Proyectos de Subversion Moodle

<?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/>.

/**

 * Grading method controller for the guide plugin

 *

 * @package    gradingform_guide

 * @copyright  2012 Dan Marsden <dan@danmarsden.com>

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

use core_external\external_format_value;

use core_external\external_multiple_structure;

use core_external\external_single_structure;

use core_external\external_value;

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

require_once($CFG->dirroot.'/grade/grading/form/lib.php');

/** guide: Used to compare our gradeitem_type against. */

const MARKING_GUIDE = 'guide';

/**

 * This controller encapsulates the guide grading logic

 *

 * @package    gradingform_guide

 * @copyright  2012 Dan Marsden <dan@danmarsden.com>

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

class gradingform_guide_controller extends gradingform_controller {

    // Modes of displaying the guide (used in gradingform_guide_renderer).

    /** guide display mode: For editing (moderator or teacher creates a guide) */

    const DISPLAY_EDIT_FULL     = 1;

    /** guide display mode: Preview the guide design with hidden fields */

    const DISPLAY_EDIT_FROZEN   = 2;

    /** guide display mode: Preview the guide design (for person with manage permission) */

    const DISPLAY_PREVIEW       = 3;

    /** guide display mode: Preview the guide (for people being graded) */

    const DISPLAY_PREVIEW_GRADED= 8;

    /** guide display mode: For evaluation, enabled (teacher grades a student) */

    const DISPLAY_EVAL          = 4;

    /** guide display mode: For evaluation, with hidden fields */

    const DISPLAY_EVAL_FROZEN   = 5;

    /** guide display mode: Teacher reviews filled guide */

    const DISPLAY_REVIEW        = 6;

    /** guide display mode: Dispaly filled guide (i.e. students see their grades) */

    const DISPLAY_VIEW          = 7;

    /** @var stdClass|false the definition structure */

    protected $moduleinstance = false;

    /**

     * Extends the module settings navigation with the guide grading settings

     *

     * This function is called when the context for the page is an activity module with the

     * FEATURE_ADVANCED_GRADING, the user has the permission moodle/grade:managegradingforms

     * and there is an area with the active grading method set to 'guide'.

     *

     * @param settings_navigation $settingsnav {@link settings_navigation}

     * @param navigation_node $node {@link navigation_node}

     */

    public function extend_settings_navigation(settings_navigation $settingsnav, navigation_node $node=null) {

        $node->add(get_string('definemarkingguide', 'gradingform_guide'),

            $this->get_editor_url(), settings_navigation::TYPE_CUSTOM,

            null, null, new pix_icon('icon', '', 'gradingform_guide'));

    }

    /**

     * Extends the module navigation

     *

     * This function is called when the context for the page is an activity module with the

     * FEATURE_ADVANCED_GRADING and there is an area with the active grading method set to the given plugin.

     *

     * @param global_navigation $navigation {@link global_navigation}

     * @param navigation_node $node {@link navigation_node}

     * @return void

     */

    public function extend_navigation(global_navigation $navigation, navigation_node $node=null) {

        if (has_capability('moodle/grade:managegradingforms', $this->get_context())) {

            // No need for preview if user can manage forms, he will have link to manage.php in settings instead.

            return;

        }

        if ($this->is_form_defined() && ($options = $this->get_options()) && !empty($options['alwaysshowdefinition'])) {

            $node->add(get_string('gradingof', 'gradingform_guide', get_grading_manager($this->get_areaid())->get_area_title()),

                    new moodle_url('/grade/grading/form/'.$this->get_method_name().'/preview.php',

                        array('areaid' => $this->get_areaid())), settings_navigation::TYPE_CUSTOM);

        }

    }

    /**

     * Saves the guide definition into the database

     *

     * @see parent::update_definition()

     * @param stdClass $newdefinition guide definition data as coming from gradingform_guide_editguide::get_data()

     * @param int $usermodified optional userid of the author of the definition, defaults to the current user

     */

    public function update_definition(stdClass $newdefinition, $usermodified = null) {

        $this->update_or_check_guide($newdefinition, $usermodified, true);

        if (isset($newdefinition->guide['regrade']) && $newdefinition->guide['regrade']) {

            $this->mark_for_regrade();

        }

    }

    /**

     * Either saves the guide definition into the database or check if it has been changed.

