block_glsubs.php

<?php

/**
 * Created by PhpStorm.
 * User: vasileios
 * Date: 28/10/2016
 * Time: 15:03
 *
 * File:     blocks/glsubs/block_glsubs.php
 *
 * Purpose:  A glossary subscriptions block plugin for Moodle
 *
 * Input:    N/A
 *
 * Output:   N/A
 *
 * Notes:    This is developed for the QM+ Moodle site of the Queen Mary university of London
 *
 * 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/>.
 */

// namespace glsubs;
defined('MOODLE_INTERNAL') || die('Direct access to this script is forbidden.');
require_once __DIR__ . '/../../config.php';
global $CFG;
include_once $CFG->dirroot . '/blocks/glsubs/classes/block_glsubs_form.php';

/** @noinspection PhpIllegalPsrClassPathInspection */

class block_glsubs extends block_base
{
    /**
     * Glossary Subscriptions Block Frontend Controller Presenter
     * Sept 2016
     * QM+
     * vasileios
     */

    public static $old_error_handler;

    /**
     * Method           init
     *
     * Purpose          initalise the class, set its title
     *
     * Parameters            N/A
     *
     * Returns           N/A
     *
     * Notes            Method must be declared, as it is defined abstract
     *                  title should be defined as it used by the Moodle system for the administration pages
     */
    public function init()
    {
        // set the title of this plugin
        $this->title = get_string('pluginname', 'block_glsubs');
//        block_glsubs::$old_error_handler = set_error_handler("block_glsubs::exception_error_handler");
//        error_reporting(E_ALL);
    }

    /**
     * Method               exception_error_handler
     *
     * Purpose              Used for debugging, capturing exceptions and throwing errors
     *                      It might not be compatible for the PHP 7 version, as it uses a Throwable parameter
     *
     * Parameters
     * @param               $errno ,  error number
     * @param               $errstr , error message
     * @param               $errfile , error file
     * @param               $errline , error code line
     *
     * Returns              N/A
     *
     * Notes                Method must be declared, as it is defined abstract
     *                      title should be defined as it used by the Moodle system for the administration pages
     *
     *
     * @throws              ErrorException
     */
    public static function exception_error_handler($errno, $errstr, $errfile, $errline)
    {
//        debug_print_backtrace();
        block_glsubs::$old_error_handler = set_error_handler(block_glsubs::$old_error_handler);
        throw new ErrorException($errstr, $errno, 0, $errfile, $errline);
    }

    /**
     * Method               applicable_formats
     *
     * Purpose              Set the default block configuration of on which type of pages to be viewable
     *
     * Parameters           N/A
     *
     * Returns             array('all' => true)
     * @return array
     * Notes                make this plugin available to all pages
     *                      avoid the configuration step of making it available to all glossary view pages manually
     */
    public function applicable_formats()
    {
        return array('all' => TRUE);
    }

    /**
     * Method               currentPageURL
     *
     * Purpose              Get the glossary view page URL with its parameters, to use it as the form action target
     *                      Used to associate the current page with the form action target,
     *                      so it returns to the same page after submit
     *
     * Parameters           N/A
     *
     * Returns              Return the current page URL
     * @return              string Get URL of the glossary view page
     *
     * Notes                It is the safest method to set the plugin form action target ,
     *                      so after submission, it will return to the same page
     *
     */
    private function currentPageURL()
    {
        $pageURL = 'http';
        if (array_key_exists('HTTPS', $_SERVER) && $_SERVER['HTTPS'] === 'on') {
            $pageURL .= 's';
        }
        $pageURL .= '://';
        if ($_SERVER['SERVER_PORT'] !== '80') {
            $pageURL .= $_SERVER['SERVER_NAME'] . ':' . $_SERVER['SERVER_PORT'] . $_SERVER['REQUEST_URI'];
        } else {
            $pageURL .= $_SERVER['SERVER_NAME'] . $_SERVER['REQUEST_URI'];
        }

