Possibility to change exposed filter when create a field

src/Plugin/Field/FieldFormatter/ViewfieldDefaultFormatter.php

@@ -11,6 +11,7 @@
 use Drupal\Core\Field\FormatterBase;
 use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\views\Views;
+use Drupal\Component\Serialization\Json;
 
 /**
  * Plugin implementation of the 'viewfield_default' formatter.
@@ -35,6 +36,9 @@ public function viewElements(FieldItemListInterface $items, $langcode) {
       $entity = $item->getEntity();
       list($view_name, $view_display) = explode('|', $item->vname, 2);
       $view = Views::getView($view_name);
+      if (!empty($item->settings)) {
+        $settings = Json::decode($item->settings);
+      }
       $elements[$delta] = array(
         '#type' => 'viewfield',
         '#view' => $view,
@@ -45,9 +49,11 @@ public function viewElements(FieldItemListInterface $items, $langcode) {
         '#entity_type' => $entity->getEntityTypeId(),
         '#entity_id' => $entity->id(),
         '#entity' => $entity,
+        '#exposed_settings' => $settings,
         '#theme' => 'viewfield_formatter_default',
       );
     }
     return $elements;
   }
+
 }

src/Plugin/Field/FieldType/ViewfieldItem.php

@@ -13,7 +13,6 @@
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\views\Views;
 
-
 /**
  * Plugin implementation of the 'viewfield' field type.
  *
@@ -58,14 +57,16 @@ public static function schema(FieldStorageDefinitionInterface $field_definition)
         'vname' => array(
           'type' => 'varchar',
           'not null' => FALSE,
-          // Views requires at least 96 chars for the view name and display, plus
-          // we need 1 for our delimiter. Round up to a common value of 128.
           'length' => 128,
         ),
         'vargs' => array(
           'type' => 'varchar',
           'not null' => FALSE,
-          'length' => 255, //viewfield_field_instance_settings_form_validate
+          'length' => 255,
+        ),
+        'settings' => array(
+          'type' => 'text',
+          'size' => 'big',
         ),
       ),
     );
@@ -79,6 +80,8 @@ public static function propertyDefinitions(FieldStorageDefinitionInterface $fiel
       ->setLabel(t('View name'));
     $properties['vargs'] = DataDefinition::create('string')
       ->setLabel(t('View args'));
+    $properties['settings'] = DataDefinition::create('string')
+      ->setLabel(t('View settings'));
     return $properties;
   }
 
@@ -127,4 +130,5 @@ public static function fieldSettingsFormValidate(array $form, FormStateInterface
       }
     }
   }
+
 }

src/Plugin/Field/FieldWidget/ViewfieldWidget.php

@@ -10,7 +10,11 @@
 use Drupal\Core\Field\WidgetBase;
 use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\Core\Form\FormStateInterface;
-use Drupal\Core\Render\Element;
+use Drupal\Core\Form\FormState;
+use Drupal\Component\Utility\Html;
+use Drupal\Component\Serialization\Json;
+use Drupal\Component\Utility\NestedArray;
+use Drupal\Component\Utility\SortArray;
 use Drupal\views\Views;
 
 /**
@@ -34,31 +38,135 @@ public function formElement(FieldItemListInterface $items, $delta, array $elemen
     $field_settings = $this->getFieldSettings();
     $options = $this->getPotentialReferences($field_settings);
 
