ex_icons.module

<?php

/**
 * @file
 * External-use icons module.
 */

use Drupal\Core\Template\Attribute;

/**
 * Implements hook_theme().
 */
function ex_icons_theme() {
  return [
    'ex_icon' => [
      'variables' => [
        'id' => '',
        'attributes' => [],
      ],
    ],
  ];
}

/**
 * Prepares variables for svg icon templates.
 *
 * Default template: ex-icon.html.twig.
 *
 * @param array $variables
 *   An associative array containing:
 *   - id: The plugin definition ID of the icon to use.
 *   - attributes: The HTML attributes to apply to the SVG element.
 */
function template_preprocess_ex_icon(array &$variables) {
  /** @var \Drupal\ex_icons\ExIconsManager $icons_manager */
  $icons_manager = \Drupal::service('ex_icons.manager');

  /** @var \Drupal\ex_icons\ExIconInterface $icon */
  $icon = $icons_manager->getInstance(['id' => $variables['id'] ?: '']);

  // Default role to be img.
  if (!isset($variables['attributes']['role'])) {
    $variables['attributes']['role'] = 'img';
  }

  $dimension_keys = &drupal_static(__FUNCTION__, array_flip(['width', 'height']));
  $dimension_attributes = array_intersect_key($variables['attributes'], $dimension_keys);

  // Calculate other dimension if only one has been specified:
  if (count($dimension_attributes) == 1) {
    $existing_length = reset($dimension_attributes);
    $missing_length_key = key(array_diff_key($dimension_keys, $dimension_attributes));

    // Flip aspect ratio value for calculating height.
    $aspect_ratio = $missing_length_key == 'height'
      ? 1 / $icon->getAspectRatio()
      : $icon->getAspectRatio();

    $variables['attributes'][$missing_length_key] = round($existing_length * $aspect_ratio, 2);
  }

  $variables['url'] = $icon->getUrl();
  \Drupal::service('renderer')->addCacheableDependency($variables, $icons_manager);
}

/**
 * Implements hook_preprocess_HOOK() for radios.html.twig.
 */
function ex_icons_preprocess_radios(&$variables) {
  if ($variables['element']['#type'] == 'ex_icon_select') {
    $variables['attributes']['class'][] = 'icon-selector';
    $variables['#attached']['library'][] = 'ex_icons/icon-selector';
  }
}

/**
 * Implements hook_page_bottom().
 */
function ex_icons_page_bottom(array &$page_bottom) {
  $icons_manager = \Drupal::service('ex_icons.manager');

  $inline_defs = [];
  if ($defs = implode('', $icons_manager->getInlineDefs())) {
    $inline_defs = [
      '#type' => 'inline_template',
      '#template' => '<svg{{ attributes }}><defs>{{ defs|raw }}</defs></svg>',
      '#context' => [
        'attributes' => new Attribute(['class' => ['visually-hidden']]),
        'defs' => $defs,
      ],
    ];
  }

  \Drupal::service('renderer')->addCacheableDependency($inline_defs, $icons_manager);
  $page_bottom['ex_icons_inline_defs'] = $inline_defs;
}

/**
 * Implements hook_page_attachments().
 */
function ex_icons_page_attachments(array &$attachments) {
  $icons_manager = \Drupal::service('ex_icons.manager');

  $paths = [];
  foreach (array_keys($icons_manager->getDefinitions()) as $id) {
    // Skip the fall-back null instance.
    if ($id == 'ex_icon_null') {
      continue;
    }

    $instance = $icons_manager->getInstance(['id' => $id]);
    $provider = $instance->getProvider();

    // Already got a URL for this provider.
    if (isset($paths[$provider])) {
      continue;
    }

    // Use first discovered icon's URL for each provider, removing it's hash
    // portion to be more generic.
    $paths[$provider] = strstr($instance->getUrl(), '#', TRUE);
  }

  $attachments['#attached']['drupalSettings']['exIcons']['paths'] = $paths;
}

/**
 * Implements hook_ex_icons_alter().
 */
function ex_icons_ex_icons_alter(array &$definitions) {
  $definitions['ex_icon_null'] = [
    'id' => 'ex_icon_null',
    'width' => 1,
    'height' => 1,
    'url' => '',
    'provider' => 'ex_icons',
    'class' => 'Drupal\\ex_icons\\ExIcon',
  ];
}

/**
 * Implements hook_themes_installed().
 */
function ex_icons_themes_installed($theme_list) {
  \Drupal::service('ex_icons.manager')->clearCachedDefinitions();
}

/**
 * Implements hook_themes_uninstalled().
 */
function ex_icons_themes_uninstalled($theme_list) {
  \Drupal::service('ex_icons.manager')->clearCachedDefinitions();
}