WordPress代码实现自动关键词与描述

//自动关键词与描述
function meta_SEO() {
global $post;
$output = '';
if (is_single()){//如果是文章页
$keywords = ''; 
$description = '';
if ($post->post_excerpt) {//如果文章摘要存在就以文章摘要为描述
$description = $post->post_excerpt;
$description = str_replace("\r\n","",$description);
$description = str_replace("\n","",$description);
$description = str_replace("\"","'",$description);
$description .= '...';
} else {//如果文章摘要不存在就截断文章前200字为描述
$description = utf8Substr(strip_tags($post->post_content),0,200);
$description = str_replace("\r\n","",$description);
$description = str_replace("\n","",$description);
$description = str_replace("\"","'",$description);
$description .= '...';
} 
$tags = wp_get_post_tags($post->ID);//取文章标签
foreach ($tags as $tag ) {
$keywordarray[] = $tag->name;
}
//以文章标签为关键字
$keywords = implode(',',array_unique((array)$keywordarray));
} else if (is_category()){
$description = strip_tags(trim(category_description()));
$keywords = single_cat_title('', false);
}else {//如果不是文章页、分类页
$keywords = 'WordPress,wordpress主题,wordpress插件,WordPress开发,代码,前端,建站'; //在引号间写入你博客的关键字用,断开
$description = '一个有关WordPress技巧与前端开发知识的个人博客，以分享、研究探讨WordPress技巧为主要内容，博主乃WordPress极客一枚';//在引号间写入你博客的简单描述，不要过200字
}
//输出关键字
$output .= '' . "\n";
$output .= '' . "\n";
//输出描述
echo "$output";
}