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styleswitcher.module in Style Switcher 8.2

Same filename and directory in other branches
  1. 6.2 styleswitcher.module
  2. 6 styleswitcher.module
  3. 7.2 styleswitcher.module
  4. 7 styleswitcher.module
  5. 3.0.x styleswitcher.module

Module's hooks implementations and helper functions.

File

styleswitcher.module
View source 
<?php

/**
 * @file
 * Module's hooks implementations and helper functions.
 */
use Drupal\Component\Utility\Html;
use Drupal\Component\Utility\UrlHelper;
use Drupal\Core\Asset\AttachedAssetsInterface;
use Drupal\Core\Render\Element;
use Drupal\Core\Url;
use Drupal\styleswitcher\StyleswitcherElementInfoAlter;

/**
 * Indicates that the cookie must live 365 days more.
 */
const STYLESWITCHER_COOKIE_EXPIRE = 31536000;

/**
 * Implements hook_page_attachments().
 */
function styleswitcher_page_attachments(array &$attachments) {

  // Add the dynamic CSS to every page. Use a library instead of straight
  // html_head_link attachment because we need our alternative stylesheets to
  // overwrite the most other css on the page and in standard html.html.twig
  // css goes after head.
  $attachments['#attached']['library'][] = 'styleswitcher/dynamic-css';
}

/**
 * Implements hook_css_alter().
 */
function styleswitcher_css_alter(&$css, AttachedAssetsInterface $assets) {
  $path = drupal_get_path('module', 'styleswitcher') . '/styleswitcher.active.css';

  // The dynamic-css library is not always attached. For example, maintenance
  // pages don't have it. So check for its presence.
  if (isset($css[$path])) {
    $asset = $css[$path];
    unset($css[$path]);

    // Use the latest standard group to be after the most of other css. Some
    // themes (like Omega) use even latter groups to set their grid layouts
    // hoping they wouldn't be overridden.
    $asset['group'] = CSS_AGGREGATE_THEME;
    $asset['weight'] = PHP_INT_MAX;
    $theme = Drupal::theme()
      ->getActiveTheme()
      ->getName();

    // Construct absolute URL explicitly to work out disabled clean URLs.
    $path = Url::fromRoute('styleswitcher.css', [
      'theme' => $theme,
    ], [
      'absolute' => TRUE,
    ])
      ->toString();
    $css[$path] = $asset;
    $css[$path]['data'] = $path;
  }
}

/**
 * Implements hook_element_info_alter().
 */
function styleswitcher_element_info_alter(&$types) {
  if (floatval(\Drupal::VERSION) >= 8.800000000000001) {
    $callback = [
      StyleswitcherElementInfoAlter::class,
      'preRenderHtmlTag',
    ];
  }
  else {
    $callback = 'styleswitcher_pre_render_html_tag';
  }

  // This pre-render callback must run before element's #markup is created in
  // HtmlTag::preRenderHtmlTag() which is a pre-render callback too.
  array_unshift($types['html_tag']['#pre_render'], $callback);
}

/**
 * Render API callback: Adds HTML id for the Style Switcher style link.
 *
 * This function is assigned as a #pre_render callback in
 * styleswitcher_element_info_alter().
 */
function styleswitcher_pre_render_html_tag(array $element) {
  if (!empty($element['#attributes']['media']) && $element['#attributes']['media'] == 'styleswitcher') {

    // Set 'media' back to its default value.
    $element['#attributes']['media'] = 'all';

    // Add an ID.
    $element['#attributes']['id'] = 'styleswitcher-css';
  }
  return $element;
}