        $pageurlparts = explode('?', $pageURL);
        $pageurlparts['protocol'] = explode('://', $pageurlparts[0])[0];
        $pageurlparts['host'] = explode('/', explode('://', $pageurlparts[0])[1])[0];
        $pageurlparts['pagepath'] = explode($pageurlparts['host'], explode('://', $pageurlparts[0])[1])[1];
        if (isset($pageurlparts[1])) {
            foreach (explode('&', $pageurlparts[1]) as $key => $parameterset) {
                $keyValueArray = explode('=', $parameterset);
                if (array_key_exists(0, $keyValueArray)) {
                    $param = $keyValueArray[0];
                } else {
                    $param = '';
                }
                if (array_key_exists(1, $keyValueArray)) {
                    $value = $keyValueArray[1];
                } else {
                    $value = '';
                }
                $pageurlparts['parameters'][$param] = $value;
            }
        }
        if (count($_REQUEST) > 0) {
            foreach ($_REQUEST as $param => $value) {
                $pageurlparts['parameters'][$param] = $value;
            }
        }

        $pageurlparts['fullurl'] = $pageURL;

        return $pageurlparts;
    }

    /**
     * Method               get_latest_messages
     *
     * Purpose              Get a batch of the latest messages for the user, to show at the top of the block
     *
     * Parameters
     * @param               $glossaryid , the glossary id to identify the relevant messages for the user
     *
     * Returns
     * @return              array , of message objects
     */
    protected function get_latest_messages($glossaryid)
    {
        global $DB, $USER;
        $messages = array();
        $glsubs_settings = get_config('block_glsubs');
        $messages_count = (int)$glsubs_settings->messagestoshow;
        try {
            $sql = 'SELECT l.id , l.userid , l.eventlogid , l.timecreated , l.timedelivered 
FROM {block_glsubs_messages_log} AS l 
JOIN {block_glsubs_event_subs_log} AS e ON l.eventlogid = e.id 
WHERE l.userid = :userid AND e.glossaryid = :glossaryid AND l.timedelivered IS NULL 
ORDER BY l.id';
            $messages = $DB->get_records_sql($sql, array('userid' => (int)$USER->id, 'glossaryid' => $glossaryid), 0, $messages_count);
            // if there are no unread messages show the latest read
            if (count($messages) === 0) {
                $sql = 'SELECT l.* FROM {block_glsubs_messages_log} l ';
                $sql .= 'JOIN {block_glsubs_event_subs_log} e ON e.id = l.eventlogid AND e.glossaryid = :glossaryid ';
                $sql .= ' WHERE l.userid = :userid ORDER BY l.id DESC ';
                $messages = $DB->get_records_sql($sql, array('userid' => (int)$USER->id, 'glossaryid' => $glossaryid), 0, $messages_count);
            }
        } catch (\Throwable $exception) {
            error_log('ERROR: glsubs get_latest_messages ' . $exception->getMessage());
            return $messages;
        }

        if (count($messages) > 0) {
            foreach ($messages as $key => & $message) {
                try {
                    $message->event = $DB->get_record('block_glsubs_event_subs_log', array('id' => (int)$message->eventlogid));
                    $message->date = date('Y-m-d H:i:s', (int)$message->event->timecreated);
                    $message->user = $DB->get_record('user', array('id' => (int)$message->event->userid));
                    $message->author = $DB->get_record('user', array('id' => (int)$message->event->authorid));
                } catch (\Throwable $exception) {
                    $this->content->text .= '<strong>' . get_string('block_could_not_access', 'block_glsubs') . $glsubs_settings->messagestoshow . get_string('block_most_recent', 'block_glsubs') . '</strong>';
                }
            }
        }
        return $messages;
    }

