Common tern with fish

     * @param array $arr array to be sorted (reference)
     * @param int $sortflag One of core_collator::SORT_NUMERIC, core_collator::SORT_STRING, core_collator::SORT_NATURAL, core_collator::SORT_REGULAR
     *      optionally "|" core_collator::CASE_SENSITIVE
     * @return bool True on success
     */
    public static function asort(array &$arr, $sortflag = core_collator::SORT_STRING) {
        if (empty($arr)) {
            // nothing to do
            return true;
        }
 
        $original = null;
 
        $casesensitive = (bool)($sortflag & core_collator::CASE_SENSITIVE);
        $sortflag = ($sortflag & ~core_collator::CASE_SENSITIVE);
        if ($sortflag != core_collator::SORT_NATURAL and $sortflag != core_collator::SORT_STRING) {
            $casesensitive = false;
        }
 
        if (self::ensure_collator_available()) {
            if ($sortflag == core_collator::SORT_NUMERIC) {
                $flag = Collator::SORT_NUMERIC;
 
            } else if ($sortflag == core_collator::SORT_REGULAR) {
                $flag = Collator::SORT_REGULAR;
 
            } else {
                $flag = Collator::SORT_STRING;
            }
 
            if ($sortflag == core_collator::SORT_NATURAL) {
                $original = $arr;
                if ($sortflag == core_collator::SORT_NATURAL) {
                    foreach ($arr as $key => $value) {
                        $arr[$key] = self::naturalise((string)$value);
                    }
                }
            }
            if ($casesensitive) {
                self::$collator->setAttribute(Collator::CASE_FIRST, Collator::UPPER_FIRST);

        }
 
        return $result;
    }
 
    /**
     * Locale aware sort of objects by a property in common to all objects
     *
     * @param array $objects An array of objects to sort (handled by reference)
     * @param string $property The property to use for comparison
     * @param int $sortflag One of core_collator::SORT_NUMERIC, core_collator::SORT_STRING, core_collator::SORT_NATURAL, core_collator::SORT_REGULAR
     *      optionally "|" core_collator::CASE_SENSITIVE
     * @return bool True on success
     */
    public static function asort_objects_by_property(array &$objects, $property, $sortflag = core_collator::SORT_STRING) {
        $original = $objects;
        foreach ($objects as $key => $object) {
            $objects[$key] = $object->$property;
        }
        $result = self::asort($objects, $sortflag);
        self::restore_array($objects, $original);
        return $result;
    }
 
    /**
     * Locale aware sort of objects by a method in common to all objects
     *
     * @param array $objects An array of objects to sort (handled by reference)
     * @param string $method The method to call to generate a value for comparison
     * @param int $sortflag One of core_collator::SORT_NUMERIC, core_collator::SORT_STRING, core_collator::SORT_NATURAL, core_collator::SORT_REGULAR
     *      optionally "|" core_collator::CASE_SENSITIVE
     * @return bool True on success
     */
    public static function asort_objects_by_method(array &$objects, $method, $sortflag = core_collator::SORT_STRING) {
        $original = $objects;
        foreach ($objects as $key => $object) {
            $objects[$key] = $object->{$method}();
        }
        $result = self::asort($objects, $sortflag);
        self::restore_array($objects, $original);

 
        $modinfo = get_fast_modinfo($courseid);
        if (!empty($modinfo->cms)) {
            $activitylist = []; // We will store all the created filters here.
 
