diff --git a/google_vision.links.task.yml b/google_vision.links.task.yml
index 5ee2624..98d41df 100644
--- a/google_vision.links.task.yml
+++ b/google_vision.links.task.yml
@@ -2,4 +2,4 @@ google_vision.related_content:
   route_name: google_vision.related_content
   base_route: entity.file.canonical
   title: 'Similar Contents'
-  weight: 10
\ No newline at end of file
+  weight: 10
diff --git a/google_vision.module b/google_vision.module
index 26eac29..067a0b5 100644
--- a/google_vision.module
+++ b/google_vision.module
@@ -94,13 +94,14 @@ function google_vision_entity_presave(EntityInterface $entity) {
         // If this field is the alt text field.
         if ($field->getName() == 'field_image_alt_text') {
           $value = $entity->get($field->getName())->getValue();
+          $fill_alt_text = \Drupal::service('google_vision.fill_alt_text');
           //Set the Alt Text using Vision API.
           if (empty($value)) {
-            google_vision_set_alt_text($entity, $field);
+            $fill_alt_text->setAltText($entity, $field);
           }
           else {
             //Change the alt text if required.
-            google_vision_edit_alt_text($entity, $field, $value);
+            $fill_alt_text->editAltText($entity, $field, $value);
           }
         }
       }
@@ -310,71 +311,3 @@ function google_vision_file_entity_dominant_color($file, $field, $vid) {
     }
   }
 }
-
-/**
- * Set the value for the alternative text field of the image file.
- */
-function google_vision_set_alt_text($entity, $field) {
-  // Initialize the output.
-  $output = '';
-  $settings = $field->getThirdPartySettings('google_vision');
-  if (!empty($settings['alt_auto_filling'])) {
-    $option = $settings['alt_auto_filling'];
-
-    $file_uri = $entity->getFileUri();
-    if ($filepath = \Drupal::service('file_system')->realpath($file_uri)) {
-      $gv_service = \Drupal::service('google_vision.api');
-      switch ($option) {
-        case 'labels':
-          $data = $gv_service->labelDetection($filepath);
-          // If we have retrieved labels.
-          if (!empty($data['responses'][0]['labelAnnotations'])) {
-            $output = $data['responses'][0]['labelAnnotations'];
-          }
-          break;
-        case 'landmark':
-          $data = $gv_service->landmarkDetection($filepath);
-          // If we have retrieved landmark.
-          if (!empty($data['responses'][0]['landmarkAnnotations'])) {
-            $output = $data['responses'][0]['landmarkAnnotations'];
-          }
-          break;
-
-        case 'logo':
-          $data = $gv_service->logoDetection($filepath);
-          // If we have retrieved logo.
-          if (!empty($data['responses'][0]['logoAnnotations'])) {
-            $output = $data['responses'][0]['logoAnnotations'];
-          }
-          break;
-
-        case 'ocr':
-          $data = $gv_service->opticalCharacterRecognition($filepath);
-          // If we have retrieved character.
-          if (!empty($data['responses'][0]['textAnnotations'])) {
-            $output = $data['responses'][0]['textAnnotations'];
-          }
-          break;
-
-        case 'none':
-          // If none is selected, do nothing.
-          break;
-      }
-    }
-
-    // If we have some data.
-    if (!empty($output)) {
-      // Grab first value (most relevant) and use it.
-      $value = reset($output)['description'];
-      $entity->set($field->getName(), $value);
-    }
-  }
-}
-
-/**
- * Edit the current value of the Alt Text field of the image file.
- */
-function google_vision_edit_alt_text($entity, $field, $value) {
-  //Set the new value to the Alt Text field.
