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/>.

//

// This file is part of BasicLTI4Moodle

//

// BasicLTI4Moodle is an IMS BasicLTI (Basic Learning Tools for Interoperability)

// consumer for Moodle 1.9 and Moodle 2.0. BasicLTI is a IMS Standard that allows web

// based learning tools to be easily integrated in LMS as native ones. The IMS BasicLTI

// specification is part of the IMS standard Common Cartridge 1.1 Sakai and other main LMS

// are already supporting or going to support BasicLTI. This project Implements the consumer

// for Moodle. Moodle is a Free Open source Learning Management System by Martin Dougiamas.

// BasicLTI4Moodle is a project iniciated and leaded by Ludo(Marc Alier) and Jordi Piguillem

// at the GESSI research group at UPC.

// SimpleLTI consumer for Moodle is an implementation of the early specification of LTI

// by Charles Severance (Dr Chuck) htp://dr-chuck.com , developed by Jordi Piguillem in a

// Google Summer of Code 2008 project co-mentored by Charles Severance and Marc Alier.

//

// BasicLTI4Moodle is copyright 2009 by Marc Alier Forment, Jordi Piguillem and Nikolas Galanis

// of the Universitat Politecnica de Catalunya http://www.upc.edu

// Contact info: Marc Alier Forment granludo @ gmail.com or marc.alier @ upc.edu.

/**

 * This file defines the main lti configuration form

 *

 * @package mod_lti

 * @copyright  2009 Marc Alier, Jordi Piguillem, Nikolas Galanis

 *  marc.alier@upc.edu

 * @copyright  2009 Universitat Politecnica de Catalunya http://www.upc.edu

 * @author     Marc Alier

 * @author     Jordi Piguillem

 * @author     Nikolas Galanis

 * @author     Chris Scribner

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

 */

defined('MOODLE_INTERNAL') || die;

require_once($CFG->dirroot.'/course/moodleform_mod.php');

require_once($CFG->dirroot.'/mod/lti/locallib.php');

class mod_lti_mod_form extends moodleform_mod {

    /** @var int the tool typeid, or 0 if the instance form is being created for a manually configured tool instance.*/

    protected int $typeid;

    /** @var string|null type */

    protected ?string $type;

    /**

     * Constructor.

     *

     * Throws an exception if trying to init the form for a new manual instance of a tool, which is not supported in 4.3 onward.

     *

     * @param \stdClass $current the current form data.

     * @param string $section the section number.

     * @param \stdClass $cm the course module object.

     * @param \stdClass $course the course object.

     * @throws moodle_exception if trying to init the form for the creation of a manual instance, which is no longer supported.

     */

    public function __construct($current, $section, $cm, $course) {

        // Setup some of the pieces used to control display in the form definition() method.

        // Type ID parameter being passed when adding an preconfigured tool from activity chooser.

        $this->typeid = optional_param('typeid', 0, PARAM_INT);

        $this->type = optional_param('type', null, PARAM_ALPHA);

        // Only permit construction if the form deals with editing an existing instance (current->id not empty), or creating an

        // instance from a preconfigured tool type ($this->typeid not empty). Make an exception for callers, such as core_completion

        // which aren't instantiating the form with the expected data, by checking whether the page has been set up, which is the

        // case for normal uses.

        global $PAGE;

        if ($PAGE->has_set_url() && str_contains($PAGE->url, '/course/modedit.php')) {

            if (empty($this->typeid) && empty($current->id)) {

                throw new moodle_exception('lti:addmanualinstanceprohibitederror', 'mod_lti');

            }

        }

        parent::__construct($current, $section, $cm, $course);

    }

    /**

     * Defines the form for legacy instances. Here tool config is frozen because the manual configuration method is deprecated.

     *

     * @param array $instancetypes the array of options for the legacy 'preconfigured tools' select.

     * @return void

     */

    protected function legacy_instance_form_definition(array $instancetypes): void {

        global $OUTPUT;

        // The legacy form handles instances which are either entirely manually configured (current->typeid = 0), or which are

        // manually configured and have been domain-matched to a preconfigured tool (current->typeid != 0).

