Implemented export.php

_export_form.php

@@ -1,118 +0,0 @@
-<?php  // $Id: export_form.php,v 1.2.2.3 2009/03/11 18:17:38 dlnsk Exp $
-
-require_once($CFG->libdir.'/formslib.php');
-
-class mod_attforblock_export_form extends moodleform {
-
-    function definition() {
-
-        global $CFG, $USER;
-        $mform    =& $this->_form;
-
-        $course        = $this->_customdata['course'];
-        $cm            = $this->_customdata['cm'];
-//        $coursecontext = $this->_customdata['coursecontext'];
-        $modcontext    = $this->_customdata['modcontext'];
-//        $forum         = $this->_customdata['forum'];
-//        $post          = $this->_customdata['post']; // hack alert
-
-
-        $mform->addElement('header', 'general', get_string('export','quiz'));
-		$mform->setHelpButton('general', array('export', get_string('export','quiz'), 'attforblock'));
-		
-//        $mform->addElement('date_selector', 'sessiondate', get_string('sessiondate','attforblock'));
-		$groupmode=groups_get_activity_groupmode($cm);
-        $groups = groups_get_activity_allowed_groups($cm, $USER->id);
-		if ($groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $modcontext)) {
-			$grouplist[0] = get_string('allparticipants');
-		}
-		if ($groups) {
-            foreach ($groups as $group) {
-                $grouplist[$group->id] = $group->name;
-            }
-        }
-        $mform->addElement('select', 'group', get_string('group'), $grouplist);
-        
-        $ident = array();
-        $ident[] =& MoodleQuickForm::createElement('checkbox', 'id', '', get_string('studentid', 'attforblock'));
-        $ident[] =& MoodleQuickForm::createElement('checkbox', 'uname', '', get_string('username'));
-        $mform->addGroup($ident, 'ident', get_string('identifyby','attforblock'), array('<br />'), true);
-        $mform->setDefaults(array('ident[id]' => true, 'ident[uname]' => true));
-        
-        
-        
-        
-
-//        for ($i=0; $i<=23; $i++) {
-//            $hours[$i] = sprintf("%02d",$i);
-//        }
-//        for ($i=0; $i<60; $i+=5) {
-//            $minutes[$i] = sprintf("%02d",$i);
-//        }
-//        $stime = array();
-//        $stime[] =& MoodleQuickForm::createElement('select', 'hours', get_string('hour', 'form'), $hours, false, true);
-//		$stime[] =& MoodleQuickForm::createElement('select', 'minutes', get_string('minute', 'form'), $minutes, false, true);
-//        $mform->addGroup($stime, 'stime', get_string('sessionstarttime','attforblock'), array(' '), true);
-        
-//        $durtime = array();
-//        $durtime[] =& MoodleQuickForm::createElement('select', 'hours', get_string('hour', 'form'), $hours, false, true);
-//		$durtime[] =& MoodleQuickForm::createElement('select', 'minutes', get_string('minute', 'form'), $minutes, false, true);
-//        $mform->addGroup($durtime, 'durtime', get_string('duration','attforblock'), array(' '), true);
-        
-        $mform->addElement('checkbox', 'includeallsessions', get_string('includeall','attforblock'), get_string('yes'));
-        $mform->setDefault('includeallsessions', true);
-        $mform->addElement('checkbox', 'includenottaken', get_string('includenottaken','attforblock'), get_string('yes'));
-        $mform->addElement('date_selector', 'sessionstartdate', get_string('startofperiod','attforblock'));
-        $mform->setDefault('sessionstartdate', $course->startdate);
-        $mform->disabledIf('sessionstartdate', 'includeallsessions', 'checked');
-        $mform->addElement('date_selector', 'sessionenddate', get_string('endofperiod','attforblock'));
-	$mform->disabledIf('sessionenddate', 'includeallsessions', 'checked');
-        
-        $mform->addElement('select', 'format', get_string('format'), 
-        					array('excel' => get_string('downloadexcel','attforblock'),
-        						  'ooo' => get_string('downloadooo','attforblock'),
-        						  'text' => get_string('downloadtext','attforblock')
-        					));
-        					
-//        $opts = array();
-//        $opts[] =& MoodleQuickForm::createElement('checkbox', 'Mon', '', get_string('monday','calendar'));
-////        $opts[] =& MoodleQuickForm::createElement('checkbox', 'Tue', '', get_string('tuesday','calendar'));
-////        $opts[] =& MoodleQuickForm::createElement('checkbox', 'Wed', '', get_string('wednesday','calendar'));
-////        $opts[] =& MoodleQuickForm::createElement('checkbox', 'Thu', '', get_string('thursday','calendar'));
-////        $opts[] =& MoodleQuickForm::createElement('checkbox', 'Fri', '', get_string('friday','calendar'));
-////        $opts[] =& MoodleQuickForm::createElement('checkbox', 'Sat', '', get_string('saturday','calendar'));
-//        $mform->addGroup($opts, 'opts', get_string('sessiondays','attforblock'), array(' '), true);
-//		$mform->disabledIf('opts', 'addmultiply', 'notchecked');
-//        
-//        $period = array(1=>1,2,3,4,5,6,7,8);
-//        $periodgroup = array();
-//        $periodgroup[] =& MoodleQuickForm::createElement('select', 'period', '', $period, false, true);
-//        $periodgroup[] =& MoodleQuickForm::createElement('static', 'perioddesc', '', get_string('week','attforblock'));
-//        $mform->addGroup($periodgroup, 'periodgroup', get_string('period','attforblock'), array(' '), false);
-//		$mform->disabledIf('periodgroup', 'addmultiply', 'notchecked');
-//        
-//        $mform->addElement('text', 'sdescription', get_string('description', 'attforblock'), 'size="48"');
-//        $mform->setType('sdescription', PARAM_TEXT);
-//        $mform->addRule('sdescription', get_string('maximumchars', '', 100), 'maxlength', 100, 'client'); 
-		
-//-------------------------------------------------------------------------------
-        // buttons
-        $submit_string = get_string('ok');
-        $this->add_action_buttons(false, $submit_string);
-
-        $mform->addElement('hidden', 'id', $cm->id);
-//        $mform->addElement('hidden', 'action', 'add');
-
-    }
-
-//    function validation($data, $files) {
-//        $errors = parent::validation($data, $files);
-//        if (($data['timeend']!=0) && ($data['timestart']!=0)
-//            && $data['timeend'] <= $data['timestart']) {
-//                $errors['timeend'] = get_string('timestartenderror', 'forum');
-//            }
-//        return $errors;
-//    }
-
-}
-?>

