内容页如何没用图片的话，如果随机调用某个图片呢

打开内容页模板，找到：[!--newstext--]
改为：

<div id="picture_if">

  <div id="random_fallback_img" style="display:none;margin-top:15px;text-align:center;"></div>
  [!--newstext--]</div>
<script>
document.addEventListener("DOMContentLoaded", function () {
  const content = document.getElementById("picture_if").innerHTML;
  if (!/<img\s/i.test(content)) {
    // 无图片，则请求随机图
    fetch('[!--news.url--]/e/public/randompic.php')
      .then(res => res.text())
      .then(html => {
        document.getElementById("random_fallback_img").innerHTML = html;
        document.getElementById("random_fallback_img").style.display = "block";
      });
  }
});
</script>

建一个PHP文件，目录及名称为：./e/public/randompic.php

文件内容为：

<?php
require('../../e/class/connect.php');
require('../../e/class/db_sql.php');
$link = db_connect();
$empire = new mysqlquery();

$sql = $empire->query("SELECT titlepic, titleurl, title FROM {$dbtbpre}ecms_news WHERE titlepic<>'' ORDER BY rand() LIMIT 1");
if ($r = $empire->fetch($sql)) {
    if (!empty($r['titlepic'])) {
        echo '<a href="' . $r['titleurl'] . '" target="_blank">';
        echo '<img src="' . $r['titlepic'] . '" alt="' . htmlspecialchars($r['title']) . '" style="max-width:100%;border-radius:5px;">';
        echo '</a>';
    }
}

db_close();
$empire = null;
?>