--- /dev/null
+<?php
+
+namespace Drupal\outside_in\Block;
+
+use Drupal\block\BlockForm;
+use Drupal\block\BlockInterface;
+use Drupal\Core\Block\BlockPluginInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Plugin\PluginWithFormsInterface;
+
+/**
+ * Provides form for block instance forms when used in the off-canvas dialog.
+ *
+ * This form removes advanced sections of regular block form such as the
+ * visibility settings, machine ID and region.
+ */
+class BlockEntityOffCanvasForm extends BlockForm {
+
+ /**
+ * Provides a title callback to get the block's admin label.
+ *
+ * @param \Drupal\block\BlockInterface $block
+ * The block entity.
+ *
+ * @return \Drupal\Core\StringTranslation\TranslatableMarkup
+ * The title.
+ */
+ public function title(BlockInterface $block) {
+ // @todo Wrap "Configure " in <span class="visually-hidden"></span> once
+ // https://www.drupal.org/node/2359901 is fixed.
+ return $this->t('Configure @block', ['@block' => $block->getPlugin()->getPluginDefinition()['admin_label']]);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function form(array $form, FormStateInterface $form_state) {
+ $form = parent::form($form, $form_state);
+
+ // Create link to full block form.
+ $query = [];
+ if ($destination = $this->getRequest()->query->get('destination')) {
+ $query['destination'] = $destination;
+ }
+ $form['advanced_link'] = [
+ '#type' => 'link',
+ '#title' => $this->t('Advanced options'),
+ '#url' => $this->entity->toUrl('edit-form', ['query' => $query]),
+ '#weight' => 1000,
+ ];
+
+ // Remove the ID and region elements.
+ unset($form['id'], $form['region'], $form['settings']['admin_label']);
+
+ return $form;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function actions(array $form, FormStateInterface $form_state) {
+ $actions = parent::actions($form, $form_state);
+ $actions['submit']['#value'] = $this->t('Save @block', ['@block' => $this->entity->getPlugin()->getPluginDefinition()['admin_label']]);
+ $actions['delete']['#access'] = FALSE;
+ return $actions;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function buildVisibilityInterface(array $form, FormStateInterface $form_state) {
+ // Do not display the visibility.
+ return [];
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function validateVisibility(array $form, FormStateInterface $form_state) {
+ // Intentionally empty.
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function submitVisibility(array $form, FormStateInterface $form_state) {
+ // Intentionally empty.
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function getPluginForm(BlockPluginInterface $block) {
+ if ($block instanceof PluginWithFormsInterface) {
+ return $this->pluginFormFactory->createInstance($block, 'off_canvas', 'configure');
+ }
+ return $block;
+ }
+
+}