--- /dev/null
+<?php
+
+namespace Drupal\views\Plugin\views\display;
+
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\views\ViewExecutable;
+
+/**
+ * The plugin that handles an attachment display.
+ *
+ * Attachment displays are secondary displays that are 'attached' to a primary
+ * display. Effectively they are a simple way to get multiple views within
+ * the same view. They can share some information.
+ *
+ * @ingroup views_display_plugins
+ *
+ * @ViewsDisplay(
+ * id = "attachment",
+ * title = @Translation("Attachment"),
+ * help = @Translation("Attachments added to other displays to achieve multiple views in the same view."),
+ * theme = "views_view",
+ * contextual_links_locations = {""}
+ * )
+ */
+class Attachment extends DisplayPluginBase {
+
+ /**
+ * Whether the display allows the use of a pager or not.
+ *
+ * @var bool
+ */
+ protected $usesPager = FALSE;
+
+ protected function defineOptions() {
+ $options = parent::defineOptions();
+
+ $options['displays'] = ['default' => []];
+ $options['attachment_position'] = ['default' => 'before'];
+ $options['inherit_arguments'] = ['default' => TRUE];
+ $options['inherit_exposed_filters'] = ['default' => FALSE];
+ $options['inherit_pager'] = ['default' => FALSE];
+ $options['render_pager'] = ['default' => FALSE];
+
+ return $options;
+ }
+
+ public function execute() {
+ return $this->view->render($this->display['id']);
+ }
+
+ public function attachmentPositions($position = NULL) {
+ $positions = [
+ 'before' => $this->t('Before'),
+ 'after' => $this->t('After'),
+ 'both' => $this->t('Both'),
+ ];
+
+ if ($position) {
+ return $positions[$position];
+ }
+
+ return $positions;
+ }
+
+ /**
+ * Provide the summary for attachment options in the views UI.
+ *
+ * This output is returned as an array.
+ */
+ public function optionsSummary(&$categories, &$options) {
+ // It is very important to call the parent function here:
+ parent::optionsSummary($categories, $options);
+
+ $categories['attachment'] = [
+ 'title' => $this->t('Attachment settings'),
+ 'column' => 'second',
+ 'build' => [
+ '#weight' => -10,
+ ],
+ ];
+
+ $displays = array_filter($this->getOption('displays'));
+ if (count($displays) > 1) {
+ $attach_to = $this->t('Multiple displays');
+ }
+ elseif (count($displays) == 1) {
+ $display = array_shift($displays);
+ if ($display = $this->view->storage->getDisplay($display)) {
+ $attach_to = $display['display_title'];
+ }
+ }
+
+ if (!isset($attach_to)) {
+ $attach_to = $this->t('Not defined');
+ }
+
+ $options['displays'] = [
+ 'category' => 'attachment',
+ 'title' => $this->t('Attach to'),
+ 'value' => $attach_to,
+ ];
+
+ $options['attachment_position'] = [
+ 'category' => 'attachment',
+ 'title' => $this->t('Attachment position'),
+ 'value' => $this->attachmentPositions($this->getOption('attachment_position')),
+ ];
+
+ $options['inherit_arguments'] = [
+ 'category' => 'attachment',
+ 'title' => $this->t('Inherit contextual filters'),
+ 'value' => $this->getOption('inherit_arguments') ? $this->t('Yes') : $this->t('No'),
+ ];
+
+ $options['inherit_exposed_filters'] = [
+ 'category' => 'attachment',
+ 'title' => $this->t('Inherit exposed filters'),
+ 'value' => $this->getOption('inherit_exposed_filters') ? $this->t('Yes') : $this->t('No'),
+ ];
+
+ $options['inherit_pager'] = [
+ 'category' => 'pager',
+ 'title' => $this->t('Inherit pager'),
+ 'value' => $this->getOption('inherit_pager') ? $this->t('Yes') : $this->t('No'),
+ ];
+
+ $options['render_pager'] = [
+ 'category' => 'pager',
+ 'title' => $this->t('Render pager'),
+ 'value' => $this->getOption('render_pager') ? $this->t('Yes') : $this->t('No'),
+ ];
+
+ }
+
+ /**
+ * Provide the default form for setting options.
