Implement honeypot field as spam countermeasure

public/typo3conf/ext/ep_theme/Classes/Controller/AjaxFormController.php

@@ -64,6 +64,13 @@ class AjaxFormController extends ActionController
     public function processFormAction(ContactForm $contactForm)
     {
         $response['status'] = 'ok';
+
+        // Don't take further actions in case honeypot field is filled in
+        // as a spam countermeasure
+        if ($contactForm->getSubject()) {
+            return json_encode($response);
+        }
+
         $this->emailService->send(
             $this->settings['contactFormToEmail'],
             $this->settings['contactFormToName'],

public/typo3conf/ext/ep_theme/Classes/Domain/Model/Dto/ContactForm.php

@@ -36,6 +36,13 @@ class ContactForm
      */
     protected $formType = 1;
 
+    /**
+     * Honeypot field!!
+     *
+     * @var string
+     */
+    protected $subject;
+
     /**
      * @var string
      * @TYPO3\CMS\Extbase\Annotation\Validate("NotEmpty")
@@ -117,6 +124,22 @@ class ContactForm
         $this->formType = $formType;
     }
 
+    /**
+     * @return string
+     */
+    public function getSubject()
+    {
+        return $this->subject;
+    }
+
+    /**
+     * @param string $subject
+     */
+    public function setSubject($subject)
+    {
+        $this->subject = $subject;
+    }
+
     /**
      * @return string
      */