MDL-59396 core_user: removed 'My courses' select from participants page

[moodle.git] / user / index.php

<?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/>.

/**
 * Lists all the users within a given course.
 *
 * @copyright 1999 Martin Dougiamas  http://dougiamas.com
 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 * @package core_user
 */

require_once('../config.php');
require_once($CFG->dirroot.'/user/lib.php');
require_once($CFG->libdir.'/tablelib.php');
require_once($CFG->libdir.'/filelib.php');

define('USER_SMALL_CLASS', 20);   // Below this is considered small.
define('USER_LARGE_CLASS', 200);  // Above this is considered large.
define('DEFAULT_PAGE_SIZE', 20);
define('SHOW_ALL_PAGE_SIZE', 5000);

$page         = optional_param('page', 0, PARAM_INT); // Which page to show.
$perpage      = optional_param('perpage', DEFAULT_PAGE_SIZE, PARAM_INT); // How many per page.
$accesssince  = optional_param('accesssince', 0, PARAM_INT); // Filter by last access. -1 = never.
$search       = optional_param('search', '', PARAM_RAW); // Make sure it is processed with p() or s() when sending to output!
$roleid       = optional_param('roleid', 0, PARAM_INT); // Optional roleid, 0 means all enrolled users (or all on the frontpage).
$contextid    = optional_param('contextid', 0, PARAM_INT); // One of this or.
$courseid     = optional_param('id', 0, PARAM_INT); // This are required.
$selectall    = optional_param('selectall', false, PARAM_BOOL); // When rendering checkboxes against users mark them all checked.

$PAGE->set_url('/user/index.php', array(
        'page' => $page,
        'perpage' => $perpage,
        'accesssince' => $accesssince,
        'search' => $search,
        'roleid' => $roleid,
        'contextid' => $contextid,
        'id' => $courseid));

if ($contextid) {
    $context = context::instance_by_id($contextid, MUST_EXIST);
    if ($context->contextlevel != CONTEXT_COURSE) {
        print_error('invalidcontext');
    }
    $course = $DB->get_record('course', array('id' => $context->instanceid), '*', MUST_EXIST);
} else {
    $course = $DB->get_record('course', array('id' => $courseid), '*', MUST_EXIST);
    $context = context_course::instance($course->id, MUST_EXIST);
}
// Not needed anymore.
unset($contextid);
unset($courseid);

require_login($course);

$systemcontext = context_system::instance();
$isfrontpage = ($course->id == SITEID);

$frontpagectx = context_course::instance(SITEID);

if ($isfrontpage) {
    $PAGE->set_pagelayout('admin');
    require_capability('moodle/site:viewparticipants', $systemcontext);
} else {
    $PAGE->set_pagelayout('incourse');
    require_capability('moodle/course:viewparticipants', $context);
}

$rolenamesurl = new moodle_url("$CFG->wwwroot/user/index.php?contextid=$context->id&sifirst=&silast=");

$rolenames = role_fix_names(get_profile_roles($context), $context, ROLENAME_ALIAS, true);
if ($isfrontpage) {
    $rolenames[0] = get_string('allsiteusers', 'role');
} else {
    $rolenames[0] = get_string('allparticipants');
}

// Make sure other roles may not be selected by any means.
if (empty($rolenames[$roleid])) {
    print_error('noparticipants');
}

// No roles to display yet?
// frontpage course is an exception, on the front page course we should display all users.
if (empty($rolenames) && !$isfrontpage) {
    if (has_capability('moodle/role:assign', $context)) {
        redirect($CFG->wwwroot.'/'.$CFG->admin.'/roles/assign.php?contextid='.$context->id);
    } else {
        print_error('noparticipants');
    }
}

// Trigger events.
user_list_view($course, $context);

$bulkoperations = has_capability('moodle/course:bulkmessaging', $context);

$countries = get_string_manager()->get_list_of_countries();

$strnever = get_string('never');

$datestring = new stdClass();
$datestring->year  = get_string('year');
$datestring->years = get_string('years');
$datestring->day   = get_string('day');
$datestring->days  = get_string('days');
$datestring->hour  = get_string('hour');
$datestring->hours = get_string('hours');
$datestring->min   = get_string('min');
$datestring->mins  = get_string('mins');
$datestring->sec   = get_string('sec');
$datestring->secs  = get_string('secs');

// Check to see if groups are being used in this course
// and if so, set $currentgroup to reflect the current group.

