Images in Email Subject

Question

I need to unicode "images" (icons) in the subject, for example, to display this image [☮], I can use the following code with the core/email model.

$subject='☮';
$mailModel=Mage::getModel('core/email');
$mailModel->setSubject('=?utf-8?B?'.base64_encode($subject).'?=')

However the following code (for the core/email_template model) is not working,

$_mailModel = Mage::getModel('core/email_template');
$_mailModel->setTemplateSubject('=?utf-8?B?'.base64_encode($subject).'?=');

it returns =?utf-8?B?SG93IHdhcyB5b3VyIG9yZGVyPyBKdXN0IGNoZWNraW5nIGluLi4u4pmlIFBMVVIg4piuIA==?=

How to display the image using the second core/email_template model.

Answer 1

I think you should just add the template subject without encoding it:

$_mailModel = Mage::getModel('core/email_template');
$_mailModel->setTemplateSubject('How was your order? Just checking in...♥ PLUR ☮');

Here is why I think it should work.
The e-mail is sent from Mage_Core_Model_Email_Template::send(). This method uses an instance of Zend_Mail. See this line: $mail = $this->getMail();. The method getMail() looks like this:

public function getMail()
{
    if (is_null($this->_mail)) {
        $this->_mail = new Zend_Mail('utf-8');
    }
    return $this->_mail;
}

And later on the subject is set on the $mail object:

$mail->setSubject('=?utf-8?B?' . base64_encode($this->getProcessedTemplateSubject($variables)) . '?='); 

and this encodes it so there is no need for you to encode the value you set.
If the subject is a simple text, then getProcessedTemplateSubject will return it as it is. That method is used to parse the short codes in the subject ({{var ...}}).