function template_preprocess_image_style_preview

Prepares variables for image style preview templates.

Default template: image-style-preview.html.twig.

Parameters

array $variables: An associative array containing:

• style: \Drupal\image\ImageStyleInterface image style being previewed.

File

core/modules/image/image.admin.inc, line 19

Code

function template_preprocess_image_style_preview(&$variables) {
    
    /** @var \Drupal\Core\File\FileUrlGeneratorInterface $file_url_generator */
    $file_url_generator = \Drupal::service('file_url_generator');
    // Style information.
    $style = $variables['style'];
    $variables['style_id'] = $style->id();
    $variables['style_name'] = $style->label();
    // Cache bypass token.
    $variables['cache_bypass'] = \Drupal::time()->getRequestTime();
    // Sample image info.
    $sample_width = 160;
    $sample_height = 160;
    $image_factory = \Drupal::service('image.factory');
    // Set up original file information.
    $original_path = \Drupal::config('image.settings')->get('preview_image');
    $original_image = $image_factory->get($original_path);
    $variables['original'] = [
        'url' => $file_url_generator->generateString($original_path),
        'width' => $original_image->getWidth(),
        'height' => $original_image->getHeight(),
    ];
    if ($variables['original']['width'] > $variables['original']['height']) {
        $variables['preview']['original']['width'] = min($variables['original']['width'], $sample_width);
        $variables['preview']['original']['height'] = round($variables['preview']['original']['width'] / $variables['original']['width'] * $variables['original']['height']);
    }
    else {
        $variables['preview']['original']['height'] = min($variables['original']['height'], $sample_height);
        $variables['preview']['original']['width'] = round($variables['preview']['original']['height'] / $variables['original']['height'] * $variables['original']['width']);
    }
    // Set up derivative file information.
    $preview_file = $style->buildUri($original_path);
    // Create derivative if necessary.
    if (!file_exists($preview_file)) {
        $style->createDerivative($original_path, $preview_file);
    }
    $preview_image = $image_factory->get($preview_file);
    // Generate an itok.
    $defaultScheme = \Drupal::config('system.file')->get('default_scheme');
    $variables['itok'] = $style->getPathToken($defaultScheme . '://' . $original_path);
    $variables['derivative'] = [
        'url' => $file_url_generator->generateString($preview_file),
        'width' => $preview_image->getWidth(),
        'height' => $preview_image->getHeight(),
    ];
    if ($variables['derivative']['width'] > $variables['derivative']['height']) {
        $variables['preview']['derivative']['width'] = min($variables['derivative']['width'], $sample_width);
        $variables['preview']['derivative']['height'] = round($variables['preview']['derivative']['width'] / $variables['derivative']['width'] * $variables['derivative']['height']);
    }
    else {
        $variables['preview']['derivative']['height'] = min($variables['derivative']['height'], $sample_height);
        $variables['preview']['derivative']['width'] = round($variables['preview']['derivative']['height'] / $variables['derivative']['height'] * $variables['derivative']['width']);
    }
    // Build the preview of the original image.
    $variables['original']['rendered'] = [
        '#theme' => 'image',
        '#uri' => $original_path,
        '#alt' => t('Sample original image'),
        '#title' => '',
        '#attributes' => [
            'width' => $variables['original']['width'],
            'height' => $variables['original']['height'],
            'style' => 'width: ' . $variables['preview']['original']['width'] . 'px; height: ' . $variables['preview']['original']['height'] . 'px;',
        ],
    ];
    // Build the preview of the image style derivative. Timestamps are added
    // to prevent caching of images on the client side.
    $variables['derivative']['rendered'] = [
        '#theme' => 'image',
        '#uri' => $variables['derivative']['url'] . '?cache_bypass=' . $variables['cache_bypass'] . '&itok=' . $variables['itok'],
        '#alt' => t('Sample modified image'),
        '#title' => '',
        '#attributes' => [
            'width' => $variables['derivative']['width'],
            'height' => $variables['derivative']['height'],
            'style' => 'width: ' . $variables['preview']['derivative']['width'] . 'px; height: ' . $variables['preview']['derivative']['height'] . 'px;',
        ],
    ];
}