appendComponent example

  public function insertComponent($delta, SectionComponent $new_component) {
    $components = $this->getComponentsByRegion($new_component->getRegion());
    $count = count($components);
    if ($delta > $count) {
      throw new \OutOfBoundsException(sprintf('Invalid delta "%s" for the "%s" component', $delta, $new_component->getUuid()));
    }

    // If the delta is the end of the list, append the component instead.     if ($delta === $count) {
      return $this->appendComponent($new_component);
    }

    // Find the weight of the component that exists at the specified delta.     $weight = array_values($components)[$delta]->getWeight();
    $this->setComponent($new_component->setWeight($weight++));

    // Increase the weight of every subsequent component.     foreach (array_slice($components, $delta) as $component) {
      $component->setWeight($weight++);
    }
    return $this;
  }

  public function buildForm(array $form, FormStateInterface $form_state, SectionStorageInterface $section_storage = NULL, $delta = NULL, $region = NULL, $plugin_id = NULL) {
    // Only generate a new component once per form submission.     if (!$component = $form_state->get('layout_builder__component')) {
      $component = new SectionComponent($this->uuidGenerator->generate(), $region, ['id' => $plugin_id]);
      $section_storage->getSection($delta)->appendComponent($component);
      $form_state->set('layout_builder__component', $component);
    }
    $form['#attributes']['data-layout-builder-target-highlight-id'] = $this->blockAddHighlightId($delta, $region);
    return $this->doBuildForm($form, $form_state, $section_storage, $delta, $component);
  }

}

class TestStateBasedSectionStorage extends SectionStorageBase {

  /** * {@inheritdoc} */
  public function getSections() {
    // Return a custom section.     $section = new Section('layout_onecol');
    $section->appendComponent(new SectionComponent('fake-uuid', 'content', [
      'id' => 'system_powered_by_block',
      'label' => 'Test block title',
      'label_display' => 'visible',
    ]));
    return [$section];
  }

  /** * {@inheritdoc} */
  public function isApplicable(RefinableCacheableDependencyInterface $cacheability) {
    

  public function testAppendComponent() {
    $expected = [
      'existing-uuid' => (new SectionComponent('existing-uuid', 'some-region', ['id' => 'existing-block-id']))->setWeight(0),
      '20000000-0000-1000-a000-000000000000' => (new SectionComponent('20000000-0000-1000-a000-000000000000', 'ordered-region', ['id' => 'second-block-id']))->setWeight(3),
      '10000000-0000-1000-a000-000000000000' => (new SectionComponent('10000000-0000-1000-a000-000000000000', 'ordered-region', ['id' => 'first-block-id']))->setWeight(2),
      'new-uuid' => (new SectionComponent('new-uuid', 'some-region', []))->setWeight(1),
    ];

    $this->section->appendComponent(new SectionComponent('new-uuid', 'some-region'));
    $this->assertComponents($expected, $this->section);
  }

  /** * @covers ::insertAfterComponent */
  public function testInsertAfterComponent() {
    $expected = [
      'existing-uuid' => (new SectionComponent('existing-uuid', 'some-region', ['id' => 'existing-block-id']))->setWeight(0),
      '20000000-0000-1000-a000-000000000000' => (new SectionComponent('20000000-0000-1000-a000-000000000000', 'ordered-region', ['id' => 'second-block-id']))->setWeight(4),
      '10000000-0000-1000-a000-000000000000' => (new SectionComponent('10000000-0000-1000-a000-000000000000', 'ordered-region', ['id' => 'first-block-id']))->setWeight(2),
      

public function onBeforePrepareLayout(PrepareLayoutEvent $event) {
    $section_storage = $event->getSectionStorage();
    $context = $section_storage->getContextValues();

    if (!empty($context['entity'])) {
      /** @var \Drupal\Core\Entity\EntityInterface $entity */
      $entity = $context['entity'];

      // Node 1 or 2: Append a block to the layout.       if (in_array($entity->id(), ['1', '2'])) {
        $section = new Section('layout_onecol');
        $section->appendComponent(new SectionComponent('fake-uuid', 'content', [
          'id' => 'static_block',
          'label' => 'Test static block title',
          'label_display' => 'visible',
          'provider' => 'fake_provider',
        ]));
        $section_storage->appendSection($section);
      }

      // Node 2: Stop event propagation.       if ($entity->id() === '2') {
        $event->stopPropagation();
      }

$configuration['id'] = 'field_block:' . $this->getTargetEntityTypeId() . ':' . $this->getTargetBundle() . ':' . $name;
        $keys = array_flip(['type', 'label', 'settings', 'third_party_settings']);
        $configuration['formatter'] = array_intersect_key($options, $keys);
      }
      else {
        $configuration['id'] = 'extra_field_block:' . $this->getTargetEntityTypeId() . ':' . $this->getTargetBundle() . ':' . $name;
      }

      $section = $this->getDefaultSection();
      $region = $options['region'] ?? $section->getDefaultRegion();
      $new_component = (new SectionComponent(\Drupal::service('uuid')->generate(), $region, $configuration));
      $section->appendComponent($new_component);
    }
    return $this;
  }

  /** * Gets a default section. * * @return \Drupal\layout_builder\Section * The default section. */
  protected function getDefaultSection() {