battles/chat.php

<?php
/**
 * Copyright (c) 2018.
 * Author: Igor Barkov <lopar.4ever@gmail.com>
 * Project name: Battles-Game
 */

use Battles\Chat;
use Battles\Database\Db;
use Battles\Template;

require_once "config.php";
$chat = new Chat(Db::getInstance());
if (!empty($_POST['msg'])) {
    $chat->sendMessage($_POST['msg']);
}

Template::header('chat');
echo $chat->getMessages();
?>
<style>
    form {
        padding: 3px;
        position: fixed;
        bottom: 0;
        width: 100%;
    }

    form input {
        border: 0;
        padding: 10px;
        width: 80%;
        margin-right: .5%;
    }

    form input[type="submit"] {
        width: 15%;
        border: none;
        padding: 10px;
    }

    span.chatsys {
        color:maroon;
        background:#faa;
    }
    span.chatsms {
        color:darkgreen;
        background:#afa;
    }
    span.chatprivate {
        background:#efe;
    }
</style>
<div>
    <?php ?>
</div>
<form action="chat.php" method="post">
    <input id="msg" name="msg" size="100" placeholder="Введите сообщение...">
    <input type="submit" value="Отправить">
</form>