禁止WordPress发布重复文件 检测标题一样的文章

如果我们在编辑文章的时候，尤其是多用户编辑的时候可能会导致文章的标题重复。这里我们可以用插件和代码实现检测是否有重复的文章，如果有的话提示。

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
}
    
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'>". _( '存在重复标题！' , '' ) ." </span>";
	} else {
		echo '<span style="color:green">'._('标题不重复！' , '').'</span>';
	} 
	die();
}
 
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 ;
	}
}
 
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('文章标题重复！' , '') ?></p>
	   </div>
	   <?php
	}
}
 
// 禁用自动保存
add_action( 'wp_print_scripts', 'disable_autosave' ) ;
function disable_autosave(){
	wp_deregister_script( 'autosave' ) ;
}

这样我们发布的文章标题会检测是否重复。