    /**
     * Method               show_messages
     *
     * Purpose              if enabled show the relevant glossary event messages for the user of the current glossary
     *
     * Parameters
     * @param               $glossaryid , the glossary id to identify the relevant messages for the user
     *
     * Returns              outputs the message links directly to the block
     */
    private function show_messages($glossaryid)
    {
        global $DB, $USER;
        // get the block settings from its configuration
        $glsubs_settings = get_config('block_glsubs');
        $messages_count = (int)$glsubs_settings->messagestoshow;
        // $msg_link = '';
        try {
            $msg_link = html_writer::link(new moodle_url('/message/index.php', array('user1' => $USER->id, 'viewing' => 'recentnotifications')), get_string('goto_messages', 'block_glsubs'));
        } catch (\Throwable $exception) {
            error_log('ERROR: glsubs show_messages ' . $exception->getMessage());
            $msg_link = '';
        }
        // $this->content->text .= '<br/>' . $msg_link . '<br/>' ;
        if ((int)$glsubs_settings->messagestoshow > 0) {
            $messages = $this->get_latest_messages($glossaryid);
            try {
                // read how many unread messages exist for this glossary
                $sql = 'SELECT l.id , l.userid , l.eventlogid , l.timecreated ,l.timedelivered FROM {block_glsubs_messages_log} AS l 
JOIN {block_glsubs_event_subs_log} AS e ON l.eventlogid = e.id  
WHERE l.userid = :userid AND e.glossaryid = :glossaryid AND l.timedelivered IS NULL 
ORDER BY l.id';
                $cmessages = $DB->get_records_sql($sql, array('userid' => (int)$USER->id, 'glossaryid' => $glossaryid), 0, $messages_count);
                $counter = count($cmessages);
                // release memory now
                $cmessages = NULL;
                $unread = ($counter > 0);
            } catch (\Throwable $exception) {
                error_log('ERROR: glsubs show_messages ' . $exception->getMessage());
                $unread = FALSE;
            }

            // Create a toggle mechanism for showing or hiding the recent messages
            if (count($messages) > 0) {
                $this->page->requires->jquery();
                $javascriptswitch = <<<JSC
<script>
    $( document ).ready(function(){
          $("#glossarymessagesshowhide").click(function(){
              $("#glossarymessagesblocktable").toggle();  
              $("#glossarymessagesshowhide").toggle();  
              $("#glossarymessagesshowhide_2").toggle();
         });
        $("#glossarymessagesshowhide_2").click(function(){
            $("#glossarymessagesblocktable").toggle();
            $("#glossarymessagesshowhide").toggle();
            $("#glossarymessagesshowhide_2").toggle();
        });
     }) ; 
</script>
JSC;
                $this->content->text .= '<div id="glossarymessagesblock">';
                $this->content->text .= '<span id="glossarymessagesshowhide">';
                $this->content->text .= get_string('view_show_hide', 'block_glsubs');
                $this->content->text .= '</span>'; // id="glossarymessagesshowhide"
                $this->content->text .= '<span id="glossarymessagesshowhide_2" style="display: none ;">';

                $this->content->text .= get_string('view_show_hide_2', 'block_glsubs');
                $this->content->text .= '</span>'; // id="glossarymessagesshowhide"

                $this->content->text .= get_string('block_found', 'block_glsubs') . count($messages);
                $link = html_writer::link(new moodle_url('/message/index.php', array()), $unread ? get_string('block_unread_messages', 'block_glsubs') : get_string('block_read_messages', 'block_glsubs'));
                $this->content->text .= $link;
                $this->content->text .= '<br/>';

                $this->content->text .= '<div id="glossarymessagesblocktable" style="display: none ;">';