+    $id = Html::getUniqueId('state-wrapper-' . $items->getName() . '-' . $delta);
+
     $element['#field_name'] = $items->getName();
     $element['vname'] = array(
       '#type' => 'select',
       '#title' => t('Views Field'),
       '#options' => $options,
       '#empty_value' => 0,
+      '#ajax' => array(
+        'callback' => array($this, 'viewsSettings'),
+        'event' => 'change',
+        'progress' => array(
+          'type' => 'throbber',
+          'message' => NULL,
+        ),
+        'wrapper' => $id,
+      ),
       '#access' => !$field_settings['force_default'],
       '#default_value' => isset($items[$delta]->vname) ? $items[$delta]->vname : NULL,
     );
+
+    $element['settings_wrapper'] = array(
+      '#type' => 'fieldset',
+    );
+
+    $element['settings_wrapper']['settings_wrapper_form'] = array(
+      '#type' => 'html_tag',
+      '#tag'  => 'div',
+    );
+
+    $element['settings_wrapper']['settings_wrapper_form']['settings'] = array(
+      '#type' => 'html_tag',
+      '#tag'  => 'div',
+      '#attributes' => array(
+        'id' => $id,
+      ),
+    );
+
+    if (isset($items[$delta]->vname)) {
+      $view = explode('|', $items[$delta]->vname);
+      $viewInstance = $this->getView($view[0], $view[1]);
+      $itemSettings = [];
+      if (!empty($items[$delta]->settings)) {
+        $itemSettings = Json::decode($items[$delta]->settings);
+      }
+      if ($viewInstance) {
+        $element['settings_wrapper']['settings_wrapper_form']['settings'] = $this->getViewSettings($viewInstance, $view[1], $itemSettings);
+        $element['settings_wrapper']['settings_wrapper_form']['settings']['#attributes']['id'] = $id;
+      }
+    }
+
     $element['vargs'] = array(
       '#type' => 'textfield',
       '#title' => t('Arguments'),
       '#default_value' => isset($items[$delta]->vargs) ? $items[$delta]->vargs : NULL,
       '#access' => !$field_settings['force_default'],
-      '#description' => t('A comma separated list of arguments to pass to the selected view. '),
+      '#description' => t('A comma separated list of arguments to pass to the selected view.'),
     );
 
     return $element;
   }
 
+  /**
+   * Helper function for get exposed filter.
+   */
+  public function getViewSettings($view, $display, $settings) {
+    $form_state = new FormState();
+    if ($settings) {
+      $form_state->setUserInput($settings);
+    }
+    $view->initHandlers();
+    $form = [];
+    // Let form plugins know this is for exposed widgets.
+    $form_state->set('exposed', TRUE);
+    $form['settings'] = [];
+
+    // Go through each handler and let it generate its exposed widget.
+    foreach ($view->display_handler->handlers as $type => $value) {
+      /** @var \Drupal\views\Plugin\views\ViewsHandlerInterface $handler */
+      foreach ($view->$type as $id => $handler) {
+        if ($handler->canExpose() && $handler->isExposed()) {
+          if ($handler->isAGroup()) {
+            $handler->groupForm($form, $form_state);
+            $id = $handler->options['group_info']['identifier'];
+          }
+          else {
+            $handler->buildExposedForm($form, $form_state);
+          }
+          if ($info = $handler->exposedInfo()) {
+            $form['#info']["$type-$id"] = $info;
+          }
+        }
+      }
+    }
+
+    foreach ($settings as $name => $set) {
+      if ($form[$name]) {
+        $form[$name]['#default_value'] = $set;
+      }
+    }
+
+    foreach ($form['#info'] as $info) {
+      if (isset($form[$info['value']])) {
+        $form[$info['value']]['#title'] = $info['label'];
+      }
+    }
+
+    $exposed_form_plugin = $view->display_handler->getPlugin('exposed_form');
+    $exposed_form_plugin->exposedFormAlter($form, $form_state);
+
+    unset($form['actions']);
+    return $form;
+  }
+
+  public function viewsSettings(array $form, FormStateInterface $form_state) {
+    $view = $form_state->getTriggeringElement()['#value'];
+    $view = explode('|', $view);
+    $viewInstance = $this->getView($view[0], $view[1]);
+    if ($viewInstance && is_a($viewInstance->getDisplay(), 'Drupal\viewfield\Plugin\views\display\ViewFieldDisplay')) {
+      return $this->getViewSettings($viewInstance, $view[1]);
+    }
+    return [];
+  }
+
   /**
    * Returns a select options list of views displays of enabled and allowed views.
    *
-   * @param array @settings
-   *   The field settings
+   * @param array $settings
+   *   The field settings.
    *
    * @return array
    *   An array with the allowed and enabled views and displays.
@@ -75,7 +183,7 @@ protected function getPotentialReferences($settings) {
       }
     }
     $options = array();
-    foreach ($views as $view_name => $view) {
+    foreach ($views as $view) {
       $displays = $view->get('display');
       foreach ($displays as $display) {
         $options[$view->id() . '|' . $display['id']] = $view->id() . ' - ' . $display['display_title'];
@@ -84,4 +192,31 @@ protected function getPotentialReferences($settings) {
     return $options;
   }
 
