--- /dev/null
+<?php
+
+namespace Drupal\system\Plugin\Block;
+
+use Drupal\Core\Block\BlockBase;
+use Drupal\Core\Cache\Cache;
+use Drupal\Core\Config\ConfigFactoryInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\Core\Url;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Provides a block to display 'Site branding' elements.
+ *
+ * @Block(
+ * id = "system_branding_block",
+ * admin_label = @Translation("Site branding")
+ * )
+ */
+class SystemBrandingBlock extends BlockBase implements ContainerFactoryPluginInterface {
+
+ /**
+ * Stores the configuration factory.
+ *
+ * @var \Drupal\Core\Config\ConfigFactoryInterface
+ */
+ protected $configFactory;
+
+ /**
+ * Creates a SystemBrandingBlock instance.
+ *
+ * @param array $configuration
+ * A configuration array containing information about the plugin instance.
+ * @param string $plugin_id
+ * The plugin_id for the plugin instance.
+ * @param mixed $plugin_definition
+ * The plugin implementation definition.
+ * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
+ * The factory for configuration objects.
+ */
+ public function __construct(array $configuration, $plugin_id, $plugin_definition, ConfigFactoryInterface $config_factory) {
+ parent::__construct($configuration, $plugin_id, $plugin_definition);
+ $this->configFactory = $config_factory;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+ return new static(
+ $configuration,
+ $plugin_id,
+ $plugin_definition,
+ $container->get('config.factory')
+ );
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function defaultConfiguration() {
+ return [
+ 'use_site_logo' => TRUE,
+ 'use_site_name' => TRUE,
+ 'use_site_slogan' => TRUE,
+ 'label_display' => FALSE,
+ ];
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function blockForm($form, FormStateInterface $form_state) {
+ // Get the theme.
+ $theme = $form_state->get('block_theme');
+
+ // Get permissions.
+ $url_system_theme_settings = new Url('system.theme_settings');
+ $url_system_theme_settings_theme = new Url('system.theme_settings_theme', ['theme' => $theme]);
+
+ if ($url_system_theme_settings->access() && $url_system_theme_settings_theme->access()) {
+ // Provide links to the Appearance Settings and Theme Settings pages
+ // if the user has access to administer themes.
+ $site_logo_description = $this->t('Defined on the <a href=":appearance">Appearance Settings</a> or <a href=":theme">Theme Settings</a> page.', [
+ ':appearance' => $url_system_theme_settings->toString(),
+ ':theme' => $url_system_theme_settings_theme->toString(),
+ ]);
+ }
+ else {
+ // Explain that the user does not have access to the Appearance and Theme
+ // Settings pages.
+ $site_logo_description = $this->t('Defined on the Appearance or Theme Settings page. You do not have the appropriate permissions to change the site logo.');
+ }
+ $url_system_site_information_settings = new Url('system.site_information_settings');
+ if ($url_system_site_information_settings->access()) {
+ // Get paths to settings pages.
+ $site_information_url = $url_system_site_information_settings->toString();
+
+ // Provide link to Site Information page if the user has access to
+ // administer site configuration.
+ $site_name_description = $this->t('Defined on the <a href=":information">Site Information</a> page.', [':information' => $site_information_url]);
+ $site_slogan_description = $this->t('Defined on the <a href=":information">Site Information</a> page.', [':information' => $site_information_url]);
+ }
+ else {
+ // Explain that the user does not have access to the Site Information
+ // page.
+ $site_name_description = $this->t('Defined on the Site Information page. You do not have the appropriate permissions to change the site logo.');
+ $site_slogan_description = $this->t('Defined on the Site Information page. You do not have the appropriate permissions to change the site logo.');
+ }
+
+ $form['block_branding'] = [
+ '#type' => 'fieldset',
+ '#title' => $this->t('Toggle branding elements'),
+ '#description' => $this->t('Choose which branding elements you want to show in this block instance.'),
+ ];
+ $form['block_branding']['use_site_logo'] = [
+ '#type' => 'checkbox',
+ '#title' => $this->t('Site logo'),
+ '#description' => $site_logo_description,
+ '#default_value' => $this->configuration['use_site_logo'],
+ ];
+
+ $form['block_branding']['use_site_name'] = [
+ '#type' => 'checkbox',
+ '#title' => $this->t('Site name'),
+ '#description' => $site_name_description,
+ '#default_value' => $this->configuration['use_site_name'],
+ ];
+ $form['block_branding']['use_site_slogan'] = [
+ '#type' => 'checkbox',
+ '#title' => $this->t('Site slogan'),
+ '#description' => $site_slogan_description,
+ '#default_value' => $this->configuration['use_site_slogan'],
+ ];
+ return $form;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function blockSubmit($form, FormStateInterface $form_state) {
+ $block_branding = $form_state->getValue('block_branding');
+ $this->configuration['use_site_logo'] = $block_branding['use_site_logo'];
+ $this->configuration['use_site_name'] = $block_branding['use_site_name'];
+ $this->configuration['use_site_slogan'] = $block_branding['use_site_slogan'];
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function build() {
+ $build = [];
+ $site_config = $this->configFactory->get('system.site');
+
+ $build['site_logo'] = [
+ '#theme' => 'image',
+ '#uri' => theme_get_setting('logo.url'),
+ '#alt' => $this->t('Home'),
+ '#access' => $this->configuration['use_site_logo'],
+ ];
+
+ $build['site_name'] = [
+ '#markup' => $site_config->get('name'),
+ '#access' => $this->configuration['use_site_name'],
+ ];
+
+ $build['site_slogan'] = [
+ '#markup' => $site_config->get('slogan'),
+ '#access' => $this->configuration['use_site_slogan'],
+ ];
+
+ return $build;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getCacheTags() {
+ return Cache::mergeTags(
+ parent::getCacheTags(),
+ $this->configFactory->get('system.site')->getCacheTags()
+ );
+ }
+
+}