theme-settings.php

<?php

/**
 * @file
 * UMD Terp (umd_terp), add custom theme settings options here.
 */

use Drupal\Core\Form\FormStateInterface;
use Drupal\file\Entity\File;

/**
 * Implements hook_form_system_theme_settings_alter().
 */
function umd_terp_form_system_theme_settings_alter(&$form, FormStateInterface $form_state) {

  // Header.
  $form['umd_terp_header_settings'] = [
    '#type' => 'details',
    '#title' => t('UMD Terp Header Settings'),
  ];
  $form['umd_terp_header_settings']['umd_terp_header_light'] = [
    '#type' => 'checkbox',
    '#title' => t('Light header style'),
    '#description' => t('Display light header version.'),
    '#default_value' => theme_get_setting('umd_terp_header_light'),
  ];

  // Footer.
  $form['umd_terp_footer_settings'] = [
    '#type' => 'details',
    '#title' => t('UMD Terp Footer Settings'),
  ];
  $form['umd_terp_footer_settings']['umd_terp_footer_logo_path'] = [
    '#type' => 'textfield',
    '#title' => t('Path to custom footer logo'),
    '#default_value' => theme_get_setting('umd_terp_footer_logo_path'),
    '#description' => t('IF AN INLINE SVG HAS BEEN ADDED BELOW, THIS WILL BE OVERRIDDEN.'),
  ];
  $form['umd_terp_footer_settings']['umd_terp_footer_logo_upload'] = [
    '#type' => 'managed_file',
    '#title' => t('Upload footer logo image'),
    '#upload_location' => 'public://',
    '#description' => t('Please upload the footer-specific logo. This should be a "dark" version of the logo that features black typography.'),
  ];
  $form['umd_terp_footer_settings']['umd_terp_footer_logo_svg'] = [
    '#type' => 'textarea',
    '#title' => t('Alternative SVG logo'),
    '#default_value' => theme_get_setting('umd_terp_footer_logo_svg'),
    '#description' => t('You may alternatively paste inline SVG code here. IF PRESENT, THIS WILL OVERRIDE ANY IMAGES ADDED ABOVE. It is important to be sure you have properly sized and formatted your SVG, as well as tested at multiple screen sizes.'),
  ];
  $form['umd_terp_footer_settings']['umd_terp_address'] = [
    '#type' => 'textfield',
    '#title' => t('Address'),
    '#default_value' => theme_get_setting('umd_terp_address'),
    '#description' => t('Please add the address you wish to display.'),
  ];
  $form['umd_terp_footer_settings']['umd_terp_phone'] = [
    '#type' => 'textfield',
    '#title' => t('Phone number'),
    '#default_value' => theme_get_setting('umd_terp_phone'),
    '#description' => t('Please add the phone number you wish to display.'),
  ];
  $form['umd_terp_footer_settings']['umd_terp_phone_secondary'] = [
    '#type' => 'textfield',
    '#title' => t('Phone number (Secondary)'),
    '#default_value' => theme_get_setting('umd_terp_phone_secondary'),
    '#description' => t('Please add the secondary phone number you wish to display, if you require one.'),
  ];
  $form['umd_terp_footer_settings']['umd_terp_email'] = [
    '#type' => 'textfield',
    '#title' => t('Email'),
    '#default_value' => theme_get_setting('umd_terp_email'),
    '#description' => t('Please add the email address you wish to display.'),
  ];
  $form['umd_terp_footer_settings']['umd_terp_email_secondary'] = [
    '#type' => 'textfield',
    '#title' => t('Email (Secondary)'),
    '#default_value' => theme_get_setting('umd_terp_email_secondary'),
    '#description' => t('Please add the secondary email address you wish to display, if you require one.'),
  ];

  // Social media.
  $form['umd_terp_social_settings'] = [
    '#type' => 'details',
    '#title' => t('UMD Terp Social Media Accounts'),
  ];
  $form['umd_terp_social_settings']['umd_terp_twitter_link'] = [
    '#type' => 'textfield',
    '#title' => t('Twitter link'),
    '#default_value' => theme_get_setting('umd_terp_twitter_link'),
    '#description' => t('Add the URL to your twitter profile.'),
  ];
  $form['umd_terp_social_settings']['umd_terp_facebook_link'] = [
    '#type' => 'textfield',
    '#title' => t('Facebook link'),
    '#default_value' => theme_get_setting('umd_terp_facebook_link'),
    '#description' => t('Add the URL to your facebook profile.'),
  ];
  $form['umd_terp_social_settings']['umd_terp_youtube_link'] = [
    '#type' => 'textfield',
    '#title' => t('Youtube link'),
    '#default_value' => theme_get_setting('umd_terp_youtube_link'),
    '#description' => t('Add the URL to your youtube profile.'),
  ];
  $form['umd_terp_social_settings']['umd_terp_instagram_link'] = [
    '#type' => 'textfield',
    '#title' => t('Instagram link'),
    '#default_value' => theme_get_setting('umd_terp_instagram_link'),
    '#description' => t('Add the URL to your instagram profile.'),
  ];