            // Create array of visible activities sorted by the name length (we are only interested in properties name and url).
            $sortedactivities = [];
            foreach ($modinfo->cms as $cm) {
                // Use normal access control and visibility, but exclude labels and hidden activities.
                if ($cm->visible && $cm->has_view() && $cm->uservisible) {
                    $sortedactivities[] = (object)[
                        'name' => $cm->name,
                        'url' => $cm->url,
                        'id' => $cm->id,
                        'namelen' => -strlen($cm->name), // Negative value for reverse sorting.
                    ];
                }
            }
            // Sort activities by the length of the activity name in reverse order.
            core_collator::asort_objects_by_property($sortedactivities, 'namelen', core_collator::SORT_NUMERIC);
 
            foreach ($sortedactivities as $cm) {
                $title = s(trim(strip_tags($cm->name)));
                $currentname = trim($cm->name);
                $entitisedname  = s($currentname);
                // Avoid empty or unlinkable activity names.
                if (!empty($title)) {
                    $hreftagbegin = html_writer::start_tag(
                        'a',
                        ['class' => 'autolink', 'title' => $title,
                        'href' => $cm->url, ]
                    );
                    $activitylist[$cm->id] = new filterobject($currentname, $hreftagbegin, '</a>', false, true);
                    if ($currentname != $entitisedname) {
                        // If name has some entity (&amp; &quot; &lt; &gt;) add that filter too. MDL-17545.
                        $activitylist[$cm->id . '-e'] = new filterobject($entitisedname, $hreftagbegin, '</a>', false, true);
                    }
                }
            }
        }

        }
    }
 
    /**
     * Get all the cached activity list for a course
     *
     * @param int $courseid id of the course
     * @return filterobject[] the activities
     */
    protected function get_cached_activity_list($courseid) {
        global $USER;
        $cached = cache::make_from_params(cache_store::MODE_REQUEST, 'filter', 'activitynames');
 
        // Return cached activity list.
        if ($cached->get('cachecourseid') == $courseid && $cached->get('cacheuserid') == $USER->id) {
            return $cached->get('activitylist');
        }
 
        // Not cached yet, get activity list and set cache.
        $activitylist = $this->get_activity_list($courseid);
        $cached->set('cacheuserid', $USER->id);
        $cached->set('cachecourseid', $courseid);
        $cached->set('activitylist', $activitylist);
        return $activitylist;
    }
 
    /**
     * Get all the activity list for a course
     *
     * @param int $courseid id of the course
     * @return filterobject[] the activities
     */
    protected function get_activity_list($courseid) {
        $activitylist = [];
 
        $modinfo = get_fast_modinfo($courseid);
        if (!empty($modinfo->cms)) {
            $activitylist = []; // We will store all the created filters here.
 
            // Create array of visible activities sorted by the name length (we are only interested in properties name and url).

 
/**
 * This filter provides automatic linking to
 * activities when its name (title) is found inside every Moodle text
 *
 * @package    filter_activitynames
 * @subpackage activitynames
 * @copyright  2004 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class text_filter extends \core_filters\text_filter {
    #[\Override]
    public function filter($text, array $options = []) {
        $coursectx = $this->context->get_course_context(false);
        if (!$coursectx) {
            return $text;
        }
        $courseid = $coursectx->instanceid;
 
        $activitylist = $this->get_cached_activity_list($courseid);
 
        $filterslist = [];
        if (!empty($activitylist)) {
            $cmid = $this->context->instanceid;
            if ($this->context->contextlevel == CONTEXT_MODULE && isset($activitylist[$cmid])) {
                // Remove filterobjects for the current module.
                $filterslist = array_values(array_diff_key($activitylist, [$cmid => 1, $cmid . '-e' => 1]));
            } else {
                $filterslist = array_values($activitylist);
            }
        }
 
        if ($filterslist) {
            return $text = filter_phrases($text, $filterslist);
        } else {
            return $text;
        }
    }
 
    /**

     * @param array $options
     * @return string
     */
    public function filter_stage_pre_clean(string $text, array $options): string {
        // NOTE: override if necessary.
        return $text;
    }
 
    /**
     * Filter HTML text at the very end after text is sanitised.
     *
     * NOTE: this is called even if $options['noclean'] is true and text is not cleaned.
     *
     * @param string $text
     * @param array $options
     * @return string
     */
    public function filter_stage_post_clean(string $text, array $options): string {
        // NOTE: override if necessary.
        return $this->filter($text, $options);
    }
 
