A K Chauhan's Blog » GD Library http://www.akchauhan.com PHP, MySql, JavaScript, JQuery, Prototype, Drupal, HTML, CSS and more... Mon, 02 Jan 2012 03:29:10 +0000 en hourly 1 http://wordpress.org/?v=3.3.1 How know recipient read the email or newsletter? http://www.akchauhan.com/how-know-recipient-read-the-email-or-newsletter/ http://www.akchauhan.com/how-know-recipient-read-the-email-or-newsletter/#comments Wed, 22 Apr 2009 04:55:32 +0000 anil http://www.akchauhan.com/?p=254 Sometimes we send the newsletters or emails to lot of peoples and we want to know how many of them read it. Normally the websites like Gmail, Yahoo, Hotmail don’t provide any facility for this purpose. But we can know that by sending HTML emails.

HTML Emails – HTML emails are emails which can contain HTML tags in email body. Like <table>, <tr>, <td>, etc.

The main thing here is we need to send some information to our server when user open the email. So for this, we can place an image in email body and when user open this email the browser send request to our webserver for this image. We can also achieve this by adding javascript code or hidden iframe but normally email clients don’t support javascript code and iframes in email body and they strips out this unwanted code form email body. So, the best way to achieve this is by using images.

<?php
/*send_newsletter.php*/
 
$newsletterid = 25;
 
// array of recipients
$recipients = array('test1@yahoo.com', 'test2@yahoo.com', 'test3@yahoo.com', 'test4@gmail.com', 'test5@gmail.com', 
	'test6@hotmail.com', 'test7@hotmail.com', 'test8@aol.com', 'test9@aol.com', 'test10@yahoo.com');
 
// subject
$subject = 'Newsletter for April';
 
// message
$message = "
<html>
<head>
  <title>Newsletter for April</title>
</head>
<body>
  <p>This is a Demo Newsletter. This is a Demo Newsletter. This is a Demo Newsletter. This is a Demo Newsletter. 
  This is a Demo Newsletter. This is a Demo Newsletter. This is a Demo Newsletter. This is a Demo Newsletter. 
  This is a Demo Newsletter. This is a Demo Newsletter. This is a Demo Newsletter. This is a Demo Newsletter. </p>
  <img src='http://www.akchauhan.com/newsletter_read.php?newsletterid={$newsletterid}' height='1' width='1' /><br/><br/>
  Thanks,<br/>
  www.akchauhan.com
</body>
</html>";
 
// To send HTML mail, the Content-type header must be set
$headers  = 'MIME-Version: 1.0' . "rn";
$headers .= 'Content-type: text/html; charset=iso-8859-1' . "rn";
$headers .= 'From: AKChauhan Blog <anil@akchauhan.com>' . "rn";
 
foreach($recipients as $to) {
	// Mail it
	mail($to, $subject, $message, $headers);
}
?>


I have used a variable $newsletterid to track newsletter. We can also send some extra information in query string as per our requirement.
Like

http://www.akchauhan.com/newsletter_read.php?newsletterid=$newsletterid&userid=$userid


Note: Here I have used mail() function only to make demonstration simple. mail() function is not suitable for sending large number of email in loop. Better we use PEAR::Mail or PEAR::Mail_Queue packages for sending large number of email.

<?php
/*newsletter_read.php*/
 
$newsletterid = $_GET['newsletterid'];
/*Write some code to update your read counter in your database. Or, do whatever you want to 
do when user open your newsletter.*/
mysql_query('UPDATE info SET newsletter_count = newsletter_count + 1 WHERE newsletterid = ' . $newsletterid);
 
// We'll be outputting a JPEG
header('Content-Type: image/jpeg');
 
$im = @imagecreatefromjpeg('images/one_pixel_small_white_image.jpg');
 
imagejpeg($img);
imagedestroy($img);
?>


In above code, first we updated our newsletter read counter in database. We can do other things also like send an email to admin etc. as per requirement. Then we set the Content-Type to image/jpeg as we are going to send a jpeg image. So, we need to tell the browser about the content type of our response. Then, we created a 1 pixel white image usng GD library and outputted it to browser using imagejpeg() function.

]]> http://www.akchauhan.com/how-know-recipient-read-the-email-or-newsletter/feed/ 2 Dynamic progress bar or status bar using GD library http://www.akchauhan.com/dynamic-progress-bar-or-status-bar-using-gd-library/ http://www.akchauhan.com/dynamic-progress-bar-or-status-bar-using-gd-library/#comments Sat, 14 Mar 2009 13:38:00 +0000 admin http://blog.akchauhan.com/?p=52 Sometime you need to show dynamic progress bars or status bars to users. You can create them using GD Library. I am showing here how you can create such kind of bars.
Dynamic bars using GD Library in PHP

Dynamic bars using GD Library in PHP


You can view the working demo here.

You can download the source code here.

PHP Code:-

<?php
header(”Content-type: image/jpeg”);$current = isset($_GET['c']) ? $_GET['c'] : 50;
$start = isset($_GET['s']) ? $_GET['s'] : 0;
$end = isset($_GET['e']) ? $_GET['e'] : 100;
$p = isset($_GET['p']) ? $_GET['p'] : 0;
 
$pos = floor(2 * $current/($end - $start) * 100);
 
$im = imagecreate(200, 16); // width , height px
$white = imagecolorallocate($im, 255, 255, 255);
$black = imagecolorallocate($im, 0, 0, 0);
$green = imagecolorallocate($im, 0, 204, 51);
 
imagesetthickness($im, 2);
 
imagerectangle($im, 0, 0, 200, 15, $white);
imagefilledrectangle($im, 0, 0, $pos, 16, $green);
 
if ($p) {
	$text = ($pos / 2) . ‘%’;
	$font = ‘arial.ttf’;
	$black = imagecolorallocate($im, 0, 0, 0);
	imagettftext($im, 8, 0, 95, 12, $black, $font, $text);
}
 
imagejpeg($im);
imagedestroy($im);
?>

How to use it:-

Save the above PHP code in bar.php file and use this file in the src attribute of <img> tag.

<img src=”bar.php?s=0&e=100&c=100&p=1″ />

Here we are passing four different parameters to this file.

‘s’ for starting value (Default is ’0′).

‘e’ for end value (Default is ’100′).

‘c’ for starting value (Default is ’50′).

‘p’ for percentage flag (Default is ’0′). If you want to show percentage on your bar then pass ‘p’ = 1.

You can view the working demo here.

You can download the source code here.

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