wordpress进阶教程(三十一):ajax实现文章顶踩

本篇教程要实现的内容为文章定踩功能，或者说“喜欢”“不喜欢”。

应用实例：

实现步骤：

本实例以上图所示喜欢和不喜欢为例。

一、新建数据表

新建数据表，将文章投票数据保存在新的数据表中，我们需要记录用户ID，文章ID，投票内容，用户ip，新数据表如下： wordpress进阶教程(三十一):ajax实现文章顶踩

实现新建数据表代码如下，将代码添加进主题的functions.php(或自定)文件中：


/*********更新重写规则***************/  
function ashu_load_theme() {   
    global $pagenow;   
    if ( is_admin() && 'themes.php' == $pagenow && isset( $_GET['activated'] ) )   
        ashu_vote_install(); //激活主题的时候执行函数   
}   
add_action( 'load-themes.php', 'ashu_load_theme' );   
function ashu_vote_install(){   
    global $wpdb;   
    //创建 _post_vote表   
    $table_name = $wpdb->prefix . 'post_vote';   
    if( $wpdb->get_var("SHOW TABLES LIKE '$table_name'") != $table_name ) :   
    $sql = " CREATE TABLE `".$wpdb->prefix."post_vote` ( 
      `id` BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY ,  
      `user` INT NOT NULL ,  
      `post` INT NOT NULL ,  
      `rating` varchar(10),  
      `ip` varchar(40)  
     ) ENGINE = myisam DEFAULT CHARSET=utf8;";   
        require_once(ABSPATH . 'wp-admin/includes/upgrade.php');   
        dbDelta($sql);   
    endif;   
}  


/*  
*添加投票函数  
*$post_id 文章id  
*$user_id 用户ID  
*$ip 用户IP  
*$rating 投票内容  
*/  
function add_vote($post_id,$user_id='',$ip='',$rating='up'){   
    global $wpdb;   
    $user_id = (int)$user_id;   
    $post_id = (int)$post_id;   
    if(($user_id=='')&&($ip=='')){   
        return "e"; //返回error   
    }   
    //检查用户对某一文章是否已经投票票了   
    if($user_id!=''){   
        $check= "select * from ".$wpdb->prefix."post_vote where post='$post_id' and user='$user_id'";   
    }else{   
        if($ip!=''){   
            $check= "select * from ".$wpdb->prefix."post_vote where post='$post_id' and ip='$ip'";   
        }   
    }   
    $coo = $wpdb->get_results($check);   
    //投票内容只能是up或者down   
    if($rating=='up'){   
        $rating='up';   
    }else{   
        $rating='down';   
    }   
    //如果不存在数据   
    if(!count($coo) > 0){   
        //插入数据 sql   
        $s = "insert into ".$wpdb->prefix."post_vote (user,post,rating,ip) values('$user_id','$post_id','$rating','$ip')";   
        $wpdb->query($s);   
        return "y"; //返回yes   
    }else{   
        return "h"; //返回have   
    }   
    return "e";//返回error   
}  


/*   
*获取文章投票数据   
*$post_id 文章ID   
*$vote 投票内容   
*/   
function get_post_vote($post_id,$vote='up'){   
    global $wpdb;   
    $post_id = (int)$post_id;   
    if($vote == 'up'){   
        $vote='up';   
    }else{   
        $vote='down';   
    }   
    //查询数据sql   
    $sql = "select count(*) from ".$wpdb->prefix."post_vote where post='$post_id' and rating='$vote'";   
    $coo = $wpdb->get_var($sql);   
    if($coo)   
    return $coo; //返回数据   
    else   
    return 0;   
}  


<span class="vote_up" id="<?php echo 'vote_up'.$post->ID;?>">   
    <a href="javascript:void(0);" rel="<?php echo 'up_',$post->ID;?>">   
    <span id="<?php echo 'vup'.$post->ID;?>">   
        <?php echo get_post_vote($post->ID,'up');?>   
    </span>   
    </a>   
人认为值得买！</span>   
  
<span class="vote_down" id="<?php echo 'vote_down'.$post->ID;?>">   
    <a href="javascript:void(0);" rel="<?php echo 'down_'.$post->ID;?>">   
    <span id="<?php echo 'vdown'.$post->ID;?>">   
        <?php echo get_post_vote($post->ID,'down');?>   
    </span>   
    </a>人认为不值得买！   
</span>  


<span class="vote_up" id="vote_up44">  
    <a href="javascript:void(0);" title="值得" rel="up_44">  
    <span id="vup44">  
        0   
    </span>  
    </a>  
人认为值得买！</span>  
<span class="vote_down" id="vote_down44">  
    <a href="javascript:void(0);" title="不值" rel="down_44">  
    <span id="vdown44">  
        1   
    </span>  
    </a>人认为不值得买！   
</span>  


<script src="<?php echo get_template_directory_uri();?>/js/jquery-1.7.2.min.js"></script>   


其中输出了ajax请求的地址：www.dba.cn/wp-admin/admin-ajax.php
<script type="text/javascript">var ajax_url = '<?php echo admin_url(); ?>admin-ajax.php';</script>  
<script src="<?php echo get_template_directory_uri();?>/js/ashu.js"></script>    


/**     
 * by ashu.     
 * URI: Http://www.dba.cn     
 */   
  
/**   
 * 获取Cookie   
 *name  cookie名称   
 */   
function getCookie(name) {   
    var start = document.cookie.indexOf( name + "=" );   
    var len = start + name.length + 1;   
  
    if ( ( !start ) && ( name != document.cookie.substring( 0, name.length ) ) )   
        return null;   
  
    if ( start == -1 )   
        return null;   
  
    var end = document.cookie.indexOf( ';', len );   
  
    if ( end == -1 )   
        end = document.cookie.length;   
    return unescape( document.cookie.substring( len, end ) );   
}   
function ashu_isCookieEnable() {   
    var today = new Date();   
    today.setTime( today.getTime() );   
    var expires_date = new Date( today.getTime() + (1000 * 60) );   
  
    document.cookie = 'ashu_cookie_test=test;expires=' + expires_date.toGMTString() + ';path=/';   
    var cookieEnable = (getCookie('ashu_cookie_test') == 'test') ?  true : false;   
    //document.cookie = 'ludou_cookie_test=;expires=Fri, 3 Aug 2001 20:47:11 UTC;path=/';   
    return cookieEnable;   
}   
    
jQuery(document).ready(function($) {   
    var ashu_token = 1;   
    $('.vote_up a').click(function(){   
        //检查浏览器是否启用cookie功能   
        if( !ashu_isCookieEnable() ) {   
            alert("很抱歉，您不能给本文投票！");   
            return;   
        }   
        if( ashu_token != 1 ) {   
            alert("您的鼠标点得也太快了吧？！");   
            return false;   
        }   
        ashu_token = 0;   
        //获取投票a标签中的rel值   
        var full_info = $(this).attr( 'rel' );   
        var arr_param = full_info.split( '_' ); //以字符"_"分割   
        //发起ajax   
        $.ajax({   
            url:ajax_url, //ajax地址   
            type:'POST',   
            //请求的参数包括action   rating  postid三项   
            data:'action=vote_post&rating=' + arr_param[ 0 ] + '&postid=' + arr_param[ 1 ],   
            //返回数据   
            success:function(results){   
                if(results=='n'){   
                    alert('评价失败');   
                    ashu_token = 1;   
  
                }   
                if (results=='y'){   
                    //如果成功，给前台数据加1   
                    var upd_vd = 'vup' + arr_param[ 1 ];   
                    $('#'+upd_vd).text(parseInt($("#"+upd_vd).text())+1);   
                    ashu_token = 1;   
                       
                }   
                if (results=='h'){   
                    ashu_token = 1;   
                    alert('已经发表过评价了');   
                }   
                if (results=='e'){   
                    ashu_token = 1;   
                    alert('评价失败');   
                }   
            }   
        });   
    });   
       
    $('.vote_down a').click(function(){   
        if( !ashu_isCookieEnable() ) {   
            alert("很抱歉，您不能给本文投票！");   
            return;   
        }   
        if(ashu_token != 1) {   
            alert("您的鼠标点得也太快了吧？！");   
            return false;   
        }   
        ashu_token = 0;   
  
        var full_info = $(this).attr( 'rel' );   
        var arr_param = full_info.split( '_' );   
        $.ajax({   
            url:ajax_url,   
            type:'POST',   
            data:'action=vote_post&rating=' + arr_param[ 0 ] + '&postid=' + arr_param[ 1 ],   
            success:function(results){   
                if(results=='n'){   
                    alert('评价失败');   
                    ashu_token = 1;   
                }   
                if (results=='y'){   
                    var upd_vd = 'vdown' + arr_param[ 1 ];   
                    $("#"+upd_vd).text(parseInt($("#"+upd_vd).text())+1);   
                    ashu_token = 1;   
                }   
                if (results=='h'){   
                    ashu_token = 1;   
                    alert('已经发表过评价了');   
                }   
                if (results=='e'){   
                    ashu_token = 1;   
                    alert('发生未知错误');   
                }   
            }   
        });   
    });   
});  


/*   
*wp的ajax都可以通过请求中的action参数来执行对应的钩子   
*示例中我们的action参数值是vote_post   
*所以我们可以直接用下面两个钩子来执行动作   
*/   
add_action("wp_ajax_vote_post", "add_votes_options");   
add_action("wp_ajax_nopriv_vote_post", "add_votes_options");   
function add_votes_options() {   
  
if( isset($_POST['action']) && ($_POST['action'] == 'vote_post') ){   
    $postid = (int)$_POST['postid'];   
    if( !$postid ){   
        echo 'e'; //输出error   
        die(0);   
    }   
    //cookie中是否已经存在投票数据   
    $voted = $_COOKIE["smzdm_voted_".$postid];   
    if( $voted ){   
        echo 'h'; //输出have   
        die(0);   
    }   
    $ip = $_SERVER['REMOTE_ADDR'];//ip   
    $rating = $_POST['rating']; //投票内容   
    //判断用户是否登录   
    if(  is_user_logged_in() ){   
        global $wpdb, $current_user;   
        get_currentuserinfo();   
        $uid = $current_user->ID;   
    }else{   
        $uid='';   
    }   
    if($rating=='up'){   
        $rating='up';   
    }else{   
        $rating='down';   
    }   
    //添加数据   
    $voted = add_vote($postid,$uid,$ip,$rating);   
    if($voted=='y'){   
        //设置cookie   
        setcookie("ashu_voted_" . $postid,$rating, time() + 3000000, '/');   
        echo 'y';//输出yes   
        die(0);   
    }   
    if($voted=='h'){   
        //设置cookie   
        setcookie("ashu_voted_" . $postid,$rating, time() + 3000000, '/');   
        echo 'h';   
        die(0);   
    }   
    if($voted=='e'){   
        echo 'n';//输出no   
        die(0);   
    }   
}else{   
    echo 'e';//输出eroor   
}   
die(0);   
}

二、准备投票和查询函数

准备数据库操作函数，包括添加数据函数和查询数据，将如下函数代码也添加到主题的functions.PHP文件(或自定)：

1、添加数据函数


/*********更新重写规则***************/  
function ashu_load_theme() {   
    global $pagenow;   
    if ( is_admin() && 'themes.php' == $pagenow && isset( $_GET['activated'] ) )   
        ashu_vote_install(); //激活主题的时候执行函数   
}   
add_action( 'load-themes.php', 'ashu_load_theme' );   
function ashu_vote_install(){   
    global $wpdb;   
    //创建 _post_vote表   
    $table_name = $wpdb->prefix . 'post_vote';   
    if( $wpdb->get_var("SHOW TABLES LIKE '$table_name'") != $table_name ) :   
    $sql = " CREATE TABLE `".$wpdb->prefix."post_vote` ( 
      `id` BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY ,  
      `user` INT NOT NULL ,  
      `post` INT NOT NULL ,  
      `rating` varchar(10),  
      `ip` varchar(40)  
     ) ENGINE = MYISAM DEFAULT CHARSET=utf8;";   
        require_once(ABSPATH . 'wp-admin/includes/upgrade.php');   
        dbDelta($sql);   
    endif;   
}  