        $manualinstance = empty($this->current->typeid);

        $matchestoolnotavailabletocourse = !$manualinstance;

        $typeid = $manualinstance ? '0' : $this->current->typeid;

        // Since 'mod/lti:addmanualinstance' capability is deprecated, determining which users may have had access to the certain

        // form fields (the manual config fields) isn't straightforward. Users without 'mod/lti:addmanualinstance' would have only

        // been permitted to edit the basic instance fields (name, etc.), so care must be taken not to display the config fields to

        // these users. Users who can add/edit course tools (mod/lti:addcoursetool) are able to view tool information anyway, via

        // the tool definitions, so this capability is used as a replacement, to control access to these tool config fields.

        $canviewmanualconfig = has_capability('mod/lti:addcoursetool', $this->context);

        $showtypes = has_capability('mod/lti:addpreconfiguredinstance', $this->context);

        if ($manualinstance && !$canviewmanualconfig) {

            // If you cannot add a manual instance and this is already a manual instance, then remove the 'types' selector.

            $showtypes = false;

        }

        $mform =& $this->_form;

        // Show the deprecation notice, regardless of whether the user can view the tool configuration details or not.

        // They will still see locked privacy fields and should be informed as to why that is.

        $mform->addElement('html', $OUTPUT->notification(

            get_string('editmanualinstancedeprecationwarning', 'mod_lti', get_docs_url('External_tool')),

            \core\output\notification::NOTIFY_WARNING, false)

        );

        // Adding the "general" fieldset, where all the common settings are shown.

        $mform->addElement('html', "<div data-attribute='dynamic-import' hidden aria-hidden='true' role='alert'></div>");

        $mform->addElement('header', 'general', get_string('general', 'form'));

        // Adding the standard "name" field.

        $mform->addElement('text', 'name', get_string('basicltiname', 'lti'), ['size' => '64']);

        $mform->setType('name', PARAM_TEXT);

        $mform->addRule('name', null, 'required', null, 'client');

        $mform->addRule('name', get_string('maximumchars', '', 255), 'maxlength', 255, 'client');

        // Adding the optional "intro" and "introformat" pair of fields.

        $this->standard_intro_elements(get_string('basicltiintro', 'lti'));

        $mform->setAdvanced('introeditor');

        // Display the label to the right of the checkbox so it looks better & matches rest of the form.

        if ($mform->elementExists('showdescription')) {

            $coursedesc = $mform->getElement('showdescription');

            if (!empty($coursedesc)) {

                $coursedesc->setText(' ' . $coursedesc->getLabel());

                $coursedesc->setLabel('&nbsp');

            }

        }

        $mform->setAdvanced('showdescription');

        $mform->addElement('checkbox', 'showtitlelaunch', get_string('display_name', 'lti'));

        $mform->setAdvanced('showtitlelaunch');

        $mform->addHelpButton('showtitlelaunch', 'display_name', 'lti');

        $mform->addElement('checkbox', 'showdescriptionlaunch', get_string('display_description', 'lti'));

        $mform->setAdvanced('showdescriptionlaunch');

        $mform->addHelpButton('showdescriptionlaunch', 'display_description', 'lti');

        if ($showtypes) {

            if ($manualinstance) {

                // Legacy, manually configured instances: only freeze the element (not hardFreeze) so that disabledIf() still works.

                // The data in the select is restricted so that only the current value is deemed valid, preventing DOM-edit changes,

                // which are possible with frozen elements.

                $tooltypes = $mform->addElement('select', 'typeid', get_string('external_tool_type', 'lti'));

                $mform->addHelpButton('typeid', 'external_tool_type', 'lti');

                $manualinstanceoption = $instancetypes[0]; // The 'Automatic, based on tool URL' option.

                $tooltypes->addOption($manualinstanceoption->name, 0, []);

                $mform->freeze('typeid');

            } else if ($matchestoolnotavailabletocourse) {

                // Legacy instances domain-matched to site tools: use a hidden field for typeid and a static visual element when

                // displaying these instances so that the string value of typeid is still visible when the element is frozen.