     *

     * Returns the level of changes:

     * 0 - no changes

     * 1 - only texts or criteria sortorders are changed, students probably do not require re-grading

     * 2 - added levels but maximum score on guide is the same, students still may not require re-grading

     * 3 - removed criteria or changed number of points, students require re-grading but may be re-graded automatically

     * 4 - removed levels - students require re-grading and not all students may be re-graded automatically

     * 5 - added criteria - all students require manual re-grading

     *

     * @param stdClass $newdefinition guide definition data as coming from gradingform_guide_editguide::get_data()

     * @param int|null $usermodified optional userid of the author of the definition, defaults to the current user

     * @param bool $doupdate if true actually updates DB, otherwise performs a check

     * @return int

     */

    public function update_or_check_guide(stdClass $newdefinition, $usermodified = null, $doupdate = false) {

        global $DB;

        // Firstly update the common definition data in the {grading_definition} table.

        if ($this->definition === false) {

            if (!$doupdate) {

                // If we create the new definition there is no such thing as re-grading anyway.

                return 5;

            }

            // If definition does not exist yet, create a blank one

            // (we need id to save files embedded in description).

            parent::update_definition(new stdClass(), $usermodified);

            parent::load_definition();

        }

        if (!isset($newdefinition->guide['options'])) {

            $newdefinition->guide['options'] = self::get_default_options();

        }

        $newdefinition->options = json_encode($newdefinition->guide['options']);

        $editoroptions = self::description_form_field_options($this->get_context());

        $newdefinition = file_postupdate_standard_editor($newdefinition, 'description', $editoroptions, $this->get_context(),

            'grading', 'description', $this->definition->id);

        // Reload the definition from the database.

        $currentdefinition = $this->get_definition(true);

        // Update guide data.

        $haschanges = array();

        if (empty($newdefinition->guide['criteria'])) {

            $newcriteria = array();

        } else {

            $newcriteria = $newdefinition->guide['criteria']; // New ones to be saved.

        }

        $currentcriteria = $currentdefinition->guide_criteria;

        $criteriafields = array('sortorder', 'description', 'descriptionformat', 'descriptionmarkers',

            'descriptionmarkersformat', 'shortname', 'maxscore');

        foreach ($newcriteria as $id => $criterion) {

            if (preg_match('/^NEWID\d+$/', $id)) {

                // Insert criterion into DB.

                $data = array('definitionid' => $this->definition->id, 'descriptionformat' => FORMAT_MOODLE,

                    'descriptionmarkersformat' => FORMAT_MOODLE); // TODO format is not supported yet.

                foreach ($criteriafields as $key) {

                    if (array_key_exists($key, $criterion)) {

                        $data[$key] = $criterion[$key];

                    }

                }

                if ($doupdate) {

                    $id = $DB->insert_record('gradingform_guide_criteria', $data);

                }

                $haschanges[5] = true;

            } else {

                // Update criterion in DB.

                $data = array();

                foreach ($criteriafields as $key) {

                    if (array_key_exists($key, $criterion) && $criterion[$key] != $currentcriteria[$id][$key]) {

                        $data[$key] = $criterion[$key];

                    }

                }

                if (!empty($data)) {

                    // Update only if something is changed.

                    $data['id'] = $id;

                    if ($doupdate) {

                        $DB->update_record('gradingform_guide_criteria', $data);

                    }

                    $haschanges[1] = true;

                }

            }

        }

        // Remove deleted criteria from DB.

        foreach (array_keys($currentcriteria) as $id) {

            if (!array_key_exists($id, $newcriteria)) {

                if ($doupdate) {

                    $DB->delete_records('gradingform_guide_criteria', array('id' => $id));

                }

                $haschanges[3] = true;

            }

        }

        // Now handle comments.

        if (empty($newdefinition->guide['comments'])) {

            $newcomment = array();

        } else {

            $newcomment = $newdefinition->guide['comments']; // New ones to be saved.

        }

        $currentcomments = $currentdefinition->guide_comments;

        $commentfields = array('sortorder', 'description');

        foreach ($newcomment as $id => $comment) {

            if (preg_match('/^NEWID\d+$/', $id)) {

                // Insert criterion into DB.

                $data = array('definitionid' => $this->definition->id, 'descriptionformat' => FORMAT_MOODLE);

                foreach ($commentfields as $key) {

                    if (array_key_exists($key, $comment)) {

                        // Check if key is the comment's description.

                        if ($key === 'description') {

                            // Get a trimmed value for the comment description.

                            $description = trim($comment[$key]);

                            // Check if the comment description is empty.

                            if (empty($description)) {

                                // Continue to the next comment object if the description is empty.

                                continue 2;

                            }

                        }

                        $data[$key] = $comment[$key];

                    }

                }

                if ($doupdate) {

                    $id = $DB->insert_record('gradingform_guide_comments', $data);

                }

            } else {

                // Update criterion in DB.

                $data = array();

                foreach ($commentfields as $key) {

                    if (array_key_exists($key, $comment) && $comment[$key] != $currentcomments[$id][$key]) {

                        $data[$key] = $comment[$key];

                    }

                }

                if (!empty($data)) {

                    // Update only if something is changed.