+ */
+ public function buildOptionsForm(&$form, FormStateInterface $form_state) {
+ // It is very important to call the parent function here:
+ parent::buildOptionsForm($form, $form_state);
+
+ switch ($form_state->get('section')) {
+ case 'inherit_arguments':
+ $form['#title'] .= $this->t('Inherit contextual filters');
+ $form['inherit_arguments'] = [
+ '#type' => 'checkbox',
+ '#title' => $this->t('Inherit'),
+ '#description' => $this->t('Should this display inherit its contextual filter values from the parent display to which it is attached?'),
+ '#default_value' => $this->getOption('inherit_arguments'),
+ ];
+ break;
+ case 'inherit_exposed_filters':
+ $form['#title'] .= $this->t('Inherit exposed filters');
+ $form['inherit_exposed_filters'] = [
+ '#type' => 'checkbox',
+ '#title' => $this->t('Inherit'),
+ '#description' => $this->t('Should this display inherit its exposed filter values from the parent display to which it is attached?'),
+ '#default_value' => $this->getOption('inherit_exposed_filters'),
+ ];
+ break;
+ case 'inherit_pager':
+ $form['#title'] .= $this->t('Inherit pager');
+ $form['inherit_pager'] = [
+ '#type' => 'checkbox',
+ '#title' => $this->t('Inherit'),
+ '#description' => $this->t('Should this display inherit its paging values from the parent display to which it is attached?'),
+ '#default_value' => $this->getOption('inherit_pager'),
+ ];
+ break;
+ case 'render_pager':
+ $form['#title'] .= $this->t('Render pager');
+ $form['render_pager'] = [
+ '#type' => 'checkbox',
+ '#title' => $this->t('Render'),
+ '#description' => $this->t('Should this display render the pager values? This is only meaningful if inheriting a pager.'),
+ '#default_value' => $this->getOption('render_pager'),
+ ];
+ break;
+ case 'attachment_position':
+ $form['#title'] .= $this->t('Position');
+ $form['attachment_position'] = [
+ '#title' => $this->t('Position'),
+ '#type' => 'radios',
+ '#description' => $this->t('Attach before or after the parent display?'),
+ '#options' => $this->attachmentPositions(),
+ '#default_value' => $this->getOption('attachment_position'),
+ ];
+ break;
+ case 'displays':
+ $form['#title'] .= $this->t('Attach to');
+ $displays = [];
+ foreach ($this->view->storage->get('display') as $display_id => $display) {
+ if ($this->view->displayHandlers->has($display_id) && $this->view->displayHandlers->get($display_id)->acceptAttachments()) {
+ $displays[$display_id] = $display['display_title'];
+ }
+ }
+ $form['displays'] = [
+ '#title' => $this->t('Displays'),
+ '#type' => 'checkboxes',
+ '#description' => $this->t('Select which display or displays this should attach to.'),
+ '#options' => array_map('\Drupal\Component\Utility\Html::escape', $displays),
+ '#default_value' => $this->getOption('displays'),
+ ];
+ break;
+ }
+ }
+
+ /**
+ * Perform any necessary changes to the form values prior to storage.
+ * There is no need for this function to actually store the data.
+ */
+ public function submitOptionsForm(&$form, FormStateInterface $form_state) {
+ // It is very important to call the parent function here:
+ parent::submitOptionsForm($form, $form_state);
+ $section = $form_state->get('section');
+ switch ($section) {
+ case 'displays':
+ $form_state->setValue($section, array_filter($form_state->getValue($section)));
+ case 'inherit_arguments':
+ case 'inherit_pager':
+ case 'render_pager':
+ case 'inherit_exposed_filters':
+ case 'attachment_position':
+ $this->setOption($section, $form_state->getValue($section));
+ break;
+ }
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function attachTo(ViewExecutable $view, $display_id, array &$build) {
+ $displays = $this->getOption('displays');
+
+ if (empty($displays[$display_id])) {
+ return;
+ }
+
+ if (!$this->access()) {
+ return;
+ }
+
+ $args = $this->getOption('inherit_arguments') ? $this->view->args : [];
+ $view->setArguments($args);
+ $view->setDisplay($this->display['id']);
+ if ($this->getOption('inherit_pager')) {
+ $view->display_handler->usesPager = $this->view->displayHandlers->get($display_id)->usesPager();
+ $view->display_handler->setOption('pager', $this->view->displayHandlers->get($display_id)->getOption('pager'));
+ }
+
+ $attachment = $view->buildRenderable($this->display['id'], $args);
+
+ switch ($this->getOption('attachment_position')) {
+ case 'before':
+ $this->view->attachment_before[] = $attachment;
+ break;
+ case 'after':
+ $this->view->attachment_after[] = $attachment;
+ break;
+ case 'both':
+ $this->view->attachment_before[] = $attachment;
+ $this->view->attachment_after[] = $attachment;
+ break;
+ }
+
+ }
+
+ /**
+ * Attachment displays only use exposed widgets if
+ * they are set to inherit the exposed filter settings
+ * of their parent display.
+ */
+ public function usesExposed() {
+ if (!empty($this->options['inherit_exposed_filters']) && parent::usesExposed()) {
+ return TRUE;
+ }
+ return FALSE;
+ }
+
+ /**
+ * If an attachment is set to inherit the exposed filter
+ * settings from its parent display, then don't render and
+ * display a second set of exposed filter widgets.
+ */
+ public function displaysExposed() {
+ return $this->options['inherit_exposed_filters'] ? FALSE : TRUE;
+ }
+
+ public function renderPager() {
+ return $this->usesPager() && $this->getOption('render_pager');
+ }
+
+}