$groupmode    = groups_get_course_groupmode($course);   // Groups are being used.
$currentgroup = groups_get_course_group($course, true);

if (!$currentgroup) {      // To make some other functions work better later.
    $currentgroup  = null;
}

$isseparategroups = ($course->groupmode == SEPARATEGROUPS and !has_capability('moodle/site:accessallgroups', $context));

$PAGE->set_title("$course->shortname: ".get_string('participants'));
$PAGE->set_heading($course->fullname);
$PAGE->set_pagetype('course-view-' . $course->format);
$PAGE->add_body_class('path-user');                     // So we can style it independently.
$PAGE->set_other_editing_capability('moodle/course:manageactivities');

echo $OUTPUT->header();
echo $OUTPUT->heading(get_string('participants'));

echo '<div class="userlist">';

if ($isseparategroups and (!$currentgroup) ) {
    // The user is not in the group so show message and exit.
    echo $OUTPUT->heading(get_string("notingroup"));
    echo $OUTPUT->footer();
    exit;
}


// Should use this variable so that we don't break stuff every time a variable is added or changed.
$baseurl = new moodle_url('/user/index.php', array(
        'contextid' => $context->id,
        'roleid' => $roleid,
        'id' => $course->id,
        'perpage' => $perpage,
        'accesssince' => $accesssince,
        'search' => s($search)));

// Setting up tags.
if ($course->id == SITEID) {
    $filtertype = 'site';
} else if ($course->id && !$currentgroup) {
    $filtertype = 'course';
    $filterselect = $course->id;
} else {
    $filtertype = 'group';
    $filterselect = $currentgroup;
}



// Get the hidden field list.
if (has_capability('moodle/course:viewhiddenuserfields', $context)) {
    $hiddenfields = array();  // Teachers and admins are allowed to see everything.
} else {
    $hiddenfields = array_flip(explode(',', $CFG->hiddenuserfields));
}

if (isset($hiddenfields['lastaccess'])) {
    // Do not allow access since filtering.
    $accesssince = 0;
}

// Print settings and things in a table across the top.
$controlstable = new html_table();
$controlstable->attributes['class'] = 'controls';
$controlstable->cellspacing = 0;
$controlstable->data[] = new html_table_row();

if ($groupmenu = groups_print_course_menu($course, $baseurl->out(), true)) {
    $controlstable->data[0]->cells[] = $groupmenu;
}

if (!isset($hiddenfields['lastaccess'])) {
    // Get minimum lastaccess for this course and display a dropbox to filter by lastaccess going back this far.
    // We need to make it diferently for normal courses and site course.
    if (!$isfrontpage) {
        $minlastaccess = $DB->get_field_sql('SELECT min(timeaccess)
                                               FROM {user_lastaccess}
                                              WHERE courseid = ?
                                                    AND timeaccess != 0', array($course->id));
        $lastaccess0exists = $DB->record_exists('user_lastaccess', array('courseid' => $course->id, 'timeaccess' => 0));
    } else {
        $minlastaccess = $DB->get_field_sql('SELECT min(lastaccess)
                                               FROM {user}
                                              WHERE lastaccess != 0');
        $lastaccess0exists = $DB->record_exists('user', array('lastaccess' => 0));
    }

    $now = usergetmidnight(time());
    $timeaccess = array();
    $baseurl->remove_params('accesssince');

    // Makes sense for this to go first.
    $timeoptions[0] = get_string('selectperiod');

    // Days.
    for ($i = 1; $i < 7; $i++) {
        if (strtotime('-'.$i.' days', $now) >= $minlastaccess) {
            $timeoptions[strtotime('-'.$i.' days', $now)] = get_string('numdays', 'moodle', $i);
        }
    }
    // Weeks.
    for ($i = 1; $i < 10; $i++) {
        if (strtotime('-'.$i.' weeks', $now) >= $minlastaccess) {
            $timeoptions[strtotime('-'.$i.' weeks', $now)] = get_string('numweeks', 'moodle', $i);
        }
    }
    // Months.
    for ($i = 2; $i < 12; $i++) {
        if (strtotime('-'.$i.' months', $now) >= $minlastaccess) {
            $timeoptions[strtotime('-'.$i.' months', $now)] = get_string('nummonths', 'moodle', $i);
        }
    }
    // Try a year.
    if (strtotime('-1 year', $now) >= $minlastaccess) {
        $timeoptions[strtotime('-1 year', $now)] = get_string('lastyear');
    }

