diff --git a/src/DiffEntityComparison.php b/src/DiffEntityComparison.php
index 8184326..b291bff 100644
--- a/src/DiffEntityComparison.php
+++ b/src/DiffEntityComparison.php
@@ -90,18 +90,19 @@ class DiffEntityComparison {
       $result[$left_key] = [
         '#name' => (isset($compare_settings['settings']['show_header']) && $compare_settings['settings']['show_header'] == 0) ? '' : $values['label'],
         '#settings' => $compare_settings,
+        '#data' => [],
       ];
 
       // Fields which exist on the right entity also.
       if (isset($right_values[$left_key])) {
-        $result[$left_key] += $this->combineFields($left_values[$left_key], $right_values[$left_key]);
+        $result[$left_key]['#data'] += $this->combineFields($left_values[$left_key], $right_values[$left_key]);
         // Unset the field from the right entity so that we know if the right
         // entity has any fields that left entity doesn't have.
         unset($right_values[$left_key]);
       }
       // This field exists only on the left entity.
       else {
-        $result[$left_key] += $this->combineFields($left_values[$left_key], []);
+        $result[$left_key]['#data'] += $this->combineFields($left_values[$left_key], []);
       }
     }
 
@@ -113,41 +114,22 @@ class DiffEntityComparison {
         '#name' => (isset($compare_settings['settings']['show_header']) && $compare_settings['settings']['show_header'] == 0) ? '' : $values['label'],
         '#settings' => $compare_settings,
       ];
-      $result[$right_key] += $this->combineFields([], $right_values[$right_key]);
+      $result[$right_key]['#data'] += $this->combineFields([], $right_values[$right_key]);
     }
 
     // Field rows. Recurse through all child elements.
     foreach (Element::children($result) as $key) {
-      $result[$key]['#states'] = array();
       // Ensure that the element follows the #states format.
-      if (isset($result[$key]['#left'])) {
+      if (isset($result[$key]['#data']['#left'])) {
         // We need to trim spaces and new lines from the end of the string
         // otherwise in some cases we have a blank not needed line.
-        $result[$key]['#states']['raw']['#left'] = trim($result[$key]['#left']);
-        unset($result[$key]['#left']);
+        $result[$key]['#data']['#left'] = trim($result[$key]['#data']['#left']);
       }
-      if (isset($result[$key]['#right'])) {
-        $result[$key]['#states']['raw']['#right'] = trim($result[$key]['#right']);
-        unset($result[$key]['#right']);
-      }
-      $field_settings = $result[$key]['#settings'];
-
-      if (!empty($field_settings['settings']['markdown'])) {
-        $result[$key]['#states']['raw_plain']['#left'] = $this->applyMarkdown($field_settings['settings']['markdown'], $result[$key]['#states']['raw']['#left']);
-        $result[$key]['#states']['raw_plain']['#right'] = $this->applyMarkdown($field_settings['settings']['markdown'], $result[$key]['#states']['raw']['#right']);
-      }
-      // In case the settings are not loaded correctly use drupal_html_to_text
-      // to avoid any possible notices when a user clicks on markdown.
-      else {
-        $result[$key]['#states']['raw_plain']['#left'] = $this->applyMarkdown('drupal_html_to_text', $result[$key]['#states']['raw']['#left']);
-        $result[$key]['#states']['raw_plain']['#right'] = $this->applyMarkdown('drupal_html_to_text', $result[$key]['#states']['raw']['#right']);
+      if (isset($result[$key]['#data']['#right'])) {
+        $result[$key]['#data']['#right'] = trim($result[$key]['#data']['#right']);
       }
     }
 
-    // Process the array (split the strings into single line strings)
-    // and get line counts per field.
-    array_walk($result, array($this, 'processStateLine'));
-
     return $result;
   }
 