export.php

@@ -0,0 +1,193 @@
+<?php
+
+/**
+ * Export attendance sessions
+ *
+ * @package    mod
+ * @subpackage attforblock
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+
+require_once(dirname(__FILE__).'/../../config.php');
+require_once(dirname(__FILE__).'/locallib.php');
+require_once(dirname(__FILE__).'/export_form.php');
+require_once(dirname(__FILE__).'/renderables.php');
+require_once(dirname(__FILE__).'/renderhelpers.php');
+
+$id             = required_param('id', PARAM_INT);
+
+$cm             = get_coursemodule_from_id('attforblock', $id, 0, false, MUST_EXIST);
+$course         = $DB->get_record('course', array('id' => $cm->course), '*', MUST_EXIST);
+$att            = $DB->get_record('attforblock', array('id' => $cm->instance), '*', MUST_EXIST);
+
+require_login($course, true, $cm);
+
+$att = new attforblock($att, $cm, $course, $PAGE->context);
+
+$att->perm->require_export_capability();
+
+$PAGE->set_url($att->url_export());
+$PAGE->set_title($course->shortname. ": ".$att->name);
+$PAGE->set_heading($course->fullname);
+$PAGE->set_cacheable(true);
+$PAGE->set_button($OUTPUT->update_module_button($cm->id, 'attforblock'));
+$PAGE->navbar->add(get_string('export', 'quiz'));
+
+$formparams = array('course' => $course, 'cm' => $cm, 'modcontext' => $PAGE->context);
+$mform = new mod_attforblock_export_form($att->url_export(), $formparams);
+
+if ($mform->is_submitted()) {
+    $formdata = $mform->get_data();
+
+    $pageparams = new att_page_with_filter_controls();
+    $pageparams->init($cm);
+    $pageparams->group = $formdata->group;
+    $pageparams->set_current_sesstype($formdata->group ? $formdata->group : att_page_with_filter_controls::SESSTYPE_ALL);
+    if (isset($formdata->includeallsessions)) {
+        if (isset($formdata->includenottaken)) {
+            $pageparams->view = VIEW_ALL;
+        } else {
+            $pageparams->view = VIEW_ALLPAST;
+            $pageparams->curdate = time();
+        }
+        $pageparams->init_start_end_date();
+    } else {
+        $pageparams->startdate = $formdata->sessionstartdate;
+        $pageparams->enddate = $formdata->sessionenddate;
+    }
+    $att->pageparams = $pageparams;
+
+    $reportdata = new attforblock_report_data($att);
+    if ($reportdata->users) {
+        $filename = clean_filename($course->shortname.'_Attendances_'.userdate(time(), '%Y%m%d-%H%M'));
+
+		$group = $formdata->group ? $reportdata->groups[$formdata->group] : 0;
+        $data->tabhead = array();
+        $data->course = $att->course->fullname;
+        $data->group = $group ? $group->name : get_string('allparticipants');
+
+        if (isset($formdata->ident['id'])) {
+            $data->tabhead[] = get_string('studentid', 'attforblock');
+        }
+        if (isset($formdata->ident['uname'])) {
+            $data->tabhead[] = get_string('username');
+        }
+        $data->tabhead[] = get_string('lastname');
+        $data->tabhead[] = get_string('firstname');
+
+
+        if (count($reportdata->sessions) > 0) {
+            foreach($reportdata->sessions as $sess) {
+                $text = userdate($sess->sessdate, get_string('strftimedmyhm', 'attforblock'));
+                $text .= ' ';
+                $text .= $sess->groupid ? $reportdata->groups[$sess->groupid]->name : get_string('commonsession', 'attforblock');
+                $data->tabhead[] = $text;