    if (!empty($lastaccess0exists)) {
        $timeoptions[-1] = get_string('never');
    }

    if (count($timeoptions) > 1) {
        $select = new single_select($baseurl, 'accesssince', $timeoptions, $accesssince, null, 'timeoptions');
        $select->set_label(get_string('usersnoaccesssince'));
        $controlstable->data[0]->cells[] = $OUTPUT->render($select);
    }
}

echo html_writer::table($controlstable);

if ($currentgroup and (!$isseparategroups or has_capability('moodle/site:accessallgroups', $context))) {
    // Display info about the group.
    if ($group = groups_get_group($currentgroup)) {
        if (!empty($group->description) or (!empty($group->picture) and empty($group->hidepicture))) {
            $groupinfotable = new html_table();
            $groupinfotable->attributes['class'] = 'groupinfobox';
            $picturecell = new html_table_cell();
            $picturecell->attributes['class'] = 'left side picture';
            $picturecell->text = print_group_picture($group, $course->id, true, true, false);

            $contentcell = new html_table_cell();
            $contentcell->attributes['class'] = 'content';

            $contentheading = $group->name;
            if (has_capability('moodle/course:managegroups', $context)) {
                $aurl = new moodle_url('/group/group.php', array('id' => $group->id, 'courseid' => $group->courseid));
                $contentheading .= '&nbsp;' . $OUTPUT->action_icon($aurl, new pix_icon('t/edit', get_string('editgroupprofile')));
            }

            $group->description = file_rewrite_pluginfile_urls($group->description, 'pluginfile.php', $context->id, 'group',
                'description', $group->id);
            if (!isset($group->descriptionformat)) {
                $group->descriptionformat = FORMAT_MOODLE;
            }
            $options = array('overflowdiv' => true);
            $formatteddesc = format_text($group->description, $group->descriptionformat, $options);
            $contentcell->text = $OUTPUT->heading($contentheading, 3) . $formatteddesc;
            $groupinfotable->data[] = new html_table_row(array($picturecell, $contentcell));
            echo html_writer::table($groupinfotable);
        }
    }
}

// Define a table showing a list of users in the current role selection.
$tablecolumns = array();
$tableheaders = array();
if ($bulkoperations) {
    $tablecolumns[] = 'select';
    $tableheaders[] = get_string('select');
}
$tablecolumns[] = 'userpic';
$tablecolumns[] = 'fullname';

$extrafields = get_extra_user_fields($context);
$tableheaders[] = get_string('userpic');
$tableheaders[] = get_string('fullnameuser');


foreach ($extrafields as $field) {
    $tablecolumns[] = $field;
    $tableheaders[] = get_user_field_name($field);
}
if (!isset($hiddenfields['city'])) {
    $tablecolumns[] = 'city';
    $tableheaders[] = get_string('city');
}
if (!isset($hiddenfields['country'])) {
    $tablecolumns[] = 'country';
    $tableheaders[] = get_string('country');
}
if (!isset($hiddenfields['lastaccess'])) {
    $tablecolumns[] = 'lastaccess';
    if ($course->id == SITEID) {
        // Exception case for viewing participants on site home.
        $tableheaders[] = get_string('lastsiteaccess');
    } else {
        $tableheaders[] = get_string('lastcourseaccess');
    }
}

$table = new flexible_table('user-index-participants-'.$course->id);
$table->define_columns($tablecolumns);
$table->define_headers($tableheaders);
$table->define_baseurl($baseurl->out());

if (!isset($hiddenfields['lastaccess'])) {
    $table->sortable(true, 'lastaccess', SORT_DESC);
} else {
    $table->sortable(true, 'firstname', SORT_ASC);
}

$table->no_sorting('roles');
$table->no_sorting('groups');
$table->no_sorting('groupings');
$table->no_sorting('select');

$table->set_attribute('cellspacing', '0');
$table->set_attribute('id', 'participants');
$table->set_attribute('class', 'generaltable generalbox');

$table->set_control_variables(array(
            TABLE_VAR_SORT    => 'ssort',
            TABLE_VAR_HIDE    => 'shide',
            TABLE_VAR_SHOW    => 'sshow',
            TABLE_VAR_IFIRST  => 'sifirst',
            TABLE_VAR_ILAST   => 'silast',
            TABLE_VAR_PAGE    => 'spage'
            ));
$table->setup();

list($esql, $params) = get_enrolled_sql($context, null, $currentgroup, true);
$joins = array("FROM {user} u");
$wheres = array();