  // Articles.
  $form['articles'] = [
    '#type' => 'details',
    '#title' => t('Local Articles Settings'),
    '#collapsible' => TRUE,
  ];

  $help_markup = "<p>These settings are for if you wish to change the default articles URL from '/articles' to something else. Be sure you also change the corresponding pathauto pattern for Articles.</p>";
  $form['articles']['articles_help'] = [
    '#type' => 'markup',
    '#markup' => $help_markup,
  ];

  $form['articles']['umd_terp_articles_path'] = [
    '#type' => 'textfield',
    '#title' => t('Back to directory path'),
    '#description' => t('Provides a site wide {{ umd_terp_articles_path }} variable for profile templates. Specifically, it is used for categorizing articles, and linking back to a pre-filtered page. Ex: /news. Defaults to "/articles".'),
    '#default_value' => theme_get_setting('umd_terp_articles_path'),
  ];

  // People.
  $form['people'] = [
    '#type' => 'details',
    '#title' => t('Local People Settings'),
    '#collapsible' => TRUE,
  ];

  $form['people']['umd_terp_people_department_label'] = [
    '#type' => 'textfield',
    '#title' => t('Department Label'),
    '#description' => t('Provides a method for changing the default \'Department Information\' label to another value'),
    '#default_value' => theme_get_setting('umd_terp_people_department_label', 'Department Information'),
  ];

  // Other.
  $form['other'] = [
    '#type' => 'details',
    '#title' => t('UMD Terp Admin Settings'),
    '#collapsible' => TRUE,
  ];

  $form['other']['umd_terp_assets_path'] = [
    '#type' => 'textfield',
    '#title' => t('Assets path'),
    '#description' => t('Provides a site wide {{ assets_path }} variable for the builds assets path relative to the theme root. Usable in twig templates. Ex: /static/build'),
    '#default_value' => theme_get_setting('umd_terp_assets_path'),
  ];

  $form['other']['umd_terp_disable_dark_mode_options'] = [
    '#type' => 'checkbox',
    '#title' => t('Disable dark mode options'),
    '#description' => t('Remove dark mode related options.'),
    '#default_value' => theme_get_setting('umd_terp_disable_dark_mode_options'),
  ];

  $form['other']['umd_terp_sidebar_right'] = [
    '#type' => 'checkbox',
    '#title' => t('Right hand sidebar'),
    '#description' => t('Display the sidebar on the right hand side of basic pages.'),
    '#default_value' => theme_get_setting('umd_terp_sidebar_right'),
  ];

  $form['#validate'][] = 'umd_terp_form_system_theme_settings_validate_test';
  $form['#submit'][] = 'umd_terp_form_system_theme_settings_submit';
}

/**
 * Custom file upload validator.
 */
function umd_terp_form_system_theme_settings_validate_test($form, FormStateInterface &$form_state) {
  // Handle file uploads.
  $validators = [
    'file_validate_is_image' => [],
  ];
  // Check for a new uploaded logo.
  $file = file_save_upload('umd_terp_footer_logo_upload', $validators, FALSE, 0);
  if (isset($file)) {
    if ($file) {
      $form_state->setValue('umd_terp_footer_logo_upload', $file);
    }
    else {
      $form_state->setErrorByName('umd_terp_footer_logo_upload', t('The footer logo could not be uploaded.'));
    }
  }
}

/**
 * Custom submit handler, to process custom footer logo.
 */
function umd_terp_form_system_theme_settings_submit(&$form, FormStateInterface $form_state) {
  $values = $form_state->getValues();
  $filename = '';
  if (!empty($values['umd_terp_footer_logo_upload'])) {
    $file = File::load($values['umd_terp_footer_logo_upload'][0]);
    if (!empty($file)) {
      $file->setPermanent();
      $file->save();
      $file_usage = \Drupal::service('file.usage');
      $file_usage->add($file, 'umd_terp', 'user', \Drupal::currentUser()->id());
      $filename = $file->getFileUri();
    }
    $values['umd_terp_footer_logo_path'] = $filename;
    $form_state->setValue(['umd_terp_footer_logo_path'], $filename);
    $form_state->unsetValue('umd_terp_footer_logo_upload');
  }
}