--- /dev/null
+<?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 defines a class with rubric grading strategy logic
+ *
+ * @package mod-workshop
+ * @copyright 2009 David Mudrak <david.mudrak@gmail.com>
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+require_once(dirname(dirname(__FILE__)) . '/lib.php'); // interface definition
+require_once($CFG->libdir . '/gradelib.php'); // to handle float vs decimal issues
+
+/**
+ * Rubric grading strategy logic.
+ */
+class workshop_rubric_strategy implements workshop_strategy {
+
+ /** @const default number of dimensions to show */
+ const MINDIMS = 3;
+
+ /** @const number of dimensions to add */
+ const ADDDIMS = 2;
+
+ /** @var workshop the parent workshop instance */
+ protected $workshop;
+
+ /** @var array definition of the assessment form fields */
+ protected $dimensions = null;
+
+ /** @var array options for dimension description fields */
+ protected $descriptionopts;
+
+ /**
+ * Constructor
+ *
+ * @param workshop $workshop The workshop instance record
+ * @return void
+ */
+ public function __construct(workshop $workshop) {
+ $this->workshop = $workshop;
+ $this->dimensions = $this->load_fields();
+ $this->descriptionopts = array('trusttext' => true, 'subdirs' => false, 'maxfiles' => -1);
+ $this->definitionopts = array('trusttext' => true, 'subdirs' => false, 'maxfiles' => -1);
+ }
+
+ /**
+ * Factory method returning an instance of an assessment form editor class
+ *
+ * @param $actionurl URL of form handler, defaults to auto detect the current url
+ */
+ public function get_edit_strategy_form($actionurl=null) {
+ global $CFG; // needed because the included files use it
+ global $PAGE;
+
+ require_once(dirname(__FILE__) . '/edit_form.php');
+
+ $fields = $this->prepare_form_fields($this->dimensions);
+ $nodimensions = count($this->dimensions);
+ $norepeatsdefault = max($nodimensions + self::ADDDIMS, self::MINDIMS);
+ $norepeats = optional_param('norepeats', $norepeatsdefault, PARAM_INT); // number of dimensions
+ $noadddims = optional_param('noadddims', '', PARAM_ALPHA); // shall we add more?
+ if ($noadddims) {
+ $norepeats += self::ADDDIMS;
+ }
+
+ // prepare the embeded files
+ for ($i = 0; $i < $nodimensions; $i++) {
+ // prepare all editor elements
+ $fields = file_prepare_standard_editor($fields, 'description__idx_'.$i, $this->descriptionopts,
+ $PAGE->context, 'workshop_dimension_description', $fields->{'dimensionid__idx_'.$i});
+ }
+
+ $customdata = array();
+ $customdata['workshop'] = $this->workshop;
+ $customdata['strategy'] = $this;
+ $customdata['norepeats'] = $norepeats;
+ $customdata['descriptionopts'] = $this->descriptionopts;
+ $customdata['current'] = $fields;
+ $attributes = array('class' => 'editstrategyform');
+
+ return new workshop_edit_rubric_strategy_form($actionurl, $customdata, 'post', '', $attributes);
+ }
+
+ /**
+ * Save the assessment dimensions into database
+ *
+ * Saves data into the main strategy form table. If the record->id is null or zero,
+ * new record is created. If the record->id is not empty, the existing record is updated. Records with
+ * empty 'description' field are removed from database.
+ * The passed data object are the raw data returned by the get_data().