@@ -231,57 +213,25 @@ class DiffEntityComparison {
    * @param $diff
    *   Array of strings.
    */
-  protected function processStateLine(&$diff) {
-    foreach ($diff['#states'] as $state => $data) {
-      if (isset($data['#left'])) {
-        if (is_string($data['#left'])) {
-          $diff['#states'][$state]['#left'] = explode("\n", $data['#left']);
-        }
-        $diff['#states'][$state]['#count_left'] = count($diff['#states'][$state]['#left']);
-      }
-      else {
-        $diff['#states'][$state]['#count_left'] = 0;
-      }
-      if (isset($data['#right'])) {
-        if (is_string($data['#right'])) {
-          $diff['#states'][$state]['#right'] = explode("\n", $data['#right']);
-        }
-        $diff['#states'][$state]['#count_right'] = count($diff['#states'][$state]['#right']);
-      }
-      else {
-        $diff['#states'][$state]['#count_right'] = 0;
+  public function processStateLine(&$diff) {
+    $data = $diff['#data'];
+    if (isset($data['#left'])) {
+      if (is_string($data['#left'])) {
+        $diff['#data']['#left'] = explode("\n", $data['#left']);
       }
+      $diff['#data']['#count_left'] = count($diff['#data']['#left']);
     }
-  }
-
-  /**
-   * Applies a markdown function to a string.
-   *
-   * @param $markdown
-   *   Key of the markdown function to be applied to the items.
-   *   One of drupal_html_to_text, filter_xss, filter_xss_all.
-   * @param $items
-   *   String to be processed.
-   *
-   * @return array|string
-   *   Result after markdown was applied on $items.
-   */
-  protected function applyMarkdown($markdown, $items) {
-    if (!$markdown) {
-      return $items;
-    }
-
-    if ($markdown == 'drupal_html_to_text') {
-      return trim(MailFormatHelper::htmlToText($items), "\n");
-    }
-    elseif ($markdown == 'filter_xss') {
-      return trim(Xss::filter($items), "\n");
+    else {
+      $diff['#data']['#count_left'] = 0;
     }
-    elseif ($markdown == 'filter_xss_all') {
-      return trim(Xss::filter($items, array()), "\n");
+    if (isset($data['#right'])) {
+      if (is_string($data['#right'])) {
+        $diff['#data']['#right'] = explode("\n", $data['#right']);
+      }
+      $diff['#data']['#count_right'] = count($diff['#data']['#right']);
     }
     else {
-      return $items;
+      $diff['#data']['#count_right'] = 0;
     }
   }
 
diff --git a/src/DiffLayoutBase.php b/src/DiffLayoutBase.php
index 4f9f9f3..8f67beb 100644
--- a/src/DiffLayoutBase.php
+++ b/src/DiffLayoutBase.php
@@ -77,21 +77,21 @@ abstract class DiffLayoutBase extends PluginBase implements DiffLayoutInterface,
    * {@inheritdoc}
    */
   public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
-    // TODO: Implement buildConfigurationForm() method.
+    // @todo Implement buildConfigurationForm() method.
   }
 
   /**
    * {@inheritdoc}
    */
   public function validateConfigurationForm(array &$form, FormStateInterface $form_state) {
-    // TODO: Implement validateConfigurationForm() method.
+    // @todo Implement validateConfigurationForm() method.
   }
 
   /**
    * {@inheritdoc}
    */
   public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {
-    // TODO: Implement submitConfigurationForm() method.
+    // @todo Implement submitConfigurationForm() method.
   }
 
   /**
@@ -105,14 +105,14 @@ abstract class DiffLayoutBase extends PluginBase implements DiffLayoutInterface,
    * {@inheritdoc}
    */
   public function getConfiguration() {
-    return $this->configFactory->getEditable('diff.layout_plugins');
+    // @todo Implement getConfiguration() method.
   }
 
   /**
    * {@inheritdoc}
    */
   public function setConfiguration(array $configuration) {
-    $config = $this->configFactory->getEditable('diff.layout_plugins');
+    // @todo Implement setConfiguration() method.
   }
 
   /**
diff --git a/src/DiffLayoutInterface.php b/src/DiffLayoutInterface.php
index b3393e9..dcfccc5 100644
--- a/src/DiffLayoutInterface.php
+++ b/src/DiffLayoutInterface.php
@@ -10,36 +10,25 @@ use Drupal\Core\Routing\RouteMatchInterface;
 interface DiffLayoutInterface extends PluginFormInterface, ConfigurablePluginInterface {
 
   /**
-   * Builds an array of strings.
+   * Builds a diff comparison between two revisions.
    *
-   * This method is responsible for transforming a FieldItemListInterface object
-   * into an array of strings. The resulted array of strings is then compared by
-   * the Diff component with another such array of strings and the result
-   * represents the difference between two entity fields.
+   * This method is responsible for building the diff comparison between
+   * revisions of the same entity. It can build a table, navigation links and
+   * headers of a diff comparison.
    *
-   * Example of FieldItemListInterface built into an array of strings:
-   * @code
-   * array(
-   *   0 => "This is an example string",
-   *   1 => "Field values or properties",
-   * )
-   * @endcode
-   *
-   * @see \Drupal\diff\Plugin\Diff\TextFieldBuilder
+   * @see \Drupal\diff\Plugin\Layout\ClassicDiffLayout
    *
    * @param array $build
-   *   Represents an entity field.
+   *   A renderable array of data.
    * @param \Drupal\Core\Entity\EntityInterface $left_revision
    *   The left revision.
    * @param \Drupal\Core\Entity\EntityInterface $right_revision
    *   The right revision.
    * @param \Drupal\Core\Entity\EntityInterface $entity
-   *   The route match.
+   *   The entity.
    *
    * @return mixed
-   *   An array of strings to be compared. If an empty array is returned it
-   *   means that a field is either empty or no properties need to be compared
-   *   for that field.
+   *   The modified build array that the plugin builds.
    */
   public function build(array $build, EntityInterface $left_revision, EntityInterface $right_revision, EntityInterface $entity);
 }
diff --git a/src/DiffLayoutManager.php b/src/DiffLayoutManager.php
index e0e6aa8..9d3f781 100644
--- a/src/DiffLayoutManager.php
+++ b/src/DiffLayoutManager.php
@@ -14,7 +14,7 @@ use Drupal\Core\Plugin\DefaultPluginManager;
 /**
  * Plugin type manager for field diff builders.
  *
- * @ingroup field_diff_builder
+ * @ingroup diff_layout_builder
  */
 class DiffLayoutManager extends DefaultPluginManager {
 
