From 95803eba882a4f72623390c4b084512975a9fcf2 Mon Sep 17 00:00:00 2001
From: Vinai Kopp <vinai@netzarbeiter.com>
Date: Wed, 11 Jul 2012 15:51:19 +0200
Subject: [PATCH] Add events to transactional email sending

The purpose of the events is to enable modules to
- add attachments
- change email templates
- modify template variables
- add template variables
- modify email content

Also, the patch makes the mailer class factory method configurable.
The purpose is to enable modules to use a diferent mailer without
reverting to a rewrite of Mage_Core_Model_Email_Template.

Additionaly the undeclared dependency on Mage_Newsletter was
removed from Mage_Core_Model_Email_Template, and an event observer
added to the newsletter module taking care the business logic
is not changed.
---
 app/code/core/Mage/Core/Helper/Mail.php       | 17 ++++++
 .../core/Mage/Core/Model/Email/Template.php   | 55 +++++++++++++------
 app/code/core/Mage/Core/etc/config.xml        |  8 ++-
 .../core/Mage/Newsletter/Model/Observer.php   | 19 +++++++
 app/code/core/Mage/Newsletter/etc/config.xml  | 10 ++++
 5 files changed, 92 insertions(+), 17 deletions(-)
 create mode 100644 app/code/core/Mage/Core/Helper/Mail.php

diff --git a/app/code/core/Mage/Core/Helper/Mail.php b/app/code/core/Mage/Core/Helper/Mail.php
new file mode 100644
index 0000000000000..1597a4ae855f9
--- /dev/null
+++ b/app/code/core/Mage/Core/Helper/Mail.php
@@ -0,0 +1,17 @@
+<?php
+
+class Mage_Core_Helper_Mail extends Mage_Core_Helper_Abstract
+{
+    /**
+     * Return a mailer instance to be used by the Mage_Core_Model_Email_Template
+     *
+     * The used factory helper and method can be configured at global/email/factory_helper.
+     * Default is Mage_Core_Helper_Mail::getMailer.
+     *
+     * @return Zend_Mail
+     */
+    public function getMailer()
+    {
+        return new Zend_Mail('utf-8');
+    }
+}
diff --git a/app/code/core/Mage/Core/Model/Email/Template.php b/app/code/core/Mage/Core/Model/Email/Template.php
index ab973ca5e6d6f..195759f596f17 100644
--- a/app/code/core/Mage/Core/Model/Email/Template.php
+++ b/app/code/core/Mage/Core/Model/Email/Template.php
@@ -73,6 +73,7 @@ class Mage_Core_Model_Email_Template extends Mage_Core_Model_Template
      * Configuration path for default email templates
      */
     const XML_PATH_TEMPLATE_EMAIL               = 'global/template/email';
+    const XML_PATH_MAIL_FACTORY                 = 'global/email/factory_helper';
     const XML_PATH_SENDING_SET_RETURN_PATH      = 'system/smtp/set_return_path';
     const XML_PATH_SENDING_RETURN_PATH_EMAIL    = 'system/smtp/return_path_email';
     const XML_PATH_DESIGN_EMAIL_LOGO            = 'design/email/logo';
@@ -140,11 +141,20 @@ protected function _getLogoAlt($store)
     /**
      * Retrieve mail object instance
      *
+     * Configure the factory helper at global/email/factory_helper using the format class::method.
+     * Default is Mage_Core_Helper_Mail::getMailer.
+     *
      * @return Zend_Mail
      */
     protected function _getMail()
     {
-        return new Zend_Mail('utf-8');
+        $factory = Mage::getConfig()->getNode(self::XML_PATH_MAIL_FACTORY);
+        $parts = explode('::', (string) $factory);
+        if (count($parts) != 2) {
+            throw new Exception(sprintf('Failed to get mail factory class and method.'));
+        }
+        $mailer = call_user_func(array(Mage::helper($parts[0]), $parts[1]));
+        return $mailer;
     }
 
     /**
@@ -349,25 +359,31 @@ public function getProcessedTemplate(array $variables = array())
             $variables['this'] = $this;
         }
 
-        if (isset($variables['subscriber']) && ($variables['subscriber'] instanceof Mage_Newsletter_Model_Subscriber)) {
-            $processor->setStoreId($variables['subscriber']->getStoreId());
-        }
-
-        if (!isset($variables['logo_url'])) {
-            $variables['logo_url'] = $this->_getLogoUrl($processor->getStoreId());
-        }
-        if (!isset($variables['logo_alt'])) {
-            $variables['logo_alt'] = $this->_getLogoAlt($processor->getStoreId());
-        }
-
-        $processor->setIncludeProcessor(array($this, 'getInclude'))
-            ->setVariables($variables);
+        $processor->setIncludeProcessor(array($this, 'getInclude'));
 