                $this->content->text .= '<table id="glossarymessagestable"><thead><tr>';
                $this->content->text .= '<th>' . get_string('view_when', 'block_glsubs') . '</th>';
                $this->content->text .= '<th>&nbsp;</th>';
                $this->content->text .= '</th><th>' . get_string('view_by_user', 'block_glsubs') . '</th>';
                $this->content->text .= '<th>&nbsp;</th>';
                $this->content->text .= '<th>' . get_string('view_on_concept', 'block_glsubs') . '</th></tr></thead><tbody>';
                foreach ($messages as $key => $message) {
                    // if there is a concept asociated with this et its name
                    if ((int)$message->event->conceptid > 0) {
                        try {
                            $record = $DB->get_record('glossary_entries', array('id' => (int)$message->event->conceptid));
                            $name = $record->concept;
                            // in case of deleted concept attempt to get it from the message
                            if (is_null($name)) {
                                $name = $this->get_entry($message->event->eventtext);
                            }
                        } catch (\Throwable $exception) {
                            error_log('ERROR: glsubs show_messages ' . $exception->getMessage());
                            $name = '';
                        }
                    } else { // else if there is a category associated with it get its name
                        try {
                            $record = $DB->get_record('glossary_categories', array('id' => (int)$message->event->categoryid));
                            $name = $record->name;
                            if (is_null($name)) {
                                $name = $this->get_category($message->event->eventtext);
                            }
                        } catch (\Throwable $exception) {
                            error_log('ERROR: glsubs show_messages ' . $exception->getMessage());
                            $name = '';
                        }
                    }
                    try {
                        $link = html_writer::link(new moodle_url('/blocks/glsubs/view.php', array('id' => $key)), substr($message->date, 0, 10), array('title' => $message->date . chr(13) . strip_tags($message->event->eventtext), 'font-size' => '90%;'));
                    } catch (\Throwable $exception) {
                        error_log('ERROR: glsubs show_messages ' . $exception->getMessage());
                        $link = '';
                    }
                    $this->content->text .= '<tr><td>' . $link . '</td>';
                    $this->content->text .= '<td>&nbsp;</td>';
                    $this->content->text .= '<td title="' . fullname($message->user) . '"> ' . $this->ellipsisString(fullname($message->user), 20) . '</td>';
                    $this->content->text .= '<td>&nbsp;</td>';
                    $this->content->text .= '<td title="' . $name . '">' . $this->ellipsisString($name, 18) . '</td></tr>';
                }
                $this->content->text .= '</tbody></table><hr style="visibility: visible !important; display: inline !important;"/>';


                $this->content->text .= '</div>'; // id="glossarymessagesblocktable"
                $this->content->text .= '</div>'; // id="glossarymessagesblock"
                $this->content->text .= $javascriptswitch;
            }
        }
    }


    /**
     * Method               get_category
     *
     * Purpose              Identify and return the message category(ies) in the message text
     *
     * Parameters
     * @param               $message_text , the message text
     *
     * Returns
     *
     * @return              mixed|string, either an empty string , either the category(ies) identified as text
     *
     */
    private function get_category($message_text)
    {
        $ret = '';
        $msg_parts = explode('<br />', $message_text);
        foreach ($msg_parts as $key => & $msg_part) {
            $msg_part = strip_tags($msg_part);
            if (stripos($msg_part, 'Category(ies)  ') !== FALSE) {
                $ret = str_ireplace('Category(ies)  ', '', $msg_part);
                // $ret = str_ireplace(']','',$ret);
                $ret = str_ireplace("\n", '', $ret);
            }
        }
        return $ret;

    }

    /**
     * Method               get_entry
     *
     * Purpose              Identify and return the message concept in the message text
     *
     * Parameters
     * @param               $message_text , the message text
     *
     * Returns
     * @return              mixed|string, either an empty string , either the concept as text
     */
    private function get_entry($message_text)
    {
        $ret = '';
        $msg_parts = explode('<br />', $message_text);
        foreach ($msg_parts as $key => & $msg_part) {
            $msg_part = strip_tags($msg_part);
            if (stripos($msg_part, 'Concept [') !== FALSE) {
                $ret = str_ireplace('Concept [', '', $msg_part);
                $ret = str_ireplace(']', '', $ret);
                $ret = str_ireplace("\n", '', $ret);
            }
        }
        return $ret;
    }

    /**
     * Method               get_content
     *
     * Purpose              create all the block contents and present it
     *                      Subscriptions Block Contents creation function
     *
     * Parameters           N/A
     *
     * Returns
     * @return              string, as HTML content for the block
     *
     */
    public function get_content()
    {
        /** @var stdClass $this */
        // define usage of global variables
        global $PAGE, $COURSE;// , $DB , $CFG ; // $USER, $SITE , $OUTPUT, $THEME, $OUTPUT ;