+ *
+ * @uses $DB
+ * @param stdClass $data Raw data returned by the dimension editor form
+ * @return void
+ */
+ public function save_edit_strategy_form(stdClass $data) {
+ global $DB, $PAGE;
+
+ $workshopid = $data->workshopid;
+ $norepeats = $data->norepeats;
+
+ $data = $this->prepare_database_fields($data);
+ $records = $data->rubric; // records to be saved into {workshopform_rubric}
+ $todelete = array(); // dimension ids to be deleted
+
+ for ($i=0; $i < $norepeats; $i++) {
+ $record = $records[$i];
+ if (empty($record->description_editor['text'])) {
+ if (!empty($record->id)) {
+ // existing record with empty description - to be deleted
+ $todelete[] = $record->id;
+ }
+ continue;
+ }
+ if (empty($record->id)) {
+ // new field
+ $record->id = $DB->insert_record('workshopform_rubric', $record);
+ } else {
+ // exiting field
+ $DB->update_record('workshopform_rubric', $record);
+ }
+ // re-save with correct path to embeded media files
+ $record = file_postupdate_standard_editor($record, 'description', $this->descriptionopts,
+ $PAGE->context, 'workshopform_rubric_description', $record->id);
+ $DB->update_record('workshopform_rubric', $record);
+ }
+ $this->delete_dimensions($todelete);
+ }
+
+ /**
+ * Factory method returning an instance of an assessment form
+ *
+ * @param moodle_url $actionurl URL of form handler, defaults to auto detect the current url
+ * @param string $mode Mode to open the form in: preview/assessment
+ */
+ public function get_assessment_form(moodle_url $actionurl=null, $mode='preview', stdClass $assessment=null) {
+ global $CFG; // needed because the included files use it
+ global $PAGE;
+ global $DB;
+ require_once(dirname(__FILE__) . '/assessment_form.php');
+
+ $fields = $this->prepare_form_fields($this->dimensions);
+ $nodimensions = count($this->dimensions);
+
+ // rewrite URLs to the embeded files
+ for ($i = 0; $i < $nodimensions; $i++) {
+ $fields->{'description__idx_'.$i} = file_rewrite_pluginfile_urls($fields->{'description__idx_'.$i},
+ 'pluginfile.php', $PAGE->context->id, 'workshopform_rubric_description', $fields->{'dimensionid__idx_'.$i});
+ }
+
+ if ('assessment' === $mode and !empty($assessment)) {
+ // load the previously saved assessment data
+ $grades = $this->get_current_assessment_data($assessment);
+ $current = new stdClass();
+ for ($i = 0; $i < $nodimensions; $i++) {
+ $dimid = $fields->{'dimensionid__idx_'.$i};
+ if (isset($grades[$dimid])) {
+ $current->{'gradeid__idx_'.$i} = $grades[$dimid]->id;
+ $current->{'grade__idx_'.$i} = $grades[$dimid]->grade;
+ $current->{'peercomment__idx_'.$i} = $grades[$dimid]->peercomment;
+ }
+ }
+ }
+
+ // set up the required custom data common for all strategies
+ $customdata['strategy'] = $this;
+ $customdata['workshop'] = $this->workshop;
+ $customdata['mode'] = $mode;
+
+ // set up strategy-specific custom data
+ $customdata['nodims'] = $nodimensions;
+ $customdata['fields'] = $fields;
+ $customdata['current'] = isset($current) ? $current : null;
+ $attributes = array('class' => 'assessmentform rubric');
+
+ return new workshop_rubric_assessment_form($actionurl, $customdata, 'post', '', $attributes);
+ }
+
+ /**
+ * Saves the filled assessment
+ *
+ * This method processes data submitted using the form returned by {@link get_assessment_form()}
+ *
+ * @param stdClass $assessment Assessment being filled
+ * @param stdClass $data Raw data as returned by the assessment form
+ * @return float|null Raw grade (0.00000 to 100.00000) for submission as suggested by the peer
+ */
+ public function save_assessment(stdClass $assessment, stdClass $data) {
+ global $DB;
+
+ if (!isset($data->nodims)) {
+ throw coding_expection('You did not send me the number of assessment dimensions to process');
+ }
+ for ($i = 0; $i < $data->nodims; $i++) {
+ $grade = new stdClass();
+ $grade->id = $data->{'gradeid__idx_' . $i};
+ $grade->assessmentid = $assessment->id;
+ $grade->strategy = 'rubric';
+ $grade->dimensionid = $data->{'dimensionid__idx_' . $i};
+ $grade->grade = $data->{'grade__idx_' . $i};
+ $grade->peercomment = $data->{'peercomment__idx_' . $i};
+ $grade->peercommentformat = FORMAT_MOODLE;
+ if (empty($grade->id)) {
+ // new grade
+ $grade->id = $DB->insert_record('workshop_grades', $grade);
+ } else {
+ // updated grade
+ $DB->update_record('workshop_grades', $grade);
+ }
+ }
+ return $this->update_peer_grade($assessment);
+ }
+
+ /**
+ * Has the assessment form been defined and is ready to be used by the reviewers?