$userfields = array('username', 'email', 'city', 'country', 'lang', 'timezone', 'maildisplay');
$mainuserfields = user_picture::fields('u', $userfields);
$extrasql = get_extra_user_fields_sql($context, 'u', '', $userfields);

if ($isfrontpage) {
    $select = "SELECT $mainuserfields, u.lastaccess$extrasql";
    $joins[] = "JOIN ($esql) e ON e.id = u.id"; // Everybody on the frontpage usually.
    if ($accesssince) {
        $wheres[] = get_user_lastaccess_sql($accesssince);
    }

} else {
    $select = "SELECT $mainuserfields, COALESCE(ul.timeaccess, 0) AS lastaccess$extrasql";
    $joins[] = "JOIN ($esql) e ON e.id = u.id"; // Course enrolled users only.
    $joins[] = "LEFT JOIN {user_lastaccess} ul ON (ul.userid = u.id AND ul.courseid = :courseid)"; // Not everybody accessed course yet.
    $params['courseid'] = $course->id;
    if ($accesssince) {
        $wheres[] = get_course_lastaccess_sql($accesssince);
    }
}

// Performance hacks - we preload user contexts together with accounts.
$ccselect = ', ' . context_helper::get_preload_record_columns_sql('ctx');
$ccjoin = "LEFT JOIN {context} ctx ON (ctx.instanceid = u.id AND ctx.contextlevel = :contextlevel)";
$params['contextlevel'] = CONTEXT_USER;
$select .= $ccselect;
$joins[] = $ccjoin;


// Limit list to users with some role only.
if ($roleid) {
    // We want to query both the current context and parent contexts.
    list($relatedctxsql, $relatedctxparams) = $DB->get_in_or_equal($context->get_parent_context_ids(true), SQL_PARAMS_NAMED, 'relatedctx');

    $wheres[] = "u.id IN (SELECT userid FROM {role_assignments} WHERE roleid = :roleid AND contextid $relatedctxsql)";
    $params = array_merge($params, array('roleid' => $roleid), $relatedctxparams);
}

$from = implode("\n", $joins);
if ($wheres) {
    $where = "WHERE " . implode(" AND ", $wheres);
} else {
    $where = "";
}

$totalcount = $DB->count_records_sql("SELECT COUNT(u.id) $from $where", $params);

if (!empty($search)) {
    $fullname = $DB->sql_fullname('u.firstname', 'u.lastname');
    $wheres[] = "(". $DB->sql_like($fullname, ':search1', false, false) .
                " OR ". $DB->sql_like('email', ':search2', false, false) .
                " OR ". $DB->sql_like('idnumber', ':search3', false, false) .") ";
    $params['search1'] = "%$search%";
    $params['search2'] = "%$search%";
    $params['search3'] = "%$search%";
}

list($twhere, $tparams) = $table->get_sql_where();
if ($twhere) {
    $wheres[] = $twhere;
    $params = array_merge($params, $tparams);
}

$from = implode("\n", $joins);
if ($wheres) {
    $where = "WHERE " . implode(" AND ", $wheres);
} else {
    $where = "";
}

if ($table->get_sql_sort()) {
    $sort = ' ORDER BY '.$table->get_sql_sort();
} else {
    $sort = '';
}

$matchcount = $DB->count_records_sql("SELECT COUNT(u.id) $from $where", $params);

$table->initialbars(true);
$table->pagesize($perpage, $matchcount);

// List of users at the current visible page - paging makes it relatively short.
$userlist = $DB->get_recordset_sql("$select $from $where $sort", $params, $table->get_page_start(), $table->get_page_size());

// If there are multiple Roles in the course, then show a drop down menu for switching.
if (count($rolenames) > 1) {
    echo '<div class="rolesform">';
    echo $OUTPUT->single_select($rolenamesurl, 'roleid', $rolenames, $roleid, null,
        'rolesform', array('label' => get_string('currentrole', 'role')));
    echo '</div>';

} else if (count($rolenames) == 1) {
    // When all users with the same role - print its name.
    echo '<div class="rolesform">';
    echo get_string('role').get_string('labelsep', 'langconfig');
    $rolename = reset($rolenames);
    echo $rolename;
    echo '</div>';
}