    /**
     * Filter simple text coming from format_string().
     *
     * Note that unless $CFG->formatstringstriptags is disabled
     * HTML tags are not expected in returned value.
     *
     * @param string $text
     * @param array $options
     * @return string
     */
    public function filter_stage_string(string $text, array $options): string {
        // NOTE: override if necessary.
        return $this->filter($text, $options);
    }
}
 
// Alias this class to the old name.
// This file will be autoloaded by the legacyclasses autoload system.

        array $options = [],
        ?array $skipfilters = null
    ) {
        if (!isset($options['stage'])) {
            $filtermethod = 'filter';
        } else if (in_array($options['stage'], ['pre_format', 'pre_clean', 'post_clean', 'string'], true)) {
            $filtermethod = 'filter_stage_' . $options['stage'];
        } else {
            $filtermethod = 'filter';
            debugging('Invalid filter stage specified in options: ' . $options['stage'], DEBUG_DEVELOPER);
        }
        if ($text === null || $text === '') {
            // Nothing to filter.
            return '';
        }
        foreach ($filterchain as $filtername => $filter) {
            if ($skipfilters !== null && in_array($filtername, $skipfilters)) {
                continue;
            }
            $text = $filter->$filtermethod($text, $options);
        }
        return $text;
    }
 
    /**
     * Get all the filters that apply to a given context for calls to format_text.
     *
     * @param context $context
     * @return moodle_text_filter[] A text filter
     */
    protected function get_text_filters($context) {
        if (!isset($this->textfilters[$context->id])) {
            $this->load_filters($context);
        }
        return $this->textfilters[$context->id];
    }
 
    /**
     * Get all the filters that apply to a given context for calls to format_string.
     *

        }
        return $this->stringfilters[$context->id];
    }
 
    /**
     * Filter some text
     *
     * @param string $text The text to filter
     * @param context $context the context.
     * @param array $options options passed to the filters
     * @param null|array $skipfilters of filter names. Any filters that should not be applied to this text.
     * @return string resulting text
     */
    public function filter_text(
        $text,
        $context,
        array $options = [],
        ?array $skipfilters = null
    ) {
        $text = $this->apply_filter_chain($text, $this->get_text_filters($context), $options, $skipfilters);
        if (!isset($options['stage']) || $options['stage'] === 'post_clean') {
            // Remove <nolink> tags for XHTML compatibility after the last filtering stage.
            $text = str_replace(['<nolink>', '</nolink>'], '', $text);
        }
        return $text;
    }
 
    /**
     * Filter a piece of string
     *
     * @param string $string The text to filter
     * @param context $context the context.
     * @return string resulting string
     */
    public function filter_string($string, $context) {
        return $this->apply_filter_chain($string, $this->get_string_filters($context), ['stage' => 'string']);
    }
 
    /**
     * Setup page with filters requirements and other prepare stuff.

            ];
        } else {
            $filtermanager = new \null_filter_manager();
            $filteroptions = [];
        }
 
        switch ($format) {
            case FORMAT_HTML:
                $filteroptions['stage'] = 'pre_format';
                $text = $filtermanager->filter_text($text, $context, $filteroptions);
                // Text is already in HTML format, so just continue to the next filtering stage.
                $filteroptions['stage'] = 'pre_clean';
                $text = $filtermanager->filter_text($text, $context, $filteroptions);
                if ($clean) {
                    $text = clean_text($text, FORMAT_HTML, [
                        'allowid' => $allowid,
                    ]);
                }
                $filteroptions['stage'] = 'post_clean';
                $text = $filtermanager->filter_text($text, $context, $filteroptions);
                break;
 
            case FORMAT_PLAIN:
                $text = s($text); // Cleans dangerous JS.
                $text = rebuildnolinktag($text);
                $text = str_replace('  ', '  ', $text);
                $text = nl2br($text);
                break;
 
            case FORMAT_MARKDOWN:
                $filteroptions['stage'] = 'pre_format';
                $text = $filtermanager->filter_text($text, $context, $filteroptions);
                $text = markdown_to_html($text);
                $filteroptions['stage'] = 'pre_clean';
                $text = $filtermanager->filter_text($text, $context, $filteroptions);
                if ($clean) {
                    $text = clean_text($text, FORMAT_HTML, [
                        'allowid' => $allowid,
                    ]);
                }

                unset($options[$option]);
            }
        }
 
        foreach ($options as $option => $value) {
            $params[$option] = $value;
        }
 