/*  
*添加投票函数  
*$post_id 文章id  
*$user_id 用户ID  
*$ip 用户IP  
*$rating 投票内容  
*/  
function add_vote($post_id,$user_id='',$ip='',$rating='up'){   
    global $wpdb;   
    $user_id = (int)$user_id;   
    $post_id = (int)$post_id;   
    if(($user_id=='')&&($ip=='')){   
        return "e"; //返回error   
    }   
    //检查用户对某一文章是否已经投票票了   
    if($user_id!=''){   
        $check= "select * from ".$wpdb->prefix."post_vote where post='$post_id' and user='$user_id'";   
    }else{   
        if($ip!=''){   
            $check= "select * from ".$wpdb->prefix."post_vote where post='$post_id' and ip='$ip'";   
        }   
    }   
    $coo = $wpdb->get_results($check);   
    //投票内容只能是up或者down   
    if($rating=='up'){   
        $rating='up';   
    }else{   
        $rating='down';   
    }   
    //如果不存在数据   
    if(!count($coo) > 0){   
        //插入数据 sql   
        $s = "insert into ".$wpdb->prefix."post_vote (user,post,rating,ip) values('$user_id','$post_id','$rating','$ip')";   
        $wpdb->query($s);   
        return "y"; //返回yes   
    }else{   
        return "h"; //返回have   
    }   
    return "e";//返回error   
}  


/*   
*获取文章投票数据   
*$post_id 文章ID   
*$vote 投票内容   
*/   
function get_post_vote($post_id,$vote='up'){   
    global $wpdb;   
    $post_id = (int)$post_id;   
    if($vote == 'up'){   
        $vote='up';   
    }else{   
        $vote='down';   
    }   
    //查询数据sql   
    $sql = "select count(*) from ".$wpdb->prefix."post_vote where post='$post_id' and rating='$vote'";   
    $coo = $wpdb->get_var($sql);   
    if($coo)   
    return $coo; //返回数据   
    else   
    return 0;   
}  


<span class="vote_up" id="<?php echo 'vote_up'.$post->ID;?>">   
    <a href="javascript:void(0);" rel="<?php echo 'up_',$post->ID;?>">   
    <span id="<?php echo 'vup'.$post->ID;?>">   
        <?php echo get_post_vote($post->ID,'up');?>   
    </span>   
    </a>   
人认为值得买！</span>   
  
<span class="vote_down" id="<?php echo 'vote_down'.$post->ID;?>">   
    <a href="javascript:void(0);" rel="<?php echo 'down_'.$post->ID;?>">   
    <span id="<?php echo 'vdown'.$post->ID;?>">   
        <?php echo get_post_vote($post->ID,'down');?>   
    </span>   
    </a>人认为不值得买！   
</span>  


<span class="vote_up" id="vote_up44">  
    <a href="javascript:void(0);" title="值得" rel="up_44">  
    <span id="vup44">  
        0   
    </span>  
    </a>  
人认为值得买！</span>  
<span class="vote_down" id="vote_down44">  
    <a href="javascript:void(0);" title="不值" rel="down_44">  
    <span id="vdown44">  
        1   
    </span>  
    </a>人认为不值得买！   
</span>  


<script src="<?php echo get_template_directory_uri();?>/js/jquery-1.7.2.min.js"></script>   


其中输出了ajax请求的地址：www.dba.cn/wp-admin/admin-ajax.php
<script type="text/javascript">var ajax_url = '<?php echo admin_url(); ?>admin-ajax.php';</script>  
<script src="<?php echo get_template_directory_uri();?>/js/ashu.js"></script>    


/**     
 * by ashu.     
 * URI: http://www.dba.cn     
 */   
  
/**   
 * 获取Cookie   
 *name  cookie名称   
 */   
function getCookie(name) {   
    var start = document.cookie.indexOf( name + "=" );   
    var len = start + name.length + 1;   
  
    if ( ( !start ) && ( name != document.cookie.substring( 0, name.length ) ) )   
        return null;   
  
    if ( start == -1 )   
        return null;   
  
    var end = document.cookie.indexOf( ';', len );   
  
    if ( end == -1 )   
        end = document.cookie.length;   
    return unescape( document.cookie.substring( len, end ) );   
}   
function ashu_isCookieEnable() {   
    var today = new Date();   
    today.setTime( today.getTime() );   
    var expires_date = new Date( today.getTime() + (1000 * 60) );   
  
    document.cookie = 'ashu_cookie_test=test;expires=' + expires_date.toGMTString() + ';path=/';   
    var cookieEnable = (getCookie('ashu_cookie_test') == 'test') ?  true : false;   
    //document.cookie = 'ludou_cookie_test=;expires=Fri, 3 Aug 2001 20:47:11 UTC;path=/';   
    return cookieEnable;   
}   
    
jQuery(document).ready(function($) {   
    var ashu_token = 1;   
    $('.vote_up a').click(function(){   
        //检查浏览器是否启用cookie功能   
        if( !ashu_isCookieEnable() ) {   
            alert("很抱歉，您不能给本文投票！");   
            return;   
        }   
        if( ashu_token != 1 ) {   
            alert("您的鼠标点得也太快了吧？！");   
            return false;   
        }   
        ashu_token = 0;   
        //获取投票a标签中的rel值   
        var full_info = $(this).attr( 'rel' );   
        var arr_param = full_info.split( '_' ); //以字符"_"分割   
        //发起ajax   
        $.ajax({   
            url:ajax_url, //ajax地址   
            type:'POST',   
            //请求的参数包括action   rating  postid三项   
            data:'action=vote_post&rating=' + arr_param[ 0 ] + '&postid=' + arr_param[ 1 ],   
            //返回数据   
            success:function(results){   
                if(results=='n'){   
                    alert('评价失败');   
                    ashu_token = 1;   
  
                }   
                if (results=='y'){   
                    //如果成功，给前台数据加1   
                    var upd_vd = 'vup' + arr_param[ 1 ];   
                    $('#'+upd_vd).text(parseInt($("#"+upd_vd).text())+1);   
                    ashu_token = 1;   
                       
                }   
                if (results=='h'){   
                    ashu_token = 1;   
                    alert('已经发表过评价了');   
                }   
                if (results=='e'){   
                    ashu_token = 1;   
                    alert('评价失败');   
                }   
            }   
        });   
    });   
       
    $('.vote_down a').click(function(){   
        if( !ashu_isCookieEnable() ) {   
            alert("很抱歉，您不能给本文投票！");   
            return;   
        }   
        if(ashu_token != 1) {   
            alert("您的鼠标点得也太快了吧？！");   
            return false;   
        }   
        ashu_token = 0;   
  
        var full_info = $(this).attr( 'rel' );   
        var arr_param = full_info.split( '_' );   
        $.ajax({   
            url:ajax_url,   
            type:'POST',   
            data:'action=vote_post&rating=' + arr_param[ 0 ] + '&postid=' + arr_param[ 1 ],   
            success:function(results){   
                if(results=='n'){   
                    alert('评价失败');   
                    ashu_token = 1;   
                }   
                if (results=='y'){   
                    var upd_vd = 'vdown' + arr_param[ 1 ];   
                    $("#"+upd_vd).text(parseInt($("#"+upd_vd).text())+1);   
                    ashu_token = 1;   
                }   
                if (results=='h'){   
                    ashu_token = 1;   
                    alert('已经发表过评价了');   
                }   
                if (results=='e'){   
                    ashu_token = 1;   
                    alert('发生未知错误');   
                }   
            }   
        });   
    });   
});  


/*   
*wp的ajax都可以通过请求中的action参数来执行对应的钩子   
*示例中我们的action参数值是vote_post   
*所以我们可以直接用下面两个钩子来执行动作   
*/   
add_action("wp_ajax_vote_post", "add_votes_options");   
add_action("wp_ajax_nopriv_vote_post", "add_votes_options");   
function add_votes_options() {   
  
if( isset($_POST['action']) && ($_POST['action'] == 'vote_post') ){   
    $postid = (int)$_POST['postid'];   
    if( !$postid ){   
        echo 'e'; //输出error   
        die(0);   
    }   
    //cookie中是否已经存在投票数据   
    $voted = $_COOKIE["smzdm_voted_".$postid];   
    if( $voted ){   
        echo 'h'; //输出have   
        die(0);   
    }   
    $ip = $_SERVER['REMOTE_ADDR'];//ip   
    $rating = $_POST['rating']; //投票内容   
    //判断用户是否登录   
    if(  is_user_logged_in() ){   
        global $wpdb, $current_user;   
        get_currentuserinfo();   
        $uid = $current_user->ID;   
    }else{   
        $uid='';   
    }   
    if($rating=='up'){   
        $rating='up';   
    }else{   
        $rating='down';   
    }   
    //添加数据   
    $voted = add_vote($postid,$uid,$ip,$rating);   
    if($voted=='y'){   
        //设置cookie   
        setcookie("ashu_voted_" . $postid,$rating, time() + 3000000, '/');   
        echo 'y';//输出yes   
        die(0);   
    }   
    if($voted=='h'){   
        //设置cookie   
        setcookie("ashu_voted_" . $postid,$rating, time() + 3000000, '/');   
        echo 'h';   
        die(0);   
    }   
    if($voted=='e'){   
        echo 'n';//输出no   
        die(0);   
    }   
}else{   
    echo 'e';//输出eroor   
}   
die(0);   
}

2、查询投票数据函数

比如查询某文章点击up的数据，则使用 get_post_vote(1,'up');


/*********更新重写规则***************/  
function ashu_load_theme() {   
    global $pagenow;   
    if ( is_admin() && 'themes.php' == $pagenow && isset( $_GET['activated'] ) )   
        ashu_vote_install(); //激活主题的时候执行函数   
}   
add_action( 'load-themes.php', 'ashu_load_theme' );   
function ashu_vote_install(){   
    global $wpdb;   
    //创建 _post_vote表   
    $table_name = $wpdb->prefix . 'post_vote';   
    if( $wpdb->get_var("SHOW TABLES LIKE '$table_name'") != $table_name ) :   
    $sql = " CREATE TABLE `".$wpdb->prefix."post_vote` ( 
      `id` BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY ,  
      `user` INT NOT NULL ,  
      `post` INT NOT NULL ,  
      `rating` varchar(10),  
      `ip` varchar(40)  
     ) ENGINE = MYISAM DEFAULT CHARSET=utf8;";   
        require_once(ABSPATH . 'wp-admin/includes/upgrade.php');   
        dbDelta($sql);   
    endif;   
}  


/*  
*添加投票函数  
*$post_id 文章id  
*$user_id 用户ID  
*$ip 用户IP  
*$rating 投票内容  
*/  
function add_vote($post_id,$user_id='',$ip='',$rating='up'){   
    global $wpdb;   
    $user_id = (int)$user_id;   
    $post_id = (int)$post_id;   
    if(($user_id=='')&&($ip=='')){   
        return "e"; //返回error   
    }   
    //检查用户对某一文章是否已经投票票了   
    if($user_id!=''){   
        $check= "select * from ".$wpdb->prefix."post_vote where post='$post_id' and user='$user_id'";   
    }else{   
        if($ip!=''){   
            $check= "select * from ".$wpdb->prefix."post_vote where post='$post_id' and ip='$ip'";   
        }   
    }   
    $coo = $wpdb->get_results($check);   
    //投票内容只能是up或者down   
    if($rating=='up'){   
        $rating='up';   
    }else{   
        $rating='down';   
    }   
    //如果不存在数据   
    if(!count($coo) > 0){   
        //插入数据 sql   
        $s = "insert into ".$wpdb->prefix."post_vote (user,post,rating,ip) values('$user_id','$post_id','$rating','$ip')";   
        $wpdb->query($s);   
        return "y"; //返回yes   
    }else{   
        return "h"; //返回have   
    }   
    return "e";//返回error   
}  


