Issue #1845526 by dawehner: User data service handler for views.

core/modules/user/lib/Drupal/user/Plugin/views/field/UserData.php

+<?php
+
+/**
+ * @file
+ * Contains \Drupal\user\Plugin\views\field\UserData.
+ */
+
+namespace Drupal\user\Plugin\views\field;
+
+use Drupal\views\Plugin\views\display\DisplayPluginBase;
+use Drupal\views\Plugin\views\field\FieldPluginBase;
+use Drupal\views\ViewExecutable;
+use Drupal\user\UserDataInterface;
+use Drupal\Core\Annotation\Plugin;
+
+/**
+ * Provides access to the user data service.
+ *
+ * @ingroup views_field_handlers
+ *
+ * @see \Drupal\user\UserDataInterface
+ *
+ * @Plugin(
+ *   id = "user_data",
+ *   module = "user"
+ * )
+ */
+class UserData extends FieldPluginBase {
+
+  /**
+   * Provides the user data service object.
+   *
+   * @var \Drupal\user\UserDataInterface
+   */
+  protected $userData;
+
+  /**
+   * Overrides \Drupal\views\Plugin\views\field\FieldPluginBase::init().
+   */
+  public function init(ViewExecutable $view, DisplayPluginBase $display, array &$options = NULL) {
+    parent::init($view, $display, $options);
+
+    $this->userData = drupal_container()->get('user.data');
+  }
+
+  /**
+   * Overrides \Drupal\views\Plugin\views\field\FieldPluginBase::defineOptions().
+   */
+  protected function defineOptions() {
+    $options = parent::defineOptions();
+
+    $options['module'] = array('default' => '');
+    $options['name'] = array('default' => '');
+
+    return $options;
+  }
+
+  /**
+   * Overrides \Drupal\views\Plugin\views\field\FieldPluginBase::defineOptions().
+   */
+  public function buildOptionsForm(&$form, &$form_state) {
+    parent::buildOptionsForm($form, $form_state);
+
+    $form['module'] = array(
+      '#title' => t('Module name'),
+      '#type' => 'select',
+      '#description' => t('The module which sets this user data.'),
+      '#default_value' => $this->options['module'],
+      '#options' => system_get_module_info('name'),
+    );
+
+    $form['name'] = array(
+      '#title' => t('Name'),
+      '#type' => 'textfield',
+      '#description' => t('The name of the data key.'),
+      '#default_value' => $this->options['name'],
+    );
+  }
+
+  /**
+   * Overrides \Drupal\views\Plugin\views\field\FieldPluginBase::render().
+   */
+  function render($values) {
+    $uid = $this->get_value($values);
+    $data = $this->userData->get($this->options['module'], $uid, $this->options['name']);
+
+    // Don't sanitize if no value was found.
+    if (isset($data)) {
+      return $this->sanitizeValue($data);
+    }
+  }
+
+}

core/modules/user/lib/Drupal/user/Tests/Views/UserDataTest.php

+<?php
+
+/**
+ * @file
+ * Contains \Drupal\user\Tests\Views\UserDataTest.
+ */
+
+namespace Drupal\user\Tests\Views;
+
+/**
+ * Tests the user data service field handler.
+ *
+ * @see \Drupal\user\Plugin\views\field\UserData
+ */
+class UserDataTest extends UserTestBase {
+
+  /**
+   * Provides the user data service object.
+   *
+   * @var \Drupal\user\UserDataInterface
+   */
+  protected $userData;
+
+  /**
+   * Views used by this test.
+   *
+   * @var array
+   */
+  public static $testViews = array('test_user_data');
+
+  public static function getInfo() {
+    return array(
+      'name' => 'User data: Field',
+      'description' => 'Tests the user data service field handler.',
+      'group' => 'Views module integration',
+    );
+  }
+
+  /**
+   * Tests field handler.
+   */
+  public function testDataField() {
+    // But some random values into the user data service.
+    $this->userData = $this->container->get('user.data');
+    $random_value = $this->randomName();
+    $this->userData->set('views_test_config', $this->users[0]->id(), 'test_value_name', $random_value);
+
+    $view = views_get_view('test_user_data');
+    $this->executeView($view);
+
+    $output = $view->field['data']->render($view->result[0]);
+    $this->assertEqual($output, $random_value, 'A valid user data got rendered.');
+
+    $view->field['data']->options['name'] = $this->randomName();
+    $output = $view->field['data']->render($view->result[0]);
+    $this->assertFalse($output, 'An invalid configuration does not return anything');
+
+  }
+
+}

core/modules/user/tests/modules/user_test_views/test_views/views.view.test_user_data.yml

+base_field: uid
+base_table: users
+core: 8.x
+description: ''
+status: '1'
+display:
+  default:
+    display_plugin: default
+    id: default
+    display_title: Master
+    position: ''
+    display_options:
+      access:
+        type: perm
+        perm: 'access user profiles'
+      cache:
+        type: none
+      query:
+        type: views_query
+      exposed_form:
+        type: basic
+      pager:
+        type: full
+      style:
+        type: default
+      row:
+        type: fields
+      fields:
+        name:
+          id: name
+          table: users
+          field: name
+          label: ''
+          alter:
+            alter_text: '0'
+            make_link: '0'
+            absolute: '0'
+            trim: '0'
+            word_boundary: '0'
+            ellipsis: '0'
+            strip_tags: '0'
+            html: '0'
+          hide_empty: '0'
+          empty_zero: '0'
+          link_to_user: '1'
+          overwrite_anonymous: '0'
+          plugin_id: string
+        data:
+          id: data
+          table: users
+          field: data
+          relationship: none
+          group_type: group
+          admin_label: ''
+          label: Data
+          exclude: '0'
+          alter:
+            alter_text: '0'
+            text: ''
+            make_link: '0'
+            path: ''
+            absolute: '0'
+            external: '0'
+            replace_spaces: '0'
+            path_case: none
+            trim_whitespace: '0'
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: '0'
+            max_length: ''
+            word_boundary: '1'
+            ellipsis: '1'
+            more_link: '0'
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: '0'
+            trim: '0'
+            preserve_tags: ''
+            html: '0'
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: '1'
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: '1'
+          empty: ''
+          hide_empty: '0'
+          empty_zero: '0'
+          hide_alter_empty: '1'
+          module: views_test_config
+          name: test_value_name
+          plugin_id: user_data
+      filters:
+        uid:
+          value:
+            0: '2'
+          table: users
+          field: uid
+          id: uid
+          expose:
+            operator: '0'
+          group: '1'
+          plugin_id: numeric
+      sorts:
+        created:
+          id: created
+          table: users
+          field: created
+          order: DESC
+          plugin_id: date
+human_name: test_user_data
+module: views
+id: test_user_data
+tag: ''

core/modules/user/user.views.inc

@@ -324,6 +324,15 @@ function user_views_data() {
     ),
   );
 
+  $data['users']['data'] = array(
+    'title' => t('Data'),
+    'help' => t('Provides access to the user data service.'),
+    'real field' => 'uid',
+    'field' => array(
+      'id' => 'user_data',
+    ),
+  );
+
   // users_roles table
 
   $data['users_roles']['table']['group']  = t('User');