function HtmlResponseAttachmentsProcessor::processAttachments

Same name and namespace in other branches

8.9.x core/lib/Drupal/Core/Render/HtmlResponseAttachmentsProcessor.php \Drupal\Core\Render\HtmlResponseAttachmentsProcessor::processAttachments()
10 core/lib/Drupal/Core/Render/HtmlResponseAttachmentsProcessor.php \Drupal\Core\Render\HtmlResponseAttachmentsProcessor::processAttachments()
11.x core/lib/Drupal/Core/Render/HtmlResponseAttachmentsProcessor.php \Drupal\Core\Render\HtmlResponseAttachmentsProcessor::processAttachments()

Processes the attachments of a response that has attachments.

Libraries, JavaScript settings, feeds, HTML <head> tags, HTML <head> links, HTTP headers, and the HTTP status code are attached to render arrays using the #attached property. The #attached property is an associative array, where the keys are the attachment types and the values are the attached data. For example:

$build['#attached']['library'][] = [
    'library' => [
        'core/jquery',
    ],
];
$build['#attached']['http_header'] = [
    [
        'Content-Type',
        'application/rss+xml; charset=utf-8',
    ],
];

The available keys are:

'library' (asset libraries)
'drupalSettings' (JavaScript settings)
'feed' (RSS feeds)
'html_head' (tags in HTML <head>)
'html_head_link' (<link> tags in HTML <head>)
'http_header' (HTTP headers and status code)

Placeholders need to be rendered first in order to have all attachments available for processing. For an example, see \Drupal\Core\Render\HtmlResponseAttachmentsProcessor::renderPlaceholders()

Parameters

\Drupal\Core\Render\AttachmentsInterface $response: The response to process.

Return value

\Drupal\Core\Render\AttachmentsInterface The processed response, with the attachments updated to reflect their final values.

Overrides AttachmentsResponseProcessorInterface::processAttachments

1 method overrides HtmlResponseAttachmentsProcessor::processAttachments()

BigPipeResponseAttachmentsProcessor::processAttachments in core/modules/big_pipe/src/Render/BigPipeResponseAttachmentsProcessor.php: Processes the attachments of a response that has attachments.

File

core/lib/Drupal/Core/Render/HtmlResponseAttachmentsProcessor.php, line 113

Class

HtmlResponseAttachmentsProcessor: Processes attachments of HTML responses.

Namespace

Drupal\Core\Render

Code

public function processAttachments(AttachmentsInterface $response) {
    assert($response instanceof HtmlResponse);
    // First, render the actual placeholders; this may cause additional
    // attachments to be added to the response, which the attachment
    // placeholders rendered by renderHtmlResponseAttachmentPlaceholders() will
    // need to include.
    //
    // @todo Exceptions should not be used for code flow control. However, the
    //   Form API does not integrate with the HTTP Kernel based architecture of
    //   Drupal 8. In order to resolve this issue properly it is necessary to
    //   completely separate form submission from rendering.
    //   @see https://www.drupal.org/node/2367555
    try {
        $response = $this->renderPlaceholders($response);
    } catch (EnforcedResponseException $e) {
        return $e->getResponse();
    }
    // Get a reference to the attachments.
    $attached = $response->getAttachments();
    // Send a message back if the render array has unsupported #attached types.
    $unsupported_types = array_diff(array_keys($attached), [
        'html_head',
        'feed',
        'html_head_link',
        'http_header',
        'library',
        'html_response_attachment_placeholders',
        'placeholders',
        'drupalSettings',
    ]);
    if (!empty($unsupported_types)) {
        throw new \LogicException(sprintf('You are not allowed to use %s in #attached.', implode(', ', $unsupported_types)));
    }
    // If we don't have any placeholders, there is no need to proceed.
    if (!empty($attached['html_response_attachment_placeholders'])) {
        // Get the placeholders from attached and then remove them.
        $attachment_placeholders = $attached['html_response_attachment_placeholders'];
        unset($attached['html_response_attachment_placeholders']);
        $assets = AttachedAssets::createFromRenderArray([
            '#attached' => $attached,
        ]);
        // Take Ajax page state into account, to allow for something like
        // Turbolinks to be implemented without altering core.
        // @see https://github.com/rails/turbolinks/
        $ajax_page_state = $this->requestStack
            ->getCurrentRequest()
            ->get('ajax_page_state');
        $assets->setAlreadyLoadedLibraries(isset($ajax_page_state) ? explode(',', $ajax_page_state['libraries']) : []);
        $variables = $this->processAssetLibraries($assets, $attachment_placeholders);
        // $variables now contains the markup to load the asset libraries. Update
        // $attached with the final list of libraries and JavaScript settings, so
        // that $response can be updated with those. Then the response object will
        // list the final, processed attachments.
        $attached['library'] = $assets->getLibraries();
        $attached['drupalSettings'] = $assets->getSettings();
        // Since we can only replace content in the HTML head section if there's a
        // placeholder for it, we can safely avoid processing the render array if
        // it's not present.
        if (!empty($attachment_placeholders['head'])) {
            // 'feed' is a special case of 'html_head_link'. We process them into
            // 'html_head_link' entries and merge them.
            if (!empty($attached['feed'])) {
                $attached = BubbleableMetadata::mergeAttachments($attached, $this->processFeed($attached['feed']));
                unset($attached['feed']);
            }
            // 'html_head_link' is a special case of 'html_head' which can be present
            // as a head element, but also as a Link: HTTP header depending on
            // settings in the render array. Processing it can add to both the
            // 'html_head' and 'http_header' keys of '#attached', so we must address
            // it before 'html_head'.
            if (!empty($attached['html_head_link'])) {
                // Merge the processed 'html_head_link' into $attached so that its
                // 'html_head' and 'http_header' values are present for further
                // processing.
                $attached = BubbleableMetadata::mergeAttachments($attached, $this->processHtmlHeadLink($attached['html_head_link']));
                unset($attached['html_head_link']);
            }
            // Now we can process 'html_head', which contains both 'feed' and
            // 'html_head_link'.
            if (!empty($attached['html_head'])) {
                $variables['head'] = $this->processHtmlHead($attached['html_head']);
            }
        }
        // Now replace the attachment placeholders.
        $this->renderHtmlResponseAttachmentPlaceholders($response, $attachment_placeholders, $variables);
    }
    // Set the HTTP headers and status code on the response if any bubbled.
    if (!empty($attached['http_header'])) {
        $this->setHeaders($response, $attached['http_header']);
    }
    // AttachmentsResponseProcessorInterface mandates that the response it
    // processes contains the final attachment values.
    $response->setAttachments($attached);
    return $response;
}

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