                    $data['id'] = $id;

                    if ($doupdate) {

                        $DB->update_record('gradingform_guide_comments', $data);

                    }

                }

            }

        }

        // Remove deleted criteria from DB.

        foreach (array_keys($currentcomments) as $id) {

            if (!array_key_exists($id, $newcomment)) {

                if ($doupdate) {

                    $DB->delete_records('gradingform_guide_comments', array('id' => $id));

                }

            }

        }

        // End comments handle.

        foreach (array('status', 'description', 'descriptionformat', 'name', 'options') as $key) {

            if (isset($newdefinition->$key) && $newdefinition->$key != $this->definition->$key) {

                $haschanges[1] = true;

            }

        }

        if ($usermodified && $usermodified != $this->definition->usermodified) {

            $haschanges[1] = true;

        }

        if (!count($haschanges)) {

            return 0;

        }

        if ($doupdate) {

            parent::update_definition($newdefinition, $usermodified);

            $this->load_definition();

        }

        // Return the maximum level of changes.

        $changelevels = array_keys($haschanges);

        sort($changelevels);

        return array_pop($changelevels);

    }

    /**

     * Marks all instances filled with this guide with the status INSTANCE_STATUS_NEEDUPDATE

     */

    public function mark_for_regrade() {

        global $DB;

        if ($this->has_active_instances()) {

            $conditions = array('definitionid'  => $this->definition->id,

                        'status'  => gradingform_instance::INSTANCE_STATUS_ACTIVE);

            $DB->set_field('grading_instances', 'status', gradingform_instance::INSTANCE_STATUS_NEEDUPDATE, $conditions);

        }

    }

    /**

     * Loads the guide form definition if it exists

     *

     * There is a new array called 'guide_criteria' appended to the list of parent's definition properties.

     */

    protected function load_definition() {

        global $DB;

        // Check to see if the user prefs have changed - putting here as this function is called on post even when

        // validation on the page fails. - hard to find a better place to locate this as it is specific to the guide.

        $showdesc = optional_param('showmarkerdesc', null, PARAM_BOOL); // Check if we need to change pref.

        $showdescstudent = optional_param('showstudentdesc', null, PARAM_BOOL); // Check if we need to change pref.

        if ($showdesc !== null) {

            set_user_preference('gradingform_guide-showmarkerdesc', $showdesc);

        }

        if ($showdescstudent !== null) {

            set_user_preference('gradingform_guide-showstudentdesc', $showdescstudent);

        }

        // Get definition.

        $definition = $DB->get_record('grading_definitions', array('areaid' => $this->areaid,

            'method' => $this->get_method_name()), '*');

        if (!$definition) {

            // The definition doesn't have to exist. It may be that we are only now creating it.

            $this->definition = false;

            return false;

        }

        $this->definition = $definition;

        // Now get criteria.

        $this->definition->guide_criteria = array();

        $this->definition->guide_comments = array();

        $criteria = $DB->get_recordset('gradingform_guide_criteria', array('definitionid' => $this->definition->id), 'sortorder');

        foreach ($criteria as $criterion) {

            foreach (array('id', 'sortorder', 'description', 'descriptionformat',

                           'maxscore', 'descriptionmarkers', 'descriptionmarkersformat', 'shortname') as $fieldname) {

                if ($fieldname == 'maxscore') {  // Strip any trailing 0.

                    $this->definition->guide_criteria[$criterion->id][$fieldname] = (float)$criterion->{$fieldname};

                } else {

                    $this->definition->guide_criteria[$criterion->id][$fieldname] = $criterion->{$fieldname};

                }

            }

        }

        $criteria->close();

        // Now get comments.

        $comments = $DB->get_recordset('gradingform_guide_comments', array('definitionid' => $this->definition->id), 'sortorder');

        foreach ($comments as $comment) {

            foreach (array('id', 'sortorder', 'description', 'descriptionformat') as $fieldname) {

                $this->definition->guide_comments[$comment->id][$fieldname] = $comment->{$fieldname};

            }

        }

        $comments->close();

        if (empty($this->moduleinstance)) { // Only set if empty.

            $modulename = $this->get_component();

            $context = $this->get_context();

            if (strpos($modulename, 'mod_') === 0) {

                $dbman = $DB->get_manager();

                $modulename = substr($modulename, 4);

                if ($dbman->table_exists($modulename)) {

                    $cm = get_coursemodule_from_id($modulename, $context->instanceid);

                    if (!empty($cm)) { // This should only occur when the course is being deleted.