         $this->_applyDesignConfig();
         $storeId = $this->getDesignConfig()->getStore();
         try {
-            $processedResult = $processor->setStoreId($storeId)
-                ->filter($this->getPreparedTemplateText());
+            $processor->setStoreId($storeId);
+            $transport = new Varien_Object(array(
+                'variables' => new Varien_Object($variables),
+                'template_text' => $this->getPreparedTemplateText(),
+                'store_id' => $storeId
+            ));
+            // Use observer to modify variables and template processor settings
+            Mage::dispatchEvent('email_template_filter_before', array(
+                'processor' => $processor,
+                'transport' => $transport
+            ));
+            if (!isset($variables['logo_url'])) {
+                $variables['logo_url'] = $this->_getLogoUrl($transport->getStoreId());
+            }
+            if (!isset($variables['logo_alt'])) {
+                $variables['logo_alt'] = $this->_getLogoAlt($transport->getStoreId());
+            }
+
+            $processedResult = $processor->setVariables($transport->getVariables()->getData())
+                    ->filter($transport->getTemplateText());
         } catch (Exception $e) {
             $this->_cancelDesignConfig();
             throw $e;
@@ -486,6 +502,13 @@ public function send($email, $name = null, array $variables = array())
         $result = false;
         $this->_sendingException = null;
         try {
+            // Note: the email body already has been processed, changes to variables will have no effect
+            Mage::dispatchEvent('email_template_send_before', array(
+                'mailer' => $mail,
+                'variables' => new Varien_Object($variables),
+                'template' => $this,
+                'store_id' => $this->getDesignConfig()->getStore()
+            ));
             $mail->send();
             $result = true;
         } catch (Exception $e) {
diff --git a/app/code/core/Mage/Core/etc/config.xml b/app/code/core/Mage/Core/etc/config.xml
index 2cd9c2937e39a..09b4127c40a4f 100644
--- a/app/code/core/Mage/Core/etc/config.xml
+++ b/app/code/core/Mage/Core/etc/config.xml
@@ -89,7 +89,13 @@
             <page_type>
                 <render_inherited>0</render_inherited>
             </page_type>
+            <design_fallback>
+                <allow_map_update>1</allow_map_update>
+            </design_fallback>
         </dev>
+        <email>
+            <factory_helper>Mage_Core_Helper_Mail::getMailer</factory_helper>
+        </email>
     </global>
     <frontend>
         <routers>
@@ -291,7 +297,7 @@
         </web>
         <admin>
             <startup>
-                <page>dashboard</page>
+                <menu_item_id>dashboard</menu_item_id>
             </startup>
             <url>
                 <use_custom>0</use_custom>
diff --git a/app/code/core/Mage/Newsletter/Model/Observer.php b/app/code/core/Mage/Newsletter/Model/Observer.php
index 2ec75112e2d6c..06133eef95505 100644
--- a/app/code/core/Mage/Newsletter/Model/Observer.php
+++ b/app/code/core/Mage/Newsletter/Model/Observer.php
@@ -69,4 +69,23 @@ public function scheduledSend($schedule)
 
          $collection->walk('sendPerSubscriber', array($countOfSubscritions));
     }
+
+    /**
+     * Set the subscriber store id on the transport object
+     *
+     * Set the subscriber store id on the transport object so the logo configuration for the
+     * subscriber store is read (which is not necessarily the current one).
+     *
+     * @param Varien_Object $observer
+     * @return Mage_Newsletter_Model_Observer
+     */
+    public function emailTemplateFilterBefore($observer)
+    {
+        // Only match newsletter subscriber events
+        $subscriber = $observer->getTransport()->getVariables()->getSubscriber();
+        if ($subscriber && $subscriber instanceof Mage_Newsletter_Model_Subscriber) {
+            $observer->getTransport()->setStoreId($subscriber->getStoreId());
+        }
+        return $this;
+    }
 }
diff --git a/app/code/core/Mage/Newsletter/etc/config.xml b/app/code/core/Mage/Newsletter/etc/config.xml
index 7dd987c964799..98107000b0a7a 100644
--- a/app/code/core/Mage/Newsletter/etc/config.xml
+++ b/app/code/core/Mage/Newsletter/etc/config.xml
@@ -61,6 +61,16 @@
         <newsletter>
             <tempate_filter>Mage_Newsletter_Model_Template_Filter</tempate_filter>
         </newsletter>
+        <events>
+            <email_template_filter_before>
+                <observers>
+                    <newsletter>
+                        <class>Mage_Newsletter_Model_Observer</class>
+                        <method>emailTemplateFilterBefore</method>
+                    </newsletter>
+                </observers>
+            </email_template_filter_before>
+        </events>
     </global>
     <adminhtml>
         <events>