// This hack by Michael H. Park
// http://www.MichaelPark.net


The first thing is to add the new field to the table.  Login to your control panel of your host and enter phpMyAdmin; 
then, select your b2 database if necessary and click "SQL" on the top of the main page.  In the textarea box, enter the 
following and click "Go".

[code]
ALTER TABLE `b2comments` ADD `comment_notify` INT(1) DEFAULT '0' NOT NULL
[/code]

Now, go to the b2comments table and verify the addition.

Ok, then.  You can logout from there.  Now, open up "b2comments.php" or "b2commentspopup.php" depending on which one you 
use.  I recommend modifying both if you use the latter.

Place the following in the commentts form with other hidden fields:

<input type="hidden" name="wxcvbn_c" value="<?php echo $wxcvbn_c; ?>" />

Place the following where you want the option for the commenter to appear (optional):

[code]
<input type="checkbox" name="notifyme" value="1" checked />
notify me of new comments on this post (your e-mail has to be valid)
[/code]

If you choose not to show the above checkbox, put the following instead along with other hidden input form tags:

[code]
<input type="hidden" name="notifyme" value="1" />
[/code]

This will turn the "notify me" option on by default.  If you don't want this, set the value to 0.  Also, make sure the
variable $wxcvbn_c is defined in the loop to count the number of comments.


Now, open "b2comments.post.php" file and locate:

[code]
$comment_post_ID = $HTTP_POST_VARS["comment_post_ID"];
[/code]

Add the following on the next line:

[code]
$notify = $HTTP_POST_VARS["notifyme"];
$wxcvbn_c = $HTTP_POST_VARS["wxcvbn_c"];
[/code]

Now locate:

[code]
$query = "INSERT INTO $tablecomments VALUES ('0','$comment_post_ID','$author','$email','$url','$user_ip','$now','$comment','0')";
[/code]

And replace it with:

[code]
$query = "INSERT INTO $tablecomments VALUES ('0','$comment_post_ID','$author','$email','$url','$user_ip','$now','$comment','0','$notify')";
[/code]

Locate the following:

[code]
@mail($recipient, $subject, $notify_message, "From: b2@".$HTTP_SERVER_VARS['SERVER_NAME']."\r\n"."X-Mailer: b2 $b2_version - PHP/" . phpversion());
[/code]

Lastly, add the following on the next line:

[code]
// "Notify Me" hack by Michael H. Park (http://www.MichaelPark.net)
if ($wxcvbn_c > 0) {
	$notify_comment  = "There's a new comment on post #$comment_post_ID.\r\n\r\n";
	$notify_comment .= "author : $comment_author\r\n";
	$notify_comment .= "url    : $comment_author_url\r\n";
	$notify_comment .= "comment: \n".stripslashes($original_comment)."\r\n\r\n";
	$notify_comment .= "You can reply via here: \r\n";
	$notify_comment .= $siteurl.'/'.$blogfilename.$querystring_start.'p'.$querystring_equal.$comment_post_ID.'&c'.$querystring_equal.'1&blogonly=1#comments';

	// get e-mails of all commenters with "notify me" turned on for a particular post
	$nquery = " SELECT DISTINCT comment_author_email, comment_notify " . 
			  " FROM $tableposts LEFT JOIN $tablecomments ON ID = comment_post_id " . 
			  " WHERE ID = '$comment_post_ID' AND comment_notify = 1 " . 
			  " ORDER BY comment_ID DESC";

	$nresult = mysql_query($nquery) or die(mysql_error());
	
	while ($row = mysql_fetch_array($nresult)) {
		$commenter_email = $row["comment_author_email"];
		$comment_notify = $row["comment_notify"];
		
		// e-mail out the new comment except to the current commenter
		if ($commenter_email <> $email) {
			@mail($commenter_email, $subject, $notify_comment, "From: b2@".$HTTP_SERVER_VARS['SERVER_NAME']."\r\n"."X-Mailer: b2 $b2_version - PHP/" . phpversion());
		}
		
		// update the "notify me" status if it's been changed since the last comment by the same commenter
		if ($commenter_email == $email && $comment_notify <> $notify) {
			$nupdate = mysql_query("UPDATE $tablecomments " . 
									" SET comment_notify = '$notify' " . 
									" WHERE comment_post_id = '$comment_post_ID' AND comment_author_email = '$email' ") 
									or die(mysql_error());

			$stat_message = "Your notification status has been changed.\r\n";
			$stat_subject = "Your notification status for post #$comment_post_ID \"".$postdata["Title"]."\"";

			@mail($commenter_email, $stat_subject, $stat_message, "From: b2@".$HTTP_SERVER_VARS['SERVER_NAME']."\r\n"."X-Mailer: b2 $b2_version - PHP/" . phpversion());
		}
	}
} // end hack
[/code]