                // This gets around the fact that a frozen select without a selected option will display nothing.

                $mform->addElement('hidden', 'typeid', $typeid);

                $mform->setType('typeid', PARAM_INT);

                $manualinstanceoption = $instancetypes[0]; // The 'Automatic, based on tool URL' option.

                $mform->addElement('static', 'typeiddisplayonly', get_string('external_tool_type', 'lti'),

                    $manualinstanceoption->name);

            }

        } else {

            // Need to submit these still, but hidden to avoid instructor modification.

            $mform->addElement('hidden', 'typeid', $typeid);

            $mform->setType('typeid', PARAM_INT);

        }

        // Disable the content selection button unconditionally. Freeze/hardFreeze is unsuitable for buttons.

        $mform->addElement('button', 'selectcontent', get_string('selectcontent', 'lti'), ['disabled' => 'disabled']);

        $mform->disabledIf('selectcontent', 'typeid', 'eq', $typeid);

        if ($canviewmanualconfig) {

            $mform->addElement('text', 'toolurl', get_string('launch_url', 'lti'), ['size' => '64']);

            $mform->setType('toolurl', PARAM_URL);

            $mform->addHelpButton('toolurl', 'launch_url', 'lti');

            $mform->addElement('text', 'securetoolurl', get_string('secure_launch_url', 'lti'), ['size' => '64']);

            $mform->setType('securetoolurl', PARAM_URL);

            $mform->setAdvanced('securetoolurl');

            $mform->addHelpButton('securetoolurl', 'secure_launch_url', 'lti');

        } else {

            // Need to submit these still, but hidden to avoid instructor modification.

            $mform->addElement('hidden', 'toolurl', '', ['id' => 'id_toolurl']);

            $mform->setType('toolurl', PARAM_URL);

            $mform->addElement('hidden', 'securetoolurl', '', ['id' => 'id_securetoolurl']);

            $mform->setType('securetoolurl', PARAM_URL);

        }

        $mform->addElement('hidden', 'lineitemresourceid', '', ['id' => 'id_lineitemresourceid']);

        $mform->setType('lineitemresourceid', PARAM_TEXT);

        $mform->addElement('hidden', 'lineitemtag', '', ['id' => 'id_lineitemtag']);

        $mform->setType('lineitemtag', PARAM_TEXT);

        $mform->addElement('hidden', 'lineitemsubreviewurl', '', ['id' => 'id_lineitemsubreviewurl']);

        $mform->setType('lineitemsubreviewurl', PARAM_URL);

        $mform->addElement('hidden', 'lineitemsubreviewparams', '', ['id' => 'id_lineitemsubreviewparams']);

        $mform->setType('lineitemsubreviewparams', PARAM_TEXT);

        $launchoptions = [

            LTI_LAUNCH_CONTAINER_DEFAULT => get_string('default', 'lti'),

            LTI_LAUNCH_CONTAINER_EMBED => get_string('embed', 'lti'),

            LTI_LAUNCH_CONTAINER_EMBED_NO_BLOCKS => get_string('embed_no_blocks', 'lti'),

            LTI_LAUNCH_CONTAINER_REPLACE_MOODLE_WINDOW => get_string('existing_window', 'lti'),

            LTI_LAUNCH_CONTAINER_WINDOW => get_string('new_window', 'lti')

        ];

        $mform->addElement('select', 'launchcontainer', get_string('launchinpopup', 'lti'), $launchoptions);

        $mform->addHelpButton('launchcontainer', 'launchinpopup', 'lti');

        $mform->setAdvanced('launchcontainer');

        if ($canviewmanualconfig) {

            $mform->addElement('text', 'resourcekey', get_string('resourcekey', 'lti'));

            $mform->setType('resourcekey', PARAM_TEXT);

            $mform->setAdvanced('resourcekey');

            $mform->addHelpButton('resourcekey', 'resourcekey', 'lti');

            $mform->setForceLtr('resourcekey');

            $mform->addElement('passwordunmask', 'password', get_string('password', 'lti'));

            $mform->setType('password', PARAM_TEXT);

            $mform->setAdvanced('password');

            $mform->addHelpButton('password', 'password', 'lti');