/**
 * Loads a style array by its machine name and a theme name.
 *
 * @param string $name
 *   Machine name of the style to load.
 * @param string $theme
 *   Machine name of the theme to get the style for.
 * @param string $type
 *   (optional) Style type: 'theme' or 'custom'. If the type is specified then
 *   it will be prefixed with a slash to the $name argument.
 *
 * @return array|null
 *   Style array on success or NULL otherwise. Style is an associative array
 *   containing:
 *   - name: Machine name.
 *   - label: Human-readable label.
 *   - path: System or external path to the CSS file.
 *   - weight: Weight of style link in the switch list.
 *   - status: Indicates whether the style is enabled or not.
 *   - is_default: Indicates that this style is the default one. This element
 *     may not always show the truth. It is recommended to use
 *     styleswitcher_default_style_key() to get the default style key.
 *   - _i: Index number of the style. It is used for sorting of styles with
 *     equal weights.
 *   - theme: Name of the theme the style is loaded for.
 *
 * @see styleswitcher_default_style_key()
 */
function styleswitcher_style_load($name, $theme, $type = '') {
  if ($type) {
    $name = $type . '/' . $name;

    // The next conversion is only rationale for auto-loader wildcards in paths
    // and there are $type arguments always set in menu items so if this
    // function is called with only one argument this conversion is redundant.
    $name = strtr($name, '-', '_');
  }
  $styles = styleswitcher_style_load_multiple($theme, [
    'name' => $name,
  ]);
  if ($styles) {
    return reset($styles);
  }
}

/**
 * Returns a list of styles.
 *
 * @param string $theme
 *   Name of the theme to get styles for.
 * @param array $filter
 *   Style properties to filter by. Each key is a property name, and value is
 *   a corresponding filter value.
 *
 * @return array
 *   Array of styles - all or just filtered by conditions from the $filter
 *   argument. Keys are machine names and each element is a corresponding style
 *   array, which structure is the same as returned from
 *   styleswitcher_style_load().
 *
 * @see styleswitcher_style_load()
 */
function styleswitcher_style_load_multiple($theme, array $filter = []) {
  $styles =& drupal_static(__FUNCTION__, []);
  if (!isset($styles[$theme])) {
    $theme_styles = styleswitcher_custom_styles() + styleswitcher_theme_styles($theme);
    $settings = styleswitcher_styles_settings($theme);
    foreach (array_keys($theme_styles) as $i => $key) {
      if (isset($settings[$key])) {
        $theme_styles[$key] += $settings[$key];
      }

      // Default settings.
      $theme_styles[$key] += [
        'is_default' => FALSE,
        'status' => TRUE,
        'weight' => 0,
        '_i' => $i,
        'theme' => $theme,
      ];
    }
    $styles[$theme] = $theme_styles;
  }
  if (empty($filter)) {
    return $styles[$theme];
  }
  $return = [];
  foreach ($styles[$theme] as $key => $style) {

    // Check the requested conditions.
    foreach ($filter as $property => $value) {
      if ($style[$property] != $value) {
        continue 2;
      }
    }
    $return[$key] = $style;
  }
  return $return;
}

/**
 * Returns a list of styles with theme-specific settings.
 *
 * @param string $theme
 *   Name of the theme to get styles settings for.
 *
 * @return array
 *   Array which keys are styles machine names and each element is a
 *   corresponding array with settings: weight, status and is_default. All
 *   settings are optional. See styleswitcher_style_load() for their
 *   descriptions.
 *
 * @see styleswitcher_style_load()
 */
function styleswitcher_styles_settings($theme) {
  $settings = Drupal::config('styleswitcher.styles_settings')
    ->get('settings') ?? [];
  if (empty($settings[$theme])) {
    $settings[$theme] = [];
    styleswitcher_theme_styles($theme);

    // Disable the blank style if theme has its own default one.
    if (styleswitcher_theme_default_style_key($theme)) {
      $settings[$theme]['custom/default']['status'] = FALSE;
    }
  }
  return $settings[$theme];
}