        // Check if the page is referring to a glossary module view activity
        if ('mod-glossary-view' !== $PAGE->pagetype) {
            return $this->content;
        }


        if (NULL !== $this->title) {
            $this->title = get_string('blockheader', 'block_glsubs');
        }

        // if the contents are already set, just return them
        if ($this->content !== NULL) {
            return $this->content;
        }

        // this is only for logged in users
        if (!isloggedin() || isguestuser()) {
            return '';
        }

        // get the current moodle configuration
        require_once __DIR__ . '/../../config.php';

        // this is only for logged in users
        require_login();

        // get the module information
        $courseinfo = get_fast_modinfo($COURSE);

        // prapare for contents
        $this->content = new stdClass;
        $this->content->text = '';
        $this->content->text .= '<strong>' . $PAGE->title . '</strong>';

        // add a footer for the block
        $this->content->footer = '<hr style="display: block!important;"/><div style="text-align:center;">' . get_string('blockfooter', 'block_glsubs') . '</div>';


        // get the id parameter if exists
        $cmid = optional_param('id', 0, PARAM_INT);

        // check if there is a valid glossary view page
        if ($cmid > 0) {
            // set page context
            $PAGE->set_context(context_module::instance($cmid));
            try {
                if ($courseinfo->get_cm($cmid)) {
                    $cm = $courseinfo->get_cm($cmid);
                } else {
                    return $this->content;
                }
            } catch (Throwable $e) {
                error_log('ERROR: glsubs get_content glsubs messages ' . $e->getMessage());
                return $this->content;
            }

            // Check if the course module is available and it is visible and it is visible to the user and it is a glossary module
            if (!(TRUE === $cm->available && '1' === $cm->visible && TRUE === $cm->uservisible && 'glossary' === $cm->modname)) {
                return $this->content;
            }

            // get glossary ID
            $glossaryid = (int)$cm->instance;

            // show unread messages
            $this->show_messages($glossaryid);

            // create a glossary subscriptions block form and assign its action to the original page
            $subscriptions_form = new block_glsubs_form($this->currentPageURL()['fullurl']);
            // test for the form status , do kee the order of cancelled, submitted, new
            if ($subscriptions_form->is_cancelled()) {
                // redirect to the original page where the Cancel button was pressed, so use the $_SERVER['HTTP_REFERER'] variable
                try {
                    $url = new moodle_url($_SERVER['HTTP_REFERER'], array());
                    redirect($url);
                } catch (Throwable $e) {
                    header('Location: ' . $_SERVER['HTTP_REFERER']);
                }
            } elseif ($subscriptions_form->is_submitted()) {
                // $this->content->text .= '<br/><u>Submitted form</u><br/>';
                $subs_data = $subscriptions_form->get_data();
                if ($subs_data) {
                    // store this data set
                    try {
                        $errors = $this->store_data($subs_data);
                    } catch (\Throwable $exception) {
                        $errors = new \stdClass();
                        $errors->messages[] = 'ERROR: glsubs get_content while attempting to save data ' . $exception->getMessage();
                    }

                    // if there were any errors, display them
                    if (is_array($errors->messages)) {
                        foreach ($errors->messages as $key => $errmsg) {
                            $this->content->text .= '<p>ERROR: glsubs ' . $errmsg . '</p>';
                        }
                    }
                }
            }

            // add the contents of the form to the block
            $this->content->text .= $subscriptions_form->render();
        }
        // Finish and return contents
        return $this->content;
    }

    /**
     * Method               store_data
     *
     * Purpose              Store the subscription preferences for the user on the current glossary
     *
     * Parameters
     * @param               $dataset , the data of the Moodle plugin form
     *
     * Returns
     * @return              null in case of success or stdClass of errors in case of errors
     */
    private function store_data($dataset)
    {
        global $DB;
        $error = new stdClass();
        $error->messages = [];
        $userid = $dataset->glossary_userid;
        $glossaryid = $dataset->glossary_glossaryid;
        $fullsubkey = get_string('glossaryformfullelementname', 'block_glsubs');
        $newcat = get_string('glossaryformcategorieselementname', 'block_glsubs');
        $newconcept = get_string('glossaryformconceptselementname', 'block_glsubs');
        $arrData = (array)$dataset;
        try {
            foreach ($arrData as $key => $value) {

