public function ResponsiveBgImageFormatter::viewElements in Background Images Formatter 8.3
Same name and namespace in other branches
- 8 modules/responsive_bg_image_formatter/src/Plugin/Field/FieldFormatter/ResponsiveBgImageFormatter.php \Drupal\responsive_bg_image_formatter\Plugin\Field\FieldFormatter\ResponsiveBgImageFormatter::viewElements()
- 8.2 modules/responsive_bg_image_formatter/src/Plugin/Field/FieldFormatter/ResponsiveBgImageFormatter.php \Drupal\responsive_bg_image_formatter\Plugin\Field\FieldFormatter\ResponsiveBgImageFormatter::viewElements()
Builds a renderable array for a field value.
Parameters
\Drupal\Core\Field\FieldItemListInterface $items: The field values to be rendered.
string $langcode: The language that should be used to render the field.
Return value
array A renderable array for $items, as an array of child elements keyed by consecutive numeric indexes starting from 0.
Overrides BgImageFormatter::viewElements
File
- modules/
responsive_bg_image_formatter/ src/ Plugin/ Field/ FieldFormatter/ ResponsiveBgImageFormatter.php, line 66
Class
- ResponsiveBgImageFormatter
- Class ResponsiveBgImageFormatter.
Namespace
Drupal\responsive_bg_image_formatter\Plugin\Field\FieldFormatterCode
public function viewElements(FieldItemListInterface $items, $langcode) {
$elements = [];
$index = 0;
$settings = $this
->getSettings();
$css_settings = $settings['css_settings'];
$selectors = array_filter(preg_split('/$/', $css_settings['bg_image_selector']));
$files = $this
->getEntitiesToView($items, $langcode);
// Filter out empty selectors.
$selectors = array_map(static function ($value) {
return trim($value, ',');
}, $selectors);
// Early opt-out if the field is empty.
if (empty($files) || empty($settings['image_style'])) {
return $elements;
}
// Prepare token data in bg image css selector.
$token_data = [
'user' => \Drupal::currentUser(),
$items
->getEntity()
->getEntityTypeId() => $items
->getEntity(),
];
foreach ($selectors as &$selector) {
$selector = \Drupal::token()
->replace($selector, $token_data);
}
// Need an empty element so views renderer will see something to render.
$elements[0] = [];
foreach ($files as $delta => $file) {
// Use specified selectors in round-robin order.
$selector = $selectors[$index % \count($selectors)];
$vars = [
'uri' => $file
->getFileUri(),
'responsive_image_style_id' => $settings['image_style'],
];
template_preprocess_responsive_image($vars);
if (empty($vars['sources'])) {
continue;
}
// Split each source into multiple rules.
foreach (array_reverse($vars['sources']) as $source_i => $source) {
$attr = $source
->toArray();
$srcset = explode(', ', $attr['srcset']);
foreach ($srcset as $src_i => $src) {
list($src, $res) = explode(' ', $src);
$media = isset($attr['media']) ? $attr['media'] : '';
// Add "retina" to media query if this is a 2x image.
if ($res && $res === '2x' && !empty($media)) {
$media = "{$media} and (-webkit-min-device-pixel-ratio: 2), {$media} and (min-resolution: 192dpi)";
}
// Correct a bug in template_preprocess_responsive_image which
// generates an invalid media rule "screen (max-width)" when no
// min-width is specified. If this bug gets fixed, this replacement
// will deactivate.
$media = str_replace('screen (max-width', 'screen and (max-width', $media);
$css_settings['bg_image_selector'] = $selector;
$css = $this
->getBackgroundImageCss($src, $css_settings);
$css['attributes']['media'] = $media;
// Define unique key to prevent collisions when displaying multiple
// background images on the same page.
$html_head_key = 'responsive_bg_image_formatter_css__' . sha1(implode('__', [
$items
->getEntity()
->uuid(),
$items
->getName(),
$settings['image_style'],
$delta,
$src_i,
$source_i,
]));
$style_element = [
'#type' => 'html_tag',
'#tag' => 'style',
'#attributes' => [
'media' => $css['attributes']['media'],
],
'#value' => Markup::create($css['data']),
];
if ($this
->isAjax() || $this->request
->isXmlHttpRequest()) {
$elements['#attached']['css'][$html_head_key] = $this->renderer
->renderPlain($style_element);
}
else {
$elements['#attached']['css'][] = $css;
}
}
}
++$index;
}
return $elements;
}