            $mform->addElement('textarea', 'instructorcustomparameters', get_string('custom', 'lti'), ['rows' => 4, 'cols' => 60]);

            $mform->setType('instructorcustomparameters', PARAM_TEXT);

            $mform->setAdvanced('instructorcustomparameters');

            $mform->addHelpButton('instructorcustomparameters', 'custom', 'lti');

            $mform->setForceLtr('instructorcustomparameters');

            $mform->addElement('text', 'icon', get_string('icon_url', 'lti'), ['size' => '64']);

            $mform->setType('icon', PARAM_URL);

            $mform->setAdvanced('icon');

            $mform->addHelpButton('icon', 'icon_url', 'lti');

            $mform->addElement('text', 'secureicon', get_string('secure_icon_url', 'lti'), ['size' => '64']);

            $mform->setType('secureicon', PARAM_URL);

            $mform->setAdvanced('secureicon');

            $mform->addHelpButton('secureicon', 'secure_icon_url', 'lti');

        } else {

            // Need to submit these still, but hidden to avoid instructor modification.

            $mform->addElement('hidden', 'resourcekey', '', ['id' => 'id_resourcekey']);

            $mform->setType('resourcekey', PARAM_TEXT);

            $mform->addElement('hidden', 'password', '', ['id' => 'id_password']);

            $mform->setType('password', PARAM_TEXT);

            $mform->addElement('hidden', 'instructorcustomparameters', '', ['id' => 'id_instructorcustomparameters']);

            $mform->setType('instructorcustomparameters', PARAM_TEXT);

            $mform->addElement('hidden', 'icon', '', ['id' => 'id_icon']);

            $mform->setType('icon', PARAM_URL);

            $mform->addElement('hidden', 'secureicon', '', ['id' => 'id_secureicon']);

            $mform->setType('secureicon', PARAM_URL);

        }

        // Add privacy preferences fieldset where users choose whether to send their data.

        $mform->addElement('header', 'privacy', get_string('privacy', 'lti'));

        $mform->addElement('advcheckbox', 'instructorchoicesendname', get_string('share_name', 'lti'));

        $mform->addHelpButton('instructorchoicesendname', 'share_name', 'lti');

        $mform->addElement('advcheckbox', 'instructorchoicesendemailaddr', get_string('share_email', 'lti'));

        $mform->addHelpButton('instructorchoicesendemailaddr', 'share_email', 'lti');

        $mform->addElement('advcheckbox', 'instructorchoiceacceptgrades', get_string('accept_grades', 'lti'));

        $mform->addHelpButton('instructorchoiceacceptgrades', 'accept_grades', 'lti');

        // Add standard course module grading elements.

        $this->standard_grading_coursemodule_elements();

        // Add standard elements, common to all modules.

        $this->standard_coursemodule_elements();

        $mform->setAdvanced('cmidnumber');

        // Add standard buttons, common to all modules.

        $this->add_action_buttons();

        $mform->hardFreeze([

            'toolurl',

            'securetoolurl',

            'launchcontainer',

            'instructorcustomparameters',

            'icon',

            'secureicon',

            'instructorchoicesendname',

            'instructorchoicesendemailaddr',

            'instructorchoiceacceptgrades'

        ]);

    }

    public function definition() {

        global $PAGE, $OUTPUT, $COURSE;

        if ($this->type) {

            component_callback("ltisource_$this->type", 'add_instance_hook');

        }

        // Determine whether this tool instance is a manually configure instance (now deprecated).

        $manualinstance = empty($this->current->typeid) && empty($this->typeid);

        // Determine whether this tool instance is using a domain-matched site tool which is not visible at the course level.

        // In such a case, the instance has a typeid (the site tool) and toolurl (the url used to domain match the site tool) set,

        // and the type still exists (is not deleted).

        $instancetypes = lti_get_types_for_add_instance();

        $matchestoolnotavailabletocourse = false;

        if (!$manualinstance && !empty($this->current->toolurl)) {

            if (lti_get_type_config($this->current->typeid)) {

                $matchestoolnotavailabletocourse = !in_array($this->current->typeid, array_keys($instancetypes));

            }

        }

        // Display the legacy form, presenting a read-only view of the configuration for unsupported (since 4.3) instances, which:

        // - Are manually configured instances (no longer supported. course tools should be configured and used instead).