                // if the data in the form is a glossary comment subscription instruction then
                if ($key === $fullsubkey) {
                    if ($DB->record_exists('block_glsubs_glossaries_subs', array('userid' => $userid, 'glossaryid' => $glossaryid))) {
                        $oldrecord = $DB->get_record('block_glsubs_glossaries_subs', array('userid' => $userid, 'glossaryid' => $glossaryid));
                        $oldrecord->active = $value;
                        $DB->update_record('block_glsubs_glossaries_subs', $oldrecord, FALSE);
                    } else {
                        $newrecord = new stdClass();
                        $newrecord->userid = $userid;
                        $newrecord->glossaryid = $glossaryid;
                        $newrecord->active = $value;
                        $newrecord->newcategories = 0;
                        $newrecord->newentriesuncategorised = 0;
                        $newentryid = $DB->insert_record('block_glsubs_glossaries_subs', $newrecord, TRUE, TRUE); // use bulk updates
                        if (!$newentryid > 0) {
                            $error->messages[] = "Cannot create new full subscription record for $userid on glossary $glossaryid ";
                        }
                    }
                    // $msg = 'glossaries table full subscription';
                    // if the data in the form is a new categories subscription instruction then
                } elseif ($key === $newcat) {
                    if ($DB->record_exists('block_glsubs_glossaries_subs', array('userid' => $userid, 'glossaryid' => $glossaryid))) {
                        $oldrecord = $DB->get_record('block_glsubs_glossaries_subs', array('userid' => $userid, 'glossaryid' => $glossaryid));
                        $oldrecord->newcategories = $value;
                        $DB->update_record('block_glsubs_glossaries_subs', $oldrecord, FALSE);
                    } else {
                        $newrecord = new stdClass();
                        $newrecord->userid = $userid;
                        $newrecord->glossaryid = $glossaryid;
                        $newrecord->active = 0;
                        $newrecord->newcategories = $value;
                        $newrecord->newentriesuncategorised = 0;
                        $newentryid = $DB->insert_record('block_glsubs_glossaries_subs', $newrecord, TRUE, TRUE); // use bulk updates
                        if (!$newentryid > 0) {
                            $error->messages[] = "Cannot create new new categories subscription record for $userid on glossary $glossaryid ";
                        }
                    }
                    // $msg = 'glossaries table new categories subscription';
                    // if the data in the form is a new uncategorised consepts sbscription instruction then
                } elseif ($key === $newconcept) {
                    if ($DB->record_exists('block_glsubs_glossaries_subs', array('userid' => $userid, 'glossaryid' => $glossaryid))) {
                        $oldrecord = $DB->get_record('block_glsubs_glossaries_subs', array('userid' => $userid, 'glossaryid' => $glossaryid));
                        $oldrecord->newentriesuncategorised = $value;
                        $DB->update_record('block_glsubs_glossaries_subs', $oldrecord, FALSE);
                    } else {
                        $newrecord = new stdClass();
                        $newrecord->userid = $userid;
                        $newrecord->glossaryid = $glossaryid;
                        $newrecord->active = 0;
                        $newrecord->newcategories = 0;
                        $newrecord->newentriesuncategorised = $value;
                        $newentryid = $DB->insert_record('block_glsubs_glossaries_subs', $newrecord, TRUE, TRUE); // use bulk updates
                        if (!$newentryid > 0) {
                            $error->messages[] = "Cannot create new uncategorised concepts subscription record for $userid on glossary $glossaryid ";
                        }
                    }
                    // $msg = 'glossaries table new concepts no category subscription';
                    // if the data inthe form is a category subscription instruction then
                } elseif (0 === strpos($key, 'glossary_category')) {
//            } elseif ( substr($key,0,17) === 'glossary_category'){
                    $categoryid = (int)preg_replace('/[^0-9,.]/', '', $key);