+ *
+ * @return boolean
+ */
+ public function form_ready() {
+ if (count($this->dimensions) > 0) {
+ return true;
+ }
+ return false;
+ }
+
+ /**
+ * Returns true if the given evaluation method is supported by this strategy
+ *
+ * To support an evaluation method, the strategy subplugin must usually implement some
+ * required public methods. In theory, this is what interfaces should be used for.
+ * Unfortunatelly, we can't extend "implements" declaration as the interface must
+ * be known to the PHP interpret. So we can't declare implementation of a non-installed
+ * evaluation subplugin.
+ *
+ * @param workshop_evaluation $evaluation the instance of grading evaluation class
+ * @return bool true if the evaluation method is supported, false otherwise
+ */
+ public function supports_evaluation(workshop_evaluation $evaluation) {
+ if (is_a($evaluation, 'workshop_best_evaluation')) {
+ return true;
+ }
+ // all other evaluation methods are not supported yet
+ return false;
+ }
+
+ ////////////////////////////////////////////////////////////////////////////////
+ // Methods required by the 'best' evaluation plugin //
+ ////////////////////////////////////////////////////////////////////////////////
+
+ /**
+ * TODO
+ *
+ * @param resource $restrict
+ * @return TODO
+ */
+ public function eval_best_get_assessments_recordset($restrict) {
+ global $DB;
+
+ $sql = 'SELECT s.id AS submissionid,
+ a.id AS assessmentid, a.weight AS assessmentweight, a.reviewerid, a.gradinggrade,
+ g.dimensionid, g.grade
+ FROM {workshop_submissions} s
+ JOIN {workshop_assessments} a ON (a.submissionid = s.id)
+ JOIN {workshop_grades} g ON (g.assessmentid = a.id AND g.strategy = :strategy)
+ WHERE s.example=0 AND s.workshopid=:workshopid'; // to be cont.
+ $params = array('workshopid' => $this->workshop->id, 'strategy' => $this->workshop->strategy);
+
+ if (is_null($restrict)) {
+ // update all users - no more conditions
+ } elseif (!empty($restrict)) {
+ list($usql, $uparams) = $DB->get_in_or_equal($restrict, SQL_PARAMS_NAMED);
+ $sql .= " AND a.reviewerid $usql";
+ $params = array_merge($params, $uparams);
+ } else {
+ throw new coding_exception('Empty value is not a valid parameter here');
+ }
+
+ $sql .= ' ORDER BY s.id'; // this is important for bulk processing
+
+ return $DB->get_recordset_sql($sql, $params);
+ }
+
+ /**
+ * TODO: short description.
+ *
+ * @return array [dimid] => stdClass (->id ->max ->min ->weight)
+ */
+ public function eval_best_dimensions_info() {
+ global $DB;
+
+ $sql = 'SELECT d.id, d.grade, d.weight, s.scale
+ FROM {workshopform_rubric} d
+ LEFT JOIN {scale} s ON (d.grade < 0 AND -d.grade = s.id)
+ WHERE d.workshopid = :workshopid';
+ $params = array('workshopid' => $this->workshop->id);
+ $dimrecords = $DB->get_records_sql($sql, $params);
+ $diminfo = array();
+ foreach ($dimrecords as $dimid => $dimrecord) {
+ $diminfo[$dimid] = new stdClass();
+ $diminfo[$dimid]->id = $dimid;
+ $diminfo[$dimid]->weight = $dimrecord->weight;
+ if ($dimrecord->grade < 0) {
+ // the dimension uses a scale
+ $diminfo[$dimid]->min = 1;
+ $diminfo[$dimid]->max = count(explode(',', $dimrecord->scale));
+ } else {
+ // the dimension uses points
+ $diminfo[$dimid]->min = 0;
+ $diminfo[$dimid]->max = grade_floatval($dimrecord->grade);
+ }
+ }
+ return $diminfo;
+ }
+
+ ////////////////////////////////////////////////////////////////////////////////
+ // Internal methods //
+ ////////////////////////////////////////////////////////////////////////////////
+
+ /**