/*   
*获取文章投票数据   
*$post_id 文章ID   
*$vote 投票内容   
*/   
function get_post_vote($post_id,$vote='up'){   
    global $wpdb;   
    $post_id = (int)$post_id;   
    if($vote == 'up'){   
        $vote='up';   
    }else{   
        $vote='down';   
    }   
    //查询数据sql   
    $sql = "select count(*) from ".$wpdb->prefix."post_vote where post='$post_id' and rating='$vote'";   
    $coo = $wpdb->get_var($sql);   
    if($coo)   
    return $coo; //返回数据   
    else   
    return 0;   
}  


<span class="vote_up" id="<?php echo 'vote_up'.$post->ID;?>">   
    <a href="javascript:void(0);" rel="<?php echo 'up_',$post->ID;?>">   
    <span id="<?php echo 'vup'.$post->ID;?>">   
        <?php echo get_post_vote($post->ID,'up');?>   
    </span>   
    </a>   
人认为值得买！</span>   
  
<span class="vote_down" id="<?php echo 'vote_down'.$post->ID;?>">   
    <a href="javascript:void(0);" rel="<?php echo 'down_'.$post->ID;?>">   
    <span id="<?php echo 'vdown'.$post->ID;?>">   
        <?php echo get_post_vote($post->ID,'down');?>   
    </span>   
    </a>人认为不值得买！   
</span>  


<span class="vote_up" id="vote_up44">  
    <a href="javascript:void(0);" title="值得" rel="up_44">  
    <span id="vup44">  
        0   
    </span>  
    </a>  
人认为值得买！</span>  
<span class="vote_down" id="vote_down44">  
    <a href="javascript:void(0);" title="不值" rel="down_44">  
    <span id="vdown44">  
        1   
    </span>  
    </a>人认为不值得买！   
</span>  


<script src="<?php echo get_template_directory_uri();?>/js/jquery-1.7.2.min.js"></script>   


其中输出了ajax请求的地址：www.dba.cn/wp-admin/admin-ajax.php
<script type="text/javascript">var ajax_url = '<?php echo admin_url(); ?>admin-ajax.php';</script>  
<script src="<?php echo get_template_directory_uri();?>/js/ashu.js"></script>    


/**     
 * by ashu.     
 * URI: http://www.dba.cn     
 */   
  
/**   
 * 获取Cookie   
 *name  cookie名称   
 */   
function getCookie(name) {   
    var start = document.cookie.indexOf( name + "=" );   
    var len = start + name.length + 1;   
  
    if ( ( !start ) && ( name != document.cookie.substring( 0, name.length ) ) )   
        return null;   
  
    if ( start == -1 )   
        return null;   
  
    var end = document.cookie.indexOf( ';', len );   
  
    if ( end == -1 )   
        end = document.cookie.length;   
    return unescape( document.cookie.substring( len, end ) );   
}   
function ashu_isCookieEnable() {   
    var today = new Date();   
    today.setTime( today.getTime() );   
    var expires_date = new Date( today.getTime() + (1000 * 60) );   
  
    document.cookie = 'ashu_cookie_test=test;expires=' + expires_date.toGMTString() + ';path=/';   
    var cookieEnable = (getCookie('ashu_cookie_test') == 'test') ?  true : false;   
    //document.cookie = 'ludou_cookie_test=;expires=Fri, 3 Aug 2001 20:47:11 UTC;path=/';   
    return cookieEnable;   
}   
    
jQuery(document).ready(function($) {   
    var ashu_token = 1;   
    $('.vote_up a').click(function(){   
        //检查浏览器是否启用cookie功能   
        if( !ashu_isCookieEnable() ) {   
            alert("很抱歉，您不能给本文投票！");   
            return;   
        }   
        if( ashu_token != 1 ) {   
            alert("您的鼠标点得也太快了吧？！");   
            return false;   
        }   
        ashu_token = 0;   
        //获取投票a标签中的rel值   
        var full_info = $(this).attr( 'rel' );   
        var arr_param = full_info.split( '_' ); //以字符"_"分割   
        //发起ajax   
        $.ajax({   
            url:ajax_url, //ajax地址   
            type:'POST',   
            //请求的参数包括action   rating  postid三项   
            data:'action=vote_post&rating=' + arr_param[ 0 ] + '&postid=' + arr_param[ 1 ],   
            //返回数据   
            success:function(results){   
                if(results=='n'){   
                    alert('评价失败');   
                    ashu_token = 1;   
  
                }   
                if (results=='y'){   
                    //如果成功，给前台数据加1   
                    var upd_vd = 'vup' + arr_param[ 1 ];   
                    $('#'+upd_vd).text(parseInt($("#"+upd_vd).text())+1);   
                    ashu_token = 1;   
                       
                }   
                if (results=='h'){   
                    ashu_token = 1;   
                    alert('已经发表过评价了');   
                }   
                if (results=='e'){   
                    ashu_token = 1;   
                    alert('评价失败');   
                }   
            }   
        });   
    });   
       
    $('.vote_down a').click(function(){   
        if( !ashu_isCookieEnable() ) {   
            alert("很抱歉，您不能给本文投票！");   
            return;   
        }   
        if(ashu_token != 1) {   
            alert("您的鼠标点得也太快了吧？！");   
            return false;   
        }   
        ashu_token = 0;   
  
        var full_info = $(this).attr( 'rel' );   
        var arr_param = full_info.split( '_' );   
        $.ajax({   
            url:ajax_url,   
            type:'POST',   
            data:'action=vote_post&rating=' + arr_param[ 0 ] + '&postid=' + arr_param[ 1 ],   
            success:function(results){   
                if(results=='n'){   
                    alert('评价失败');   
                    ashu_token = 1;   
                }   
                if (results=='y'){   
                    var upd_vd = 'vdown' + arr_param[ 1 ];   
                    $("#"+upd_vd).text(parseInt($("#"+upd_vd).text())+1);   
                    ashu_token = 1;   
                }   
                if (results=='h'){   
                    ashu_token = 1;   
                    alert('已经发表过评价了');   
                }   
                if (results=='e'){   
                    ashu_token = 1;   
                    alert('发生未知错误');   
                }   
            }   
        });   
    });   
});  


/*   
*wp的ajax都可以通过请求中的action参数来执行对应的钩子   
*示例中我们的action参数值是vote_post   
*所以我们可以直接用下面两个钩子来执行动作   
*/   
add_action("wp_ajax_vote_post", "add_votes_options");   
add_action("wp_ajax_nopriv_vote_post", "add_votes_options");   
function add_votes_options() {   
  
if( isset($_POST['action']) && ($_POST['action'] == 'vote_post') ){   
    $postid = (int)$_POST['postid'];   
    if( !$postid ){   
        echo 'e'; //输出error   
        die(0);   
    }   
    //cookie中是否已经存在投票数据   
    $voted = $_COOKIE["smzdm_voted_".$postid];   
    if( $voted ){   
        echo 'h'; //输出have   
        die(0);   
    }   
    $ip = $_SERVER['REMOTE_ADDR'];//ip   
    $rating = $_POST['rating']; //投票内容   
    //判断用户是否登录   
    if(  is_user_logged_in() ){   
        global $wpdb, $current_user;   
        get_currentuserinfo();   
        $uid = $current_user->ID;   
    }else{   
        $uid='';   
    }   
    if($rating=='up'){   
        $rating='up';   
    }else{   
        $rating='down';   
    }   
    //添加数据   
    $voted = add_vote($postid,$uid,$ip,$rating);   
    if($voted=='y'){   
        //设置cookie   
        setcookie("ashu_voted_" . $postid,$rating, time() + 3000000, '/');   
        echo 'y';//输出yes   
        die(0);   
    }   
    if($voted=='h'){   
        //设置cookie   
        setcookie("ashu_voted_" . $postid,$rating, time() + 3000000, '/');   
        echo 'h';   
        die(0);   
    }   
    if($voted=='e'){   
        echo 'n';//输出no   
        die(0);   
    }   
}else{   
    echo 'e';//输出eroor   
}   
die(0);   
}

三、准备前台HTML和js

建立好了新的数据表，也准备好了实现投票功能的函数，接下来看前台的html和js。

1、网页前台显示数据，将下面的代码放在输出文章的循环内，即常说的loop中。


/*********更新重写规则***************/  
function ashu_load_theme() {   
    global $pagenow;   
    if ( is_admin() && 'themes.php' == $pagenow && isset( $_GET['activated'] ) )   
        ashu_vote_install(); //激活主题的时候执行函数   
}   
add_action( 'load-themes.php', 'ashu_load_theme' );   
function ashu_vote_install(){   
    global $wpdb;   
    //创建 _post_vote表   
    $table_name = $wpdb->prefix . 'post_vote';   
    if( $wpdb->get_var("SHOW TABLES LIKE '$table_name'") != $table_name ) :   
    $sql = " CREATE TABLE `".$wpdb->prefix."post_vote` ( 
      `id` BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY ,  
      `user` INT NOT NULL ,  
      `post` INT NOT NULL ,  
      `rating` varchar(10),  
      `ip` varchar(40)  
     ) ENGINE = MYISAM DEFAULT CHARSET=utf8;";   
        require_once(ABSPATH . 'wp-admin/includes/upgrade.php');   
        dbDelta($sql);   
    endif;   
}  


/*  
*添加投票函数  
*$post_id 文章id  
*$user_id 用户ID  
*$ip 用户IP  
*$rating 投票内容  
*/  
function add_vote($post_id,$user_id='',$ip='',$rating='up'){   
    global $wpdb;   
    $user_id = (int)$user_id;   
    $post_id = (int)$post_id;   
    if(($user_id=='')&&($ip=='')){   
        return "e"; //返回error   
    }   
    //检查用户对某一文章是否已经投票票了   
    if($user_id!=''){   
        $check= "select * from ".$wpdb->prefix."post_vote where post='$post_id' and user='$user_id'";   
    }else{   
        if($ip!=''){   
            $check= "select * from ".$wpdb->prefix."post_vote where post='$post_id' and ip='$ip'";   
        }   
    }   
    $coo = $wpdb->get_results($check);   
    //投票内容只能是up或者down   
    if($rating=='up'){   
        $rating='up';   
    }else{   
        $rating='down';   
    }   
    //如果不存在数据   
    if(!count($coo) > 0){   
        //插入数据 sql   
        $s = "insert into ".$wpdb->prefix."post_vote (user,post,rating,ip) values('$user_id','$post_id','$rating','$ip')";   
        $wpdb->query($s);   
        return "y"; //返回yes   
    }else{   
        return "h"; //返回have   
    }   
    return "e";//返回error   
}  


/*   
*获取文章投票数据   
*$post_id 文章ID   
*$vote 投票内容   
*/   
function get_post_vote($post_id,$vote='up'){   
    global $wpdb;   
    $post_id = (int)$post_id;   
    if($vote == 'up'){   
        $vote='up';   
    }else{   
        $vote='down';   
    }   
    //查询数据sql   
    $sql = "select count(*) from ".$wpdb->prefix."post_vote where post='$post_id' and rating='$vote'";   
    $coo = $wpdb->get_var($sql);   
    if($coo)   
    return $coo; //返回数据   
    else   
    return 0;   
}  


<span class="vote_up" id="<?php echo 'vote_up'.$post->ID;?>">   
    <a href="javascript:void(0);" rel="<?php echo 'up_',$post->ID;?>">   
    <span id="<?php echo 'vup'.$post->ID;?>">   
        <?php echo get_post_vote($post->ID,'up');?>   
    </span>   
    </a>   
人认为值得买！</span>   
  
<span class="vote_down" id="<?php echo 'vote_down'.$post->ID;?>">   
    <a href="javascript:void(0);" rel="<?php echo 'down_'.$post->ID;?>">   
    <span id="<?php echo 'vdown'.$post->ID;?>">   
        <?php echo get_post_vote($post->ID,'down');?>   
    </span>   
    </a>人认为不值得买！   
</span>  


