MAGETWO-67680: Replace Zend_Mail (ZF1) with Zend\Mail (ZF2) #8608

 - Introduced new interface MailMessageInterface and deprecated MessageInterface to keep backward compatibility
 - get rid of temporal coupling (setMessageType() + setBody())
 - deprecated setMessageType(), setBody() and getBody()
 - implemented setBodyHtml(), setBodyText(), getBodyHtml() and getBodyText()
 - changed usage in \Magento\Framework\Mail\Template\TransportBuilder::prepareMessage()

Author: Oleksii Korshenko

lib/internal/Magento/Framework/Mail/MailMessageInterface.php

@@ -0,0 +1,43 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace Magento\Framework\Mail;
+
+/**
+ * Mail Message interface
+ *
+ * @api
+ */
+interface MailMessageInterface extends MessageInterface
+{
+    /**
+     * @param string $html
+     * @return $this
+     */
+    public function setBodyHtml($html);
+
+    /**
+     * @param string $text
+     * @return $this
+     */
+    public function setBodyText($text);
+
+    /**
+     * @return string
+     */
+    public function getBodyText();
+
+    /**
+     * @return string
+     */
+    public function getBodyHtml();
+
+    /**
+     * Get message source code
+     *
+     * @return string
+     */
+    public function getRawMessage();
+}

lib/internal/Magento/Framework/Mail/Message.php

@@ -7,31 +7,20 @@
  */
 namespace Magento\Framework\Mail;
 
+use Magento\Framework\Exception\LocalizedException;
 use Zend\Mime\Mime;
 use Zend\Mime\Part;
 
 /**
- * @todo get rid of temporal coupling (setMessageType() + setBody())
- * - deprecate setMessageType(), setBody() and getBody()
- * - implement setBodyHtml(), setBodyText(), getBodyHtml() and getBodyText()
- * - change usage in \Magento\Framework\Mail\Template\TransportBuilder::prepareMessage()
+ * Class Message.
  */
-class Message implements MessageInterface
+class Message implements MailMessageInterface
 {
     /**
      * @var \Zend\Mail\Message
      */
     private $zendMessage;
 
-    /**
-     * @param string $encoding
-     */
-    public function __construct($encoding = 'utf-8')
-    {
-        $this->zendMessage = new \Zend\Mail\Message;
-        $this->zendMessage->setEncoding($encoding);
-    }
-
     /**
      * Message type
      *
@@ -40,10 +29,24 @@ public function __construct($encoding = 'utf-8')
     protected $messageType = self::TYPE_TEXT;
 
     /**
-     * Set message type
+     * Initialize dependencies.
      *
-     * @param string $type
-     * @return $this
+     * @param string $charset
+     */
+    public function __construct($charset = 'utf-8')
+    {
+        $this->zendMessage = new \Zend\Mail\Message();
+        $this->zendMessage->setEncoding($charset);
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @deprecated
+     * @see \Magento\Framework\Mail\Message::getBodyText
+     * @see \Magento\Framework\Mail\Message::getBodyHtml
+     * @see \Magento\Framework\Mail\Message::setBodyText
+     * @see \Magento\Framework\Mail\Message::setBodyHtml
      */
     public function setMessageType($type)
     {
@@ -52,12 +55,15 @@ public function setMessageType($type)
     }
 
     /**
-     * @param null|object|string|\Zend\Mime\Message $body
-     * @return $this
+     * {@inheritdoc}
+     *
+     * @deprecated
+     * @see \Magento\Framework\Mail\Message::setBodyText
+     * @see \Magento\Framework\Mail\Message::setBodyHtml
      */
     public function setBody($body)
     {
-        if (is_string($body) && $this->messageType === MessageInterface::TYPE_HTML) {
+        if (is_string($body) && $this->messageType === MailMessageInterface::TYPE_HTML) {
             $body = self::createHtmlMimeFromString($body);
         }
         $this->zendMessage->setBody($body);
@@ -83,7 +89,11 @@ public function getSubject()
     }
 
