[FEATURE] Adds a function to overwrite the email body

Classes/Service/MailTemplateService.php

@@ -104,6 +104,11 @@ class MailTemplateService {
 	 */
 	private $subject;
 
+	/**
+	 * @var string $overwrittenEmailBody
+	 */
+	private $overwrittenEmailBody = '';
+
 	/**
 	 * @var string $extensionKey
 	 */
@@ -486,6 +491,20 @@ class MailTemplateService {
 		$this->subject = $subject;
 	}
 
+	/**
+	 * @return string
+	 */
+	public function getOverwrittenEmailBody(): string {
+		return $this->overwrittenEmailBody;
+	}
+
+	/**
+	 * @param string $overwrittenEmailBody
+	 */
+	public function setOverwrittenEmailBody(string $overwrittenEmailBody): void {
+		$this->overwrittenEmailBody = $overwrittenEmailBody;
+	}
+
 	/**
 	 * Return default markers for sg_mail
 	 *
@@ -662,7 +681,8 @@ class MailTemplateService {
 			$emailView->setTemplateSource(\trim($template->getSubject()));
 			$subject = $emailView->render();
 
-			$emailView->setTemplateSource($template->getContent());
+			$overwrittenEmailBody = $this->getOverwrittenEmailBody();
+			$emailView->setTemplateSource(empty($overwrittenEmailBody) ? $template->getContent() : $overwrittenEmailBody);
 		} else {
 			$subject = $registerService->getRegisterArray()[$this->extensionKey][$this->templateName]['subject'];
 			if (\is_array($subject)) {
@@ -678,7 +698,7 @@ class MailTemplateService {
 				$emailView->setTemplateSource($subject);
 				$subject = $emailView->render();
 			}
-			$emailView->setTemplateSource($defaultTemplateContent);
+			$emailView->setTemplateSource(empty($overwrittenEmailBody) ? $defaultTemplateContent : $overwrittenEmailBody);
 		}
 
 		if ($this->subject !== '' && $this->subject !== NULL) {