+            }
+        } else {
+            print_error('sessionsnotfound', 'attforblock', $att->url_manage());
+        }
+        if ($reportdata->gradable)
+            $data->tabhead[] = get_string('grade');
+
+        $i = 0;
+        $data->table = array();
+        foreach($reportdata->users as $user) {
+            if (isset($formdata->ident['id'])) {
+                $data->table[$i][] = $user->id;
+            }
+            if (isset($formdata->ident['uname'])) {
+                $data->table[$i][] = $user->username;
+            }
+            $data->table[$i][] = $user->lastname;
+            $data->table[$i][] = $user->firstname;
+            $cellsgenerator = new user_sessions_cells_text_generator($reportdata, $user);
+            $data->table[$i] = array_merge($data->table[$i], $cellsgenerator->get_cells());
+            if ($reportdata->gradable)
+                $data->table[$i][] = $reportdata->grades[$user->id].' / '.$reportdata->maxgrades[$user->id];
+            $i++;
+        }
+
+        if ($formdata->format === 'text') {
+            ExportToCSV($data, $filename);
+        } else {
+            ExportToTableEd($data, $filename, $formdata->format);
+        }
+        exit;
+    } else {
+        print_error('studentsnotfound', 'attendance', $att->url_manage());
+    }
+}
+
+$output = $PAGE->get_renderer('mod_attforblock');
+$tabs = new attforblock_tabs($att, attforblock_tabs::TAB_EXPORT);
+echo $output->header();
+echo $output->heading(get_string('attendanceforthecourse','attforblock').' :: ' .$course->fullname);
+echo $output->render($tabs);
+
+$mform->display();
+
+echo $OUTPUT->footer();
+
+
+function ExportToTableEd($data, $filename, $format) {
+	global $CFG;
+
+    if ($format === 'excel') {
+	    require_once("$CFG->libdir/excellib.class.php");
+	    $filename .= ".xls";
+	    $workbook = new MoodleExcelWorkbook("-");
+    } else {
+	    require_once("$CFG->libdir/odslib.class.php");
+	    $filename .= ".ods";
+	    $workbook = new MoodleODSWorkbook("-");
+    }
+/// Sending HTTP headers
+    $workbook->send($filename);
+/// Creating the first worksheet
+    $myxls =& $workbook->add_worksheet('Attendances');
+/// format types
+    $formatbc =& $workbook->add_format();
+    $formatbc->set_bold(1);
+
+    $myxls->write(0, 0, get_string('course'), $formatbc);
+    $myxls->write(0, 1, $data->course);
+    $myxls->write(1, 0, get_string('group'), $formatbc);
+    $myxls->write(1, 1, $data->group);
+
+    $i = 3;
+    $j = 0;
+    foreach ($data->tabhead as $cell) {
+    	$myxls->write($i, $j++, $cell, $formatbc);
+    }
+    $i++;
+    $j = 0;
+    foreach ($data->table as $row) {
+    	foreach ($row as $cell) {
+    		$myxls->write($i, $j++, $cell);
+    	}
+		$i++;
+		$j = 0;
+    }
+	$workbook->close();
+}
+
+function ExportToCSV($data, $filename) {
+    $filename .= ".txt";
+
+    header("Content-Type: application/download\n");
+    header("Content-Disposition: attachment; filename=\"$filename\"");
+    header("Expires: 0");
+    header("Cache-Control: must-revalidate,post-check=0,pre-check=0");
+    header("Pragma: public");
+
+    echo get_string('course')."\t".$data->course."\n";
+    echo get_string('group')."\t".$data->group."\n\n";
+
+    echo implode("\t", $data->tabhead)."\n";
+    foreach ($data->table as $row) {
+    	echo implode("\t", $row)."\n";
+    }
+}
+
+?>