        // - Are domain-matched to a hidden site level tool (no longer supported. to be replaced by URL-based course tool creation)

        // Instances based on preconfigured tools and which are not domain matched as above, are still valid and will be shown using

        // the non-legacy form.

        if ($manualinstance || $matchestoolnotavailabletocourse) {

            $this->legacy_instance_form_definition($instancetypes);

            return;

        }

        $tooltypeid = $this->current->typeid ?? $this->typeid;

        $tooltype = lti_get_type($tooltypeid);

        // Store the id of the tool type should it be linked to a tool proxy, to aid in disabling certain form elements.

        $toolproxytypeid = $tooltype->toolproxyid ? $tooltypeid : '';

        $issitetooltype = $tooltype->course == get_site()->id;

        $mform =& $this->_form;

        // Adding the "general" fieldset, where all the common settings are shown.

        $mform->addElement('html', "<div data-attribute='dynamic-import' hidden aria-hidden='true' role='alert'></div>");

        $mform->addElement('header', 'general', get_string('general', 'form'));

        // For tools supporting content selection, add the 'Select content button'.

        $config = lti_get_type_config($tooltypeid);

        $supportscontentitemselection = !empty($config['contentitem']);

        if ($supportscontentitemselection) {

            $contentitemurl = new moodle_url('/mod/lti/contentitem.php');

            $contentbuttonattributes = [

                'data-contentitemurl' => $contentitemurl->out(false),

            ];

            // If this is an instance, was it created based on content selection in a prior-edit (need to infer since not stored).

            $iscontentitem = !empty($this->current->id)

                && (!empty($this->current->toolurl) || !empty($this->current->instructorcustomparameters)

                || !empty($this->current->secureicon) || !empty($this->current->icon));

            $selectcontentindicatorinner = $iscontentitem ?

                $OUTPUT->pix_icon('i/valid', get_string('contentselected', 'mod_lti'), 'moodle', ['class' => 'mr-1'])

                . get_string('contentselected', 'mod_lti') : '';

            $selectcontentindicator = html_writer::div($selectcontentindicatorinner, '',

                ['aria-role' => 'status', 'id' => 'id_selectcontentindicator']);

            $selectcontentstatus = $iscontentitem ? 'true' : 'false';

            $selectcontentgrp = [

                $mform->createElement('button', 'selectcontent', get_string('selectcontent', 'mod_lti'), $contentbuttonattributes,

                    ['customclassoverride' => 'btn-primary']),

                $mform->createElement('html', $selectcontentindicator),

                $mform->createElement('hidden', 'selectcontentstatus', $selectcontentstatus),

            ];

            $mform->setType('selectcontentstatus', PARAM_TEXT);

            $mform->addGroup($selectcontentgrp, 'selectcontentgroup', get_string('content'), ' ', false);

            $mform->addRule('selectcontentgroup', get_string('selectcontentvalidationerror', 'mod_lti'), 'required');

        }

        // Adding the standard "name" field.

        $mform->addElement('text', 'name', get_string('basicltiname', 'lti'), ['size' => '64']);

        $mform->setType('name', PARAM_TEXT);

        $mform->addRule('name', null, 'required', null, 'server');

        $mform->addRule('name', get_string('maximumchars', '', 255), 'maxlength', 255, 'server');

        // Show activity name when launched only applies to embedded type launches.

        if (in_array($config['launchcontainer'], [LTI_LAUNCH_CONTAINER_EMBED, LTI_LAUNCH_CONTAINER_EMBED_NO_BLOCKS])) {

            $mform->addElement('checkbox', 'showtitlelaunch', get_string('display_name', 'lti'));

            $mform->setDefault('showtitlelaunch', true);

            $mform->addHelpButton('showtitlelaunch', 'display_name', 'lti');

        } else {

            // Include in the form anyway, so we retain the setting value in case the tool launch container is changed back.

