Add a views field handle rthat is NOT broken and will handle all computed fields for nodes

Closes #3349082

src/Plugin/views/field/NodeComputedField.php

+<?php
+
+/**
+ * @file
+ * Definition of Drupal\computed_field\Plugin\views\field\NodeComputedField
+ */
+
+namespace Drupal\computed_field\Plugin\views\field;
+
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\computed_field\Entity\ComputedField;
+use Drupal\views\Plugin\views\field\FieldPluginBase;
+use Drupal\views\ResultRow;
+use Stringable;
+
+/**
+ * Field handler to display a selected computed field.
+ *
+ * @ingroup views_field_handlers
+ *
+ * @ViewsField("node_computed_field")
+ */
+class NodeComputedField extends FieldPluginBase {
+
+  /**
+   * @{inheritdoc}
+   */
+  public function query() {
+    // Leave empty to avoid a query on this field.
+  }
+
+  /**
+   * Define the available options
+   * @return array
+   */
+  protected function defineOptions() {
+    $options = parent::defineOptions();
+    $options['computed_field'] = ['default' => ''];
+    return $options;
+  }
+
+  /**
+   * Provide the options form.
+   */
+  public function buildOptionsForm(&$form, FormStateInterface $form_state) {
+    /** @var \Drupal\computed_field\ComputedFieldManager $computedFieldManager */
+    $computedFieldManager = \Drupal::service('plugin.manager.computed_field');
+    // $entity_type_node = \Drupal::entityTypeManager()->getDefinition('node');
+    // $automatic_plugins = $computedFieldManager->getAutomaticPlugins($entity_type_node);
+    $plugins = $computedFieldManager->getDefinitions();
+    $options = [];
+    foreach ($plugins as $id => $definition) {
+      $options[$id] = $definition['label'];
+    }
+
+    $form['computed_field'] = array(
+      '#title' => $this->t('Computed field to use'),
+      '#type' => 'select',
+      '#default_value' => $this->options['computed_field'],
+      '#options' => $options,
+      '#description' => $this->t('Computed fields not relevant to the content types available on this view will still be shown here but will not work. No configuration for the computed field is currently possible.')
+    );
+
+    parent::buildOptionsForm($form, $form_state);
+  }
+
+  /**
+   * @{inheritdoc}
+   */
+  public function render(ResultRow $values) {
+    $node = $this->getEntity($values);
+    $computed_field_plugin_id = $this->options['computed_field'];
+    $computedFieldManager = \Drupal::service('plugin.manager.computed_field');
+    $instance = $computedFieldManager->createInstance($computed_field_plugin_id);
+    $computed = $instance->computeValue($node, new ComputedField([], 'computed_field'));
+    $build = [];
+    foreach ($computed as $index => $value) {
+      if (is_string($value) || is_object($value)) {
+        // Protect from fatal errors by making sure any object we get is stringable.
+        if (is_object($value) && !($value instanceof Stringable)) {
+          continue;
+        }
+        // All strings need to be renderable arrays.
+        $build[$index] = ['#markup' => $value];
+      }
+      else {
+        // It is probably a render array or hopefully somehow renderable.
+        $build[$index] = $value;
+      }
+    }
+    return $build;
+  }
+}