librenms-librenms/html/pages/eventlog.inc.php

<?php

$no_refresh = true;

$param = array();

if ($vars['action'] == 'expunge' && $_SESSION['userlevel'] >= '10') {
    dbQuery('TRUNCATE TABLE `eventlog`');
    print_message('Event log truncated');
}

$pagetitle[] = 'Eventlog';

print_optionbar_start();

?>

<form method="post" action="" class="form-inline" role="form" id="result_form">
    <div class="form-group">
      <label>
        <strong>Device</strong>
      </label>
      <select name="device" id="device" class="form-control input-sm">
        <option value="">All Devices</option>
        <?php
        foreach (get_all_devices() as $hostname) {
            $device_id = getidbyname($hostname);
            if (device_permitted($device_id)) {
                echo "<option value='".$device_id."'";
                if ($device_id == $_POST['device']) {
                    echo 'selected';
                }

                echo '>'.$hostname.'</option>';
            }
        }
        ?>
      </select>
    </div>
    <button type="submit" class="btn btn-default input-sm">Filter</button>
</form>

<?php
print_optionbar_end();
?>

<table id="eventlog" class="table table-hover table-condensed table-striped">
    <thead>
        <tr>
            <th data-column-id="datetime" data-order="desc">Datetime</th>
            <th data-column-id="hostname">Hostname</th>
            <th data-column-id="type">Type</th>
            <th data-column-id="message">Message</th>
        </tr>
    </thead>
</table>

<script>

var grid = $("#eventlog").bootgrid({
    ajax: true,
    post: function ()
    {
        return {
            id: "eventlog",
            device: '<?php echo htmlspecialchars($_POST['device']); ?>'
        };
    },
    url: "/ajax_table.php"
});

</script>