            $mform->addElement('hidden', 'showtitlelaunch');

            $mform->setType('showtitlelaunch', PARAM_BOOL);

        }

        // Adding the optional "intro" and "introformat" pair of fields.

        $this->standard_intro_elements(get_string('basicltiintro', 'lti'));

        // Display the label to the right of the checkbox so it looks better & matches rest of the form.

        if ($mform->elementExists('showdescription')) {

            $coursedesc = $mform->getElement('showdescription');

            if (!empty($coursedesc)) {

                $coursedesc->setText(' ' . $coursedesc->getLabel());

                $coursedesc->setLabel('&nbsp');

            }

        }

        // Show activity description when launched only applies to embedded type launches.

        if (in_array($config['launchcontainer'], [LTI_LAUNCH_CONTAINER_EMBED, LTI_LAUNCH_CONTAINER_EMBED_NO_BLOCKS])) {

            $mform->addElement('checkbox', 'showdescriptionlaunch', get_string('display_description', 'lti'));

            $mform->addHelpButton('showdescriptionlaunch', 'display_description', 'lti');

        } else {

            // Include in the form anyway, so we retain the setting value in case the tool launch container is changed back.

            $mform->addElement('hidden', 'showdescriptionlaunch');

            $mform->setType('showdescriptionlaunch', PARAM_BOOL);

        }

        // Tool settings.

        $mform->addElement('hidden', 'typeid', $tooltypeid, ['id' => 'hidden_typeid']);

        $mform->setType('typeid', PARAM_INT);

        if (!empty($config['contentitem'])) {

            $mform->addElement('hidden', 'contentitem', 1);

            $mform->setType('contentitem', PARAM_INT);

        }

        // Included to support deep linking return, but hidden to avoid instructor modification.

        $mform->addElement('hidden', 'toolurl', '', ['id' => 'id_toolurl']);

        $mform->setType('toolurl', PARAM_URL);

        $mform->addElement('hidden', 'securetoolurl', '', ['id' => 'id_securetoolurl']);

        $mform->setType('securetoolurl', PARAM_URL);

        $mform->addElement('hidden', 'urlmatchedtypeid', '', ['id' => 'id_urlmatchedtypeid']);

        $mform->setType('urlmatchedtypeid', PARAM_INT);

        $mform->addElement('hidden', 'lineitemresourceid', '', ['id' => 'id_lineitemresourceid']);

        $mform->setType('lineitemresourceid', PARAM_TEXT);

        $mform->addElement('hidden', 'lineitemtag', '', ['id' => 'id_lineitemtag']);

        $mform->setType('lineitemtag', PARAM_TEXT);

        $mform->addElement('hidden', 'lineitemsubreviewurl', '', ['id' => 'id_lineitemsubreviewurl']);

        $mform->setType('lineitemsubreviewurl', PARAM_URL);

        $mform->addElement('hidden', 'lineitemsubreviewparams', '', ['id' => 'id_lineitemsubreviewparams']);

        $mform->setType('lineitemsubreviewparams', PARAM_TEXT);

        // Launch container is set to 'LTI_LAUNCH_CONTAINER_DEFAULT', meaning it'll delegate to the tool's configuration.

        // Existing instances using values other than this can continue to use their existing value but cannot change it.

        $mform->addElement('hidden', 'launchcontainer', LTI_LAUNCH_CONTAINER_DEFAULT);

        $mform->setType('launchcontainer', PARAM_INT);

        // Included to support deep linking return, but hidden to avoid instructor modification.