+ * Loads the fields of the assessment form currently used in this workshop
+ *
+ * @return array definition of assessment dimensions
+ */
+ protected function load_fields() {
+ global $DB;
+
+ $sql = 'SELECT r.id AS rid, l.id AS lid, *
+ FROM {workshopform_rubric} r
+ LEFT JOIN {workshopform_rubric_levels} l ON (l.dimensionid = r.id}
+ WHERE r.workshopid = :workshopid
+ ORDER BY r.sort, l.grade';
+ $params = array('workshopid' => $this->workshop->id);
+
+ $rs = $DB->get_recordset_sql($sql, $param);
+ $fields = array();
+ foreach ($rs as $record) {
+ // if (!isset($fields
+ print_object($record); die(); // DONOTCOMMIT
+ }
+ $rs->close();
+
+ return $fields;
+ }
+
+ /**
+ * Maps the dimension data from DB to the form fields
+ *
+ * @param array $raw Array of raw dimension records as returned by {@link load_fields()}
+ * @return array Array of fields data to be used by the mform set_data
+ */
+ protected function prepare_form_fields(array $raw) {
+
+ $formdata = new stdClass();
+ $key = 0;
+ foreach ($raw as $dimension) {
+ $formdata->{'dimensionid__idx_' . $key} = $dimension->id;
+ $formdata->{'description__idx_' . $key} = $dimension->description;
+ $formdata->{'description__idx_' . $key.'format'} = $dimension->descriptionformat;
+ $formdata->{'grade__idx_' . $key} = $dimension->grade;
+ $formdata->{'weight__idx_' . $key} = $dimension->weight;
+ $key++;
+ }
+ return $formdata;
+ }
+
+ /**
+ * Deletes dimensions and removes embedded media from its descriptions
+ *
+ * todo we may check that there are no assessments done using these dimensions and probably remove them
+ *
+ * @param array $masterids
+ * @return void
+ */
+ protected function delete_dimensions(array $ids) {
+ global $DB, $PAGE;
+
+ $fs = get_file_storage();
+ foreach ($ids as $id) {
+ if (!empty($id)) { // to prevent accidental removal of all files in the area
+ $fs->delete_area_files($PAGE->context->id, 'workshopform_rubric_description', $id);
+ }
+ }
+ $DB->delete_records_list('workshopform_rubric', 'id', $ids);
+ }
+
+ /**
+ * Prepares data returned by {@link workshop_edit_rubric_strategy_form} so they can be saved into database
+ *
+ * It automatically adds some columns into every record. The sorting is
+ * done by the order of the returned array and starts with 1.
+ * Called internally from {@link save_edit_strategy_form()} only. Could be private but
+ * keeping protected for unit testing purposes.
+ *
+ * @param stdClass $raw Raw data returned by mform
+ * @return array Array of objects to be inserted/updated in DB
+ */
+ protected function prepare_database_fields(stdClass $raw) {
+ global $PAGE;
+
+ $cook = new stdClass(); // to be returned
+ $cook->rubric = array(); // records to be stored in {workshopform_rubric}
+
+ for ($i = 0; $i < $raw->norepeats; $i++) {
+ $cook->rubric[$i] = new stdClass();
+ $cook->rubric[$i]->id = $raw->{'dimensionid__idx_'.$i};
+ $cook->rubric[$i]->workshopid = $this->workshop->id;
+ $cook->rubric[$i]->sort = $i + 1;
+ $cook->rubric[$i]->description_editor = $raw->{'description__idx_'.$i.'_editor'};
+ $cook->rubric[$i]->grade = $raw->{'grade__idx_'.$i};
+ $cook->rubric[$i]->weight = $raw->{'weight__idx_'.$i};
+ }
+ return $cook;
+ }
+
+ /**
+ * Returns the list of current grades filled by the reviewer indexed by dimensionid
+ *
+ * @param stdClass $assessment Assessment record
+ * @return array [int dimensionid] => stdClass workshop_grades record
+ */
+ protected function get_current_assessment_data(stdClass $assessment) {
+ global $DB;
+