Also, because trackbacks and pingbacks are stored in the same table, a little modification to their INSERT statements is 
needed; therefore, locate the following in b2trackback.php file:

[code]
$query = "INSERT INTO $tablecomments VALUES ('0','$comment_post_ID','$author','$email','$url','$user_ip','$now','$comment','0')";
[/code]

And replace it with:

[code]
$query = "INSERT INTO $tablecomments VALUES ('0','$comment_post_ID','$author','$email','$url','$user_ip','$now','$comment','0','0')";
[/code]

Then in xmlprc.php file, locate:

[code]
$sql = "INSERT INTO $tablecomments (comment_post_ID, comment_author, comment_author_url, comment_date, comment_content) VALUES ($post_ID, '$title', '$pagelinkedfrom', NOW(), '$context')";

And replace it with:

[code]
$sql = "INSERT INTO $tablecomments (comment_post_ID, comment_author, comment_author_url, comment_date, comment_content, comment_notify) VALUES ($post_ID, '$title', '$pagelinkedfrom', NOW(), '$context','0')";
[/code]


UPGRADE
-------

If you want a separate form that a visitor use to subscribe or unsubscribe to a post without entering a comment,
implement the following instructions.

Create a new file and name it b2comments.notify.php with the following codes:

[code]
<?php

# if you want to change the paths here, remember to put your new path BEFORE $b2inc,
#  like this: "b2/$b2inc/b2functions.php"

//original
require("b2config.php");
require("$b2inc/b2template.functions.php");
include("$b2inc/b2vars.php");
include("$b2inc/b2functions.php");

dbconnect();

function add_magic_quotes($array) {
	foreach ($array as $k => $v) {
		if (is_array($v)) {
			$array[$k] = add_magic_quotes($v);
		} else {
			$array[$k] = addslashes($v);
		}
	}
	return $array;
} 

if (!get_magic_quotes_gpc()) {
	$HTTP_GET_VARS    = add_magic_quotes($HTTP_GET_VARS);
	$HTTP_POST_VARS   = add_magic_quotes($HTTP_POST_VARS);
	$HTTP_COOKIE_VARS = add_magic_quotes($HTTP_COOKIE_VARS);
}
//end original

$email = trim($HTTP_POST_VARS["email"]);
$comment_post_ID = $HTTP_POST_VARS["comment_post_ID"];
$sub = $HTTP_POST_VARS["sub"];
$unsub = $HTTP_POST_VARS["unsub"];

if (empty($email) || $email == "@") { 
	echo "Error: please type in your e-mail address.";
	echo "\n<br /><br />\n<a href=\"javascript:history.go(-1);\">go back</a>\n\n";
	exit;
}
//by Michael E. (marshack)
elseif ((!eregi("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$", $email))) { 
   echo "Error: e-mail address is mal-formed.";
	echo "\n<br /><br />\n<a href=\"javascript:history.go(-1);\">go back</a>\n\n";
   exit;
}
elseif (!$sub && !$unsub) {
   echo "Error: please select either subscribe or unsubscribe option.";
	echo "\n<br /><br />\n<a href=\"javascript:history.go(-1);\">go back</a>\n\n";
   exit;
}

//original
$user_ip = $REMOTE_ADDR;
$user_domain = gethostbyaddr($user_ip);
$time_difference = get_settings("time_difference");
$now = date("Y-m-d H:i:s",(time() + ($time_difference * 3600)));

$email = strip_tags($email);
if (strlen($email) < 6) {
	$email = '';
}

$comment_author_email = $email;
$email = addslashes($email);

/* flood-protection */
$query = "SELECT comment_date FROM $tablecomments WHERE comment_author_IP='$user_ip' ORDER BY comment_date DESC LIMIT 1";
$result = mysql_query($query);
$ok=1;
if (!empty($result)) {
	while($row = mysql_fetch_object($result)) {
		$then=$row->comment_date;
	}
	$time_lastcomment=mysql2date("U","$then");
	$time_newcomment=mysql2date("U","$now");
	if (($time_newcomment - $time_lastcomment) < 30)
		$ok=0;
}
/* end flood-protection */
//end original

if ($ok) {
	$postdata = get_postdata($comment_post_ID);
	$stat_subject = "Your subscription status for post #$comment_post_ID \"".$postdata["Title"]."\"";

	if ($sub) {
		$checksub = mysql_query("SELECT DISTINCT comment_author_email FROM $tablecomments " . 
					" WHERE comment_post_id = '$comment_post_ID' AND comment_author_email = '$email' AND comment_notify = 1 " . 
					" ORDER BY comment_date DESC") 
					or die(mysql_error());
		$numrows = mysql_num_rows($checksub);
		
		if ($numrows > 0) {
			echo "You are already subscribed to this post.\n\n";
			echo "\n<br /><br />\n<a href=\"javascript:history.go(-1);\">go back</a>\n\n";
			exit;
		} 
		else {
			$query = "INSERT INTO $tablecomments (comment_post_ID,comment_author_email,comment_author_ip,comment_date,comment_notify) VALUES ('$comment_post_ID','$email','$user_ip','$now','$sub')";
			$result = mysql_query($query) or die(mysql_error());
			
