Porting the source code of the previous “Mailer” class to PHP 5 is actually a very simple process, since all that it requires is using the correct syntax, and changing some statements of the class.

However, this procedure will be better understood if you have a look at the definition of the brand new MIME mailer class listed below. It has now been properly migrated to PHP 5. Here it is:

class Mailer{

private $sender;

private $recipient;

private $subject;

private $headers=array();

private $mimeTypes=array();

private $html=array();

private $attachments=array();

public function __construct($sender,$recipient,$subject,$message){

// validate incoming parameters

if(!preg_match("/^.+@.+$/",$sender)){

throw new Exception('Invalid value for email sender.');

}

if(!preg_match("/^.+@.+$/",$recipient)){

throw new Exception('Invalid value for email recipient.');

}

if(!$subject||strlen($subject)>255){

throw new Exception('Invalid length for email subject.');

}

if(!$message){

throw new Exception('Invalid value for email message.');

}

$this->sender=$sender;

$this->recipient=$recipient;

$this->subject=$subject;

$this->message=$message;

// define some default MIME headers

$this->headers['MIME-Version']='1.0';

$this->headers['Content-Type']='multipart/mixed;boundary="MIME_BOUNDRY"';

$this->headers['From']='<'.$this->sender.'>';

$this->headers['Return-Path']='<'.$this->sender.'>';

$this->headers['Reply-To']=$this->sender;

$this->headers['X-Mailer']='PHP5';

$this->headers['X-Sender']=$this->sender;

$this->headers['X-Priority']='3';

// define some default MIME types

$this->mimeTypes['image/jpeg']='jpg';

$this->mimeTypes['image/jpg']='jpg';

$this->mimeTypes['image/gif']='gif';

$this->mimeTypes['text/plain']='txt';

$this->mimeTypes['text/html']='htm';

$this->mimeTypes['text/xml']='xml';

$this->mimeTypes['application/pdf']='pdf';

}

// add new MIME header

public function addHeader($name,$value){

$this->headers[$name]=$value;

}

// add HTML to message

public function addHTML($html){

if(!$html){

throw new Exception('Invalid HTML.');

}

$this->html[]=$html;

}

// add new attachment

public function addAttachment($attachment){

if(!file_exists($attachment)){

throw new Exception('Invalid attachment.');

}

$this->attachments[]=$attachment;

}

// get MIME Type of attachment

private function getMimeType($attachment){

$attachment=explode('.',basename($attachment));

if(!$mimeType=array_search(strtolower($attachment[count($attachment)-
1]),$this->mimeTypes)){

throw new Exception('MIME Type not found.');

}

return $mimeType;

}

// create message MIME headers

private function buildHeaders(){

foreach($this->headers as $name=>$value){

$headers[]=$name.': '.$value;

}

return implode("\n",$headers)."\nThis is a multi-part message in MIME format.\n";

}

// create text part of the message

private function buildTextPart(){

return "--MIME_BOUNDRY\nContent-Type: text/plain; charset=iso-8859-1
\nContent-Transfer-Encoding: quoted-printable\n\n\n".$this->message."\n\n";

}

// create HTML part of the message

private function buildHTMLPart(){

if(count($this->html)>0){

$htmlPart='';

foreach($this->html as $html){

$htmlPart.="--MIME_BOUNDRY\nContent-Type: text/html; charset=iso-8859-1
\nContent-Transfer-Encoding: 8bit\n\n\n".$html."\n\n";

}

return $htmlPart;

}

}

// create attachments part of the message

private function buildAttachmentPart(){

if(count($this->attachments)>0){

$attachmentPart='';

foreach($this->attachments as $attachment){

if(!$fileStr=file_get_contents($attachment)){

throw new Exception('Error reading contents of attachment.');

}

$fileStr=chunk_split(base64_encode($fileStr));

$attachmentPart.="--MIME_BOUNDRY\nContent-Type: ".$this->getMimeType
($attachment)."; name="".basename($attachment).""\nContent-disposition:
attachment\nContent-Transfer-Encoding: base64\n\n".$fileStr."\n\n";

}

return $attachmentPart;

}

}

// send email

public function send(){

$to=$this->recipient;

$subject=$this->subject;

$headers=$this->buildHeaders();

$message=$this->buildTextPart().$this->buildHTMLPart().$this-
>buildAttachmentPart()."--MIME_BOUNDRY--\n";

if(!mail($to,$subject,$message,$headers)){

throw new Exception('Error sending email.');

}

}

}

The PHP 5 version of the MIME mailer class doesn’t differ much from its counterpart coded in PHP 4. Of course, I used the syntax supported by PHP 5 in order to implement the different methods of the class. I also utilized a few simple exceptions to handle basically all of the errors that might occur during its execution. But other than the mentioned modifications, the signature of the class remains nearly the same.

Well, I showed you how to recode the pertaining “Mailer” class with PHP 5, a process that hopefully didn’t cause you major headaches. Therefore, the only thing left to do is develop an illustrational example that shows how to use the class in question.

As you might have guessed, this hands-on example will be created in the final section of this article, so jump forward and read the next few lines. I’ll be there waiting for you.