You can use this method as starting point:
app/code/core/Mage/Sales/Model/Order.php::queueNewOrderEmail()
public function queueNewOrderEmail($forceMode = false)
{
$storeId = $this->getStore()->getId();
if (!Mage::helper('sales')->canSendNewOrderEmail($storeId)) {
return $this;
}
// Get the destination email addresses to send copies to
$copyTo = $this->_getEmails(self::XML_PATH_EMAIL_COPY_TO);
$copyMethod = Mage::getStoreConfig(self::XML_PATH_EMAIL_COPY_METHOD, $storeId);
// Start store emulation process
/** @var $appEmulation Mage_Core_Model_App_Emulation */
$appEmulation = Mage::getSingleton('core/app_emulation');
$initialEnvironmentInfo = $appEmulation->startEnvironmentEmulation($storeId);
try {
// Retrieve specified view block from appropriate design package (depends on emulated store)
$paymentBlock = Mage::helper('payment')->getInfoBlock($this->getPayment())
->setIsSecureMode(true);
$paymentBlock->getMethod()->setStore($storeId);
$paymentBlockHtml = $paymentBlock->toHtml();
} catch (Exception $exception) {
// Stop store emulation process
$appEmulation->stopEnvironmentEmulation($initialEnvironmentInfo);
throw $exception;
}
// Stop store emulation process
$appEmulation->stopEnvironmentEmulation($initialEnvironmentInfo);
// Retrieve corresponding email template id and customer name
if ($this->getCustomerIsGuest()) {
$templateId = Mage::getStoreConfig(self::XML_PATH_EMAIL_GUEST_TEMPLATE, $storeId);
$customerName = $this->getBillingAddress()->getName();
} else {
$templateId = Mage::getStoreConfig(self::XML_PATH_EMAIL_TEMPLATE, $storeId);
$customerName = $this->getCustomerName();
}
/** @var $mailer Mage_Core_Model_Email_Template_Mailer */
$mailer = Mage::getModel('core/email_template_mailer');
/** @var $emailInfo Mage_Core_Model_Email_Info */
$emailInfo = Mage::getModel('core/email_info');
$emailInfo->addTo($this->getCustomerEmail(), $customerName);
if ($copyTo && $copyMethod == 'bcc') {
// Add bcc to customer email
foreach ($copyTo as $email) {
$emailInfo->addBcc($email);
}
}
$mailer->addEmailInfo($emailInfo);
// Email copies are sent as separated emails if their copy method is 'copy'
if ($copyTo && $copyMethod == 'copy') {
foreach ($copyTo as $email) {
$emailInfo = Mage::getModel('core/email_info');
$emailInfo->addTo($email);
$mailer->addEmailInfo($emailInfo);
}
}
// Set all required params and send emails
$mailer->setSender(Mage::getStoreConfig(self::XML_PATH_EMAIL_IDENTITY, $storeId));
$mailer->setStoreId($storeId);
$mailer->setTemplateId($templateId);
$mailer->setTemplateParams(array(
'order' => $this,
'billing' => $this->getBillingAddress(),
'payment_html' => $paymentBlockHtml
));
/** @var $emailQueue Mage_Core_Model_Email_Queue */
$emailQueue = Mage::getModel('core/email_queue');
$emailQueue->setEntityId($this->getId())
->setEntityType(self::ENTITY)
->setEventType(self::EMAIL_EVENT_NAME_NEW_ORDER)
->setIsForceCheck(!$forceMode);
$mailer->setQueue($emailQueue)->send();
$this->setEmailSent(true);
$this->_getResource()->saveAttribute($this, 'email_sent');
return $this;
}
Obviously you have to implement some methods to retrieve configuration like $storeId and $templateId that in the example are already there (since is declared inside the order model).
I think that the best approach could be hook the order status change and implement all the email send logic in a helper in order be reused in the future and even better split that method and abstract all the order logic, so you will have a good base to send any kind of emails.
I assume that you already know how to save and load configuration but i recommend you to use some method (like getEmailTemplateByStatus($status)) with a default return value to avoid errors just if someone add a custom status and it hasn't any template mapped.
Hope it help
