WordPress中利用AJAX技术进行评论提交的实现示例

//以下大部分代码出自 yinheli 经由该部分代码，排除部分错误、优化精简得出以下代码。
//yinheli博客不做了，所以这里就不给链接了。
//Edited by XiangZi DEC.17TH 2011
function fail($s) {//虚拟错误头部分
  header('HTTP/1.0 500 Internal Server Error');
  echo $s;
  exit;
}
function ajax_post_comment_slow (){
 fail('用不用说这么快？想好了再说！');
}
//评论太快输出代码。
add_filter('comment_flood_trigger','ajax_post_comment_slow', 0);
//挂一个评论太快，返回内容的钩子
function ajax_comment(){
// Ajax php 响应部分代码
if($_POST['action'] == 'ajax_comment') {
  global $wpdb, $db_check;
    // Check DB
    if(!$wpdb->dbh) {
      echo('Our database has issues. Try again later.');
  die();
    } 
nocache_headers();
$comment_post_ID = (int) $_POST['comment_post_ID'];
 $status = $wpdb->get_row("SELECT post_status, comment_status FROM $wpdb->posts WHERE ID = '$comment_post_ID'");
if ( empty($status->comment_status) ) {
//这一套判断貌似抄的 wp 源代码 。详见：include/comment.php
  do_action('comment_id_not_found', $comment_post_ID);
  fail('The post you are trying to comment on does not currently exist in the database.');
} elseif ( 'closed' == $status->comment_status ) {
  do_action('comment_closed', $comment_post_ID);;
  fail('Sorry, comments are closed for this item.');
} elseif ( in_array($status->post_status, array('draft', 'pending') ) ) {
  do_action('comment_on_draft', $comment_post_ID);
  fail('The post you are trying to comment on has not been published.');
}
$comment_author    = trim(strip_tags($_POST['author']));
$comment_author_email = trim($_POST['email']);
$comment_author_url  = trim($_POST['url']);
$comment_content   = trim($_POST['comment']);
// If the user is logged in
$user = wp_get_current_user();
if ( $user->ID ) {
  $comment_author    = $wpdb->escape($user->display_name);
  $comment_author_email = $wpdb->escape($user->user_email);
  $comment_author_url  = $wpdb->escape($user->user_url);
  if ( current_user_can('unfiltered_html') ) {
    if ( wp_create_nonce('unfiltered-html-comment_' . $comment_post_ID) != $_POST['_wp_unfiltered_html_comment'] ) {
      kses_remove_filters(); // start with a clean slate
      kses_init_filters(); // set up the filters
    }
  }
} else {
  if ( get_option('comment_registration') )
    fail('火星人？注册个?');
}
$comment_type = '';
if ( get_option('require_name_email') && !$user->ID ) {
  if ( 6> strlen($comment_author_email) || '' == $comment_author )
    fail('Oopps,名字[Name]或邮箱[email]不对。');
  elseif ( !is_email($comment_author_email))
    fail('Oopps,邮箱地址[Email]不对。');
}
if ( '' == $comment_content )
  fail('是不是应该写点什么再提交？');
// Simple duplicate check
$dupe = "SELECT comment_ID FROM $wpdb->comments WHERE comment_post_ID = '$comment_post_ID' AND ( comment_author = '$comment_author' ";
if ( $comment_author_email ) $dupe .= "OR comment_author_email = '$comment_author_email' ";
$dupe .= ") AND comment_content = '$comment_content' LIMIT 1";
if ( $wpdb->get_var($dupe) ) {
  fail('评论重复了!有木有!');
}
$commentdata = compact('comment_post_ID', 'comment_author', 'comment_author_email', 'comment_author_url', 'comment_content', 'comment_type', 'user_ID');
if( !$user->ID ){
 $result_set = $wpdb->get_results("SELECT display_name, user_email FROM $wpdb->users WHERE display_name = '" . $comment_author . "' OR user_email = '" . $comment_author_email . "'");
 if ($result_set) {
 if ($result_set[0]->display_name == $comment_author){
 fail('博主你也敢冒充？');
 } else {
 fail('博主你也敢冒充？');
 }
 }
}
$comment_id = wp_new_comment( $commentdata );
$comment = get_comment($comment_id);
 
if( !$user->ID ){
 setcookie('comment_author_' . COOKIEHASH, $comment->comment_author, time() + 30000000, COOKIEPATH, COOKIE_DOMAIN);
 setcookie('comment_author_email_' . COOKIEHASH, $comment->comment_author_email, time() + 30000000, COOKIEPATH, COOKIE_DOMAIN);
 setcookie('comment_author_url_' . COOKIEHASH, clean_url($comment->comment_author_url), time() + 30000000, COOKIEPATH, COOKIE_DOMAIN);
}
@header('Content-type: ' . get_option('html_type') . '; charset=' . get_option('blog_charset'));
 xz_comment($comment, null);//这是我的调用评论函数，换成你的函数名。
 die();
}
}
add_action('init', 'ajax_comment');

if (jQuery('#commentform').length) {
  jQuery('#commentform').submit(function(){  
// 截获提交动作
//ID为 commentform 的表单提交时发生的函数，也就是整个留言输入框 form 的ID。
 var ajaxCommentsURL = window.location.href;
    jQuery.ajax({
      url: ajaxCommentsURL,
      data: jQuery('#commentform').serialize()+'&action=ajax_comment',  
      type: 'POST',
      beforeSend: function() {
        jQuery('#commenterror').hide();
        jQuery('#commentload').fadeIn();
      },
      error: function(request) {  //发生错误时
        jQuery('#commenterror').html(request.responseText);
        jQuery('#commentload').hide();  //隐藏 submit
        jQuery('#commenterror').fadeIn(); //显示 error 
      },
      success: function(data) {
        jQuery('textarea').each(function(){
          this.value='';
        });
        jQuery('#commenterror').fadeOut();
        if(jQuery(".commentlist li.comment").first().length != 0){jQuery(".commentlist li.comment").first().before(data)}  
        else {jQuery("ol.commentlist").append(data)}
        jQuery(".commentlist li.comment").first().hide(0,function(){$(this).slideDown(1000)});
        jQuery('#cmt-submit').attr('disabled', true).css({"background-color":"#6C6C6C","color":"#E0E0E0"});
        jQuery('#commentload').fadeOut(1600);
 setTimeout(function() {
        jQuery('#cmt-submit').removeAttr('disabled').css({"background-color":"#0086C5","color":"#FFFFFF"});
        },3000); 
      }
    });
    return false;
  } );
}

#commentload,#commenterror{
 display: none;
 margin: 5px 0 0 0;
 color:#D29A04;
 float: left;
 font-size:16px;
 padding:0 0 0 20px;
}
#commentload{
 background: url("img/loading.gif") no-repeat bottom left ;
}
#commenterror{
 background: url("img/error.png") no-repeat bottom left ;
}