/**
 * Returns a list of custom styles.
 *
 * @return array
 *   Array which keys are styles machine names and each element is a
 *   corresponding array with properties: name, label and path. All properties
 *   are mandatory. See styleswitcher_style_load() for their descriptions.
 *
 * @see styleswitcher_style_load()
 */
function styleswitcher_custom_styles() {
  $defaults['custom/default'] = [
    'name' => 'custom/default',
    'label' => 'Default',
    'path' => NULL,
  ];
  $styles = Drupal::config('styleswitcher.custom_styles')
    ->get('styles');
  return $styles ? $styles : $defaults;
}

/**
 * Returns a list of styles provided by a theme.
 *
 * @param string $theme
 *   Name of the theme to retrieve styles of.
 * @param string|null $original_theme
 *   (optional) Name of the theme which the function was originally called with.
 *   While iterating over base themes the $theme argument changes but
 *   $original_theme keeps the same value.
 *
 * @return array
 *   Array of styles. Keys are machine names and each element is a corresponding
 *   array of style properties: name, label and path. All properties are
 *   mandatory. See styleswitcher_style_load() for their descriptions.
 *
 * @see styleswitcher_style_load()
 */
function styleswitcher_theme_styles($theme, $original_theme = NULL) {
  $styles =& drupal_static(__FUNCTION__, []);

  // Theme can be an empty string if custom style is loading.
  if (!$theme) {
    return [];
  }
  if (isset($styles[$theme])) {
    return $styles[$theme];
  }
  $theme_styles = [];
  $theme_path = drupal_get_path('theme', $theme);
  $themes = Drupal::service('theme_handler')
    ->listInfo();
  $theme_info = isset($themes[$theme]) ? $themes[$theme]->info : [];
  if (!isset($original_theme)) {
    $original_theme = $theme;
  }

  // Search base themes for styleswitcher info.
  if (isset($theme_info['base theme'])) {
    $theme_styles = styleswitcher_theme_styles($theme_info['base theme'], $original_theme);
  }
  if (!empty($theme_info['styleswitcher'])) {
    $info = $theme_info['styleswitcher'];

    // Array of alternatives.
    if (!empty($info['css'])) {
      foreach ($info['css'] as $label => $path) {
        $name = 'theme/' . _styleswitcher_style_name($label);
        $theme_styles[$name] = [
          'name' => $name,
          'label' => $label,
          'path' => UrlHelper::isExternal($path) ? $path : $theme_path . '/' . $path,
        ];
      }
    }

    // Default style.
    if (isset($info['default'])) {
      $default = $info['default'];
    }
    elseif (isset($info['css']['default'])) {
      $default = $info['css']['default'];
      unset($theme_styles['theme/default']);
    }
    if (isset($default)) {
      $default_in_existing = FALSE;

      // Check if Default points to one of existing alternatives.
      foreach ($theme_styles as $name => $style) {
        if ($default == $style['label'] || $default == $style['path'] || $theme_path . '/' . $default == $style['path']) {
          styleswitcher_theme_default_style_key($original_theme, $name);
          $default_in_existing = TRUE;
          break;
        }
      }

      // Default is a path not mentioned in css array.
      if (!$default_in_existing) {
        $defaults['theme/default'] = [
          'name' => 'theme/default',
          'label' => 'Default',
          'path' => UrlHelper::isExternal($default) ? $default : $theme_path . '/' . $default,
        ];

        // Place default style above others.
        $theme_styles = $defaults + $theme_styles;
        styleswitcher_theme_default_style_key($original_theme, 'theme/default');
      }
    }
  }

  // Do not inflate the memory.
  if ($theme == $original_theme) {
    $styles[$theme] = $theme_styles;
  }
  return $theme_styles;
}

/**
 * Transliterates a human-readable name to a machine name.
 *
 * @param string $display_name
 *   Style label.
 *
 * @return string
 *   Transliterated name.
 *
 * @see Drupal.behaviors.machineName.transliterate()
 * @see \Drupal\Component\Utility\Html::cleanCssIdentifier()
 * @see \Drupal\Component\Utility\Html::getId()
 */
function _styleswitcher_style_name($display_name) {
  $name = mb_strtolower($display_name);
  $name = strtr($name, [
    ' ' => '_',
    '-' => '_',
  ]);
  $name = preg_replace('/[^a-z0-9_]/', '', $name);
  return $name;
}