$editlink = '';
if ($course->id != SITEID && has_capability('moodle/course:enrolreview', $context)) {
    $editlink = new moodle_url('/enrol/users.php', array('id' => $course->id));
}

if ($roleid > 0) {
    $a = new stdClass();
    $a->number = $totalcount;
    $a->role = $rolenames[$roleid];
    $heading = format_string(get_string('xuserswiththerole', 'role', $a));

    if ($currentgroup and !empty($group)) {
        $a->group = $group->name;
        $heading .= ' ' . format_string(get_string('ingroup', 'role', $a));
    }

    if ($accesssince && !empty($timeoptions[$accesssince])) {
        $a->timeperiod = $timeoptions[$accesssince];
        $heading .= ' ' . format_string(get_string('inactiveformorethan', 'role', $a));
    }

    $heading .= ": $a->number";

    if (!empty($editlink)) {
        $editlink->param('role', $roleid);
        $heading .= $OUTPUT->action_icon($editlink, new pix_icon('t/edit', get_string('edit')));
    }
    echo $OUTPUT->heading($heading, 3);
} else {
    if ($course->id == SITEID and $roleid < 0) {
        $strallparticipants = get_string('allsiteusers', 'role');
    } else {
        $strallparticipants = get_string('allparticipants');
    }

    if (!empty($editlink)) {
        $editlink = $OUTPUT->action_icon($editlink, new pix_icon('t/edit', get_string('edit')));
    }

    if ($matchcount < $totalcount) {
        echo $OUTPUT->heading($strallparticipants.get_string('labelsep', 'langconfig').$matchcount.'/'.$totalcount . $editlink, 3);
    } else {
        echo $OUTPUT->heading($strallparticipants.get_string('labelsep', 'langconfig').$matchcount . $editlink, 3);
    }
}


if ($bulkoperations) {
    echo '<form action="action_redir.php" method="post" id="participantsform">';
    echo '<div>';
    echo '<input type="hidden" name="sesskey" value="'.sesskey().'" />';
    echo '<input type="hidden" name="returnto" value="'.s($PAGE->url->out(false)).'" />';
}

$countrysort = (strpos($sort, 'country') !== false);
$timeformat = get_string('strftimedate');

if ($userlist) {

    $usersprinted = array();
    foreach ($userlist as $user) {
        if (in_array($user->id, $usersprinted)) { // Prevent duplicates by r.hidden - MDL-13935.
            continue;
        }
        $usersprinted[] = $user->id; // Add new user to the array of users printed.

        context_helper::preload_from_record($user);

        if ($user->lastaccess) {
            $lastaccess = format_time(time() - $user->lastaccess, $datestring);
        } else {
            $lastaccess = $strnever;
        }

        if (empty($user->country)) {
            $country = '';

        } else {
            if ($countrysort) {
                $country = '('.$user->country.') '.$countries[$user->country];
            } else {
                $country = $countries[$user->country];
            }
        }

        $usercontext = context_user::instance($user->id);

        if ($piclink = ($USER->id == $user->id || has_capability('moodle/user:viewdetails', $context) || has_capability('moodle/user:viewdetails', $usercontext))) {
            $profilelink = '<strong><a href="'.$CFG->wwwroot.'/user/view.php?id='.$user->id.'&amp;course='.$course->id.'">'.fullname($user).'</a></strong>';
        } else {
            $profilelink = '<strong>'.fullname($user).'</strong>';
        }

        $data = array();
        if ($bulkoperations) {
            if ($selectall) {
                $checked = 'checked="true"';
            } else {
                $checked = '';
            }
            $data[] = '<input type="checkbox" class="usercheckbox" name="user'.$user->id.'" ' . $checked .'/>';
        }
        $data[] = $OUTPUT->user_picture($user, array('size' => 35, 'courseid' => $course->id));
        $data[] = $profilelink;

        foreach ($extrafields as $field) {
            $data[] = $user->{$field};
        }

        if (!isset($hiddenfields['city'])) {
            $data[] = $user->city;
        }
        if (!isset($hiddenfields['country'])) {
            $data[] = $country;
        }
        if (!isset($hiddenfields['lastaccess'])) {
            $data[] = $lastaccess;
        }

        $table->add_data($data);
    }
}

$table->print_html();

$perpageurl = clone($baseurl);
$perpageurl->remove_params('perpage');
if ($perpage == SHOW_ALL_PAGE_SIZE) {
    $perpageurl->param('perpage', DEFAULT_PAGE_SIZE);
    echo $OUTPUT->container(html_writer::link($perpageurl, get_string('showperpage', '', DEFAULT_PAGE_SIZE)), array(), 'showall');