export_form.php

@@ -0,0 +1,70 @@
+<?php  // $Id: export_form.php,v 1.2.2.3 2009/03/11 18:17:38 dlnsk Exp $
+
+require_once($CFG->libdir.'/formslib.php');
+
+class mod_attforblock_export_form extends moodleform {
+
+    function definition() {
+
+        global $CFG, $USER;
+        $mform    =& $this->_form;
+
+        $course        = $this->_customdata['course'];
+        $cm            = $this->_customdata['cm'];
+        $modcontext    = $this->_customdata['modcontext'];
+
+
+        $mform->addElement('header', 'general', get_string('export','quiz'));
+		
+		$groupmode=groups_get_activity_groupmode($cm);
+        $groups = groups_get_activity_allowed_groups($cm, $USER->id);
+		if ($groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $modcontext)) {
+			$grouplist[0] = get_string('allparticipants');
+		}
+		if ($groups) {
+            foreach ($groups as $group) {
+                $grouplist[$group->id] = $group->name;
+            }
+        }
+        $mform->addElement('select', 'group', get_string('group'), $grouplist);
+        
+        $ident = array();
+        $ident[] =& MoodleQuickForm::createElement('checkbox', 'id', '', get_string('studentid', 'attforblock'));
+        $ident[] =& MoodleQuickForm::createElement('checkbox', 'uname', '', get_string('username'));
+        $mform->addGroup($ident, 'ident', get_string('identifyby','attforblock'), array('<br />'), true);
+        $mform->setDefaults(array('ident[id]' => true, 'ident[uname]' => true));
+        
+        $mform->addElement('checkbox', 'includeallsessions', get_string('includeall','attforblock'), get_string('yes'));
+        $mform->setDefault('includeallsessions', true);
+        $mform->addElement('checkbox', 'includenottaken', get_string('includenottaken','attforblock'), get_string('yes'));
+        $mform->addElement('date_selector', 'sessionstartdate', get_string('startofperiod','attforblock'));
+        $mform->setDefault('sessionstartdate', $course->startdate);
+        $mform->disabledIf('sessionstartdate', 'includeallsessions', 'checked');
+        $mform->addElement('date_selector', 'sessionenddate', get_string('endofperiod','attforblock'));
+        $mform->disabledIf('sessionenddate', 'includeallsessions', 'checked');
+        
+        $mform->addElement('select', 'format', get_string('format'), 
+        					array('excel' => get_string('downloadexcel','attforblock'),
+        						  'ooo' => get_string('downloadooo','attforblock'),
+        						  'text' => get_string('downloadtext','attforblock')
+        					));
+        					
+        // buttons
+        $submit_string = get_string('ok');
+        $this->add_action_buttons(false, $submit_string);
+
+        $mform->addElement('hidden', 'id', $cm->id);
+
+    }
+
+//    function validation($data, $files) {
+//        $errors = parent::validation($data, $files);
+//        if (($data['timeend']!=0) && ($data['timestart']!=0)
+//            && $data['timeend'] <= $data['timestart']) {
+//                $errors['timeend'] = get_string('timestartenderror', 'forum');
+//            }
+//        return $errors;
+//    }
+
+}
+?>

locallib.php

@@ -240,7 +240,7 @@ class att_page_with_filter_controls {
                 $this->sesstype = $SESSION->attsessiontype[$this->cm->course];
             }
 