+  /**
+   * Helper function for retrieve view.
+   *
+   * @param string $viewId
+   *   View machinable name to load.
+   * @param string $display
+   *   Display plugin to load.
+   */
+  public function getView($viewId, $display) {
+    $view = Views::getView($viewId);
+    if ($view) {
+      $view->setDisplay($display);
+      return $view;
+    }
+    return FALSE;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function massageFormValues(array $values, array $form, FormStateInterface $formState) {
+    foreach ($values as $key => $value) {
+      $values[$key]['settings'] = Json::encode($value['settings_wrapper']['settings_wrapper_form']['settings']);
+    }
+    return $values;
+  }
+
 }

src/Plugin/views/display/ViewFieldDisplay.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace Drupal\viewfield\Plugin\views\display;
+
+use Drupal\views\Plugin\views\display\DisplayPluginBase;
+
+/**
+ * The plugin that handles an embed display.
+ *
+ * @ingroup views_display_plugins
+ *
+ * @todo: Wait until annotations/plugins support access methods.
+ * no_ui => !\Drupal::config('views.settings')->get('ui.show.display_embed'),
+ *
+ * @ViewsDisplay(
+ *   id = "viewfield",
+ *   title = @Translation("Viewfield"),
+ *   help = @Translation("Provide a display which can be embedded using the views api."),
+ *   theme = "views_view",
+ *   uses_menu_links = FALSE
+ * )
+ */
+class ViewFieldDisplay extends DisplayPluginBase {
+
+  public function displaysExposed() {
+    return FALSE;
+  }
+
+}

viewfield.module

@@ -1,13 +1,12 @@
 <?php
 
-use \Drupal\Core\Form\FormStateInterface;
-use Drupal\Core\Url;
-
 /**
  * @file
  * Defines a field type to display a view.
  */
 
+use Drupal\Core\Url;
+
 /**
  * Implements hook_theme().
  */
@@ -24,8 +23,9 @@ function viewfield_theme() {
  */
 function viewfield_preprocess_viewfield_formatter_default(&$variables) {
   $element = $variables['element'];
+  $element['#view']->setExposedInput($element['#exposed_settings']);
   $view_el = $element['#view']->preview($element['#view_display'], array($element['#view_arguments']));
-  $output = render ($view_el);
+  $output = render($view_el);
   $variables['output'] = $output;
 }
 
@@ -42,7 +42,7 @@ function viewfield_element_info() {
 }
 
 /**
- * #pre_render callback for a viewfield field.
+ * pre_render callback for a viewfield field.
  *
  * @see viewfield_post_render()
  */
@@ -75,7 +75,7 @@ function viewfield_pre_render($element) {
 }
 
 /**
- * #post_render callback for a viewfield field.
+ * post_render callback for a viewfield field.
  *
  * @see viewfield_pre_render()
  */
@@ -85,9 +85,8 @@ function viewfield_post_render($content, $element) {
   return $content;
 }
 
-
 /**
- * Perform argument replacement
+ * Perform argument replacement.
  */
 function _viewfield_get_view_args($vargs, $entity_type, $entity) {
   $args = array();