我正在尝试向我的站点添加一个函数，该函数将计算贴在帖子上的图像数量，如果只有一个，则向其中任何一个添加一个类<img> 或到包含<a>.

我想我已经很接近了，但还没有PHP语法技能来完成它。我破解的代码来源于该主题的各个线程，是：

/**
 *
 * Single-image posts will receive a separate class name
 *
 */

add_filter( \'the_content\', \'single_image_content_filter\', 20 );

// Count images in post
function single_image_content_filter( $content ) {

$attachments = get_children(array(\'post_parent\'=>$post->ID));
$imgcount = count($attachments);

    // If only one attachment, add a new CSS class
    if ( $imgcount === 1 ) {

        global $post;
        $classes = \'single-img\'; // separated by spaces, e.g. \'img image-link\'

        // check if there are already classes assigned to the anchor, and/or add one via $classes
        if ( preg_match(\'/<a.*? class=".*?">/\', $content) ) {
        $content = preg_replace(\'/(<a.*? class=".*?)(".*?>)/\', \'$1 \' . $classes . \'$2\', $content);
      } else {
        $content = preg_replace(\'/(<a.*?)>/\', \'$1 class="\' . $classes . \'" >\', $content);
      }

return $content;

    }
}