<span class="vote_up" id="vote_up44">  
    <a href="javascript:void(0);" title="值得" rel="up_44">  
    <span id="vup44">  
        0   
    </span>  
    </a>  
人认为值得买！</span>  
<span class="vote_down" id="vote_down44">  
    <a href="javascript:void(0);" title="不值" rel="down_44">  
    <span id="vdown44">  
        1   
    </span>  
    </a>人认为不值得买！   
</span>  


<script src="<?php echo get_template_directory_uri();?>/js/jquery-1.7.2.min.js"></script>   


其中输出了ajax请求的地址：www.dba.cn/wp-admin/admin-ajax.php
<script type="text/javascript">var ajax_url = '<?php echo admin_url(); ?>admin-ajax.php';</script>  
<script src="<?php echo get_template_directory_uri();?>/js/ashu.js"></script>    


/**     
 * by ashu.     
 * URI: http://www.dba.cn     
 */   
  
/**   
 * 获取Cookie   
 *name  cookie名称   
 */   
function getCookie(name) {   
    var start = document.cookie.indexOf( name + "=" );   
    var len = start + name.length + 1;   
  
    if ( ( !start ) && ( name != document.cookie.substring( 0, name.length ) ) )   
        return null;   
  
    if ( start == -1 )   
        return null;   
  
    var end = document.cookie.indexOf( ';', len );   
  
    if ( end == -1 )   
        end = document.cookie.length;   
    return unescape( document.cookie.substring( len, end ) );   
}   
function ashu_isCookieEnable() {   
    var today = new Date();   
    today.setTime( today.getTime() );   
    var expires_date = new Date( today.getTime() + (1000 * 60) );   
  
    document.cookie = 'ashu_cookie_test=test;expires=' + expires_date.toGMTString() + ';path=/';   
    var cookieEnable = (getCookie('ashu_cookie_test') == 'test') ?  true : false;   
    //document.cookie = 'ludou_cookie_test=;expires=Fri, 3 Aug 2001 20:47:11 UTC;path=/';   
    return cookieEnable;   
}   
    
jQuery(document).ready(function($) {   
    var ashu_token = 1;   
    $('.vote_up a').click(function(){   
        //检查浏览器是否启用cookie功能   
        if( !ashu_isCookieEnable() ) {   
            alert("很抱歉，您不能给本文投票！");   
            return;   
        }   
        if( ashu_token != 1 ) {   
            alert("您的鼠标点得也太快了吧？！");   
            return false;   
        }   
        ashu_token = 0;   
        //获取投票a标签中的rel值   
        var full_info = $(this).attr( 'rel' );   
        var arr_param = full_info.split( '_' ); //以字符"_"分割   
        //发起ajax   
        $.ajax({   
            url:ajax_url, //ajax地址   
            type:'POST',   
            //请求的参数包括action   rating  postid三项   
            data:'action=vote_post&rating=' + arr_param[ 0 ] + '&postid=' + arr_param[ 1 ],   
            //返回数据   
            success:function(results){   
                if(results=='n'){   
                    alert('评价失败');   
                    ashu_token = 1;   
  
                }   
                if (results=='y'){   
                    //如果成功，给前台数据加1   
                    var upd_vd = 'vup' + arr_param[ 1 ];   
                    $('#'+upd_vd).text(parseInt($("#"+upd_vd).text())+1);   
                    ashu_token = 1;   
                       
                }   
                if (results=='h'){   
                    ashu_token = 1;   
                    alert('已经发表过评价了');   
                }   
                if (results=='e'){   
                    ashu_token = 1;   
                    alert('评价失败');   
                }   
            }   
        });   
    });   
       
    $('.vote_down a').click(function(){   
        if( !ashu_isCookieEnable() ) {   
            alert("很抱歉，您不能给本文投票！");   
            return;   
        }   
        if(ashu_token != 1) {   
            alert("您的鼠标点得也太快了吧？！");   
            return false;   
        }   
        ashu_token = 0;   
  
        var full_info = $(this).attr( 'rel' );   
        var arr_param = full_info.split( '_' );   
        $.ajax({   
            url:ajax_url,   
            type:'POST',   
            data:'action=vote_post&rating=' + arr_param[ 0 ] + '&postid=' + arr_param[ 1 ],   
            success:function(results){   
                if(results=='n'){   
                    alert('评价失败');   
                    ashu_token = 1;   
                }   
                if (results=='y'){   
                    var upd_vd = 'vdown' + arr_param[ 1 ];   
                    $("#"+upd_vd).text(parseInt($("#"+upd_vd).text())+1);   
                    ashu_token = 1;   
                }   
                if (results=='h'){   
                    ashu_token = 1;   
                    alert('已经发表过评价了');   
                }   
                if (results=='e'){   
                    ashu_token = 1;   
                    alert('发生未知错误');   
                }   
            }   
        });   
    });   
});  


/*   
*wp的ajax都可以通过请求中的action参数来执行对应的钩子   
*示例中我们的action参数值是vote_post   
*所以我们可以直接用下面两个钩子来执行动作   
*/   
add_action("wp_ajax_vote_post", "add_votes_options");   
add_action("wp_ajax_nopriv_vote_post", "add_votes_options");   
function add_votes_options() {   
  
if( isset($_POST['action']) && ($_POST['action'] == 'vote_post') ){   
    $postid = (int)$_POST['postid'];   
    if( !$postid ){   
        echo 'e'; //输出error   
        die(0);   
    }   
    //cookie中是否已经存在投票数据   
    $voted = $_COOKIE["smzdm_voted_".$postid];   
    if( $voted ){   
        echo 'h'; //输出have   
        die(0);   
    }   
    $ip = $_SERVER['REMOTE_ADDR'];//ip   
    $rating = $_POST['rating']; //投票内容   
    //判断用户是否登录   
    if(  is_user_logged_in() ){   
        global $wpdb, $current_user;   
        get_currentuserinfo();   
        $uid = $current_user->ID;   
    }else{   
        $uid='';   
    }   
    if($rating=='up'){   
        $rating='up';   
    }else{   
        $rating='down';   
    }   
    //添加数据   
    $voted = add_vote($postid,$uid,$ip,$rating);   
    if($voted=='y'){   
        //设置cookie   
        setcookie("ashu_voted_" . $postid,$rating, time() + 3000000, '/');   
        echo 'y';//输出yes   
        die(0);   
    }   
    if($voted=='h'){   
        //设置cookie   
        setcookie("ashu_voted_" . $postid,$rating, time() + 3000000, '/');   
        echo 'h';   
        die(0);   
    }   
    if($voted=='e'){   
        echo 'n';//输出no   
        die(0);   
    }   
}else{   
    echo 'e';//输出eroor   
}   
die(0);   
}

上面代码将会输出一个如下的html结构


/*********更新重写规则***************/  
function ashu_load_theme() {   
    global $pagenow;   
    if ( is_admin() && 'themes.php' == $pagenow && isset( $_GET['activated'] ) )   
        ashu_vote_install(); //激活主题的时候执行函数   
}   
add_action( 'load-themes.php', 'ashu_load_theme' );   
function ashu_vote_install(){   
    global $wpdb;   
    //创建 _post_vote表   
    $table_name = $wpdb->prefix . 'post_vote';   
    if( $wpdb->get_var("SHOW TABLES LIKE '$table_name'") != $table_name ) :   
    $sql = " CREATE TABLE `".$wpdb->prefix."post_vote` ( 
      `id` BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY ,  
      `user` INT NOT NULL ,  
      `post` INT NOT NULL ,  
      `rating` varchar(10),  
      `ip` varchar(40)  
     ) ENGINE = MYISAM DEFAULT CHARSET=utf8;";   
        require_once(ABSPATH . 'wp-admin/includes/upgrade.php');   
        dbDelta($sql);   
    endif;   
}  


/*  
*添加投票函数  
*$post_id 文章id  
*$user_id 用户ID  
*$ip 用户IP  
*$rating 投票内容  
*/  
function add_vote($post_id,$user_id='',$ip='',$rating='up'){   
    global $wpdb;   
    $user_id = (int)$user_id;   
    $post_id = (int)$post_id;   
    if(($user_id=='')&&($ip=='')){   
        return "e"; //返回error   
    }   
    //检查用户对某一文章是否已经投票票了   
    if($user_id!=''){   
        $check= "select * from ".$wpdb->prefix."post_vote where post='$post_id' and user='$user_id'";   
    }else{   
        if($ip!=''){   
            $check= "select * from ".$wpdb->prefix."post_vote where post='$post_id' and ip='$ip'";   
        }   
    }   
    $coo = $wpdb->get_results($check);   
    //投票内容只能是up或者down   
    if($rating=='up'){   
        $rating='up';   
    }else{   
        $rating='down';   
    }   
    //如果不存在数据   
    if(!count($coo) > 0){   
        //插入数据 sql   
        $s = "insert into ".$wpdb->prefix."post_vote (user,post,rating,ip) values('$user_id','$post_id','$rating','$ip')";   
        $wpdb->query($s);   
        return "y"; //返回yes   
    }else{   
        return "h"; //返回have   
    }   
    return "e";//返回error   
}  


/*   
*获取文章投票数据   
*$post_id 文章ID   
*$vote 投票内容   
*/   
function get_post_vote($post_id,$vote='up'){   
    global $wpdb;   
    $post_id = (int)$post_id;   
    if($vote == 'up'){   
        $vote='up';   
    }else{   
        $vote='down';   
    }   
    //查询数据sql   
    $sql = "select count(*) from ".$wpdb->prefix."post_vote where post='$post_id' and rating='$vote'";   
    $coo = $wpdb->get_var($sql);   
    if($coo)   
    return $coo; //返回数据   
    else   
    return 0;   
}  


<span class="vote_up" id="<?php echo 'vote_up'.$post->ID;?>">   
    <a href="javascript:void(0);" rel="<?php echo 'up_',$post->ID;?>">   
    <span id="<?php echo 'vup'.$post->ID;?>">   
        <?php echo get_post_vote($post->ID,'up');?>   
    </span>   
    </a>   
人认为值得买！</span>   
  
<span class="vote_down" id="<?php echo 'vote_down'.$post->ID;?>">   
    <a href="javascript:void(0);" rel="<?php echo 'down_'.$post->ID;?>">   
    <span id="<?php echo 'vdown'.$post->ID;?>">   
        <?php echo get_post_vote($post->ID,'down');?>   
    </span>   
    </a>人认为不值得买！   
</span>  


<span class="vote_up" id="vote_up44">  
    <a href="javascript:void(0);" title="值得" rel="up_44">  
    <span id="vup44">  
        0   
    </span>  
    </a>  
人认为值得买！</span>  
<span class="vote_down" id="vote_down44">  
    <a href="javascript:void(0);" title="不值" rel="down_44">  
    <span id="vdown44">  
        1   
    </span>  
    </a>人认为不值得买！   
</span>  


<script src="<?php echo get_template_directory_uri();?>/js/jquery-1.7.2.min.js"></script>   


其中输出了ajax请求的地址：www.dba.cn/wp-admin/admin-ajax.php
<script type="text/javascript">var ajax_url = '<?php echo admin_url(); ?>admin-ajax.php';</script>  
<script src="<?php echo get_template_directory_uri();?>/js/ashu.js"></script>    