			$stat_message = "You are now subscribed to post #$comment_post_ID.\r\n";
			@mail($email, $stat_subject, $stat_message, "From: b2@".$HTTP_SERVER_VARS['SERVER_NAME']."\r\n"."X-Mailer: b2 $b2_version - PHP/" . phpversion());
		}
	}
	elseif ($unsub) {
		$checkunsub = mysql_query("SELECT DISTINCT comment_author_email FROM $tablecomments " . 
					" WHERE comment_post_id = '$comment_post_ID' AND comment_author_email = '$email' AND comment_notify = 1 " . 
					" ORDER BY comment_date DESC") 
					or die(mysql_error());
		$numrows = mysql_num_rows($checkunsub);
		
		if ($numrows == 0) {
			echo "You have not subscribed to this post.\n\n";
			echo "\n<br /><br />\n<a href=\"javascript:history.go(-1);\">go back</a>\n\n";
			exit;
		} 
		else {
			$nupdate = mysql_query("UPDATE $tablecomments " . 
						" SET comment_notify = 0 " . 
						" WHERE comment_post_id = '$comment_post_ID' AND comment_author_email = '$email' AND comment_notify = 1") 
						or die(mysql_error());

			$stat_message = "Your subscription on post #$comment_post_ID has been cancelled.\r\n";
			@mail($email, $stat_subject, $stat_message, "From: b2@".$HTTP_SERVER_VARS['SERVER_NAME']."\r\n"."X-Mailer: b2 $b2_version - PHP/" . phpversion());
		}
	}
	
	//original
	if ($email == "") {
		$email = " "; // this to make sure a cookie is set for 'no email'
	}
	setcookie("comment_author_email",$email, time()+30000000, "/", ".michaelpark.net");

	header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
	header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
	header("Cache-Control: no-cache, must-revalidate");
	header("Pragma: no-cache");
	$location = (!empty($HTTP_POST_VARS['redirect_to'])) ? $HTTP_POST_VARS['redirect_to'] : $HTTP_SERVER_VARS["HTTP_REFERER"];
	if ($is_IIS) {
		header("Refresh: 0;url=$location");
	} else {
		header("Location: $location");
	}
	//end original
} else {
	echo "Sorry, you can only use this every 30 second";
	echo "\n<br /><br /><a href=\"javascript:history.go(-1);\">go back</a>\n\n";
	die();
}
?>
[/code]

Then in b2comments.php and/or b2commentspopup.php, put the following where you want the form to appear:

[code]
<form action="b2comments.notify.php" method="post">
	<input type="hidden" name="comment_post_ID" value="<?php echo $id; ?>" />
	<input type="hidden" name="redirect_to" value="<?php echo htmlspecialchars($HTTP_SERVER_VARS["REQUEST_URI"]); ?>" />
	<input type="hidden" name="comment_ID" value="<?php echo comment_ID(); ?>" />
	<input type="text" name="email" value="<?php echo $comment_author_email ?>" size="20" /><br />
	<input type="radio" name="sub" value="1" />Subscribe&nbsp;<input type="radio" name="unsub" value="1" />Unsubscribe<br />
	<input type="submit" value="Submit" />
</form>
[/code]

Because the above does not insert any contents in the comments table, you have to modify several other functions for
proper operations of your blog.

First, in b2comment.php and/or b2commentpopup.php, locate:

[code]
$queryc = "SELECT * FROM $tablecomments WHERE comment_post_ID = $id AND comment_content NOT LIKE '%<trackback />%' ORDER BY comment_date";
[/code]

And replace it with:

[code]
$queryc = "SELECT * FROM $tablecomments WHERE comment_post_ID = $id AND (comment_content NOT LIKE '%<trackback />%' AND comment_content != '') ORDER BY comment_date";
[/code]


Then in b2template_functions.php under generic_ctp_number function, locate:

[code]
$query = "SELECT * FROM $tablecomments WHERE comment_post_ID = $post_id";
[/code]

And replace it with:

[code]
$query = "SELECT * FROM $tablecomments WHERE comment_post_ID = $post_id AND comment_content != ''";
[/code]