@@ -36,7 +36,7 @@ class DiffLayoutManager extends DefaultPluginManager {
   protected $layoutPluginsConfig;
 
   /**
-   * Constructs a FieldDiffBuilderManager object.
+   * Constructs a DiffLayoutManager object.
    *
    * @param \Traversable $namespaces
    *   An object that implements \Traversable which contains the root paths
diff --git a/src/Plugin/Layout/ClassicDiffLayout.php b/src/Plugin/Layout/ClassicDiffLayout.php
index c750036..9afeb2e 100644
--- a/src/Plugin/Layout/ClassicDiffLayout.php
+++ b/src/Plugin/Layout/ClassicDiffLayout.php
@@ -2,15 +2,12 @@
 
 namespace Drupal\diff\Plugin\Layout;
 
-use Drupal\Component\Render\FormattableMarkup;
 use Drupal\Component\Utility\Xss;
 use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Datetime\DateFormatter;
 use Drupal\Core\Entity\EntityInterface;
-use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
 use Drupal\Core\Render\RendererInterface;
-use Drupal\Core\Routing\RouteMatchInterface;
 use Drupal\Core\Url;
 use Drupal\diff\DiffEntityComparison;
 use Drupal\diff\DiffEntityParser;
@@ -100,35 +97,40 @@ class ClassicDiffLayout extends DiffLayoutBase {
     foreach ($fields as $field) {
       $field_label_row = '';
       if (!empty($field['#name'])) {
-        $field_label_row = array(
+        $field_label_row = [
           'data' => $this->t('%name', ['%name' => $field['#name']]),
           'colspan' => 4,
-          'class' => array('field-name'),
-        );
+          'class' => ['field-name'],
+        ];
       }
+
+      // Process the array (split the strings into single line strings)
+      // and get line counts per field.
+      $this->entityComparison->processStateLine($field);
+
       $field_diff_rows = $this->entityComparison->getRows(
-        $field['#states']['raw']['#left'],
-        $field['#states']['raw']['#right']
+        $field['#data']['#left'],
+        $field['#data']['#right']
       );
 
       // Add the field label to the table only if there are changes to that field.
       if (!empty($field_diff_rows) && !empty($field_label_row)) {
-        $diff_rows[] = array($field_label_row);
+        $diff_rows[] = [$field_label_row];
       }
 
       // Add field diff rows to the table rows.
       $diff_rows = array_merge($diff_rows, $field_diff_rows);
     }
 
-    $build['diff'] = array(
+    $build['diff'] = [
       '#type' => 'table',
       '#header' => $diff_header,
       '#rows' => $diff_rows,
       '#empty' => $this->t('No visible changes'),
-      '#attributes' => array(
-        'class' => array('diff'),
-      ),
-    );
+      '#attributes' => [
+        'class' => ['diff'],
+      ],
+    ];
 
     $build['#attached']['library'][] = 'diff/diff.github';
     return $build;
@@ -180,10 +182,6 @@ class ClassicDiffLayout extends DiffLayoutBase {
       elseif ($revision instanceof NodeInterface) {
         $revision_log = $revision->revision_log->value;
       }
-      $username = [
-        '#theme' => 'username',
-        '#account' => $revision->uid->entity,
-      ];
       $revision_date = $this->date->format($revision->getRevisionCreationTime(), 'short');
       $route_name = $entity_type_id != 'node' ? "entity.$entity_type_id.revisions_diff" : 'entity.node.revision';
       $revision_link = $this->t($revision_log . '@date', [
diff --git a/src/Plugin/Layout/MarkdownDiffLayout.php b/src/Plugin/Layout/MarkdownDiffLayout.php
index 799b93d..4d2d6a4 100644
--- a/src/Plugin/Layout/MarkdownDiffLayout.php
+++ b/src/Plugin/Layout/MarkdownDiffLayout.php
@@ -2,15 +2,13 @@
 
 namespace Drupal\diff\Plugin\Layout;
 