-  $entity->set($field->getName(), $value);
-}
diff --git a/google_vision.routing.yml b/google_vision.routing.yml
index b901e53..95ab2e1 100644
--- a/google_vision.routing.yml
+++ b/google_vision.routing.yml
@@ -13,4 +13,4 @@ google_vision.related_content:
     _title: 'Similar Contents'
   requirements:
     _permission: 'administer files'
-    file: \d+
\ No newline at end of file
+    file: \d+
diff --git a/google_vision.services.yml b/google_vision.services.yml
index be39f19..ba15783 100644
--- a/google_vision.services.yml
+++ b/google_vision.services.yml
@@ -1,4 +1,7 @@
 services:
   google_vision.api:
     class: Drupal\google_vision\GoogleVisionAPI
-    arguments: ['@config.factory', '@http_client']
\ No newline at end of file
+    arguments: ['@config.factory', '@http_client']
+  google_vision.fill_alt_text:
+    class: Drupal\google_vision\AutoAltTextFill
+    arguments: ['@file_system', '@google_vision.api']
diff --git a/src/AutoAltTextFill.php b/src/AutoAltTextFill.php
new file mode 100644
index 0000000..7fcb41d
--- /dev/null
+++ b/src/AutoAltTextFill.php
@@ -0,0 +1,128 @@
+<?php
+
+namespace Drupal\google_vision;
+
+use Drupal\Core\File\FileSystem;
+use Drupal\Component\Utility\Html;
+use Drupal\google_vision\GoogleVisionAPI;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+class AutoAltTextFill {
+
+  /**
+   * The file system.
+   *
+   * @var \Drupal\Core\File\FileSystem
+   */
+  protected $fileSystem;
+
+  /**
+   * The GoogleVisionAPI object.
+   *
+   * @var \Drupal\google_vision\GoogleVisionAPI
+   */
+  protected $googlevisionapi;
+
+  /**
+   * Construct an AutoAltTextFill object.
+   *
+   * @param \Drupal\Core\File\FileSystem $file_system
+   *   The file system.
+   *
+   * @param \Drupal\google_vision\GoogleVisionAPI $google_vision_api
+   *   A GoogleVisionAPI object.
+   */
+  public function __construct(FileSystem $file_system, GoogleVisionAPI $google_vision_api) {
+    $this->fileSystem = $file_system;
+    $this->googlevisionapi = $google_vision_api;
+  }
+
+  /**
+   * Set the value for the alternative text field of the image file.
+   *
+   * @param \Drupal\file\FileInterface $file
+   *  The file entity.
+   * @param \Drupal\Core\Field\FieldDefinitionInterface $field
+   *  The field definition.
+   */
+  public function setAltText($file, $field) {
+    // Initialize the output.
+    $output = '';
+    $settings = $field->getThirdPartySettings('google_vision');
+    if (!empty($settings['alt_auto_filling'])) {
+      $option = $settings['alt_auto_filling'];
+
+      $file_uri = $file->getFileUri();
+      if ($filepath = $this->fileSystem->realpath($file_uri)) {
+        switch ($option) {
+          case 'labels':
+            $data = $this->googlevisionapi->labelDetection($filepath);
+            // If we have retrieved labels.
+            if (!empty($data['responses'][0]['labelAnnotations'])) {
+              $output = $data['responses'][0]['labelAnnotations'];
+            }
+            break;
+
+          case 'landmark':
+            $data = $this->googlevisionapi->landmarkDetection($filepath);
+            // If we have retrieved landmark.
+            if (!empty($data['responses'][0]['landmarkAnnotations'])) {
+              $output = $data['responses'][0]['landmarkAnnotations'];
+            }
+            break;
+
+          case 'logo':
+            $data = $this->googlevisionapi->logoDetection($filepath);
+            // If we have retrieved logo.
+            if (!empty($data['responses'][0]['logoAnnotations'])) {
+              $output = $data['responses'][0]['logoAnnotations'];
+            }
+            break;
+
+          case 'ocr':
+            $data = $this->googlevisionapi->opticalCharacterRecognition($filepath);
+            // If we have retrieved character.
+            if (!empty($data['responses'][0]['textAnnotations'])) {
+              $output = $data['responses'][0]['textAnnotations'];
+            }
+            break;
+
+          case 'none':
+            // If none is selected, do nothing.
+            break;
+        }
+      }
+      // If we have some data.
+      if (!empty($output)) {
+        // Grab first value (most relevant) and use it.
+        $value = reset($output)['description'];
+        $file->set($field->getName(), $value);
+      }
+    }
+  }
+
+  /**
+   * Edit the current value of the Alt Text field of the image file.
+   *
+   * @param \Drupal\file\FileInterface $file
+   *  The file entity.
+   * @param \Drupal\Core\Field\FieldDefinitionInterface $field
+   *  The field definition.
+   * @param string $value
+   *  The Alt Text field value.
+   */
+  public function editAltText($file, $field, $value) {
+    //Set the new value to the Alt Text field.
+    $file->set($field->getName(), $value);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get('google_vision.api'),
+      $container->get('file_system')
+    );
+  }
+}