PHP模板怎么部分加载_PHP模板部分加载方法及按需渲染。

<header>
  <h1>网站标题</h1>
  <nav><a href="/">首页</a></nav>
</header>

<?php include 'header.php'; ?>
<main>
  <h2>主页内容</h2>
</main>
<?php include 'footer.php'; ?>

<?php if ($user->isLoggedIn()): ?>
  <?php include 'partials/admin-menu.php'; ?>
<?php endif; ?>

<?php
function render_partial($file, $data = []) {
  if (file_exists($file)) {
    extract($data);
    include $file;
  }
}
?>

<?php render_partial('partials/alert.php', ['type' => 'success', 'msg' => '操作成功']); ?>

$page = $_GET['page'] ?? 'home';
$allowed_pages = ['home', 'about', 'contact'];

if (in_array($page, $allowed_pages)) {
  $content_file = "views/{$page}.php";
} else {
  $content_file = "views/404.php";
}

include 'layout/header.php';
include $content_file;
include 'layout/footer.php';

{% extends "base.html.twig" %}

{% block sidebar %}
  <div class="sidebar">
    <h3>侧边栏内容</h3>
  </div>
{% endblock %}