/**     
 * by ashu.     
 * URI: http://www.dba.cn     
 */   
  
/**   
 * 获取Cookie   
 *name  cookie名称   
 */   
function getCookie(name) {   
    var start = document.cookie.indexOf( name + "=" );   
    var len = start + name.length + 1;   
  
    if ( ( !start ) && ( name != document.cookie.substring( 0, name.length ) ) )   
        return null;   
  
    if ( start == -1 )   
        return null;   
  
    var end = document.cookie.indexOf( ';', len );   
  
    if ( end == -1 )   
        end = document.cookie.length;   
    return unescape( document.cookie.substring( len, end ) );   
}   
function ashu_isCookieEnable() {   
    var today = new Date();   
    today.setTime( today.getTime() );   
    var expires_date = new Date( today.getTime() + (1000 * 60) );   
  
    document.cookie = 'ashu_cookie_test=test;expires=' + expires_date.toGMTString() + ';path=/';   
    var cookieEnable = (getCookie('ashu_cookie_test') == 'test') ?  true : false;   
    //document.cookie = 'ludou_cookie_test=;expires=Fri, 3 Aug 2001 20:47:11 UTC;path=/';   
    return cookieEnable;   
}   
    
jQuery(document).ready(function($) {   
    var ashu_token = 1;   
    $('.vote_up a').click(function(){   
        //检查浏览器是否启用cookie功能   
        if( !ashu_isCookieEnable() ) {   
            alert("很抱歉，您不能给本文投票！");   
            return;   
        }   
        if( ashu_token != 1 ) {   
            alert("您的鼠标点得也太快了吧？！");   
            return false;   
        }   
        ashu_token = 0;   
        //获取投票a标签中的rel值   
        var full_info = $(this).attr( 'rel' );   
        var arr_param = full_info.split( '_' ); //以字符"_"分割   
        //发起ajax   
        $.ajax({   
            url:ajax_url, //ajax地址   
            type:'POST',   
            //请求的参数包括action   rating  postid三项   
            data:'action=vote_post&rating=' + arr_param[ 0 ] + '&postid=' + arr_param[ 1 ],   
            //返回数据   
            success:function(results){   
                if(results=='n'){   
                    alert('评价失败');   
                    ashu_token = 1;   
  
                }   
                if (results=='y'){   
                    //如果成功，给前台数据加1   
                    var upd_vd = 'vup' + arr_param[ 1 ];   
                    $('#'+upd_vd).text(parseInt($("#"+upd_vd).text())+1);   
                    ashu_token = 1;   
                       
                }   
                if (results=='h'){   
                    ashu_token = 1;   
                    alert('已经发表过评价了');   
                }   
                if (results=='e'){   
                    ashu_token = 1;   
                    alert('评价失败');   
                }   
            }   
        });   
    });   
       
    $('.vote_down a').click(function(){   
        if( !ashu_isCookieEnable() ) {   
            alert("很抱歉，您不能给本文投票！");   
            return;   
        }   
        if(ashu_token != 1) {   
            alert("您的鼠标点得也太快了吧？！");   
            return false;   
        }   
        ashu_token = 0;   
  
        var full_info = $(this).attr( 'rel' );   
        var arr_param = full_info.split( '_' );   
        $.ajax({   
            url:ajax_url,   
            type:'POST',   
            data:'action=vote_post&rating=' + arr_param[ 0 ] + '&postid=' + arr_param[ 1 ],   
            success:function(results){   
                if(results=='n'){   
                    alert('评价失败');   
                    ashu_token = 1;   
                }   
                if (results=='y'){   
                    var upd_vd = 'vdown' + arr_param[ 1 ];   
                    $("#"+upd_vd).text(parseInt($("#"+upd_vd).text())+1);   
                    ashu_token = 1;   
                }   
                if (results=='h'){   
                    ashu_token = 1;   
                    alert('已经发表过评价了');   
                }   
                if (results=='e'){   
                    ashu_token = 1;   
                    alert('发生未知错误');   
                }   
            }   
        });   
    });   
});  


/*   
*wp的ajax都可以通过请求中的action参数来执行对应的钩子   
*示例中我们的action参数值是vote_post   
*所以我们可以直接用下面两个钩子来执行动作   
*/   
add_action("wp_ajax_vote_post", "add_votes_options");   
add_action("wp_ajax_nopriv_vote_post", "add_votes_options");   
function add_votes_options() {   
  
if( isset($_POST['action']) && ($_POST['action'] == 'vote_post') ){   
    $postid = (int)$_POST['postid'];   
    if( !$postid ){   
        echo 'e'; //输出error   
        die(0);   
    }   
    //cookie中是否已经存在投票数据   
    $voted = $_COOKIE["smzdm_voted_".$postid];   
    if( $voted ){   
        echo 'h'; //输出have   
        die(0);   
    }   
    $ip = $_SERVER['REMOTE_ADDR'];//ip   
    $rating = $_POST['rating']; //投票内容   
    //判断用户是否登录   
    if(  is_user_logged_in() ){   
        global $wpdb, $current_user;   
        get_currentuserinfo();   
        $uid = $current_user->ID;   
    }else{   
        $uid='';   
    }   
    if($rating=='up'){   
        $rating='up';   
    }else{   
        $rating='down';   
    }   
    //添加数据   
    $voted = add_vote($postid,$uid,$ip,$rating);   
    if($voted=='y'){   
        //设置cookie   
        setcookie("ashu_voted_" . $postid,$rating, time() + 3000000, '/');   
        echo 'y';//输出yes   
        die(0);   
    }   
    if($voted=='h'){   
        //设置cookie   
        setcookie("ashu_voted_" . $postid,$rating, time() + 3000000, '/');   
        echo 'h';   
        die(0);   
    }   
    if($voted=='e'){   
        echo 'n';//输出no   
        die(0);   
    }   
}else{   
    echo 'e';//输出eroor   
}   
die(0);   
}

四、js代码
本篇教程中和上一篇一样，我们同样使用jquery发起ajax请求，所以首先在网页头部加载jquery代码，我在主题底部文件footer.php中加载jqeury。我将jquery-1.7.2.min.js放在了主题文件夹的js文件夹里面，所以用get_template_directory_uri()函数来输出主题的url


/*********更新重写规则***************/  
function ashu_load_theme() {   
    global $pagenow;   
    if ( is_admin() && 'themes.php' == $pagenow && isset( $_GET['activated'] ) )   
        ashu_vote_install(); //激活主题的时候执行函数   
}   
add_action( 'load-themes.php', 'ashu_load_theme' );   
function ashu_vote_install(){   
    global $wpdb;   
    //创建 _post_vote表   
    $table_name = $wpdb->prefix . 'post_vote';   
    if( $wpdb->get_var("SHOW TABLES LIKE '$table_name'") != $table_name ) :   
    $sql = " CREATE TABLE `".$wpdb->prefix."post_vote` ( 
      `id` BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY ,  
      `user` INT NOT NULL ,  
      `post` INT NOT NULL ,  
      `rating` varchar(10),  
      `ip` varchar(40)  
     ) ENGINE = MYISAM DEFAULT CHARSET=utf8;";   
        require_once(ABSPATH . 'wp-admin/includes/upgrade.php');   
        dbDelta($sql);   
    endif;   
}  


/*  
*添加投票函数  
*$post_id 文章id  
*$user_id 用户ID  
*$ip 用户IP  
*$rating 投票内容  
*/  
function add_vote($post_id,$user_id='',$ip='',$rating='up'){   
    global $wpdb;   
    $user_id = (int)$user_id;   
    $post_id = (int)$post_id;   
    if(($user_id=='')&&($ip=='')){   
        return "e"; //返回error   
    }   
    //检查用户对某一文章是否已经投票票了   
    if($user_id!=''){   
        $check= "select * from ".$wpdb->prefix."post_vote where post='$post_id' and user='$user_id'";   
    }else{   
        if($ip!=''){   
            $check= "select * from ".$wpdb->prefix."post_vote where post='$post_id' and ip='$ip'";   
        }   
    }   
    $coo = $wpdb->get_results($check);   
    //投票内容只能是up或者down   
    if($rating=='up'){   
        $rating='up';   
    }else{   
        $rating='down';   
    }   
    //如果不存在数据   
    if(!count($coo) > 0){   
        //插入数据 sql   
        $s = "insert into ".$wpdb->prefix."post_vote (user,post,rating,ip) values('$user_id','$post_id','$rating','$ip')";   
        $wpdb->query($s);   
        return "y"; //返回yes   
    }else{   
        return "h"; //返回have   
    }   
    return "e";//返回error   
}  


/*   
*获取文章投票数据   
*$post_id 文章ID   
*$vote 投票内容   
*/   
function get_post_vote($post_id,$vote='up'){   
    global $wpdb;   
    $post_id = (int)$post_id;   
    if($vote == 'up'){   
        $vote='up';   
    }else{   
        $vote='down';   
    }   
    //查询数据sql   
    $sql = "select count(*) from ".$wpdb->prefix."post_vote where post='$post_id' and rating='$vote'";   
    $coo = $wpdb->get_var($sql);   
    if($coo)   
    return $coo; //返回数据   
    else   
    return 0;   
}  


<span class="vote_up" id="<?php echo 'vote_up'.$post->ID;?>">   
    <a href="javascript:void(0);" rel="<?php echo 'up_',$post->ID;?>">   
    <span id="<?php echo 'vup'.$post->ID;?>">   
        <?php echo get_post_vote($post->ID,'up');?>   
    </span>   
    </a>   
人认为值得买！</span>   
  
<span class="vote_down" id="<?php echo 'vote_down'.$post->ID;?>">   
    <a href="javascript:void(0);" rel="<?php echo 'down_'.$post->ID;?>">   
    <span id="<?php echo 'vdown'.$post->ID;?>">   
        <?php echo get_post_vote($post->ID,'down');?>   
    </span>   
    </a>人认为不值得买！   
</span>  


<span class="vote_up" id="vote_up44">  
    <a href="javascript:void(0);" title="值得" rel="up_44">  
    <span id="vup44">  
        0   
    </span>  
    </a>  
人认为值得买！</span>  
<span class="vote_down" id="vote_down44">  
    <a href="javascript:void(0);" title="不值" rel="down_44">  
    <span id="vdown44">  
        1   
    </span>  
    </a>人认为不值得买！   
</span>  


<script src="<?php echo get_template_directory_uri();?>/js/jquery-1.7.2.min.js"></script>   


其中输出了ajax请求的地址：www.dba.cn/wp-admin/admin-ajax.php
<script type="text/javascript">var ajax_url = '<?php echo admin_url(); ?>admin-ajax.php';</script>  
<script src="<?php echo get_template_directory_uri();?>/js/ashu.js"></script>    


/**     
 * by ashu.     
 * URI: http://www.dba.cn     
 */   
  
/**   
 * 获取Cookie   
 *name  cookie名称   
 */   
function getCookie(name) {   
    var start = document.cookie.indexOf( name + "=" );   
    var len = start + name.length + 1;   
  
    if ( ( !start ) && ( name != document.cookie.substring( 0, name.length ) ) )   
        return null;   
  
    if ( start == -1 )   
        return null;   
  
    var end = document.cookie.indexOf( ';', len );   
  
    if ( end == -1 )   
        end = document.cookie.length;   
    return unescape( document.cookie.substring( len, end ) );   
}   
function ashu_isCookieEnable() {   
    var today = new Date();   
    today.setTime( today.getTime() );   
    var expires_date = new Date( today.getTime() + (1000 * 60) );   
  
    document.cookie = 'ashu_cookie_test=test;expires=' + expires_date.toGMTString() + ';path=/';   
    var cookieEnable = (getCookie('ashu_cookie_test') == 'test') ?  true : false;   
    //document.cookie = 'ludou_cookie_test=;expires=Fri, 3 Aug 2001 20:47:11 UTC;path=/';   
    return cookieEnable;   
}   
    
jQuery(document).ready(function($) {   
    var ashu_token = 1;   
    $('.vote_up a').click(function(){   
        //检查浏览器是否启用cookie功能   
        if( !ashu_isCookieEnable() ) {   
            alert("很抱歉，您不能给本文投票！");   
            return;   
        }   
        if( ashu_token != 1 ) {   
            alert("您的鼠标点得也太快了吧？！");   
            return false;   
        }   
        ashu_token = 0;   
        //获取投票a标签中的rel值   
        var full_info = $(this).attr( 'rel' );   
        var arr_param = full_info.split( '_' ); //以字符"_"分割   
        //发起ajax   
        $.ajax({   
            url:ajax_url, //ajax地址   
            type:'POST',   
            //请求的参数包括action   rating  postid三项   
            data:'action=vote_post&rating=' + arr_param[ 0 ] + '&postid=' + arr_param[ 1 ],   
            //返回数据   
            success:function(results){   
                if(results=='n'){   
                    alert('评价失败');   
                    ashu_token = 1;   
  