-            $this->calc_sessgroupslist();
+            if (is_null($this->sesstype)) $this->calc_sessgroupslist();
         } elseif ($this->selectortype == self::SELECTOR_GROUP) {
             if ($group == 0) {
                 $SESSION->attsessiontype[$this->cm->course] = self::SESSTYPE_ALL;
@@ -296,6 +296,10 @@ class att_page_with_filter_controls {
 
         return $this->sesstype;
     }
+
+    public function set_current_sesstype($sesstype) {
+        $this->sesstype = $sesstype;
+    }
 }
 
 class att_view_page_params extends att_page_with_filter_controls {

renderer.php

@@ -1,7 +1,7 @@
 <?php
 
 /**
- * Attendance module renderering methods are defined here
+ * Attendance module renderering methods
  *
  * @package    mod
  * @subpackage attforblock
@@ -12,6 +12,7 @@ defined('MOODLE_INTERNAL') || die();
 
 require_once(dirname(__FILE__).'/locallib.php');
 require_once(dirname(__FILE__).'/renderables.php');
+require_once(dirname(__FILE__).'/renderhelpers.php');
 
 /**
  * Attendance module renderer class
@@ -696,44 +697,8 @@ class mod_attforblock_renderer extends plugin_renderer_base {
 
             $row->cells[] = $this->output->user_picture($user);
             $row->cells[] = html_writer::link($reportdata->url_view(array('studentid' => $user->id)), fullname($user));
-
+            $cellsgenerator = new user_sessions_cells_html_generator($reportdata, $user);
-            $cell = null;
+            $row->cells = array_merge($row->cells, $cellsgenerator->get_cells());
-            foreach ($reportdata->sessions as $sess) {
-                if (array_key_exists($sess->id, $reportdata->sessionslog[$user->id])) {
-                    $statusid = $reportdata->sessionslog[$user->id][$sess->id]->statusid;
-                    if (array_key_exists($statusid, $reportdata->statuses)) {
-                        $row->cells[] = $reportdata->statuses[$statusid]->acronym;
-                    } else {
-                        $row->cells[] = html_writer::tag('s', $reportdata->allstatuses[$statusid]->acronym);
-                    }
-                } else {
-                    if ($user->enrolmentstart > $sess->sessdate) {
-                        $starttext = get_string('enrolmentstart', 'attforblock', userdate($user->enrolmentstart, '%d.%m.%Y'));
-                        $this->construct_report_cell($starttext, $cell);
-                    }
-                    elseif ($user->enrolmentend and $user->enrolmentend < $sess->sessdate) {
-                        $endtext = get_string('enrolmentend', 'attforblock', userdate($user->enrolmentend, '%d.%m.%Y'));
-                        $this->construct_report_cell($endtext, $cell);
-                    }
-                    // no enrolmentend and ENROL_USER_SUSPENDED
-                    elseif (!$user->enrolmentend and $user->enrolmentstatus == ENROL_USER_SUSPENDED) {
-                        $suspendext = get_string('enrolmentsuspended', 'attforblock', userdate($user->enrolmentend, '%d.%m.%Y'));
-                        $this->construct_report_cell($suspendext, $cell);
-                    }
-                    else {
-                        if ($cell) {
-                            $row->cells[] = $cell;
-                            $cell = null;
-                        }
-
-                        if ($sess->groupid == 0 or array_key_exists($sess->groupid, $reportdata->usersgroups[$user->id]))
-                            $row->cells[] = '?';
-                        else
-                            $row->cells[] = '';
-                    }
-                }
-            }
-            if ($cell) $row->cells[] = $cell;
 
             foreach ($reportdata->statuses as $status) {
                 if (array_key_exists($status->id, $reportdata->usersstats[$user->id]))
@@ -753,23 +718,6 @@ class mod_attforblock_renderer extends plugin_renderer_base {
         return html_writer::table($table);
     }
 
-    private function construct_report_cell($text, &$cell) {
-        if (is_null($cell)) {
-            $cell = new html_table_cell($text);
-            $cell->colspan = 1;
-        }
-        else {
-            if ($cell->text != $text) {
-                $row->cells[] = $cell;
-                $cell = new html_table_cell($text);
-                $cell->colspan = 1;
-            }
-            else
-                $cell->colspan++;
-
-        }
-    }
-
     protected function render_attforblock_preferences_data(attforblock_preferences_data $prefdata) {
         $this->page->requires->js('/mod/attforblock/module.js');
 