/**
 * Saves/returns the key of default style provided by a theme.
 *
 * When theme's .info file is scanned for styles to switch this function is
 * called with argument to statically save a style key for further use. And
 * after, when this function is called it returns the key saved earlier.
 *
 * @param string $theme
 *   Name of the theme which default style is being saved/requested.
 * @param string|null $key
 *   The key of theme's default style.
 *
 * @return string|null
 *   The key of theme's default style.
 */
function styleswitcher_theme_default_style_key($theme, $key = NULL) {
  $default_key =& drupal_static(__FUNCTION__, []);
  if (isset($key)) {
    $default_key[$theme] = $key;
  }
  return isset($default_key[$theme]) ? $default_key[$theme] : NULL;
}

/**
 * Finds the default style and returns its key.
 *
 * @param string $theme
 *   Name of the theme to find the default style for.
 *
 * @return string
 *   The key of the default style.
 */
function styleswitcher_default_style_key($theme) {
  $default_key =& drupal_static(__FUNCTION__, []);

  // Search the default style explicitly set by admin.
  if (!isset($default_key[$theme])) {
    $styles = styleswitcher_style_load_multiple($theme, [
      'is_default' => TRUE,
    ]);
    $default_key[$theme] = key($styles);
  }

  // Plan B. If default style is not set in styles configuration form by admin
  // then find out initial default style defined by theme.
  if (!isset($default_key[$theme])) {
    styleswitcher_theme_styles($theme);
    $default_key[$theme] = styleswitcher_theme_default_style_key($theme);
  }

  // Fallback to the blank style.
  if (!isset($default_key[$theme])) {
    $styles = styleswitcher_style_load_multiple($theme, [
      'path' => NULL,
    ]);
    $default_key[$theme] = key($styles);
  }
  return $default_key[$theme];
}

/**
 * Implements hook_theme().
 */
function styleswitcher_theme() {
  return [
    'styleswitcher_admin_styles_table' => [
      'render element' => 'form',
      'function' => 'theme_styleswitcher_admin_styles_table',
    ],
    'styleswitcher_admin_style_overview' => [
      'variables' => [
        'style' => NULL,
      ],
      'function' => 'theme_styleswitcher_admin_style_overview',
    ],
  ];
}

/**
 * Returns HTML for the styles settings overview form element.
 *
 * @param array $variables
 *   An associative array containing:
 *   - form: An element representing the form.
 *
 * @ingroup themeable
 */
function theme_styleswitcher_admin_styles_table(array $variables) {
  $form = $variables['form'];
  $header = [
    t('Style'),
    t('Enabled'),
    t('Default'),
    t('Weight'),
  ];
  $rows = [];
  if (!empty($form['weight'])) {
    foreach (Element::children($form['weight']) as $key) {
      if ($key == $form['default']['#default_value']) {
        $form['enabled'][$key]['#attributes']['disabled'] = 'disabled';
      }
      $label = $form['label'][$key]['#markup'];
      $form['enabled'][$key]['#title'] = t('Enable @title', [
        '@title' => $label,
      ]);
      $form['enabled'][$key]['#title_display'] = 'invisible';
      $form['default'][$key]['#title'] = t('Set @title as default', [
        '@title' => $label,
      ]);
      $form['default'][$key]['#title_display'] = 'invisible';