                }   
                if (results=='y'){   
                    //如果成功，给前台数据加1   
                    var upd_vd = 'vup' + arr_param[ 1 ];   
                    $('#'+upd_vd).text(parseInt($("#"+upd_vd).text())+1);   
                    ashu_token = 1;   
                       
                }   
                if (results=='h'){   
                    ashu_token = 1;   
                    alert('已经发表过评价了');   
                }   
                if (results=='e'){   
                    ashu_token = 1;   
                    alert('评价失败');   
                }   
            }   
        });   
    });   
       
    $('.vote_down a').click(function(){   
        if( !ashu_isCookieEnable() ) {   
            alert("很抱歉，您不能给本文投票！");   
            return;   
        }   
        if(ashu_token != 1) {   
            alert("您的鼠标点得也太快了吧？！");   
            return false;   
        }   
        ashu_token = 0;   
  
        var full_info = $(this).attr( 'rel' );   
        var arr_param = full_info.split( '_' );   
        $.ajax({   
            url:ajax_url,   
            type:'POST',   
            data:'action=vote_post&rating=' + arr_param[ 0 ] + '&postid=' + arr_param[ 1 ],   
            success:function(results){   
                if(results=='n'){   
                    alert('评价失败');   
                    ashu_token = 1;   
                }   
                if (results=='y'){   
                    var upd_vd = 'vdown' + arr_param[ 1 ];   
                    $("#"+upd_vd).text(parseInt($("#"+upd_vd).text())+1);   
                    ashu_token = 1;   
                }   
                if (results=='h'){   
                    ashu_token = 1;   
                    alert('已经发表过评价了');   
                }   
                if (results=='e'){   
                    ashu_token = 1;   
                    alert('发生未知错误');   
                }   
            }   
        });   
    });   
});  


/*   
*wp的ajax都可以通过请求中的action参数来执行对应的钩子   
*示例中我们的action参数值是vote_post   
*所以我们可以直接用下面两个钩子来执行动作   
*/   
add_action("wp_ajax_vote_post", "add_votes_options");   
add_action("wp_ajax_nopriv_vote_post", "add_votes_options");   
function add_votes_options() {   
  
if( isset($_POST['action']) && ($_POST['action'] == 'vote_post') ){   
    $postid = (int)$_POST['postid'];   
    if( !$postid ){   
        echo 'e'; //输出error   
        die(0);   
    }   
    //cookie中是否已经存在投票数据   
    $voted = $_COOKIE["smzdm_voted_".$postid];   
    if( $voted ){   
        echo 'h'; //输出have   
        die(0);   
    }   
    $ip = $_SERVER['REMOTE_ADDR'];//ip   
    $rating = $_POST['rating']; //投票内容   
    //判断用户是否登录   
    if(  is_user_logged_in() ){   
        global $wpdb, $current_user;   
        get_currentuserinfo();   
        $uid = $current_user->ID;   
    }else{   
        $uid='';   
    }   
    if($rating=='up'){   
        $rating='up';   
    }else{   
        $rating='down';   
    }   
    //添加数据   
    $voted = add_vote($postid,$uid,$ip,$rating);   
    if($voted=='y'){   
        //设置cookie   
        setcookie("ashu_voted_" . $postid,$rating, time() + 3000000, '/');   
        echo 'y';//输出yes   
        die(0);   
    }   
    if($voted=='h'){   
        //设置cookie   
        setcookie("ashu_voted_" . $postid,$rating, time() + 3000000, '/');   
        echo 'h';   
        die(0);   
    }   
    if($voted=='e'){   
        echo 'n';//输出no   
        die(0);   
    }   
}else{   
    echo 'e';//输出eroor   
}   
die(0);   
}

然后我将发起ajax请求代码也放在了主题里面js文件夹中的ashu.js文件，所以再加上一个


/*********更新重写规则***************/  
function ashu_load_theme() {   
    global $pagenow;   
    if ( is_admin() && 'themes.php' == $pagenow && isset( $_GET['activated'] ) )   
        ashu_vote_install(); //激活主题的时候执行函数   
}   
add_action( 'load-themes.php', 'ashu_load_theme' );   
function ashu_vote_install(){   
    global $wpdb;   
    //创建 _post_vote表   
    $table_name = $wpdb->prefix . 'post_vote';   
    if( $wpdb->get_var("SHOW TABLES LIKE '$table_name'") != $table_name ) :   
    $sql = " CREATE TABLE `".$wpdb->prefix."post_vote` ( 
      `id` BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY ,  
      `user` INT NOT NULL ,  
      `post` INT NOT NULL ,  
      `rating` varchar(10),  
      `ip` varchar(40)  
     ) ENGINE = MYISAM DEFAULT CHARSET=utf8;";   
        require_once(ABSPATH . 'wp-admin/includes/upgrade.php');   
        dbDelta($sql);   
    endif;   
}  


/*  
*添加投票函数  
*$post_id 文章id  
*$user_id 用户ID  
*$ip 用户IP  
*$rating 投票内容  
*/  
function add_vote($post_id,$user_id='',$ip='',$rating='up'){   
    global $wpdb;   
    $user_id = (int)$user_id;   
    $post_id = (int)$post_id;   
    if(($user_id=='')&&($ip=='')){   
        return "e"; //返回error   
    }   
    //检查用户对某一文章是否已经投票票了   
    if($user_id!=''){   
        $check= "select * from ".$wpdb->prefix."post_vote where post='$post_id' and user='$user_id'";   
    }else{   
        if($ip!=''){   
            $check= "select * from ".$wpdb->prefix."post_vote where post='$post_id' and ip='$ip'";   
        }   
    }   
    $coo = $wpdb->get_results($check);   
    //投票内容只能是up或者down   
    if($rating=='up'){   
        $rating='up';   
    }else{   
        $rating='down';   
    }   
    //如果不存在数据   
    if(!count($coo) > 0){   
        //插入数据 sql   
        $s = "insert into ".$wpdb->prefix."post_vote (user,post,rating,ip) values('$user_id','$post_id','$rating','$ip')";   
        $wpdb->query($s);   
        return "y"; //返回yes   
    }else{   
        return "h"; //返回have   
    }   
    return "e";//返回error   
}  


/*   
*获取文章投票数据   
*$post_id 文章ID   
*$vote 投票内容   
*/   
function get_post_vote($post_id,$vote='up'){   
    global $wpdb;   
    $post_id = (int)$post_id;   
    if($vote == 'up'){   
        $vote='up';   
    }else{   
        $vote='down';   
    }   
    //查询数据sql   
    $sql = "select count(*) from ".$wpdb->prefix."post_vote where post='$post_id' and rating='$vote'";   
    $coo = $wpdb->get_var($sql);   
    if($coo)   
    return $coo; //返回数据   
    else   
    return 0;   
}  


<span class="vote_up" id="<?php echo 'vote_up'.$post->ID;?>">   
    <a href="javascript:void(0);" rel="<?php echo 'up_',$post->ID;?>">   
    <span id="<?php echo 'vup'.$post->ID;?>">   
        <?php echo get_post_vote($post->ID,'up');?>   
    </span>   
    </a>   
人认为值得买！</span>   
  
<span class="vote_down" id="<?php echo 'vote_down'.$post->ID;?>">   
    <a href="javascript:void(0);" rel="<?php echo 'down_'.$post->ID;?>">   
    <span id="<?php echo 'vdown'.$post->ID;?>">   
        <?php echo get_post_vote($post->ID,'down');?>   
    </span>   
    </a>人认为不值得买！   
</span>  


<span class="vote_up" id="vote_up44">  
    <a href="javascript:void(0);" title="值得" rel="up_44">  
    <span id="vup44">  
        0   
    </span>  
    </a>  
人认为值得买！</span>  
<span class="vote_down" id="vote_down44">  
    <a href="javascript:void(0);" title="不值" rel="down_44">  
    <span id="vdown44">  
        1   
    </span>  
    </a>人认为不值得买！   
</span>  


<script src="<?php echo get_template_directory_uri();?>/js/jquery-1.7.2.min.js"></script>   


其中输出了ajax请求的地址：www.dba.cn/wp-admin/admin-ajax.php
<script type="text/javascript">var ajax_url = '<?php echo admin_url(); ?>admin-ajax.php';</script>  
<script src="<?php echo get_template_directory_uri();?>/js/ashu.js"></script>    


/**     
 * by ashu.     
 * URI: http://www.dba.cn     
 */   
  
/**   
 * 获取Cookie   
 *name  cookie名称   
 */   
function getCookie(name) {   
    var start = document.cookie.indexOf( name + "=" );   
    var len = start + name.length + 1;   
  
    if ( ( !start ) && ( name != document.cookie.substring( 0, name.length ) ) )   
        return null;   
  
    if ( start == -1 )   
        return null;   
  
    var end = document.cookie.indexOf( ';', len );   
  
    if ( end == -1 )   
        end = document.cookie.length;   
    return unescape( document.cookie.substring( len, end ) );   
}   
function ashu_isCookieEnable() {   
    var today = new Date();   
    today.setTime( today.getTime() );   
    var expires_date = new Date( today.getTime() + (1000 * 60) );   
  
    document.cookie = 'ashu_cookie_test=test;expires=' + expires_date.toGMTString() + ';path=/';   
    var cookieEnable = (getCookie('ashu_cookie_test') == 'test') ?  true : false;   
    //document.cookie = 'ludou_cookie_test=;expires=Fri, 3 Aug 2001 20:47:11 UTC;path=/';   
    return cookieEnable;   
}   
    
jQuery(document).ready(function($) {   
    var ashu_token = 1;   
    $('.vote_up a').click(function(){   
        //检查浏览器是否启用cookie功能   
        if( !ashu_isCookieEnable() ) {   
            alert("很抱歉，您不能给本文投票！");   
            return;   
        }   
        if( ashu_token != 1 ) {   
            alert("您的鼠标点得也太快了吧？！");   
            return false;   
        }   
        ashu_token = 0;   
        //获取投票a标签中的rel值   
        var full_info = $(this).attr( 'rel' );   
        var arr_param = full_info.split( '_' ); //以字符"_"分割   
        //发起ajax   
        $.ajax({   
            url:ajax_url, //ajax地址   
            type:'POST',   
            //请求的参数包括action   rating  postid三项   
            data:'action=vote_post&rating=' + arr_param[ 0 ] + '&postid=' + arr_param[ 1 ],   
            //返回数据   
            success:function(results){   
                if(results=='n'){   
                    alert('评价失败');   
                    ashu_token = 1;   
  
                }   
                if (results=='y'){   
                    //如果成功，给前台数据加1   
                    var upd_vd = 'vup' + arr_param[ 1 ];   
                    $('#'+upd_vd).text(parseInt($("#"+upd_vd).text())+1);   
                    ashu_token = 1;   
                       
                }   
                if (results=='h'){   
                    ashu_token = 1;   
                    alert('已经发表过评价了');   
                }   
                if (results=='e'){   
                    ashu_token = 1;   
                    alert('评价失败');   
                }   
            }   
        });   
    });   
       
