在AJAX和PHP注释系统中将注释排序到页面中

时间:2015-02-04 16:45:35

标签: php jquery ajax comments system

我正在使用这个评论系统,但问题是当用户提交他们的评论时,它只是填充整个页面,无论如何它是否只在页面中出现10个而在另一个页面中出现?

我还是个新手,所以请用你的话来善良和简单。

demo.php

<?php

// Error reporting:
error_reporting(E_ALL^E_NOTICE);

include "connect.php";
include "comment.class.php";


/*
/   Select all the comments and populate the $comments array with objects
*/

$comments = array();
$result = mysql_query("SELECT * FROM comments ORDER BY id ASC");

while($row = mysql_fetch_assoc($result))
{
    $comments[] = new Comment($row);
}

?>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Simple AJAX Commenting System | Tutorialzine demo</title>

<link rel="stylesheet" type="text/css" href="styles.css" />

</head>

<body>

<div id="main">

<div id="addCommentContainer">
    <p>Add a Comment</p>
    <form id="addCommentForm" method="post" action="">
        <div>
            <label for="name">Your Name</label>
            <input type="text" name="name" id="name" />

            <label for="body">Comment Body</label>
            <textarea name="body" id="body" cols="20" rows="5"></textarea>

            <input type="submit" id="submit" value="Submit" />
        </div>
    </form>
</div>
<?php

/*
/   Output the comments one by one:
*/

foreach($comments as $c){
    echo $c->markup();
}

?>
</div>

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
<script type="text/javascript" src="script.js"></script>

</body>
</html>

submit.php

<?php

// Error reporting:
error_reporting(E_ALL^E_NOTICE);

include "connect.php";
include "comment.class.php";

/*
/   This array is going to be populated with either
/   the data that was sent to the script, or the
/   error messages.
/*/

$arr = array();
$validates = Comment::validate($arr);

if($validates)
{
    /* Everything is OK, insert to database: */

    mysql_query("   INSERT INTO comments(name,url,email,body)
                    VALUES (
                        '".$arr['name']."',
                        '".$arr['url']."',
                        '".$arr['email']."',
                        '".$arr['body']."'
                    )");

    $arr['dt'] = date('r',time());
    $arr['id'] = mysql_insert_id();

    /*
    /   The data in $arr is escaped for the mysql query,
    /   but we need the unescaped variables, so we apply,
    /   stripslashes to all the elements in the array:
    /*/

    $arr = array_map('stripslashes',$arr);

    $insertedComment = new Comment($arr);

    /* Outputting the markup of the just-inserted comment: */

    echo json_encode(array('status'=>1,'html'=>$insertedComment->markup()));

}
else
{
    /* Outputtng the error messages */
    echo '{"status":0,"errors":'.json_encode($arr).'}';
}

?>

comment.class.php

<?php

class Comment
{
    private $data = array();

    public function __construct($row)
    {
        /*
        /   The constructor
        */

        $this->data = $row;
    }

    public function markup()
    {
        /*
        /   This method outputs the XHTML markup of the comment
        */

        // Setting up an alias, so we don't have to write $this->data every time:
        $d = &$this->data;

        $link_open = '';
        $link_close = '';

        if($d['url']){

            // If the person has entered a URL when adding a comment,
            // define opening and closing hyperlink tags

            $link_open = '<a href="'.$d['url'].'">';
            $link_close =  '</a>';
        }

        // Converting the time to a UNIX timestamp:
        $d['dt'] = strtotime($d['dt']);

        // Needed for the default gravatar image:
        $url = 'http://'.dirname($_SERVER['SERVER_NAME'].$_SERVER["REQUEST_URI"]).'/img/default_avatar.gif';

        return '

            <div class="comment">
                <div class="avatar">
                    '.$link_open.'
                    <img src="http://www.gravatar.com/avatar/'.md5($d['email']).'?size=50&amp;default='.urlencode($url).'" />
                    '.$link_close.'
                </div>

                <div class="name">'.$link_open.$d['name'].$link_close.'</div>
                <div class="date" title="Added at '.date('H:i \o\n d M Y',$d['dt']).'">'.date('d M Y',$d['dt']).'</div>
                <p>'.$d['body'].'</p>
            </div>
        ';
    }

    public static function validate(&$arr)
    {
        /*
        /   This method is used to validate the data sent via AJAX.
        /
        /   It return true/false depending on whether the data is valid, and populates
        /   the $arr array passed as a paremter (notice the ampersand above) with
        /   either the valid input data, or the error messages.
        */

        $errors = array();
        $data   = array();

        // Using the filter_input function introduced in PHP 5.2.0

        if(!($data['url'] = filter_input(INPUT_POST,'url',FILTER_VALIDATE_URL)))
        {
            // If the URL field was not populated with a valid URL,
            // act as if no URL was entered at all:

            $url = '';
        }

        // Using the filter with a custom callback function:

        if(!($data['body'] = filter_input(INPUT_POST,'body',FILTER_CALLBACK,array('options'=>'Comment::validate_text'))))
        {
            $errors['body'] = 'Please enter a comment body.';
        }

        if(!($data['name'] = filter_input(INPUT_POST,'name',FILTER_CALLBACK,array('options'=>'Comment::validate_text'))))
        {
            $errors['name'] = 'Please enter a name.';
        }

        if(!empty($errors)){

            // If there are errors, copy the $errors array to $arr:

            $arr = $errors;
            return false;
        }

        // If the data is valid, sanitize all the data and copy it to $arr:

        foreach($data as $k=>$v){
            $arr[$k] = mysql_real_escape_string($v);
        }

        // Ensure that the email is lower case:

        $arr['email'] = strtolower(trim($arr['email']));

        return true;

    }

    private static function validate_text($str)
    {
        /*
        /   This method is used internally as a FILTER_CALLBACK
        */

        if(mb_strlen($str,'utf8')<1)
            return false;

        // Encode all html special characters (<, >, ", & .. etc) and convert
        // the new line characters to <br> tags:

        $str = nl2br(htmlspecialchars($str));

        // Remove the new line characters that are left
        $str = str_replace(array(chr(10),chr(13)),'',$str);

        return $str;
    }

}

?>

1 个答案:

答案 0 :(得分:0)

由于demo.php顶部的此查询显示所有注释:

mysql_query("SELECT * FROM comments ORDER BY id ASC");

MySQL有一个LIMIT子句,它将限制它返回的行。此示例仅返回第1行到第10行:

mysql_query("SELECT * FROM comments ORDER BY id ASC LIMIT 1,10");

第一个数字是要返回的第一行,第二个数字是要返回的总行数。如果您想要第二页或第11行到第20行,请将查询更改为:

mysql_query("SELECT * FROM comments ORDER BY id ASC LIMIT 11,10");

您需要在页面上显示一些链接,这些链接会将所需的页码发送到服务器,您可以使用页码来更改您的mysql查询。