自动为wordpress站点/文章添加关键词与描述的方法

​​​​​​​<?php
$description = '';
$keywords = '';
if (is_home() || is_page()) {
// 将以下引号中的内容改成你的主页description
$description = "博客描述";
// 将以下引号中的内容改成你的主页keywords
$keywords = "关键词，注意关键词之前以英文逗号隔开";
}
elseif (is_single()) {
$description1 = get_post_meta($post->ID, "description", true);
$description2 = str_replace("n","",mb_strimwidth(strip_tags($post->post_content), 0, 200, "…", 'utf-8'));
// 填写自定义字段description时显示自定义字段的内容，否则使用文章内容前200字作为描述
$description = $description1 ? $description1 : $description2;
// 填写自定义字段keywords时显示自定义字段的内容，否则使用文章tags作为关键词
$keywords = get_post_meta($post->ID, "keywords", true);
if($keywords == '') {
$tags = wp_get_post_tags($post->ID);
foreach ($tags as $tag ) {
$keywords = $keywords . $tag->name . ", ";
}
$keywords = rtrim($keywords, ', ');
}
}
elseif (is_category()) {
// 分类的description可以到后台 - 文章 -分类目录，修改分类的描述
$description = category_description();
$keywords = single_cat_title('', false);
}
elseif (is_tag()){
// 标签的description可以到后台 - 文章 - 标签，修改标签的描述
$description = tag_description();
$keywords = single_tag_title('', false);
}
$description = trim(strip_tags($description));
$keywords = trim(strip_tags($keywords));
?>
<meta name="description" content="<?php echo $description; ?>" />
<meta name="keywords" content="<?php echo $keywords; ?>" />

add_action ( 'wp_head', 'wp_keywords' ); // 添加关键字
add_action ( 'wp_head', 'wp_description' ); // 添加页面描述
function wp_keywords() {
global $s, $post;
$keywords = '';
if (is_single ()) { //如果是文章页，关键词则是：标签+分类ID
if (get_the_tags ( $post->ID )) {
foreach ( get_the_tags ( $post->ID ) as $tag )
$keywords .= $tag->name . ', ';
}
foreach ( get_the_category ( $post->ID ) as $category )
$keywords .= $category->cat_name . ', ';
$keywords = substr_replace ( $keywords, '', - 2 );
} elseif (is_home ()) {
$keywords = '我是主页关键词'; //主页关键词设置
} elseif (is_tag ()) { //标签页关键词设置
$keywords = single_tag_title ( '', false );
} elseif (is_category ()) {//分类页关键词设置
$keywords = single_cat_title ( '', false );
} elseif (is_search ()) {//搜索页关键词设置
$keywords = esc_html ( $s, 1 );
} else {//默认页关键词设置
$keywords = trim ( wp_title ( '', false ) );
}
if ($keywords) { //输出关键词
echo "<meta name="keywords" content="$keywords" />n";
}
}

function wp_description() {
global $s, $post;
$description = '';
$blog_name = get_bloginfo ( 'name' );
if (is_singular ()) { //文章页如果存在描述字段，则显示描述，否则截取文章内容
if (! empty ( $post->post_excerpt )) {
$text = $post->post_excerpt;
} else {
$text = $post->post_content;
}
$description = trim ( str_replace ( array (
"rn",
"r",
"n",
"　",
" "
), " ", str_replace ( """, "'", strip_tags ( $text ) ) ) );
if (! ($description))
$description = $blog_name . "-" . trim ( wp_title ( '', false ) );
} elseif (is_home ()) {//首页显示描述设置
$description = $blog_name . "-" . get_bloginfo ( 'description' ) .'首页要显示的描述'; // 首頁要自己加
} elseif (is_tag ()) {//标签页显示描述设置
$description = $blog_name . "有关 '" . single_tag_title ( '', false ) . "' 的文章";
} elseif (is_category ()) {//分类页显示描述设置
$description = $blog_name . "有关 '" . single_cat_title ( '', false ) . "' 的文章";
} elseif (is_archive ()) {//文档页显示描述设置
$description = $blog_name . "在: '" . trim ( wp_title ( '', false ) ) . "' 的文章";
} elseif (is_search ()) {//搜索页显示描述设置
$description = $blog_name . ": '" . esc_html ( $s, 1 ) . "' 的搜索結果";
} else {//默认其他页显示描述设置
$description = $blog_name . "有关 '" . trim ( wp_title ( '', false ) ) . "' 的文章";
}
//输出描述
$description = mb_substr ( $description, 0, 220, 'utf-8' ) . '..';
echo "<meta name="description" content="$description" />n";
}