                        $this->moduleinstance = $DB->get_record($modulename, array("id"=>$cm->instance));

                    }

                }

            }

        }

    }

    /**

     * Returns the default options for the guide display

     *

     * @return array

     */

    public static function get_default_options() {

        $options = array(

            'alwaysshowdefinition' => 1,

            'showmarkspercriterionstudents' => 1,

        );

        return $options;

    }

    /**

     * Gets the options of this guide definition, fills the missing options with default values

     *

     * @return array

     */

    public function get_options() {

        $options = self::get_default_options();

        if (!empty($this->definition->options)) {

            $thisoptions = json_decode($this->definition->options);

            foreach ($thisoptions as $option => $value) {

                $options[$option] = $value;

            }

        }

        return $options;

    }

    /**

     * Converts the current definition into an object suitable for the editor form's set_data()

     *

     * @param bool $addemptycriterion whether to add an empty criterion if the guide is completely empty (just being created)

     * @return stdClass

     */

    public function get_definition_for_editing($addemptycriterion = false) {

        $definition = $this->get_definition();

        $properties = new stdClass();

        $properties->areaid = $this->areaid;

        if (isset($this->moduleinstance->grade)) {

            $properties->modulegrade = $this->moduleinstance->grade;

        }

        if ($definition) {

            foreach (array('id', 'name', 'description', 'descriptionformat', 'status') as $key) {

                $properties->$key = $definition->$key;

            }

            $options = self::description_form_field_options($this->get_context());

            $properties = file_prepare_standard_editor($properties, 'description', $options, $this->get_context(),

                'grading', 'description', $definition->id);

        }

        $properties->guide = array('criteria' => array(), 'options' => $this->get_options(), 'comments' => array());

        if (!empty($definition->guide_criteria)) {

            $properties->guide['criteria'] = $definition->guide_criteria;

        } else if (!$definition && $addemptycriterion) {

            $properties->guide['criteria'] = array('addcriterion' => 1);

        }

        if (!empty($definition->guide_comments)) {

            $properties->guide['comments'] = $definition->guide_comments;

        } else if (!$definition && $addemptycriterion) {

            $properties->guide['comments'] = array('addcomment' => 1);

        }

        return $properties;

    }

    /**

     * Returns the form definition suitable for cloning into another area

     *

     * @see parent::get_definition_copy()

     * @param gradingform_controller $target the controller of the new copy

     * @return stdClass definition structure to pass to the target's {@link update_definition()}

     */

    public function get_definition_copy(gradingform_controller $target) {

        $new = parent::get_definition_copy($target);

        $old = $this->get_definition_for_editing();

        $new->description_editor = $old->description_editor;

        $new->guide = array('criteria' => array(), 'options' => $old->guide['options'], 'comments' => array());

        $newcritid = 1;

        foreach ($old->guide['criteria'] as $oldcritid => $oldcrit) {

            unset($oldcrit['id']);

            $new->guide['criteria']['NEWID'.$newcritid] = $oldcrit;

            $newcritid++;

        }

        $newcomid = 1;

        foreach ($old->guide['comments'] as $oldcritid => $oldcom) {

            unset($oldcom['id']);

            $new->guide['comments']['NEWID'.$newcomid] = $oldcom;

            $newcomid++;

        }

        return $new;

    }

    /**

     * Options for displaying the guide description field in the form

     *

     * @param context $context

     * @return array options for the form description field

     */

    public static function description_form_field_options($context) {

        global $CFG;

        return array(

            'maxfiles' => -1,

            'maxbytes' => get_max_upload_file_size($CFG->maxbytes),

            'context'  => $context,

        );

    }

    /**

     * Formats the definition description for display on page

     *

     * @return string

     */

    public function get_formatted_description() {

        if (!isset($this->definition->description)) {

            return '';

        }

        $context = $this->get_context();

        $options = self::description_form_field_options($this->get_context());

        $description = file_rewrite_pluginfile_urls($this->definition->description, 'pluginfile.php', $context->id,

            'grading', 'description', $this->definition->id, $options);

        $formatoptions = array(

            'noclean' => false,

            'trusted' => false,

            'filter' => true,

            'context' => $context

        );

        return format_text($description, $this->definition->descriptionformat, $formatoptions);

    }

    /**

     * Returns the guide plugin renderer

     *

     * @param moodle_page $page the target page

     * @return gradingform_guide_renderer

     */

    public function get_renderer(moodle_page $page) {

        return $page->get_renderer('gradingform_'. $this->get_method_name());

    }

    /**

     * Returns the HTML code displaying the preview of the grading form

     *

     * @param moodle_page $page the target page

     * @return string

     */

    public function render_preview(moodle_page $page) {

        if (!$this->is_form_defined()) {

            throw new coding_exception('It is the caller\'s responsibility to make sure that the form is actually defined');