} else if ($matchcount > 0 && $perpage < $matchcount) {
    $perpageurl->param('perpage', SHOW_ALL_PAGE_SIZE);
    echo $OUTPUT->container(html_writer::link($perpageurl, get_string('showall', '', $matchcount)), array(), 'showall');
}

if ($bulkoperations) {
    echo '<br /><div class="buttons">';

    if ($matchcount > 0 && $perpage < $matchcount) {
        $perpageurl = clone($baseurl);
        $perpageurl->remove_params('perpage');
        $perpageurl->param('perpage', SHOW_ALL_PAGE_SIZE);
        $perpageurl->param('selectall', true);
        $showalllink = $perpageurl;
    } else {
        $showalllink = false;
    }

    echo html_writer::start_tag('div', array('class' => 'btn-group'));
    if ($perpage < $matchcount) {
        // Select all users, refresh page showing all users and mark them all selected.
        $label = get_string('selectalluserswithcount', 'moodle', $matchcount);
        echo html_writer::tag('input', "", array('type' => 'button', 'id' => 'checkall', 'class' => 'btn btn-secondary',
                'value' => $label, 'data-showallink' => $showalllink));
        // Select all users, mark all users on page as selected.
        echo html_writer::tag('input', "", array('type' => 'button', 'id' => 'checkallonpage', 'class' => 'btn btn-secondary',
        'value' => get_string('selectallusersonpage')));
    } else {
        echo html_writer::tag('input', "", array('type' => 'button', 'id' => 'checkallonpage', 'class' => 'btn btn-secondary',
        'value' => get_string('selectall')));
    }

    echo html_writer::tag('input', "", array('type' => 'button', 'id' => 'checknone', 'class' => 'btn btn-secondary',
        'value' => get_string('deselectall')));
    echo html_writer::end_tag('div');
    $displaylist = array();
    $displaylist['messageselect.php'] = get_string('messageselectadd');
    if (!empty($CFG->enablenotes) && has_capability('moodle/notes:manage', $context) && $context->id != $frontpagectx->id) {
        $displaylist['addnote.php'] = get_string('addnewnote', 'notes');
        $displaylist['groupaddnote.php'] = get_string('groupaddnewnote', 'notes');
    }

    echo $OUTPUT->help_icon('withselectedusers');
    echo html_writer::tag('label', get_string("withselectedusers"), array('for' => 'formactionid'));
    echo html_writer::select($displaylist, 'formaction', '', array('' => 'choosedots'), array('id' => 'formactionid'));

    echo '<input type="hidden" name="id" value="'.$course->id.'" />';
    echo '<noscript style="display:inline">';
    echo '<div><input type="submit" value="'.get_string('ok').'" /></div>';
    echo '</noscript>';
    echo '</div></div>';
    echo '</form>';

    $module = array('name' => 'core_user', 'fullpath' => '/user/module.js');
    $PAGE->requires->js_init_call('M.core_user.init_participation', null, false, $module);
}

// Show a search box if all participants don't fit on a single screen.
if ($totalcount > $perpage) {
    echo '<form action="index.php" class="searchform"><div><input type="hidden" name="id" value="'.$course->id.'" />';
    echo '<label for="search">' . get_string('search', 'search') . ' </label>';
    echo '<input type="text" id="search" name="search" value="'.s($search).'" />&nbsp;<input type="submit" value="'.get_string('search').'" /></div></form>'."\n";
}

echo '</div>';  // Userlist.

echo $OUTPUT->footer();

if ($userlist) {
    $userlist->close();
}

/**
 * Returns SQL that can be used to limit a query to a period where the user last accessed a course..
 *
 * @param string $accesssince
 * @return string
 */
function get_course_lastaccess_sql($accesssince='') {
    if (empty($accesssince)) {
        return '';
    }
    if ($accesssince == -1) { // Never.
        return 'ul.timeaccess = 0';
    } else {
        return 'ul.timeaccess != 0 AND ul.timeaccess < '.$accesssince;
    }
}

/**
 * Returns SQL that can be used to limit a query to a period where the user last accessed the system.
 *
 * @param string $accesssince
 * @return string
 */
function get_user_lastaccess_sql($accesssince='') {
    if (empty($accesssince)) {
        return '';
    }
    if ($accesssince == -1) { // Never.
        return 'u.lastaccess = 0';
    } else {
        return 'u.lastaccess != 0 AND u.lastaccess < '.$accesssince;
    }
}