                    if ($DB->record_exists('block_glsubs_categories_subs', array('userid' => $userid, 'glossaryid' => $glossaryid, 'categoryid' => $categoryid))) {
                        $old_category_record = $DB->get_record('block_glsubs_categories_subs', array('userid' => $userid, 'glossaryid' => $glossaryid, 'categoryid' => $categoryid));
                        $old_category_record->active = $value;
                        $DB->update_record('block_glsubs_categories_subs', $old_category_record, FALSE);
                    } else {
                        $newrecord = new stdClass();
                        $newrecord->userid = $userid;
                        $newrecord->glossaryid = $glossaryid;
                        $newrecord->categoryid = (int)preg_replace('/[^0-9,.]/', '', $key);
                        $newrecord->active = $value;
                        $newentryid = $DB->insert_record('block_glsubs_categories_subs', $newrecord, TRUE, TRUE); //use bulk updates
                        if (!$newentryid > 0) {
                            $error->messages[] = "Cannot create new category subscription record for $userid on glossary $glossaryid and category $key";
                        }
                    }
                    // $msg = "categories table $categoryid ";
                    // if the data in the form is a concept subscription instruction then
                } elseif (0 === strpos($key, 'glossary_concept')) {
//            } elseif ( substr($key,0,16) === 'glossary_concept') {
                    $conceptid = (int)preg_replace('/[^0-9,.]/', '', $key);
                    if ($DB->record_exists('block_glsubs_concept_subs', array('userid' => $userid, 'glossaryid' => $glossaryid, 'conceptid' => $conceptid))) {
                        $oldrecord = $DB->get_record('block_glsubs_concept_subs', array('userid' => $userid, 'glossaryid' => $glossaryid, 'conceptid' => $conceptid));
                        $oldrecord->conceptactive = $value;
                        $DB->update_record('block_glsubs_concept_subs', $oldrecord, FALSE);
                    } else {
                        $newrecord = new stdClass();
                        $newrecord->userid = $userid;
                        $newrecord->glossaryid = $glossaryid;
                        $newrecord->conceptid = $conceptid;
                        $newrecord->conceptactive = $value;
                        $newrecord->commentsactive = 0;
                        $newentryid = $DB->insert_record('block_glsubs_concept_subs', $newrecord, TRUE, TRUE); // use bulk updates
                        if (!$newentryid > 0) {
                            $error->messages[] = "Cannot create new concept subscription record for $userid on glossary $glossaryid and concept $key ";
                        }
                    }
                    // $msg = 'concepts table';
                    // if the data in the form is a concept comments subscription instruction then
                } elseif (0 === strpos($key, 'glossary_comment')) {
//            } elseif ( substr($key ,0  ,16) === 'glossary_comment') {
                    $conceptid = (int)preg_replace('/[^0-9,.]/', '', $key);
                    if ($DB->record_exists('block_glsubs_concept_subs', array('userid' => $userid, 'glossaryid' => $glossaryid, 'conceptid' => $conceptid))) {
                        $oldrecord = $DB->get_record('block_glsubs_concept_subs', array('userid' => $userid, 'glossaryid' => $glossaryid, 'conceptid' => $conceptid));
                        $oldrecord->commentsactive = $value;
                        $DB->update_record('block_glsubs_concept_subs', $oldrecord, FALSE);
                    } else {
                        $newrecord = new stdClass();
                        $newrecord->userid = $userid;
                        $newrecord->glossaryid = $glossaryid;
                        $newrecord->conceptid = $conceptid;
                        $newrecord->conceptactive = 0;
                        $newrecord->commentsactive = $value;
                        $newentryid = $DB->insert_record('block_glsubs_concept_subs', $newrecord, TRUE, TRUE); // use bulk updates
                        if (!$newentryid > 0) {
                            $error->messages[] = "Cannot create new concept comments subscription record for $userid on glossary $glossaryid and concept $key ";
                        }
                    }
                    // $msg = 'concepts table for comments';
                    // if the data in the form is an author subscription instruction then
                } elseif (0 === strpos($key, 'glossary_author')) {
//            } elseif ( substr($key ,0  ,15) === 'glossary_author') {
                    $authorid = (int)preg_replace('/[^0-9,.]/', '', $key);
                    if ($DB->record_exists('block_glsubs_authors_subs', array('userid' => $userid, 'glossaryid' => $glossaryid, 'authorid' => $authorid))) {
                        // $oldrecord = new stdClass();
                        $oldrecord = $DB->get_record('block_glsubs_authors_subs', array('userid' => $userid, 'glossaryid' => $glossaryid, 'authorid' => $authorid));
                        $oldrecord->active = $value;
                        $DB->update_record('block_glsubs_authors_subs', $oldrecord, FALSE);
                        // $msg = 'active author subscription';
                    } else {
                        $newrecord = new stdClass();
                        $newrecord->userid = $userid;
                        $newrecord->glossaryid = $glossaryid;
                        $newrecord->authorid = $authorid;
                        $newrecord->active = $value;
                        $newentryid = $DB->insert_record('block_glsubs_authors_subs', $newrecord, TRUE, TRUE); // use bulk updates
                        if (!$newentryid > 0) {
                            $error->messages[] = "Cannot create new author subscription record for $userid on glossary $glossaryid and author $authorid ";
                        }
                    }
                    // $msg = 'concepts table for authors';
                }
                // if there is a message to show then add it to the messages
                /*            if(! is_null($msg)){
                                $m[$key] = $msg . " $key = $value";
                                $msg = NULL;
                            }*/
            }
        } catch (\Throwable $exception) {
            $error->messages[] = 'ERROR: glsubs while attempting to store data ' . $exception->getMessage();
        }