        }

        // Check if current user is able to see preview

        $options = $this->get_options();

        if (empty($options['alwaysshowdefinition']) && !has_capability('moodle/grade:managegradingforms', $page->context))  {

            return '';

        }

        $criteria = $this->definition->guide_criteria;

        $comments = $this->definition->guide_comments;

        $output = $this->get_renderer($page);

        $guide = '';

        $guide .= $output->box($this->get_formatted_description(), 'gradingform_guide-description');

        if (has_capability('moodle/grade:managegradingforms', $page->context)) {

            $guide .= $output->display_guide_mapping_explained($this->get_min_max_score());

            $guide .= $output->display_guide($criteria, $comments, $options, self::DISPLAY_PREVIEW, 'guide');

        } else {

            $guide .= $output->display_guide($criteria, $comments, $options, self::DISPLAY_PREVIEW_GRADED, 'guide');

        }

        return $guide;

    }

    /**

     * Deletes the guide definition and all the associated information

     */

    protected function delete_plugin_definition() {

        global $DB;

        // Get the list of instances.

        $instances = array_keys($DB->get_records('grading_instances', array('definitionid' => $this->definition->id), '', 'id'));

        // Delete all fillings.

        $DB->delete_records_list('gradingform_guide_fillings', 'instanceid', $instances);

        // Delete instances.

        $DB->delete_records_list('grading_instances', 'id', $instances);

        // Get the list of criteria records.

        $criteria = array_keys($DB->get_records('gradingform_guide_criteria',

            array('definitionid' => $this->definition->id), '', 'id'));

        // Delete critera.

        $DB->delete_records_list('gradingform_guide_criteria', 'id', $criteria);

        // Delete comments.

        $DB->delete_records('gradingform_guide_comments', array('definitionid' => $this->definition->id));

    }

    /**

     * If instanceid is specified and grading instance exists and it is created by this rater for

     * this item, this instance is returned.

     * If there exists a draft for this raterid+itemid, take this draft (this is the change from parent)

     * Otherwise new instance is created for the specified rater and itemid

     *

     * @param int $instanceid

     * @param int $raterid

     * @param int $itemid

     * @return gradingform_instance

     */

    public function get_or_create_instance($instanceid, $raterid, $itemid) {

        global $DB;

        if ($instanceid &&

                $instance = $DB->get_record('grading_instances',

                    array('id'  => $instanceid, 'raterid' => $raterid, 'itemid' => $itemid), '*', IGNORE_MISSING)) {

            return $this->get_instance($instance);

        }

        if ($itemid && $raterid) {

            $params = array('definitionid' => $this->definition->id, 'raterid' => $raterid, 'itemid' => $itemid);

            if ($rs = $DB->get_records('grading_instances', $params, 'timemodified DESC', '*', 0, 1)) {

                $record = reset($rs);

                $currentinstance = $this->get_current_instance($raterid, $itemid);

                if ($record->status == gradingform_guide_instance::INSTANCE_STATUS_INCOMPLETE &&

                        (!$currentinstance || $record->timemodified > $currentinstance->get_data('timemodified'))) {

                    $record->isrestored = true;

                    return $this->get_instance($record);

                }

            }

        }

        return $this->create_instance($raterid, $itemid);

    }

    /**

     * Returns html code to be included in student's feedback.

     *

     * @param moodle_page $page

     * @param int $itemid

     * @param array $gradinginfo result of function grade_get_grades

     * @param string $defaultcontent default string to be returned if no active grading is found

     * @param bool $cangrade whether current user has capability to grade in this context

     * @return string

     */

    public function render_grade($page, $itemid, $gradinginfo, $defaultcontent, $cangrade) {

        return $this->get_renderer($page)->display_instances($this->get_active_instances($itemid), $defaultcontent, $cangrade);

    }

    // Full-text search support.

    /**

     * Prepare the part of the search query to append to the FROM statement

     *

     * @param string $gdid the alias of grading_definitions.id column used by the caller

     * @return string

     */

    public static function sql_search_from_tables($gdid) {

        return " LEFT JOIN {gradingform_guide_criteria} gc ON (gc.definitionid = $gdid)";

    }

    /**

     * Prepare the parts of the SQL WHERE statement to search for the given token

     *

     * The returned array cosists of the list of SQL comparions and the list of

     * respective parameters for the comparisons. The returned chunks will be joined

     * with other conditions using the OR operator.

     *

     * @param string $token token to search for

     * @return array An array containing two more arrays

     *     Array of search SQL fragments

     *     Array of params for the search fragments

     */

    public static function sql_search_where($token) {

        global $DB;

        $subsql = array();

        $params = array();

        // Search in guide criteria description.