        // The noclean option has been renamed to clean.
        if (array_key_exists('noclean', $params)) {
            $params['clean'] = !$params['noclean'];
            unset($params['noclean']);
        }
    }
 
    if ($format !== null) {
        $params['format'] = $format;
    }
 
    return \core\di::get(\core\formatting::class)->format_text(...$params);
}
 
/**
 * Resets some data related to filters, called during upgrade or when general filter settings change.
 *
 * @param bool $phpunitreset true means called from our PHPUnit integration test reset
 * @return void
 */
function reset_text_filters_cache($phpunitreset = false) {
    global $CFG, $DB;
 
    if ($phpunitreset) {
        // HTMLPurifier does not change, DB is already reset to defaults,
        // nothing to do here, the dataroot was cleared too.
        return;
    }
 
    // The purge_all_caches() deals with cachedir and localcachedir purging,
    // the individual filter caches are invalidated as necessary elsewhere.
 

        $code = resourcelib_embed_pdf($moodleurl->out(), $title, $clicktoopen);
 
    } else if ($mediamanager->can_embed_url($moodleurl, $embedoptions)) {
        // Media (audio/video) file.
        $code = $mediamanager->embed_url($moodleurl, $title, 0, 0, $embedoptions);
 
    } else {
        // We need a way to discover if we are loading remote docs inside an iframe.
        $moodleurl->param('embed', 1);
 
        // anything else - just try object tag enlarged as much as possible
        $code = resourcelib_embed_general($moodleurl, $title, $clicktoopen, $mimetype);
    }
 
    // Let the module handle the display.
    $PAGE->activityheader->set_description(resource_get_intro($resource, $cm));
 
    resource_print_header($resource, $cm, $course);
 
    echo format_text($code, FORMAT_HTML, ['noclean' => true]);
 
    echo $OUTPUT->footer();
    die;
}
 
/**
 * Display resource frames.
 * @param object $resource
 * @param object $cm
 * @param object $course
 * @param stored_file $file main file
 * @return does not return
 */
function resource_display_frame($resource, $cm, $course, $file) {
    global $PAGE, $OUTPUT, $CFG;
 
    $frame = optional_param('frameset', 'main', PARAM_ALPHA);
 
    if ($frame === 'top') {
        $PAGE->set_pagelayout('frametop');

}
 
// Don't redirect teachers, otherwise they can not access course or module settings.
if ($redirect && !course_get_format($course)->has_view_page() &&
        (has_capability('moodle/course:manageactivities', $context) ||
        has_capability('moodle/course:update', context_course::instance($course->id)))) {
    $redirect = false;
}
 
if ($redirect && !$forceview) {
    // coming from course page or url index page
    // this redirect trick solves caching problems when tracking views ;-)
    $path = '/'.$context->id.'/mod_resource/content/'.$resource->revision.$file->get_filepath().$file->get_filename();
    $fullurl = moodle_url::make_file_url('/pluginfile.php', $path, $displaytype == RESOURCELIB_DISPLAY_DOWNLOAD);
    redirect($fullurl);
}
 
switch ($displaytype) {
    case RESOURCELIB_DISPLAY_EMBED:
        resource_display_embed($resource, $cm, $course, $file);
        break;
    case RESOURCELIB_DISPLAY_FRAME:
        resource_display_frame($resource, $cm, $course, $file);
        break;
    default:
        resource_print_workaround($resource, $cm, $course, $file);
        break;
}