        // what to report at the end ?
        if (count($error->messages) > 0) {
            return $error;
        } else {
            return NULL;
        }
    }

    /**
     * Method               instance_allow_multiple
     *
     * Purpose              enable only one instance per page to associate with the viewable glossary
     *
     * Parameters           N/A
     *
     * Returns
     * @return              bool , false to disable multiple instances of the block on one page
     *
     */
    public function instance_allow_multiple()
    {
        return FALSE;
    }

    /**
     * Method               has_config
     *
     * Purpose              This function is required by Moodle to overide the default inherited function and to
     *                      return true in order to be able to store and use relevant universal plugin settings.
     *                      If you need more fine grained settings such as user or role or other classification
     *                      you must provide a set of database structures and their associated business logic
     *
     * Parameters           N/A
     *
     * Returns
     * @return              bool, true as this block has an administration settings functionality
     */
    public function has_config()
    {
        return parent::has_config() || TRUE;
    }

    /****************************************************************
     *
     * Method:       ellipsisString
     *
     * Purpose:      Create short form of a string including ellipsis (...)
     *              if required. Used for making use in narrow elements of
     *              the web screens
     *
     * Parameters:   $text , the text (any bytes form), $size , the legnth to cut off
     *
     * Returns:      the shortened text version plus optional ellipsis
     ****************************************************************
     * Reduce text to the maximum parameterised length
     * @param $text
     * @param $size
     *
     * @return string
     */
    protected function ellipsisString($text, $size)
    {
        $retstr = $text;
        if ($size < 1) {
            $size = 3;
        }
        if ($this->is_multibyte($text)) {
            if (mb_strlen($text) > $size) {
                $retstr = mb_substr($retstr, 0, $size - 3) . '...';
            }
        } else {
            if (strlen($text) > $size) {
                $retstr = substr($retstr, 0, $size - 3) . '...';
            }
        }
        return $retstr;
    }

    /****************************************************************
     *
     * Method:       is_multibyte
     *
     * Purpose:     checks if the text contains mutli byte characters
     *
     *
     *
     * Parameters:   $s , the text (any bytes form)
     *
     * Returns:      true if at least one character is multi byte
     ****************************************************************
     * check for multibyte strings
     */
    protected function is_multibyte($s)
    {
        return mb_strlen($s, 'utf-8') < strlen($s);
    }

}