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。