renderhelpers.php

@@ -0,0 +1,157 @@
+<?php
+/**
+ * Attendance module renderering helpers
+ *
+ * @package    mod
+ * @subpackage attforblock
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+require_once(dirname(__FILE__).'/renderables.php');
+
+/**
+ * Template method for generating user's session's cells
+ */
+class user_sessions_cells_generator {
+    protected $cells = array();
+
+    protected $reportdata;
+    protected $user;
+
+    public function  __construct(attforblock_report_data $reportdata, $user) {
+        $this->reportdata = $reportdata;
+        $this->user = $user;
+    }
+
+    public function get_cells() {
+        $this->init_cells();
+        foreach ($this->reportdata->sessions as $sess) {
+            if (array_key_exists($sess->id, $this->reportdata->sessionslog[$this->user->id])) {
+                $statusid = $this->reportdata->sessionslog[$this->user->id][$sess->id]->statusid;
+                if (array_key_exists($statusid, $this->reportdata->statuses)) {
+                    $this->construct_existing_status_cell($this->reportdata->statuses[$statusid]->acronym);
+                } else {
+                    $this->construct_hidden_status_cell($this->reportdata->allstatuses[$statusid]->acronym);
+                }
+            } else {
+                if ($this->user->enrolmentstart > $sess->sessdate) {
+                    $starttext = get_string('enrolmentstart', 'attforblock', userdate($this->user->enrolmentstart, '%d.%m.%Y'));
+                    $this->construct_enrolments_info_cell($starttext);
+                }
+                elseif ($this->user->enrolmentend and $this->user->enrolmentend < $sess->sessdate) {
+                    $endtext = get_string('enrolmentend', 'attforblock', userdate($this->user->enrolmentend, '%d.%m.%Y'));
+                    $this->construct_enrolments_info_cell($endtext);
+                }
+                // no enrolmentend and ENROL_USER_SUSPENDED
+                elseif (!$this->user->enrolmentend and $this->user->enrolmentstatus == ENROL_USER_SUSPENDED) {
+                    $suspendext = get_string('enrolmentsuspended', 'attforblock', userdate($this->user->enrolmentend, '%d.%m.%Y'));
+                    $this->construct_enrolments_info_cell($suspendext);
+                }
+                else {
+                    if ($sess->groupid == 0 or array_key_exists($sess->groupid, $this->reportdata->usersgroups[$this->user->id]))
+                        $this->construct_not_taken_cell('?');
+                    else
+                        $this->construct_not_existing_for_user_session_cell('');
+                }
+            }
+        }
+        $this->finalize_cells();
+
+        return $this->cells;
+    }
+
+    protected function init_cells() {
+
+    }
+
+    protected function construct_existing_status_cell($text) {
+        $this->cells[] = $text;
+    }
+
+    protected function construct_hidden_status_cell($text) {
+        $this->cells[] = $text;
+    }
+
+    protected function construct_enrolments_info_cell($text) {
+        $this->cells[] = $text;
+    }
+
+    protected function construct_not_taken_cell($text) {
+        $this->cells[] = $text;
+    }
+
+    protected function construct_not_existing_for_user_session_cell($text) {
+        $this->cells[] = $text;
+    }
+
+    protected function finalize_cells() {
+        
+    }
+}
+
+class user_sessions_cells_html_generator extends user_sessions_cells_generator {
+    private $cell;
+    
+    protected function construct_hidden_status_cell($text) {
+        $this->cells[] = html_writer::tag('s', $text);
+    }
+
+    protected function construct_enrolments_info_cell($text) {
+        if (is_null($this->cell)) {
+            $this->cell = new html_table_cell($text);
+            $this->cell->colspan = 1;
+        }
+        else {
+            if ($this->cell->text != $text) {
+                $this->cells[] = $this->cell;
+                $this->cell = new html_table_cell($text);
+                $this->cell->colspan = 1;
+            }
+            else
+                $this->cell->colspan++;
+        }
+    }
+
+    private function close_open_cell_if_needed(){
+        if ($this->cell) {
+            $this->cells[] = $this->cell;
+            $this->cell = null;
+        }
+    }
+    
+    protected function construct_not_taken_cell($text) {
+        $this->close_open_cell_if_needed();
+        $this->cells[] = $text;
+    }
+
+    protected function construct_not_existing_for_user_session_cell($text) {
+        $this->close_open_cell_if_needed();
+        $this->cells[] = $text;
+    }
+
+    protected function finalize_cells() {
+        if ($this->cell)
+            $this->cells[] = $this->cell;
+    }
+}
+
+class user_sessions_cells_text_generator extends user_sessions_cells_generator {
+    private $enrolments_info_cell_text;
+
+    protected function construct_hidden_status_cell($text) {
+        $this->cells[] = '-'.$text;
+    }
+
+    protected function construct_enrolments_info_cell($text) {
+        if ($this->enrolments_info_cell_text != $text) {
+            $this->enrolments_info_cell_text = $text;
+            $this->cells[] = $text;
+        }
+        else
+            $this->cells[] = '←';
+    }
+}
+
+?>