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<?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 previously, the time after which statistics are automatically recomputed.* @deprecated since Moodle 4.3. Use of pre-computed stats is no longer time-limited.* @todo MDL-78090 Final deprecation in Moodle 4.7*/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.*/protected $calculationtime;/*** @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.** 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 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->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 = self::get_last_analysed_time($qubaids, $whichtries);// Variable name 'analyses' is the plural of 'analysis'.$responseanalyses = $DB->get_records('question_response_analysis',['hashcode' => $qubaids->get_hash_code(), 'whichtries' => $whichtries,'questionid' => $this->questiondata->id, 'timemodified' => $timemodified]);if (!$responseanalyses) {return false;}$analysisids = [];foreach ($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[] = $responseanalysis->id;}[$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;return $DB->get_field('question_response_analysis', 'MAX(timemodified)',['hashcode' => $qubaids->get_hash_code(), 'whichtries' => $whichtries,'questionid' => $this->questiondata->id]);}}