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Im using this comment system, but the problem is when users submit their comments, it just populates the entire page, is there anyway to make them appear only 10 in a page and others in an another page?

Im still a novice , so please be kind and simple with your words.

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;
    }

}

?>
adi4u4882
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1 Answers1

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All of the comments are being shown because of this query at the top of demo.php:

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

MySQL has a LIMIT clause that will restrict the rows it returns. This example will only return rows 1 through 10:

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

The first number is the first row to return and the second number is the total number of rows to return. If you wanted the second page, or rows 11 through 20, change your query to:

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

You will need some links on your page that send the desired page number to the server, where you can use the page number to change your mysql query.

Evan OJack
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  • Thank for your reply, i have another scenario. Lets say, i want to display only the last 10 latest comments in the database. How to do that? I want only the last 10 latest comments in the page, since this saves all the effort for creating several pages. – adi4u4882 Feb 04 '15 at 17:13
  • You can sort DESC (descending) so the 'last' comments are now first, then still do LIMIT 1,10. Or, you can get a count of all the rows and do some math to get your offset for the LIMIT. – Evan OJack Feb 04 '15 at 17:16
  • EDIT: The query for that is `mysql_query("SELECT * FROM comments ORDER BY id DESC LIMIT 10");` Any chance of implementing real time feed to this form? When a new comment is received it should push it down without the user refreshing the page? – adi4u4882 Feb 04 '15 at 17:27
  • That's probably a whole other discussion. The page would have to continuously make requests to the server to check for updates. – Evan OJack Feb 04 '15 at 17:42