-use Drupal\Component\Render\FormattableMarkup;
 use Drupal\Component\Utility\Xss;
 use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Datetime\DateFormatter;
 use Drupal\Core\Entity\EntityInterface;
-use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Mail\MailFormatHelper;
 use Drupal\Core\Render\RendererInterface;
-use Drupal\Core\Routing\RouteMatchInterface;
 use Drupal\Core\Url;
 use Drupal\diff\DiffEntityComparison;
 use Drupal\diff\DiffEntityParser;
@@ -100,35 +98,51 @@ class MarkdownDiffLayout extends DiffLayoutBase {
     foreach ($fields as $field) {
       $field_label_row = '';
       if (!empty($field['#name'])) {
-        $field_label_row = array(
+        $field_label_row = [
           'data' => $this->t('%name', ['%name' => $field['#name']]),
           'colspan' => 4,
-          'class' => array('field-name'),
-        );
+          'class' => ['field-name'],
+        ];
       }
+      $field_settings = $field['#settings'];
+      if (!empty($field_settings['settings']['markdown'])) {
+        $field['#data']['#left'] = $this->applyMarkdown($field_settings['settings']['markdown'], $field['#data']['#left']);
+        $field['#data']['#right'] = $this->applyMarkdown($field_settings['settings']['markdown'], $field['#data']['#right']);
+      }
+      // In case the settings are not loaded correctly use drupal_html_to_text
+      // to avoid any possible notices when a user clicks on markdown.
+      else {
+        $field['#data']['#left'] = $this->applyMarkdown('drupal_html_to_text', $field['#data']['#left']);
+        $field['#data']['#right'] = $this->applyMarkdown('drupal_html_to_text', $field['#data']['#right']);
+      }
+
+      // Process the array (split the strings into single line strings)
+      // and get line counts per field.
+      $this->entityComparison->processStateLine($field);
+
       $field_diff_rows = $this->entityComparison->getRows(
-        $field['#states']['raw_plain']['#left'],
-        $field['#states']['raw_plain']['#right']
+        $field['#data']['#left'],
+        $field['#data']['#right']
       );
 
       // Add the field label to the table only if there are changes to that field.
       if (!empty($field_diff_rows) && !empty($field_label_row)) {
-        $diff_rows[] = array($field_label_row);
+        $diff_rows[] = [$field_label_row];
       }
 
       // Add field diff rows to the table rows.
       $diff_rows = array_merge($diff_rows, $field_diff_rows);
     }
 
-    $build['diff'] = array(
+    $build['diff'] = [
       '#type' => 'table',
       '#header' => $diff_header,
       '#rows' => $diff_rows,
       '#empty' => $this->t('No visible changes'),
-      '#attributes' => array(
-        'class' => array('diff'),
-      ),
-    );
+      '#attributes' => [
+        'class' => ['diff'],
+      ],
+    ];
 
     $build['#attached']['library'][] = 'diff/diff.github';
     return $build;
@@ -180,10 +194,6 @@ class MarkdownDiffLayout extends DiffLayoutBase {
       elseif ($revision instanceof NodeInterface) {
         $revision_log = $revision->revision_log->value;
       }
-      $username = [
-        '#theme' => 'username',
-        '#account' => $revision->uid->entity,
-      ];
       $revision_date = $this->date->format($revision->getRevisionCreationTime(), 'short');
       $route_name = $entity_type_id != 'node' ? "entity.$entity_type_id.revisions_diff" : 'entity.node.revision';
       $revision_link = $this->t($revision_log . '@date', [
@@ -199,4 +209,36 @@ class MarkdownDiffLayout extends DiffLayoutBase {
     return $revision_link;
   }
 
+
+  /**
+   * Applies a markdown function to a string.
+   *
+   * @param $markdown
+   *   Key of the markdown function to be applied to the items.
+   *   One of drupal_html_to_text, filter_xss, filter_xss_all.
+   * @param $items
+   *   String to be processed.
+   *
+   * @return array|string
+   *   Result after markdown was applied on $items.
+   */
+  protected function applyMarkdown($markdown, $items) {
+    if (!$markdown) {
+      return $items;
+    }
+
+    if ($markdown == 'drupal_html_to_text') {
+      return trim(MailFormatHelper::htmlToText($items), "\n");
+    }
+    elseif ($markdown == 'filter_xss') {
+      return trim(Xss::filter($items), "\n");
+    }
+    elseif ($markdown == 'filter_xss_all') {
+      return trim(Xss::filter($items, []), "\n");
+    }
+    else {
+      return $items;
+    }
+  }
+
 }