     /**
-     * @return object
+     * {@inheritdoc}
+     *
+     * @deprecated
+     * @see \Magento\Framework\Mail\Message::getBodyText
+     * @see \Magento\Framework\Mail\Message::getBodyHtml
      */
     public function getBody()
     {
@@ -161,4 +171,48 @@ private function createHtmlMimeFromString($htmlBody)
         $mimeMessage->addPart($htmlPart);
         return $mimeMessage;
     }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function setBodyHtml($html)
+    {
+        $this->setMessageType(self::TYPE_HTML);
+        return $this->setBody($html);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function setBodyText($text)
+    {
+        $this->setMessageType(self::TYPE_TEXT);
+        return $this->setBody($text);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getBodyText()
+    {
+        if ($this->messageType != self::TYPE_TEXT) {
+            throw new LocalizedException(
+                __('Text message body is not set')
+            );
+        }
+        return $this->getBody();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getBodyHtml()
+    {
+        if ($this->messageType != self::TYPE_HTML) {
+            throw new LocalizedException(
+                __('HTML message body is not set')
+            );
+        }
+        return $this->getBody();
+    }
 }

lib/internal/Magento/Framework/Mail/MessageInterface.php

@@ -9,6 +9,8 @@
  * Mail Message interface
  *
  * @api
+ * @deprecated
+ * @see \Magento\Framework\Mail\MailMessageInterface
  */
 interface MessageInterface
 {
@@ -39,13 +41,21 @@ public function getSubject();
      *
      * @param mixed $body
      * @return $this
+     *
+     * @deprecated
+     * @see \Magento\Framework\Mail\MailMessageInterface::setBodyHtml
+     * @see \Magento\Framework\Mail\MailMessageInterface::setBodyText()
      */
     public function setBody($body);
 
     /**
      * Get message body
      *
      * @return mixed
+     *
+     * @deprecated
+     * @see \Magento\Framework\Mail\MailMessageInterface::getBodyHtml
+     * @see \Magento\Framework\Mail\MailMessageInterface::getBodyText()
      */
     public function getBody();
 
@@ -94,13 +104,12 @@ public function setReplyTo($replyToAddress);
      *
      * @param string $type
      * @return $this
-     */
-    public function setMessageType($type);
-
-    /**
-     * Get message source code
      *
-     * @return string
+     * @deprecated
+     * @see \Magento\Framework\Mail\MailMessageInterface::setBodyHtml
+     * @see \Magento\Framework\Mail\MailMessageInterface::getBodyHtml
+     * @see \Magento\Framework\Mail\MailMessageInterface::setBodyText()
+     * @see \Magento\Framework\Mail\MailMessageInterface::getBodyText()
      */
-    public function getRawMessage();
+    public function setMessageType($type);
 }

lib/internal/Magento/Framework/Mail/Template/TransportBuilder.php

@@ -9,6 +9,7 @@
 namespace Magento\Framework\Mail\Template;
 
 use Magento\Framework\App\TemplateTypesInterface;
+use Magento\Framework\Exception\LocalizedException;
 use Magento\Framework\Mail\MessageInterface;
 use Magento\Framework\Mail\TransportInterfaceFactory;
 use Magento\Framework\ObjectManagerInterface;
@@ -260,23 +261,32 @@ protected function getTemplate()
     }
 
     /**
-     * Prepare message
+     * Prepare message.
      *
      * @return $this
+     * @throws LocalizedException if template type is unknown
      */
     protected function prepareMessage()
     {
         $template = $this->getTemplate();
-        $types = [
-            TemplateTypesInterface::TYPE_TEXT => MessageInterface::TYPE_TEXT,
-            TemplateTypesInterface::TYPE_HTML => MessageInterface::TYPE_HTML,
-        ];
-
         $body = $template->processTemplate();
-        $this->message->setMessageType($types[$template->getType()])
-            ->setBody($body)
-            ->setSubject(html_entity_decode($template->getSubject(), ENT_QUOTES));
 
+        switch ($template->getType()) {
+            case MessageInterface::TYPE_TEXT:
+                $this->message->setBodyText($body);
+                break;
+
+            case MessageInterface::TYPE_HTML:
+                $this->message->setBodyHtml($body);
+                break;
+
+            default;
+                throw new LocalizedException(
+                    __('Unknown template type')
+                );
+            break;
+        }
+        $this->message->setSubject(html_entity_decode($template->getSubject(), ENT_QUOTES));
         return $this;
     }
 }