        $subsql[] = $DB->sql_like('gc.description', '?', false, false);

        $params[] = '%'.$DB->sql_like_escape($token).'%';

        return array($subsql, $params);

    }

    /**

     * Calculates and returns the possible minimum and maximum score (in points) for this guide

     *

     * @return array

     */

    public function get_min_max_score() {

        if (!$this->is_form_available()) {

            return null;

        }

        $returnvalue = array('minscore' => 0, 'maxscore' => 0);

        $maxscore = 0;

        foreach ($this->get_definition()->guide_criteria as $id => $criterion) {

            $maxscore += $criterion['maxscore'];

        }

        $returnvalue['maxscore'] = $maxscore;

        $returnvalue['minscore'] = 0;

        if (!$this->is_shared_template()) {

            $fieldname = \core_grades\component_gradeitems::get_field_name_for_itemname($this->component, $this->area, 'grade');

            if (!empty($this->moduleinstance->{$fieldname})) {

                $graderange = make_grades_menu($this->moduleinstance->{$fieldname});

                $returnvalue['modulegrade'] = count($graderange) - 1;

            }

        }

        return $returnvalue;

    }

    /**

     * @return array An array containing 2 key/value pairs which hold the external_multiple_structure

     * for the 'guide_criteria' and the 'guide_comments'.

     * @see gradingform_controller::get_external_definition_details()

     * @since Moodle 2.5

     */

    public static function get_external_definition_details() {

        $guide_criteria = new external_multiple_structure(

                              new external_single_structure(

                                  array(

                                      'id'   => new external_value(PARAM_INT, 'criterion id', VALUE_OPTIONAL),

                                      'sortorder' => new external_value(PARAM_INT, 'sortorder', VALUE_OPTIONAL),

                                      'description' => new external_value(PARAM_RAW, 'description', VALUE_OPTIONAL),

                                      'descriptionformat' => new external_format_value('description', VALUE_OPTIONAL),

                                      'shortname' => new external_value(PARAM_TEXT, 'description'),

                                      'descriptionmarkers' => new external_value(PARAM_RAW, 'markers description', VALUE_OPTIONAL),

                                      'descriptionmarkersformat' => new external_format_value('descriptionmarkers', VALUE_OPTIONAL),

                                      'maxscore' => new external_value(PARAM_FLOAT, 'maximum score')

                                      )

                                  )

        );

        $guide_comments = new external_multiple_structure(

                              new external_single_structure(

                                  array(

                                      'id'   => new external_value(PARAM_INT, 'criterion id', VALUE_OPTIONAL),

                                      'sortorder' => new external_value(PARAM_INT, 'sortorder', VALUE_OPTIONAL),

                                      'description' => new external_value(PARAM_RAW, 'description', VALUE_OPTIONAL),

                                      'descriptionformat' => new external_format_value('description', VALUE_OPTIONAL)

                                   )

                              ), 'comments', VALUE_OPTIONAL

        );

        return array('guide_criteria' => $guide_criteria, 'guide_comments' => $guide_comments);

    }

    /**

     * Returns an array that defines the structure of the guide's filling. This function is used by

     * the web service function core_grading_external::get_gradingform_instances().

     *

     * @return An array containing a single key/value pair with the 'criteria' external_multiple_structure

     * @see gradingform_controller::get_external_instance_filling_details()

     * @since Moodle 2.6

     */

    public static function get_external_instance_filling_details() {

        $criteria = new external_multiple_structure(

            new external_single_structure(

                array(

                    'id' => new external_value(PARAM_INT, 'filling id'),

                    'criterionid' => new external_value(PARAM_INT, 'criterion id'),

                    'levelid' => new external_value(PARAM_INT, 'level id', VALUE_OPTIONAL),

                    'remark' => new external_value(PARAM_RAW, 'remark', VALUE_OPTIONAL),

                    'remarkformat' => new external_format_value('remark', VALUE_OPTIONAL),

                    'score' => new external_value(PARAM_FLOAT, 'maximum score')

                )

            ), 'filling', VALUE_OPTIONAL

        );

        return array ('criteria' => $criteria);

    }

}

/**

 * Class to manage one guide grading instance. Stores information and performs actions like

 * update, copy, validate, submit, etc.

 *

 * @package    gradingform_guide

 * @copyright  2012 Dan Marsden <dan@danmarsden.com>

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

class gradingform_guide_instance extends gradingform_instance {

    /** @var array */

    protected $guide;

    /** @var array An array of validation errors */

    protected $validationerrors = array();

    /**

     * Deletes this (INCOMPLETE) instance from database.