    $('.vote_down a').click(function(){   
        if( !ashu_isCookieEnable() ) {   
            alert("很抱歉，您不能给本文投票！");   
            return;   
        }   
        if(ashu_token != 1) {   
            alert("您的鼠标点得也太快了吧？！");   
            return false;   
        }   
        ashu_token = 0;   
  
        var full_info = $(this).attr( 'rel' );   
        var arr_param = full_info.split( '_' );   
        $.ajax({   
            url:ajax_url,   
            type:'POST',   
            data:'action=vote_post&rating=' + arr_param[ 0 ] + '&postid=' + arr_param[ 1 ],   
            success:function(results){   
                if(results=='n'){   
                    alert('评价失败');   
                    ashu_token = 1;   
                }   
                if (results=='y'){   
                    var upd_vd = 'vdown' + arr_param[ 1 ];   
                    $("#"+upd_vd).text(parseInt($("#"+upd_vd).text())+1);   
                    ashu_token = 1;   
                }   
                if (results=='h'){   
                    ashu_token = 1;   
                    alert('已经发表过评价了');   
                }   
                if (results=='e'){   
                    ashu_token = 1;   
                    alert('发生未知错误');   
                }   
            }   
        });   
    });   
});  


/*   
*wp的ajax都可以通过请求中的action参数来执行对应的钩子   
*示例中我们的action参数值是vote_post   
*所以我们可以直接用下面两个钩子来执行动作   
*/   
add_action("wp_ajax_vote_post", "add_votes_options");   
add_action("wp_ajax_nopriv_vote_post", "add_votes_options");   
function add_votes_options() {   
  
if( isset($_POST['action']) && ($_POST['action'] == 'vote_post') ){   
    $postid = (int)$_POST['postid'];   
    if( !$postid ){   
        echo 'e'; //输出error   
        die(0);   
    }   
    //cookie中是否已经存在投票数据   
    $voted = $_COOKIE["smzdm_voted_".$postid];   
    if( $voted ){   
        echo 'h'; //输出have   
        die(0);   
    }   
    $ip = $_SERVER['REMOTE_ADDR'];//ip   
    $rating = $_POST['rating']; //投票内容   
    //判断用户是否登录   
    if(  is_user_logged_in() ){   
        global $wpdb, $current_user;   
        get_currentuserinfo();   
        $uid = $current_user->ID;   
    }else{   
        $uid='';   
    }   
    if($rating=='up'){   
        $rating='up';   
    }else{   
        $rating='down';   
    }   
    //添加数据   
    $voted = add_vote($postid,$uid,$ip,$rating);   
    if($voted=='y'){   
        //设置cookie   
        setcookie("ashu_voted_" . $postid,$rating, time() + 3000000, '/');   
        echo 'y';//输出yes   
        die(0);   
    }   
    if($voted=='h'){   
        //设置cookie   
        setcookie("ashu_voted_" . $postid,$rating, time() + 3000000, '/');   
        echo 'h';   
        die(0);   
    }   
    if($voted=='e'){   
        echo 'n';//输出no   
        die(0);   
    }   
}else{   
    echo 'e';//输出eroor   
}   
die(0);   
}

ashu.js文件中的代码


/*********更新重写规则***************/  
function ashu_load_theme() {   
    global $pagenow;   
    if ( is_admin() && 'themes.php' == $pagenow && isset( $_GET['activated'] ) )   
        ashu_vote_install(); //激活主题的时候执行函数   
}   
add_action( 'load-themes.php', 'ashu_load_theme' );   
function ashu_vote_install(){   
    global $wpdb;   
    //创建 _post_vote表   
    $table_name = $wpdb->prefix . 'post_vote';   
    if( $wpdb->get_var("SHOW TABLES LIKE '$table_name'") != $table_name ) :   
    $sql = " CREATE TABLE `".$wpdb->prefix."post_vote` ( 
      `id` BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY ,  
      `user` INT NOT NULL ,  
      `post` INT NOT NULL ,  
      `rating` varchar(10),  
      `ip` varchar(40)  
     ) ENGINE = MYISAM DEFAULT CHARSET=utf8;";   
        require_once(ABSPATH . 'wp-admin/includes/upgrade.php');   
        dbDelta($sql);   
    endif;   
}  


/*  
*添加投票函数  
*$post_id 文章id  
*$user_id 用户ID  
*$ip 用户IP  
*$rating 投票内容  
*/  
function add_vote($post_id,$user_id='',$ip='',$rating='up'){   
    global $wpdb;   
    $user_id = (int)$user_id;   
    $post_id = (int)$post_id;   
    if(($user_id=='')&&($ip=='')){   
        return "e"; //返回error   
    }   
    //检查用户对某一文章是否已经投票票了   
    if($user_id!=''){   
        $check= "select * from ".$wpdb->prefix."post_vote where post='$post_id' and user='$user_id'";   
    }else{   
        if($ip!=''){   
            $check= "select * from ".$wpdb->prefix."post_vote where post='$post_id' and ip='$ip'";   
        }   
    }   
    $coo = $wpdb->get_results($check);   
    //投票内容只能是up或者down   
    if($rating=='up'){   
        $rating='up';   
    }else{   
        $rating='down';   
    }   
    //如果不存在数据   
    if(!count($coo) > 0){   
        //插入数据 sql   
        $s = "insert into ".$wpdb->prefix."post_vote (user,post,rating,ip) values('$user_id','$post_id','$rating','$ip')";   
        $wpdb->query($s);   
        return "y"; //返回yes   
    }else{   
        return "h"; //返回have   
    }   
    return "e";//返回error   
}  


/*   
*获取文章投票数据   
*$post_id 文章ID   
*$vote 投票内容   
*/   
function get_post_vote($post_id,$vote='up'){   
    global $wpdb;   
    $post_id = (int)$post_id;   
    if($vote == 'up'){   
        $vote='up';   
    }else{   
        $vote='down';   
    }   
    //查询数据sql   
    $sql = "select count(*) from ".$wpdb->prefix."post_vote where post='$post_id' and rating='$vote'";   
    $coo = $wpdb->get_var($sql);   
    if($coo)   
    return $coo; //返回数据   
    else   
    return 0;   
}  


<span class="vote_up" id="<?php echo 'vote_up'.$post->ID;?>">   
    <a href="javascript:void(0);" rel="<?php echo 'up_',$post->ID;?>">   
    <span id="<?php echo 'vup'.$post->ID;?>">   
        <?php echo get_post_vote($post->ID,'up');?>   
    </span>   
    </a>   
人认为值得买！</span>   
  
<span class="vote_down" id="<?php echo 'vote_down'.$post->ID;?>">   
    <a href="javascript:void(0);" rel="<?php echo 'down_'.$post->ID;?>">   
    <span id="<?php echo 'vdown'.$post->ID;?>">   
        <?php echo get_post_vote($post->ID,'down');?>   
    </span>   
    </a>人认为不值得买！   
</span>  


<span class="vote_up" id="vote_up44">  
    <a href="javascript:void(0);" title="值得" rel="up_44">  
    <span id="vup44">  
        0   
    </span>  
    </a>  
人认为值得买！</span>  
<span class="vote_down" id="vote_down44">  
    <a href="javascript:void(0);" title="不值" rel="down_44">  
    <span id="vdown44">  
        1   
    </span>  
    </a>人认为不值得买！   
</span>  


<script src="<?php echo get_template_directory_uri();?>/js/jquery-1.7.2.min.js"></script>   


其中输出了ajax请求的地址：www.dba.cn/wp-admin/admin-ajax.php
<script type="text/javascript">var ajax_url = '<?php echo admin_url(); ?>admin-ajax.php';</script>  
<script src="<?php echo get_template_directory_uri();?>/js/ashu.js"></script>    


/**     
 * by ashu.     
 * URI: http://www.dba.cn     
 */   
  
/**   
 * 获取Cookie   
 *name  cookie名称   
 */   
function getCookie(name) {   
    var start = document.cookie.indexOf( name + "=" );   
    var len = start + name.length + 1;   
  
    if ( ( !start ) && ( name != document.cookie.substring( 0, name.length ) ) )   
        return null;   
  
    if ( start == -1 )   
        return null;   
  
    var end = document.cookie.indexOf( ';', len );   
  
    if ( end == -1 )   
        end = document.cookie.length;   
    return unescape( document.cookie.substring( len, end ) );   
}   
function ashu_isCookieEnable() {   
    var today = new Date();   
    today.setTime( today.getTime() );   
    var expires_date = new Date( today.getTime() + (1000 * 60) );   
  
    document.cookie = 'ashu_cookie_test=test;expires=' + expires_date.toGMTString() + ';path=/';   
    var cookieEnable = (getCookie('ashu_cookie_test') == 'test') ?  true : false;   
    //document.cookie = 'ludou_cookie_test=;expires=Fri, 3 Aug 2001 20:47:11 UTC;path=/';   
    return cookieEnable;   
}   
    
jQuery(document).ready(function($) {   
    var ashu_token = 1;   
    $('.vote_up a').click(function(){   
        //检查浏览器是否启用cookie功能   
        if( !ashu_isCookieEnable() ) {   
            alert("很抱歉，您不能给本文投票！");   
            return;   
        }   
        if( ashu_token != 1 ) {   
            alert("您的鼠标点得也太快了吧？！");   
            return false;   
        }   
        ashu_token = 0;   
        //获取投票a标签中的rel值   
        var full_info = $(this).attr( 'rel' );   
        var arr_param = full_info.split( '_' ); //以字符"_"分割   
        //发起ajax   
        $.ajax({   
            url:ajax_url, //ajax地址   
            type:'POST',   
            //请求的参数包括action   rating  postid三项   
            data:'action=vote_post&rating=' + arr_param[ 0 ] + '&postid=' + arr_param[ 1 ],   
            //返回数据   
            success:function(results){   
                if(results=='n'){   
                    alert('评价失败');   
                    ashu_token = 1;   
  
                }   
                if (results=='y'){   
                    //如果成功，给前台数据加1   
                    var upd_vd = 'vup' + arr_param[ 1 ];   
                    $('#'+upd_vd).text(parseInt($("#"+upd_vd).text())+1);   
                    ashu_token = 1;   
                       
                }   
                if (results=='h'){   
                    ashu_token = 1;   
                    alert('已经发表过评价了');   
                }   
                if (results=='e'){   
                    ashu_token = 1;   
                    alert('评价失败');   
                }   
            }   
        });   
    });   
       
    $('.vote_down a').click(function(){   
        if( !ashu_isCookieEnable() ) {   
            alert("很抱歉，您不能给本文投票！");   
            return;   
        }   
        if(ashu_token != 1) {   
            alert("您的鼠标点得也太快了吧？！");   
            return false;   
        }   
        ashu_token = 0;   
  
        var full_info = $(this).attr( 'rel' );   
        var arr_param = full_info.split( '_' );   
        $.ajax({   
            url:ajax_url,   
            type:'POST',   
            data:'action=vote_post&rating=' + arr_param[ 0 ] + '&postid=' + arr_param[ 1 ],   
            success:function(results){   
                if(results=='n'){   
                    alert('评价失败');   
                    ashu_token = 1;   
                }   
                if (results=='y'){   
                    var upd_vd = 'vdown' + arr_param[ 1 ];   
                    $("#"+upd_vd).text(parseInt($("#"+upd_vd).text())+1);   
                    ashu_token = 1;   
                }   
                if (results=='h'){   
                    ashu_token = 1;   
                    alert('已经发表过评价了');   
                }   
                if (results=='e'){   
                    ashu_token = 1;   
                    alert('发生未知错误');   
                }   
            }   
        });   
    });   
});  


