Typecho 上一篇下一篇改进，并获取缩略图

Typecho 获取上一篇下一篇的获取方法是

$this->theNext();
$this->thePrev();

这个返回只有部分信息不方便获取额外信息。
其实翻看代码直接抽取查询代码就可以自己扩展了

function getNextPost($archive)
{
    $db = Typecho_Db::get();
    $post = $db->fetchRow($db->select()->from('table.contents')->where('table.contents.created > ? AND table.contents.created < ?', $archive->created, Helper::options()->time)
        ->where('table.contents.status = ?', 'publish')
        ->where('table.contents.type = ?', $archive->type)
        ->where("table.contents.password IS NULL OR table.contents.password = ''")
        ->order('table.contents.created', Typecho_Db::SORT_ASC)
        ->limit(1));

    return $post;
}
function getPrevPost($archive)
{
    $db = Typecho_Db::get();
    $post = $db->fetchRow($db->select()->from('table.contents')->where('table.contents.created < ?', $archive->created)
        ->where('table.contents.status = ?', 'publish')
        ->where('table.contents.type = ?', $archive->type)
        ->where("table.contents.password IS NULL OR table.contents.password = ''")
        ->order('table.contents.created', Typecho_Db::SORT_DESC)
        ->limit(1));
    return $post;
}

使用很简单，比如我想获取缩略图

$post = getPrevPost($this);
$thumbnail = getThumbnail($post['conent'])

$post是一个数组，getThumbnail()是我写的用于获取缩略图的方法。
如果想获取文章创建时间

date('Y-m-d H:i:s', $post['created'])

如果想把获取的的查询结果转成 $widget 对象的话，通过$widget->content来获取文章内容，可以这么操作（这个方法只需要一次数据库查询）

function getNextPost($archive)
{
    $post = new Widget_Abstract_Contents(Typecho_Request::getInstance(), Typecho_Widget_Helper_Empty::getInstance(), null);
    $db = Typecho_Db::get();
    $db->fetchAll($db->select()->from('table.contents')->where('table.contents.created > ? AND table.contents.created < ?', $archive->created, Helper::options()->time)
        ->where('table.contents.status = ?', 'publish')
        ->where('table.contents.type = ?', $archive->type)
        ->where("table.contents.password IS NULL OR table.contents.password = ''")
        ->order('table.contents.created', Typecho_Db::SORT_ASC)
        ->limit(1), array($post, 'push'));

    return $post;
}

获取缩略图函数

function getThumbnail($widget)
{
    $pattern = '/\<img.*?src\=\"(.*?)\"[^>]*>/i';
    $patternMD = '/\!\[.*?\]\((http(s)?:\/\/.*?(jpg|jpeg|gif|png|webp))/i';
    $patternMDfoot = '/\[.*?\]:\s*(http(s)?:\/\/.*?(jpg|jpeg|gif|png|webp))/i';
    if ($widget->fields->thumb && !empty(trim($widget->fields->thumb))) {
        return $widget->fields->thumb;
    }

    preg_match_all($pattern, $widget->content, $matches);
    $thumbs = array_filter($matches[1], 'thumbFilter');
    if (count($thumbs)) {
        $thumb = $thumbs[0];
    }
    if (!isset($thumb)) {
        preg_match_all($patternMD, $widget->content, $matches);
        $thumbs = array_filter($matches[1], 'thumbFilter');
        if (count($thumbs)) {
            $thumb = $thumbs[0];
        }
    }
    if (!isset($thumb)) {
        preg_match_all($patternMDfoot, $widget->content, $matches);
        $thumbs = array_filter($matches[1], 'thumbFilter');
        if (count($thumbs)) {
            $thumb = $thumbs[0];
        }
    }
    
    // 主题目录下新建 random 目录，自行加入25张随机图
    $random = staticUrl("/random/") . rand(1, 25) . '.jpg';

    return isset($thumb) ? $thumb : $random;
}
function thumbFilter($item)
{
    return strpos($item, __TYPECHO_PLUGIN_DIR__ . "/") === false;
}

然后就可以通过

<?php $nextPost = getNextPost($this); ?>
<a href="<?php $nextPost->permalink() ?>">
   <span class="item"><?php $nextPost->title(); ?></span>
   <span class="item"><img src="<?php echo getThumbnail($nextPost); ?>"/></span>
   <span class="item"><?php $this->created(); ?></span>
   <span class="item"><?php $this->date(); ?></span>
</a>

来获取下一篇文章对应的信息了

2021.02.25更新

判断下一篇不存在不输出

<?php $nextPost = getNextPost($this); ?>
<?php if ($nextPost->have()) : ?>
<a href="<?php $nextPost->permalink() ?>">
   <span class="item"><?php $nextPost->title(); ?></span>
   <span class="item"><img src="<?php echo getThumbnail($nextPost); ?>"/></span>
   <span class="item"><?php $this->created(); ?></span>
   <span class="item"><?php $this->date(); ?></span>
</a>
<?php endif; ?>