Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

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// GNU General Public License for more details.

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/**

 * This file contains the code to analyse all the responses to a particular

 * question.

 *

 * @package    core_question

 * @copyright  2013 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();

/**

 * Analysis for possible responses for parts of a question. It is up to a question type designer to decide on how many parts their

 * question has. See {@link \question_type::get_possible_responses()} and sub classes where the sub parts and response classes are

 * defined.

 *

 * A sub part might represent a sub question embedded in the question for example in a matching question there are

 * several sub parts. A numeric question with a unit might be divided into two sub parts for the purposes of response analysis

 * or the question type designer might decide to treat the answer, both the numeric and unit part,

 * as a whole for the purposes of response analysis.

 *

 * - There is a separate data structure for each question or sub question's analysis

 * {@link \core_question\statistics\responses\analysis_for_question}

 * or {@link \core_question\statistics\responses\analysis_for_question_all_tries}.

 * - There are separate analysis for each variant in this top level instance.

 * - Then there are class instances representing the analysis of each of the sub parts of each variant of the question.

 * {@link \core_question\statistics\responses\analysis_for_subpart}.

 * - Then within the sub part analysis there are response class analysis

 * {@link \core_question\statistics\responses\analysis_for_class}.

 * - Then within each class analysis there are analysis for each actual response

 * {@link \core_question\statistics\responses\analysis_for_actual_response}.

 *

 * @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 analysis_for_question {

    /**

     * Constructor method.

     *

     * @param 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.

     *                    Value in array is instance of {@link \question_possible_response}

     *                    This is the return value from {@link \question_type::get_possible_responses()}

     *                    see that method for fuller documentation.

     */

    public function __construct(array $possiblereponses = null) {

        if ($possiblereponses !== null) {

            $this->possibleresponses = $possiblereponses;

        }

    }

    /**

     * @var array[] See description above in constructor method.

     */

    protected $possibleresponses = array();

    /**

     * A multidimensional array whose first index is variant no and second index is subpart id, array contents are of type

     * {@link analysis_for_subpart}.

     *

     * @var array[]

     */

    protected $subparts = array();

    /**

     * Initialise data structure for response analysis of one variant.

     *

     * @param int $variantno

     */

    protected function initialise_stats_for_variant($variantno) {

        $this->subparts[$variantno] = array();

        foreach ($this->possibleresponses as $subpartid => $classes) {

            $this->subparts[$variantno][$subpartid] = new analysis_for_subpart($classes);

        }

    }

    /**

     * Variant nos found in this question's attempt data.

     *

     * @return int[]

     */

    public function get_variant_nos() {

        return array_keys($this->subparts);

    }

    /**

     * Unique ids for sub parts.

     *

     * @param int $variantno

     * @return string[]

     */

    public function get_subpart_ids($variantno) {

        return array_keys($this->subparts[$variantno]);

    }

    /**

     * Get the response counts etc. for variant $variantno, question sub part $subpartid.

     *

     * Or if there is no recorded analysis yet then initialise the data structure for that part of the analysis and return the

     * initialised analysis objects.

     *

     * @param int    $variantno

     * @param string $subpartid id for sub part.

     * @return analysis_for_subpart

     */

    public function get_analysis_for_subpart($variantno, $subpartid) {

        if (!isset($this->subparts[$variantno])) {

            $this->initialise_stats_for_variant($variantno);

        }

        if (!isset($this->subparts[$variantno][$subpartid])) {

            debugging('Unexpected sub-part id ' . $subpartid .

                    ' encountered.');

            $this->subparts[$variantno][$subpartid] = new analysis_for_subpart();

        }

        return $this->subparts[$variantno][$subpartid];

    }

    /**

     * Used to work out what kind of table is needed to display stats.

     *

     * @return bool whether this question has (a subpart with) more than one response class.

     */

    public function has_multiple_response_classes() {

        foreach ($this->get_variant_nos() as $variantno) {

            foreach ($this->get_subpart_ids($variantno) as $subpartid) {

                if ($this->get_analysis_for_subpart($variantno, $subpartid)->has_multiple_response_classes()) {

                    return true;

                }

            }

        }

        return false;

    }

    /**

     * Used to work out what kind of table is needed to display stats.

     *

     * @return bool whether this analysis has more than one subpart.

     */

    public function has_subparts() {

        foreach ($this->get_variant_nos() as $variantno) {

            if (count($this->get_subpart_ids($variantno)) > 1) {

                return true;

            }

        }

        return false;

    }

    /**

     * @return bool Does this response analysis include counts for responses for multiple tries of the question?

     */

    public function has_multiple_tries_data() {

        return false;

    }

    /**

     * What is the highest number of tries at this question?

     *

     * @return int always 1 as this class is for analysing only one try.

     */

    public function get_maximum_tries() {

        return 1;

    }

    /**

     * Takes an array of {@link \question_classified_response} and adds counts of the responses to the sub parts and classes.

     *

     * @param int                             $variantno

     * @param \question_classified_response[] $responseparts keys are sub-part id.

     */

    public function count_response_parts($variantno, $responseparts) {

        foreach ($responseparts as $subpartid => $responsepart) {

            $this->get_analysis_for_subpart($variantno, $subpartid)->count_response($responsepart);

        }

    }

    /**

     * Save the analysis to the DB, first cleaning up any old ones.

     *

     * @param \qubaid_condition $qubaids    which question usages have been analysed.

     * @param string            $whichtries which tries have been analysed?

     * @param int               $questionid which question.

     * @param int|null          $calculationtime time when the analysis was done. (Defaults to time()).

     */

    public function cache($qubaids, $whichtries, $questionid, $calculationtime = null) {

        global $DB;

        $transaction = $DB->start_delegated_transaction();

        $analysisids = $DB->get_fieldset(

            'question_response_analysis',

            'id',

            [

                'hashcode' => $qubaids->get_hash_code(),

                'whichtries' => $whichtries,

                'questionid' => $questionid,

            ]

        );

        if (!empty($analysisids)) {

            [$insql, $params] = $DB->get_in_or_equal($analysisids);

            $DB->delete_records_select('question_response_count', 'analysisid ' . $insql, $params);

            $DB->delete_records_select('question_response_analysis', 'id ' . $insql, $params);

        }

        foreach ($this->get_variant_nos() as $variantno) {

            foreach ($this->get_subpart_ids($variantno) as $subpartid) {

                $analysisforsubpart = $this->get_analysis_for_subpart($variantno, $subpartid);

                $analysisforsubpart->cache($qubaids, $whichtries, $questionid, $variantno, $subpartid, $calculationtime);

            }

        }

        $transaction->allow_commit();

    }

    /**

     * @return bool whether this analysis has a response class with more than one

     *      different actual response, or if the actual response is different from

     *      the model response.

     */

    public function has_actual_responses() {

        foreach ($this->get_variant_nos() as $variantno) {

            foreach ($this->get_subpart_ids($variantno) as $subpartid) {

                if ($this->get_analysis_for_subpart($variantno, $subpartid)->has_actual_responses()) {

                    return true;

                }

            }

        }

        return false;

    }

}