has_response_classes() { foreach ($this->responseclasses as $partclasses) { if (count($partclasses) > 1) { return true; } } return false; } /**
< * Analyse all the response data for for all the specified attempts at this question.
> * Analyse all the response data for all the specified attempts at this question.
* * @param \qubaid_condition $qubaids which attempts to consider. * @param string $whichtries which tries to analyse. Will be one of * \question_attempt::FIRST_TRY, LAST_TRY or ALL_TRIES. * @return analysis_for_question */ public function calculate($qubaids, $whichtries = \question_attempt::LAST_TRY) {
> $this->calculationtime = time();
// Load data. $dm = new \question_engine_data_mapper(); $questionattempts = $dm->load_attempts_at_question($this->questiondata->id, $qubaids); // Analyse it. foreach ($questionattempts as $qa) { $responseparts = $qa->classify_response($whichtries); if ($this->breakdownbyvariant) { $this->analysis->count_response_parts($qa->get_variant(), $responseparts); } else { $this->analysis->count_response_parts(1, $responseparts); } }
< $this->analysis->cache($qubaids, $whichtries, $this->questiondata->id);
> $this->analysis->cache($qubaids, $whichtries, $this->questiondata->id, $this->calculationtime);
return $this->analysis; } /** * Retrieve the computed response analysis from the question_response_analysis table. * * @param \qubaid_condition $qubaids load the analysis of which question usages? * @param string $whichtries load the analysis of which tries? * @return analysis_for_question|boolean analysis or false if no cached analysis found. */ public function load_cached($qubaids, $whichtries) { global $DB;
< $timemodified = time() - self::TIME_TO_CACHE;
> $timemodified = self::get_last_analysed_time($qubaids, $whichtries);
// Variable name 'analyses' is the plural of 'analysis'.
< $responseanalyses = $DB->get_records_select('question_response_analysis', < 'hashcode = ? AND whichtries = ? AND questionid = ? AND timemodified > ?', < array($qubaids->get_hash_code(), $whichtries, $this->questiondata->id, $timemodified));
> $responseanalyses = $DB->get_records('question_response_analysis', > ['hashcode' => $qubaids->get_hash_code(), 'whichtries' => $whichtries, > 'questionid' => $this->questiondata->id, 'timemodified' => $timemodified]);
if (!$responseanalyses) { return false; }
< $analysisids = array();
> $analysisids = [];
foreach ($responseanalyses as $responseanalysis) { $analysisforsubpart = $this->analysis->get_analysis_for_subpart($responseanalysis->variant, $responseanalysis->subqid); $class = $analysisforsubpart->get_response_class($responseanalysis->aid); $class->add_response($responseanalysis->response, $responseanalysis->credit); $analysisids[] = $responseanalysis->id; }
< list($sql, $params) = $DB->get_in_or_equal($analysisids);
> [$sql, $params] = $DB->get_in_or_equal($analysisids);
$counts = $DB->get_records_select('question_response_count', "analysisid {$sql}", $params); foreach ($counts as $count) { $responseanalysis = $responseanalyses[$count->analysisid]; $analysisforsubpart = $this->analysis->get_analysis_for_subpart($responseanalysis->variant, $responseanalysis->subqid); $class = $analysisforsubpart->get_response_class($responseanalysis->aid); $class->set_response_count($responseanalysis->response, $count->try, $count->rcount); } return $this->analysis; } /** * Find time of non-expired analysis in the database. * * @param \qubaid_condition $qubaids check for the analysis of which question usages? * @param string $whichtries check for the analysis of which tries? * @return integer|boolean Time of cached record that matches this qubaid_condition or false if none found. */ public function get_last_analysed_time($qubaids, $whichtries) { global $DB;
< < $timemodified = time() - self::TIME_TO_CACHE; < return $DB->get_field_select('question_response_analysis', 'timemodified', < 'hashcode = ? AND whichtries = ? AND questionid = ? AND timemodified > ?', < array($qubaids->get_hash_code(), $whichtries, $this->questiondata->id, $timemodified), < IGNORE_MULTIPLE);
> return $DB->get_field('question_response_analysis', 'MAX(timemodified)', > ['hashcode' => $qubaids->get_hash_code(), 'whichtries' => $whichtries, > 'questionid' => $this->questiondata->id]);
} }