     */

    public function cancel() {

        global $DB;

        parent::cancel();

        $DB->delete_records('gradingform_guide_fillings', array('instanceid' => $this->get_id()));

    }

    /**

     * Duplicates the instance before editing (optionally substitutes raterid and/or itemid with

     * the specified values)

     *

     * @param int $raterid value for raterid in the duplicate

     * @param int $itemid value for itemid in the duplicate

     * @return int id of the new instance

     */

    public function copy($raterid, $itemid) {

        global $DB;

        $instanceid = parent::copy($raterid, $itemid);

        $currentgrade = $this->get_guide_filling();

        foreach ($currentgrade['criteria'] as $criterionid => $record) {

            $params = array('instanceid' => $instanceid, 'criterionid' => $criterionid,

                'score' => $record['score'], 'remark' => $record['remark'], 'remarkformat' => $record['remarkformat']);

            $DB->insert_record('gradingform_guide_fillings', $params);

        }

        return $instanceid;

    }

    /**

     * Determines whether the submitted form was empty.

     *

     * @param array $elementvalue value of element submitted from the form

     * @return boolean true if the form is empty

     */

    public function is_empty_form($elementvalue) {

        $criteria = $this->get_controller()->get_definition()->guide_criteria;

        foreach ($criteria as $id => $criterion) {

            $score = $elementvalue['criteria'][$id]['score'];

            $remark = $elementvalue['criteria'][$id]['remark'];

            if ((isset($score) && $score !== '')

                    || ((isset($remark) && $remark !== ''))) {

                return false;

            }

        }

        return true;

    }

    /**

     * Validates that guide is fully completed and contains valid grade on each criterion

     *

     * @param array $elementvalue value of element as came in form submit

     * @return boolean true if the form data is validated and contains no errors

     */

    public function validate_grading_element($elementvalue) {

        $criteria = $this->get_controller()->get_definition()->guide_criteria;

        if (!isset($elementvalue['criteria']) || !is_array($elementvalue['criteria']) ||

            count($elementvalue['criteria']) < count($criteria)) {

            return false;

        }

        // Reset validation errors.

        $this->validationerrors = null;

        foreach ($criteria as $id => $criterion) {

            if (!isset($elementvalue['criteria'][$id]['score'])

                    || $criterion['maxscore'] < $elementvalue['criteria'][$id]['score']

                    || !is_numeric($elementvalue['criteria'][$id]['score'])

                    || $elementvalue['criteria'][$id]['score'] < 0) {

                $this->validationerrors[$id]['score'] = $elementvalue['criteria'][$id]['score'];

            }

        }

        if (!empty($this->validationerrors)) {

            return false;

        }

        return true;

    }

    /**

     * Retrieves from DB and returns the data how this guide was filled

     *

     * @param bool $force whether to force DB query even if the data is cached

     * @return array

     */

    public function get_guide_filling($force = false) {

        global $DB;

        if ($this->guide === null || $force) {

            $records = $DB->get_records('gradingform_guide_fillings', array('instanceid' => $this->get_id()));

            $this->guide = array('criteria' => array());

            foreach ($records as $record) {

                $record->score = (float)$record->score; // Strip trailing 0.

                $this->guide['criteria'][$record->criterionid] = (array)$record;

            }

        }

        return $this->guide;

    }

    /**

     * Updates the instance with the data received from grading form. This function may be

     * called via AJAX when grading is not yet completed, so it does not change the

     * status of the instance.

     *

     * @param array $data

     */

    public function update($data) {

        global $DB;

        $currentgrade = $this->get_guide_filling();

        parent::update($data);

        foreach ($data['criteria'] as $criterionid => $record) {

            if (!array_key_exists($criterionid, $currentgrade['criteria'])) {

                $newrecord = array('instanceid' => $this->get_id(), 'criterionid' => $criterionid,

                    'score' => $record['score'], 'remarkformat' => FORMAT_MOODLE);

                if (isset($record['remark'])) {

                    $newrecord['remark'] = $record['remark'];

                }

                $DB->insert_record('gradingform_guide_fillings', $newrecord);

            } else {

                $newrecord = array('id' => $currentgrade['criteria'][$criterionid]['id']);

                foreach (array('score', 'remark'/*, 'remarkformat' TODO */) as $key) {

                    if (isset($record[$key]) && $currentgrade['criteria'][$criterionid][$key] != $record[$key]) {

                        $newrecord[$key] = $record[$key];

                    }

                }

                if (count($newrecord) > 1) {

                    $DB->update_record('gradingform_guide_fillings', $newrecord);

                }

            }

        }

        foreach ($currentgrade['criteria'] as $criterionid => $record) {

            if (!array_key_exists($criterionid, $data['criteria'])) {

                $DB->delete_records('gradingform_guide_fillings', array('id' => $record['id']));