      // Build the table row.
      $row = [
        [
          'data' => $form['name'][$key],
        ],
        [
          'data' => $form['enabled'][$key],
        ],
        [
          'data' => $form['default'][$key],
        ],
        [
          'data' => $form['weight'][$key],
        ],
      ];
      $rows[] = [
        'data' => $row,
        'class' => [
          'draggable',
        ],
      ];
    }
  }
  $table = [
    '#type' => 'table',
    '#header' => $header,
    '#rows' => $rows,
    '#empty' => t('No styles to switch.'),
    '#attributes' => [
      'id' => 'styleswitcher-styles-table',
    ],
    '#tabledrag' => [
      0 => [
        'action' => 'order',
        'relationship' => 'sibling',
        'group' => 'styleswitcher-style-weight',
      ],
    ],
  ];
  return Drupal::service('renderer')
    ->render($table);
}

/**
 * Returns HTML for a style description on the styles overview page.
 *
 * @param array $variables
 *   An associative array containing:
 *   - style: A style array as returned from styleswitcher_style_load().
 *
 * @see styleswitcher_style_load()
 *
 * @ingroup themeable
 */
function theme_styleswitcher_admin_style_overview(array $variables) {
  $style = $variables['style'];
  $output = Html::escape($style['label']);
  $output .= ' <small>' . t('(Machine name: @name)', [
    '@name' => $style['name'],
  ]) . '</small>';
  if (isset($style['path'])) {
    $description = $style['path'];
  }
  else {
    $description = t('Blank style which just removes effect of others.');
  }
  $output .= '<div class="description">' . $description . '</div>';
  return $output;
}

/**
 * Sorts styles by weight and index.
 *
 * This function first compares style weights, and then - if weights are equal -
 * style index numbers.
 *
 * The compared items (function parameters) should be associative arrays that
 * include a 'weight' and an '_i' elements.
 *
 * Callback for uasort() within
 * Drupal\styleswitcher\Plugin\Block\Styleswitcher::build() and
 * Drupal\styleswitcher\Form\StyleswitcherConfigTheme::buildForm().
 *
 * @see \Drupal\styleswitcher\Plugin\Block\Styleswitcher::build()
 * @see \Drupal\styleswitcher\Form\StyleswitcherConfigTheme::buildForm()
 */
function styleswitcher_sort(array $a, array $b) {
  $property = $a['weight'] != $b['weight'] ? 'weight' : '_i';
  return $a[$property] - $b[$property];
}

/**
 * Implements hook_themes_uninstalled().
 */
function styleswitcher_themes_uninstalled(array $theme_list) {

  // Delete styleswitcher settings of disabled themes.
  $config = Drupal::configFactory()
    ->getEditable('styleswitcher.styles_settings');
  $settings = $config
    ->get('settings') ?? [];
  $settings = array_diff_key($settings, array_flip($theme_list));
  $config
    ->set('settings', $settings)
    ->save();
}

Functions

Namesort descending Description
styleswitcher_css_alter Implements hook_css_alter().
styleswitcher_custom_styles Returns a list of custom styles.
styleswitcher_default_style_key Finds the default style and returns its key.
styleswitcher_element_info_alter Implements hook_element_info_alter().
styleswitcher_page_attachments Implements hook_page_attachments().
styleswitcher_pre_render_html_tag Render API callback: Adds HTML id for the Style Switcher style link.
styleswitcher_sort Sorts styles by weight and index.
styleswitcher_styles_settings Returns a list of styles with theme-specific settings.
styleswitcher_style_load Loads a style array by its machine name and a theme name.
styleswitcher_style_load_multiple Returns a list of styles.
styleswitcher_theme Implements hook_theme().
styleswitcher_themes_uninstalled Implements hook_themes_uninstalled().
styleswitcher_theme_default_style_key Saves/returns the key of default style provided by a theme.
styleswitcher_theme_styles Returns a list of styles provided by a theme.
theme_styleswitcher_admin_styles_table Returns HTML for the styles settings overview form element.
theme_styleswitcher_admin_style_overview Returns HTML for a style description on the styles overview page.
_styleswitcher_style_name Transliterates a human-readable name to a machine name.

Constants

Namesort descending Description
STYLESWITCHER_COOKIE_EXPIRE Indicates that the cookie must live 365 days more.