WordPress防止发表重复标题的文章[代码版]

/**
 * 发表文章时禁止与已存在的标题相重复
 * Modify from Plugin: Duplicate Title Validate
 * Description: this plugin help , not allow publish Duplicate Title . 
 * Author: hasan movahed
 * Reviser: INLOJV
 * Version: 1.0
 * Author URI: http://www.wallfa.com
 * Reviser URI: http://www.inlojv.com
 */ // 发表文章页面，前端抓取标题并使用AJAX发送请求
add_action( 'admin_print_footer_scripts', 'duplicate_titles_enqueue_scripts', 100 ); function duplicate_titles_enqueue_scripts() { ?> <script>
jQuery(function($){ function checkTitleAjax(title, id,post_type) { var data = {
            action: 'title_checks',
            post_title: title,
            post_type: post_type,
            post_id: id
        };
        $.post(ajaxurl, data, function(response) {
            $('#message').remove();
            $('#poststuff').prepend('<div id=\"message\" class=\"updated below-h2 fade \"><p>'+response+'</p></div>'); }); };
    $('#title').change(function() { var title = $('#title').val(); var id = $('#post_ID').val(); var post_type = $('#post_type').val();
        checkTitleAjax(title, id,post_type); }); }); </script> <?php
} // 接收前端ajax参数
add_action('wp_ajax_title_checks', 'duplicate_title_checks_callback'); function duplicate_title_checks_callback(){ global $wpdb;            
	$title = $_POST['post_title'];
	$post_id = $_POST['post_id']; 
	$titles = "SELECT post_title FROM $wpdb->posts WHERE post_status = 'publish' AND post_type = 'post' 
				AND post_title = '{$title}' AND ID != {$post_id} "; 
	$results = $wpdb->get_results($titles); if($results) {
		echo "<span style='color:red'>". _( '此标题已存在，请换一个标题！' , '' ) ." </span>"; } else {
		echo '<span style="color:green">'._('恭喜，此标题未与其他文章标题重复！' , '').'</span>'; } die(); } // 检测后端标题并且避免同名文章更新草稿
add_action( 'publish_post','duplicate_titles_wallfa_bc' ) ; function duplicate_titles_wallfa_bc( $post ){ global $wpdb ;
	$title = $_POST['post_title'] ;
	$post_id = $post ; 
	$wtitles = "SELECT post_title FROM $wpdb->posts WHERE post_status = 'publish' AND post_type = 'post' 
						AND post_title = '{$title}' AND ID != {$post_id} " ; 
	$wresults = $wpdb->get_results( $wtitles ) ; if ( $wresults ){
		$wpdb->update( $wpdb->posts, array( 'post_status' => 'draft' ), array( 'ID' => $post ) ) ;
        $arr_params = array( 'message' => '10', 'wallfaerror' => '1' ) ;      
		$location = add_query_arg( $arr_params , get_edit_post_link( $post , 'url' ) ) ;
		wp_redirect( $location  ) ; exit ; } } /// 文章提交更新后的提示
add_action( 'admin_notices', 'not_published_error_notice' ); function not_published_error_notice() { if(isset($_GET['wallfaerror']) == 1 ){ ?> <div class="updated"> <p style='color:red' ><?php _e('貌似已经存在相同标题的文章，若您使用了文章别名作为固定链接，则可以通过修改本文的固定链接来使标题不再重复！' , '') ?></p> </div> <?php
	} } // 禁用自动保存
add_action( 'wp_print_scripts', 'disable_autosave' ) ; function disable_autosave(){
	wp_deregister_script( 'autosave' ) ; }