            }

        }

        $this->get_guide_filling(true);

    }

    /**

     * Removes the attempt from the gradingform_guide_fillings table

     * @param array $data the attempt data

     */

    public function clear_attempt($data) {

        global $DB;

        foreach ($data['criteria'] as $criterionid => $record) {

            $DB->delete_records('gradingform_guide_fillings',

                array('criterionid' => $criterionid, 'instanceid' => $this->get_id()));

        }

    }

    /**

     * Calculates the grade to be pushed to the gradebook

     *

     * @return float|int the valid grade from $this->get_controller()->get_grade_range()

     */

    public function get_grade() {

        $grade = $this->get_guide_filling();

        if (!($scores = $this->get_controller()->get_min_max_score()) || $scores['maxscore'] <= $scores['minscore']) {

            return -1;

        }

        $graderange = array_keys($this->get_controller()->get_grade_range());

        if (empty($graderange)) {

            return -1;

        }

        sort($graderange);

        $mingrade = $graderange[0];

        $maxgrade = $graderange[count($graderange) - 1];

        $curscore = 0;

        foreach ($grade['criteria'] as $record) {

            $curscore += $record['score'];

        }

        $gradeoffset = ($curscore-$scores['minscore'])/($scores['maxscore']-$scores['minscore'])*

            ($maxgrade-$mingrade);

        if ($this->get_controller()->get_allow_grade_decimals()) {

            return $gradeoffset + $mingrade;

        }

        return round($gradeoffset, 0) + $mingrade;

    }

    /**

     * Returns html for form element of type 'grading'.

     *

     * @param moodle_page $page

     * @param MoodleQuickForm_grading $gradingformelement

     * @return string

     */

    public function render_grading_element($page, $gradingformelement) {

        if (!$gradingformelement->_flagFrozen) {

            $module = array('name'=>'gradingform_guide', 'fullpath'=>'/grade/grading/form/guide/js/guide.js');

            $page->requires->js_init_call('M.gradingform_guide.init', array(

                array('name' => $gradingformelement->getName())), true, $module);

            $mode = gradingform_guide_controller::DISPLAY_EVAL;

        } else {

            if ($gradingformelement->_persistantFreeze) {

                $mode = gradingform_guide_controller::DISPLAY_EVAL_FROZEN;

            } else {

                $mode = gradingform_guide_controller::DISPLAY_REVIEW;

            }

        }

        $criteria = $this->get_controller()->get_definition()->guide_criteria;

        $comments = $this->get_controller()->get_definition()->guide_comments;

        $options = $this->get_controller()->get_options();

        $value = $gradingformelement->getValue();

        $html = '';

        if ($value === null) {

            $value = $this->get_guide_filling();

        } else if (!$this->validate_grading_element($value)) {

            $html .= html_writer::tag('div', get_string('guidenotcompleted', 'gradingform_guide'),

                array('class' => 'gradingform_guide-error'));

            if (!empty($this->validationerrors)) {

                foreach ($this->validationerrors as $id => $err) {

                    $a = new stdClass();

                    $a->criterianame = format_text($criteria[$id]['shortname'], FORMAT_HTML);

                    $a->maxscore = $criteria[$id]['maxscore'];

                    if ($this->validationerrors[$id]['score'] < 0) {

                        $html .= html_writer::tag('div', get_string('err_scoreisnegative', 'gradingform_guide', $a),

                        array('class' => 'gradingform_guide-error'));

                    } else {

                        $html .= html_writer::tag('div', get_string('err_scoreinvalid', 'gradingform_guide', $a),

                        array('class' => 'gradingform_guide-error'));

                    }

                }

            }

        }

        $currentinstance = $this->get_current_instance();

        if ($currentinstance && $currentinstance->get_status() == gradingform_instance::INSTANCE_STATUS_NEEDUPDATE) {

            $html .= html_writer::tag('div', get_string('needregrademessage', 'gradingform_guide'),

                array('class' => 'gradingform_guide-regrade', 'role' => 'alert'));

        }

        $haschanges = false;

        if ($currentinstance) {

            $curfilling = $currentinstance->get_guide_filling();

            foreach ($curfilling['criteria'] as $criterionid => $curvalues) {

                $value['criteria'][$criterionid]['score'] = $curvalues['score'];

                $newremark = null;

                $newscore = null;

                if (isset($value['criteria'][$criterionid]['remark'])) {

                    $newremark = $value['criteria'][$criterionid]['remark'];

                }

                if (isset($value['criteria'][$criterionid]['score'])) {

                    $newscore = $value['criteria'][$criterionid]['score'];

                }

                if ($newscore != $curvalues['score'] || $newremark != $curvalues['remark']) {

                    $haschanges = true;