        $mform->addElement('hidden', 'resourcekey', '', ['id' => 'id_resourcekey']);

        $mform->setType('resourcekey', PARAM_TEXT);

        $mform->addElement('hidden', 'password', '', ['id' => 'id_password']);

        $mform->setType('password', PARAM_TEXT);

        $mform->addElement('textarea', 'instructorcustomparameters', get_string('custom', 'lti'),

            ['rows' => 4, 'cols' => 60]);

        $mform->setType('instructorcustomparameters', PARAM_TEXT);

        $mform->setAdvanced('instructorcustomparameters');

        $mform->addHelpButton('instructorcustomparameters', 'custom', 'lti');

        $mform->setForceLtr('instructorcustomparameters');

        $mform->addElement('hidden', 'icon', '', ['id' => 'id_icon']);

        $mform->setType('icon', PARAM_URL);

        $mform->addElement('hidden', 'secureicon', '', ['id' => 'id_secureicon']);

        $mform->setType('secureicon', PARAM_URL);

        // Add standard course module grading elements, and show them if the tool type + instance config permits it.

        if (!empty($config['acceptgrades']) && in_array($config['acceptgrades'], [LTI_SETTING_ALWAYS, LTI_SETTING_DELEGATE])) {

            $elementnamesbeforegrading = $this->_form->_elementIndex;

            $this->standard_grading_coursemodule_elements();

            $elementnamesaftergrading = $this->_form->_elementIndex;

            // For all 'real' elements (not hidden or header) added as part of the standard grading elements, add a hideIf rule

            // making the element dependent on the 'accept grades from the tool' checkbox (instructorchoiceacceptgrades).

            $diff = array_diff($elementnamesaftergrading, $elementnamesbeforegrading);

            $diff = array_filter($diff, fn($key) => !in_array($this->_form->_elements[$key]->_type, ['hidden', 'header']));

            foreach ($diff as $gradeelementname => $gradeelementindex) {

                $mform->hideIf($gradeelementname, 'instructorchoiceacceptgrades', 'eq', 0);

            }

            // Extend the grade section with the 'accept grades from the tool' checkbox, allowing per-instance overrides of that

            // value according to the following rules:

            // - Site tools with 'acceptgrades' set to 'ALWAYS' do not permit overrides at the instance level; the checkbox is

            // omitted in such cases.

            // - Site tools with 'acceptgrades' set to 'DELEGATE' result in a checkbox that is defaulted to unchecked but which

            // permits overrides to 'yes/checked'.

            // - Course tools with 'acceptgrades' set to 'ALWAYS' result in a checkbox that is defaulted to checked but which

            // permits overrides to 'no/unchecked'.

            // - Course tools with 'acceptgrades' set to 'DELEGATE' result in a checkbox that is defaulted to unchecked but which

            // permits overrides to 'yes/checked'.

            if (($issitetooltype && $config['acceptgrades'] == LTI_SETTING_DELEGATE) || !$issitetooltype) {

                $mform->insertElementBefore(

                    $mform->createElement(

                        'advcheckbox',

                        'instructorchoiceacceptgrades',

                        get_string('accept_grades_from_tool', 'mod_lti', $tooltype->name)

                    ),

                    array_keys($diff)[0]

                );

                $acceptgradesdefault = !$issitetooltype && $config['acceptgrades'] == LTI_SETTING_ALWAYS ? '1' : '0';

                $mform->setDefault('instructorchoiceacceptgrades', $acceptgradesdefault);

                $mform->disabledIf('instructorchoiceacceptgrades', 'typeid', 'in', [$toolproxytypeid]); // LTI 2 only.

            }

        }

        // Add standard elements, common to all modules.

        $this->standard_coursemodule_elements();

        $mform->setAdvanced('cmidnumber');

        // Add standard buttons, common to all modules.

        $this->add_action_buttons();

        if ($supportscontentitemselection) {

            $PAGE->requires->js_call_amd('mod_lti/mod_form', 'init', [$COURSE->id]);

        }

    }

    /**

     * Sets the current values handled by services in case of update.

     *

     * @param object $defaultvalues default values to populate the form with.

     */

    public function set_data($defaultvalues) {

        $services = lti_get_services();

        if (is_object($defaultvalues)) {

            foreach ($services as $service) {

                $service->set_instance_form_values( $defaultvalues );

            }

        }

        parent::set_data($defaultvalues);

    }

    public function validation($data, $files) {

        $errors = parent::validation($data, $files);

        if (isset($data['selectcontentstatus']) && $data['selectcontentstatus'] === 'false') {

            $errors['selectcontentgroup'] = get_string('selectcontentvalidationerror', 'mod_lti');

        }

        return $errors;

    }

}