/*   
*wp的ajax都可以通过请求中的action参数来执行对应的钩子   
*示例中我们的action参数值是vote_post   
*所以我们可以直接用下面两个钩子来执行动作   
*/   
add_action("wp_ajax_vote_post", "add_votes_options");   
add_action("wp_ajax_nopriv_vote_post", "add_votes_options");   
function add_votes_options() {   
  
if( isset($_POST['action']) && ($_POST['action'] == 'vote_post') ){   
    $postid = (int)$_POST['postid'];   
    if( !$postid ){   
        echo 'e'; //输出error   
        die(0);   
    }   
    //cookie中是否已经存在投票数据   
    $voted = $_COOKIE["smzdm_voted_".$postid];   
    if( $voted ){   
        echo 'h'; //输出have   
        die(0);   
    }   
    $ip = $_SERVER['REMOTE_ADDR'];//ip   
    $rating = $_POST['rating']; //投票内容   
    //判断用户是否登录   
    if(  is_user_logged_in() ){   
        global $wpdb, $current_user;   
        get_currentuserinfo();   
        $uid = $current_user->ID;   
    }else{   
        $uid='';   
    }   
    if($rating=='up'){   
        $rating='up';   
    }else{   
        $rating='down';   
    }   
    //添加数据   
    $voted = add_vote($postid,$uid,$ip,$rating);   
    if($voted=='y'){   
        //设置cookie   
        setcookie("ashu_voted_" . $postid,$rating, time() + 3000000, '/');   
        echo 'y';//输出yes   
        die(0);   
    }   
    if($voted=='h'){   
        //设置cookie   
        setcookie("ashu_voted_" . $postid,$rating, time() + 3000000, '/');   
        echo 'h';   
        die(0);   
    }   
    if($voted=='e'){   
        echo 'n';//输出no   
        die(0);   
    }   
}else{   
    echo 'e';//输出eroor   
}   
die(0);   
}

五、后台php处理代码。

在前面的教程中，我们的ajax请求地址直接是网站页码地址，但是本篇教程中，我们的ajax请求地址是类似：www.dba.cn/wp-admin/admin-ajax.php

使用这个地址来处理ajax请求，请一定记得请求中需要有action参数，然后我们只需要在functions.php文件(或自定)中添加下马代码，即可处理我们的请求，注意执行完请求输出内容之后，添加die函数结束：


/*********更新重写规则***************/  
function ashu_load_theme() {   
    global $pagenow;   
    if ( is_admin() && 'themes.php' == $pagenow && isset( $_GET['activated'] ) )   
        ashu_vote_install(); //激活主题的时候执行函数   
}   
add_action( 'load-themes.php', 'ashu_load_theme' );   
function ashu_vote_install(){   
    global $wpdb;   
    //创建 _post_vote表   
    $table_name = $wpdb->prefix . 'post_vote';   
    if( $wpdb->get_var("SHOW TABLES LIKE '$table_name'") != $table_name ) :   
    $sql = " CREATE TABLE `".$wpdb->prefix."post_vote` ( 
      `id` BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY ,  
      `user` INT NOT NULL ,  
      `post` INT NOT NULL ,  
      `rating` varchar(10),  
      `ip` varchar(40)  
     ) ENGINE = MYISAM DEFAULT CHARSET=utf8;";   
        require_once(ABSPATH . 'wp-admin/includes/upgrade.php');   
        dbDelta($sql);   
    endif;   
}  


/*  
*添加投票函数  
*$post_id 文章id  
*$user_id 用户ID  
*$ip 用户IP  
*$rating 投票内容  
*/  
function add_vote($post_id,$user_id='',$ip='',$rating='up'){   
    global $wpdb;   
    $user_id = (int)$user_id;   
    $post_id = (int)$post_id;   
    if(($user_id=='')&&($ip=='')){   
        return "e"; //返回error   
    }   
    //检查用户对某一文章是否已经投票票了   
    if($user_id!=''){   
        $check= "select * from ".$wpdb->prefix."post_vote where post='$post_id' and user='$user_id'";   
    }else{   
        if($ip!=''){   
            $check= "select * from ".$wpdb->prefix."post_vote where post='$post_id' and ip='$ip'";   
        }   
    }   
    $coo = $wpdb->get_results($check);   
    //投票内容只能是up或者down   
    if($rating=='up'){   
        $rating='up';   
    }else{   
        $rating='down';   
    }   
    //如果不存在数据   
    if(!count($coo) > 0){   
        //插入数据 sql   
        $s = "insert into ".$wpdb->prefix."post_vote (user,post,rating,ip) values('$user_id','$post_id','$rating','$ip')";   
        $wpdb->query($s);   
        return "y"; //返回yes   
    }else{   
        return "h"; //返回have   
    }   
    return "e";//返回error   
}  


/*   
*获取文章投票数据   
*$post_id 文章ID   
*$vote 投票内容   
*/   
function get_post_vote($post_id,$vote='up'){   
    global $wpdb;   
    $post_id = (int)$post_id;   
    if($vote == 'up'){   
        $vote='up';   
    }else{   
        $vote='down';   
    }   
    //查询数据sql   
    $sql = "select count(*) from ".$wpdb->prefix."post_vote where post='$post_id' and rating='$vote'";   
    $coo = $wpdb->get_var($sql);   
    if($coo)   
    return $coo; //返回数据   
    else   
    return 0;   
}  


<span class="vote_up" id="<?php echo 'vote_up'.$post->ID;?>">   
    <a href="javascript:void(0);" rel="<?php echo 'up_',$post->ID;?>">   
    <span id="<?php echo 'vup'.$post->ID;?>">   
        <?php echo get_post_vote($post->ID,'up');?>   
    </span>   
    </a>   
人认为值得买！</span>   
  
<span class="vote_down" id="<?php echo 'vote_down'.$post->ID;?>">   
    <a href="javascript:void(0);" rel="<?php echo 'down_'.$post->ID;?>">   
    <span id="<?php echo 'vdown'.$post->ID;?>">   
        <?php echo get_post_vote($post->ID,'down');?>   
    </span>   
    </a>人认为不值得买！   
</span>  


<span class="vote_up" id="vote_up44">  
    <a href="javascript:void(0);" title="值得" rel="up_44">  
    <span id="vup44">  
        0   
    </span>  
    </a>  
人认为值得买！</span>  
<span class="vote_down" id="vote_down44">  
    <a href="javascript:void(0);" title="不值" rel="down_44">  
    <span id="vdown44">  
        1   
    </span>  
    </a>人认为不值得买！   
</span>  


<script src="<?php echo get_template_directory_uri();?>/js/jquery-1.7.2.min.js"></script>   


其中输出了ajax请求的地址：www.dba.cn/wp-admin/admin-ajax.php
<script type="text/javascript">var ajax_url = '<?php echo admin_url(); ?>admin-ajax.php';</script>  
<script src="<?php echo get_template_directory_uri();?>/js/ashu.js"></script>    


/**     
 * by ashu.     
 * URI: http://www.dba.cn     
 */   
  
/**   
 * 获取Cookie   
 *name  cookie名称   
 */   
function getCookie(name) {   
    var start = document.cookie.indexOf( name + "=" );   
    var len = start + name.length + 1;   
  
    if ( ( !start ) && ( name != document.cookie.substring( 0, name.length ) ) )   
        return null;   
  
    if ( start == -1 )   
        return null;   
  
    var end = document.cookie.indexOf( ';', len );   
  
    if ( end == -1 )   
        end = document.cookie.length;   
    return unescape( document.cookie.substring( len, end ) );   
}   
function ashu_isCookieEnable() {   
    var today = new Date();   
    today.setTime( today.getTime() );   
    var expires_date = new Date( today.getTime() + (1000 * 60) );   
  
    document.cookie = 'ashu_cookie_test=test;expires=' + expires_date.toGMTString() + ';path=/';   
    var cookieEnable = (getCookie('ashu_cookie_test') == 'test') ?  true : false;   
    //document.cookie = 'ludou_cookie_test=;expires=Fri, 3 Aug 2001 20:47:11 UTC;path=/';   
    return cookieEnable;   
}   
    
jQuery(document).ready(function($) {   
    var ashu_token = 1;   
    $('.vote_up a').click(function(){   
        //检查浏览器是否启用cookie功能   
        if( !ashu_isCookieEnable() ) {   
            alert("很抱歉，您不能给本文投票！");   
            return;   
        }   
        if( ashu_token != 1 ) {   
            alert("您的鼠标点得也太快了吧？！");   
            return false;   
        }   
        ashu_token = 0;   
        //获取投票a标签中的rel值   
        var full_info = $(this).attr( 'rel' );   
        var arr_param = full_info.split( '_' ); //以字符"_"分割   
        //发起ajax   
        $.ajax({   
            url:ajax_url, //ajax地址   
            type:'POST',   
            //请求的参数包括action   rating  postid三项   
            data:'action=vote_post&rating=' + arr_param[ 0 ] + '&postid=' + arr_param[ 1 ],   
            //返回数据   
            success:function(results){   
                if(results=='n'){   
                    alert('评价失败');   
                    ashu_token = 1;   
  
                }   
                if (results=='y'){   
                    //如果成功，给前台数据加1   
                    var upd_vd = 'vup' + arr_param[ 1 ];   
                    $('#'+upd_vd).text(parseInt($("#"+upd_vd).text())+1);   
                    ashu_token = 1;   
                       
                }   
                if (results=='h'){   
                    ashu_token = 1;   
                    alert('已经发表过评价了');   
                }   
                if (results=='e'){   
                    ashu_token = 1;   
                    alert('评价失败');   
                }   
            }   
        });   
    });   
       
    $('.vote_down a').click(function(){   
        if( !ashu_isCookieEnable() ) {   
            alert("很抱歉，您不能给本文投票！");   
            return;   
        }   
        if(ashu_token != 1) {   
            alert("您的鼠标点得也太快了吧？！");   
            return false;   
        }   
        ashu_token = 0;   
  
        var full_info = $(this).attr( 'rel' );   
        var arr_param = full_info.split( '_' );   
        $.ajax({   
            url:ajax_url,   
            type:'POST',   
            data:'action=vote_post&rating=' + arr_param[ 0 ] + '&postid=' + arr_param[ 1 ],   
            success:function(results){   
                if(results=='n'){   
                    alert('评价失败');   
                    ashu_token = 1;   
                }   
                if (results=='y'){   
                    var upd_vd = 'vdown' + arr_param[ 1 ];   
                    $("#"+upd_vd).text(parseInt($("#"+upd_vd).text())+1);   
                    ashu_token = 1;   
                }   
                if (results=='h'){   
                    ashu_token = 1;   
                    alert('已经发表过评价了');   
                }   
                if (results=='e'){   
                    ashu_token = 1;   
                    alert('发生未知错误');   
                }   
            }   
        });   
    });   
});  


/*   
*wp的ajax都可以通过请求中的action参数来执行对应的钩子   
*示例中我们的action参数值是vote_post   
*所以我们可以直接用下面两个钩子来执行动作   
*/   
add_action("wp_ajax_vote_post", "add_votes_options");   
add_action("wp_ajax_nopriv_vote_post", "add_votes_options");   
function add_votes_options() {   
  
if( isset($_POST['action']) && ($_POST['action'] == 'vote_post') ){   
    $postid = (int)$_POST['postid'];   
    if( !$postid ){   
        echo 'e'; //输出error   
        die(0);   
    }   
    //cookie中是否已经存在投票数据   
    $voted = $_COOKIE["smzdm_voted_".$postid];   
    if( $voted ){   
        echo 'h'; //输出have   
        die(0);   
    }   
    $ip = $_SERVER['REMOTE_ADDR'];//ip   
    $rating = $_POST['rating']; //投票内容   
    //判断用户是否登录   
    if(  is_user_logged_in() ){   
        global $wpdb, $current_user;   
        get_currentuserinfo();   
        $uid = $current_user->ID;   
    }else{   
        $uid='';   
    }   
    if($rating=='up'){   
        $rating='up';   
    }else{   
        $rating='down';   
    }   
    //添加数据   
    $voted = add_vote($postid,$uid,$ip,$rating);   
    if($voted=='y'){   
        //设置cookie   
        setcookie("ashu_voted_" . $postid,$rating, time() + 3000000, '/');   
        echo 'y';//输出yes   
        die(0);   
    }   
    if($voted=='h'){   
        //设置cookie   
        setcookie("ashu_voted_" . $postid,$rating, time() + 3000000, '/');   
        echo 'h';   
        die(0);   
    }   
    if($voted=='e'){   
        echo 'n';//输出no   
        die(0);   
    }   
}else{   
    echo 'e';//输出eroor   
}   
die(0);   
}

六、结束
本票教程并非实现定踩或喜欢功能的最佳选择，只是提供一个ajax的简单示例...

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