工作方式

先用PHP作为接口将Feed转换为Json，再由Js输出为HTML，自定义字段输出在前段Js请求接口的参数中，这样就可以通过自定义字段控制订阅那些RSS。

接口部分PHP

<?php
$feedParam = isset($_GET['feed'])? explode(',', $_GET['feed']) : [];

$rssSources = [];
if (!empty($feedParam)) {
    $rssSources = array_map(function ($feed) {
        return $feed. 'feed/';
    }, $feedParam);
}

if (!empty($rssSources)) {
    $allItems = array_reduce($rssSources, function ($carry, $source) {
        $rss = simplexml_load_file($source);
        foreach ($rss->channel->item as $item) {
            $carry[] = [
                'title' => (string)$item->title,
                'description' => (string)$item->description,
                'link' => (string)$item->link,
                'pubDate' => (string)$item->pubDate,
                'creator' => (string)$item->children('http://purl.org/dc/elements/1.1/')->creator,
            ];
        }
        return $carry;
    }, []);


    usort($allItems, fn($a, $b) => strtotime($b['pubDate']) - strtotime($a['pubDate']));


    header('Content-Type: application/json');
    echo json_encode(['items' => $allItems]);
} else {
    header('Content-Type: application/json');
    echo json_encode(['description' => 'No valid feed sources provided']);
}
?>

主题自定义页面部分

<?php
/**
 * Feed
 *
 * @package custom
 */
$this->need('components/header.php');
?>

    <div class="PAP">
        <div class="PAP-content">
            <div id="FriendsArt"><center>正在加载中…<br>若长时间无响应，请尝试刷新页面</center></div>
            <script>
                document.addEventListener('DOMContentLoaded', function() {
                    const container = document.getElementById('FriendsArt');
                    fetch('https://i.eastblues.cn/feed.php?feed=<?php echo $this->fields->feedURL;?>')//建议自建API，否则可能会导致我的服务器压力骤增
                        .then(response => response.json())
                        .then(data => {
                            container.innerHTML = '';
                            data.items.forEach(({ title, creator, pubDate, description, link }) => {
                                const entryDiv = document.createElement('div');
                                entryDiv.innerHTML = `
                                    <h3>${title}</h3>
                                    <blockquote><small>作者：${creator}<br>发布日期：${pubDate}</small></blockquote>
                                    <p><q>${description}</q> <a href="${link}" target="_blank">查看详情</a></p><hr>
                                `;
                                container.appendChild(entryDiv);
                            });
                        });
                });
            </script>
        </div>
    </div>

<?php if ($this->fields->enableComment == 1): ?>
    <?php $this->need('components/comments.php'); ?>
<?php endif; ?>
<?php $this->need('components/footer.php'); ?>

自定义字段

格式：https://i.eastblues.cn/feed/,地址2,地址3