+ if (empty($this->dimensions)) {
+ return array();
+ }
+ list($dimsql, $dimparams) = $DB->get_in_or_equal(array_keys($this->dimensions), SQL_PARAMS_NAMED);
+ // beware! the caller may rely on the returned array is indexed by dimensionid
+ $sql = "SELECT dimensionid, *
+ FROM {workshop_grades}
+ WHERE assessmentid = :assessmentid AND strategy= :strategy AND dimensionid $dimsql";
+ $params = array('assessmentid' => $assessment->id, 'strategy' => 'rubric');
+ $params = array_merge($params, $dimparams);
+
+ return $DB->get_records_sql($sql, $params);
+ }
+
+ /**
+ * Aggregates the assessment form data and sets the grade for the submission given by the peer
+ *
+ * @param stdClass $assessment Assessment record
+ * @return float|null Raw grade (from 0.00000 to 100.00000) for submission as suggested by the peer
+ */
+ protected function update_peer_grade(stdClass $assessment) {
+ $grades = $this->get_current_assessment_data($assessment);
+ $suggested = $this->calculate_peer_grade($grades);
+ if (!is_null($suggested)) {
+ $this->workshop->set_peer_grade($assessment->id, $suggested);
+ }
+ return $suggested;
+ }
+
+ /**
+ * Calculates the aggregated grade given by the reviewer
+ *
+ * @param array $grades Grade records as returned by {@link get_current_assessment_data}
+ * @uses $this->dimensions
+ * @return float|null Raw grade (from 0.00000 to 100.00000) for submission as suggested by the peer
+ */
+ protected function calculate_peer_grade(array $grades) {
+
+ if (empty($grades)) {
+ return null;
+ }
+ $sumgrades = 0;
+ $sumweights = 0;
+ foreach ($grades as $grade) {
+ $dimension = $this->dimensions[$grade->dimensionid];
+ if ($dimension->weight < 0) {
+ throw new coding_exception('Negative weights are not supported any more. Something is wrong with your data');
+ }
+ if (grade_floats_equal($dimension->weight, 0) or grade_floats_equal($dimension->grade, 0)) {
+ // does not influence the final grade
+ continue;
+ }
+ if ($dimension->grade < 0) {
+ // this is a scale
+ $scaleid = -$dimension->grade;
+ $sumgrades += $this->scale_to_grade($scaleid, $grade->grade) * $dimension->weight * 100;
+ $sumweights += $dimension->weight;
+ } else {
+ // regular grade
+ $sumgrades += ($grade->grade / $dimension->grade) * $dimension->weight * 100;
+ $sumweights += $dimension->weight;
+ }
+ }
+
+ if ($sumweights === 0) {
+ return 0;
+ }
+ return grade_floatval($sumgrades / $sumweights);
+ }
+
+ /**
+ * Convert scale grade to numerical grades
+ *
+ * In rubric grading strategy, scales are considered as grades from 0 to M-1, where M is the number of scale items.
+ *
+ * @throws coding_exception
+ * @param string $scaleid Scale identifier
+ * @param int $item Selected scale item number, numbered 1, 2, 3, ... M
+ * @return float
+ */
+ protected function scale_to_grade($scaleid, $item) {
+ global $DB;
+
+ /** @var cache of numbers of scale items */
+ static $numofscaleitems = array();
+
+ if (!isset($numofscaleitems[$scaleid])) {
+ $scale = $DB->get_field('scale', 'scale', array('id' => $scaleid), MUST_EXIST);
+ $items = explode(',', $scale);
+ $numofscaleitems[$scaleid] = count($items);
+ unset($scale);
+ unset($items);
+ }
+
+ if ($numofscaleitems[$scaleid] <= 1) {
+ throw new coding_exception('Invalid scale definition, no scale items found');
+ }
+
+ if ($item <= 0 or $numofscaleitems[$scaleid] < $item) {
+ throw new coding_exception('Invalid scale item number');
+ }
+
+ return ($item - 1) / ($numofscaleitems[$scaleid] - 1);
+ }
+}
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