WordPress默认的搜索功能是只要文章出现的词搜索的时候一起匹配，虽然这种搜索方式很全面，但是这种一般会得到很多不正确的结果，会增加信息获取的难度，那么如何使用WordPress代码实现只搜索文章标题？如果不想匹配文章内容中出现的关键词，我们可以通过posts_search过滤器，将搜索结果替换成我们自己的搜索逻辑即可。
操作步骤：
新增配置项
在主题设置配置文件options.php中添加如下配置项，位置随便你，建议添加到基本选项卡中。
$options[] = array(
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’name\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’ => __(\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’搜索时关键字只匹配标题\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’, \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’haoui\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’),
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’id\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’ => \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’search_title\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’,
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’type\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’ => \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\”checkbox\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\”,
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’std\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’ => true,
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’desc\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’ => __(\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’开启\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’, \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’haoui\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’));
替换搜索逻辑
以下代码放在functions.php中，或者被functions.php引用的文件中。
function hui_search_by_title_only( $search ){
global $wpdb, $wp_query;
if ( empty( $search ) )
return $search;
$q = $wp_query->query_vars;
$n = ! empty( $q[\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’exact\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’] ) ? \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’ : \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’%\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’;
$search =
$searchand = \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’;
foreach ( (array) $q[\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’search_terms\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’] as $term ) {
$term = esc_sql( $wpdb->esc_like( $term ) );
$search .= \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\”{$searchand}($wpdb->posts.post_title LIKE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\'{$n}{$term}{$n}\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’)\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\”;
$searchand = \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’ AND \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’;
}
if ( ! empty( $search ) ) {
$search = \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\” AND ({$search}) \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\”;
if ( ! is_user_logged_in() )
$search .= \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\” AND ($wpdb->posts.post_password = \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’) \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\”;
}
return $search;
}
使用主题配置项控制，请在上面代码结束后添加如下代码
if( _hui(\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’search_title\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’) ){
add_filter( \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’posts_search\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’, \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’hui_search_by_title_only\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’, 500, 2 );
}
如果你不想要后台选项，可以将上面代码替换掉。
add_filter( \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’posts_search\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’, \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’hui_search_by_title_only\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\’, 500, 2 );