HtmlResponseAttachmentsProcessor.php
Same filename in other branches
Namespace
Drupal\Core\RenderFile
-
core/
lib/ Drupal/ Core/ Render/ HtmlResponseAttachmentsProcessor.php
View source
<?php
namespace Drupal\Core\Render;
// cspell:ignore turbolinks
use Drupal\Core\Asset\AssetCollectionRendererInterface;
use Drupal\Core\Asset\AssetResolverInterface;
use Drupal\Core\Asset\AttachedAssets;
use Drupal\Core\Asset\AttachedAssetsInterface;
use Drupal\Core\Config\ConfigFactoryInterface;
use Drupal\Core\Form\EnforcedResponseException;
use Drupal\Core\Extension\ModuleHandlerInterface;
use Drupal\Core\Language\LanguageManagerInterface;
use Symfony\Component\HttpFoundation\RequestStack;
/**
* Processes attachments of HTML responses.
*
* This class is used by the rendering service to process the #attached part of
* the render array, for HTML responses.
*
* To render attachments to HTML for testing without a controller, use the
* 'bare_html_page_renderer' service to generate a
* Drupal\Core\Render\HtmlResponse object. Then use its getContent(),
* getStatusCode(), and/or the headers property to access the result.
*
* @see template_preprocess_html()
* @see \Drupal\Core\Render\AttachmentsResponseProcessorInterface
* @see \Drupal\Core\Render\BareHtmlPageRenderer
* @see \Drupal\Core\Render\HtmlResponse
* @see \Drupal\Core\Render\MainContent\HtmlRenderer
*/
class HtmlResponseAttachmentsProcessor implements AttachmentsResponseProcessorInterface {
/**
* A config object for the system performance configuration.
*
* @var \Drupal\Core\Config\Config
*/
protected $config;
/**
* Constructs a HtmlResponseAttachmentsProcessor object.
*
* @param \Drupal\Core\Asset\AssetResolverInterface $assetResolver
* An asset resolver.
* @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
* A config factory for retrieving required config objects.
* @param \Drupal\Core\Asset\AssetCollectionRendererInterface $cssCollectionRenderer
* The CSS asset collection renderer.
* @param \Drupal\Core\Asset\AssetCollectionRendererInterface $jsCollectionRenderer
* The JS asset collection renderer.
* @param \Symfony\Component\HttpFoundation\RequestStack $requestStack
* The request stack.
* @param \Drupal\Core\Render\RendererInterface $renderer
* The renderer.
* @param \Drupal\Core\Extension\ModuleHandlerInterface $moduleHandler
* The module handler service.
* @param \Drupal\Core\Language\LanguageManagerInterface $languageManager
* The language manager.
*/
public function __construct(AssetResolverInterface $assetResolver, ConfigFactoryInterface $config_factory, AssetCollectionRendererInterface $cssCollectionRenderer, AssetCollectionRendererInterface $jsCollectionRenderer, RequestStack $requestStack, RendererInterface $renderer, ModuleHandlerInterface $moduleHandler, LanguageManagerInterface $languageManager) {
$this->config = $config_factory->get('system.performance');
}
/**
* {@inheritdoc}
*/
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;
}
/**
* Formats an attribute string for an HTTP header.
*
* @param array $attributes
* An associative array of attributes such as 'rel'.
*
* @return string
* A ; separated string ready for insertion in a HTTP header. No escaping is
* performed for HTML entities, so this string is not safe to be printed.
*
* @internal
*
* @see https://www.drupal.org/node/3000051
*/
public static function formatHttpHeaderAttributes(array $attributes = []) {
foreach ($attributes as $attribute => &$data) {
if (is_array($data)) {
$data = implode(' ', $data);
}
$data = $attribute . '="' . $data . '"';
}
return $attributes ? ' ' . implode('; ', $attributes) : '';
}
/**
* Renders placeholders (#attached['placeholders']).
*
* First, the HTML response object is converted to an equivalent render array,
* with #markup being set to the response's content and #attached being set to
* the response's attachments. Among these attachments, there may be
* placeholders that need to be rendered (replaced).
*
* Next, RendererInterface::renderRoot() is called, which renders the
* placeholders into their final markup.
*
* The markup that results from RendererInterface::renderRoot() is now the
* original HTML response's content, but with the placeholders rendered. We
* overwrite the existing content in the original HTML response object with
* this markup. The markup that was rendered for the placeholders may also
* have attachments (e.g. for CSS/JS assets) itself, and cacheability metadata
* that indicates what that markup depends on. That metadata is also added to
* the HTML response object.
*
* @param \Drupal\Core\Render\HtmlResponse $response
* The HTML response whose placeholders are being replaced.
*
* @return \Drupal\Core\Render\HtmlResponse
* The updated HTML response, with replaced placeholders.
*
* @see \Drupal\Core\Render\Renderer::replacePlaceholders()
* @see \Drupal\Core\Render\Renderer::renderPlaceholder()
*/
protected function renderPlaceholders(HtmlResponse $response) {
$build = [
'#markup' => Markup::create($response->getContent()),
'#attached' => $response->getAttachments(),
];
// RendererInterface::renderRoot() renders the $build render array and
// updates it in place. We don't care about the return value (which is just
// $build['#markup']), but about the resulting render array.
// @todo Simplify this when https://www.drupal.org/node/2495001 lands.
$this->renderer
->renderRoot($build);
// Update the Response object now that the placeholders have been rendered.
$placeholders_bubbleable_metadata = BubbleableMetadata::createFromRenderArray($build);
$response->setContent($build['#markup'])
->addCacheableDependency($placeholders_bubbleable_metadata)
->setAttachments($placeholders_bubbleable_metadata->getAttachments());
return $response;
}
/**
* Processes asset libraries into render arrays.
*
* @param \Drupal\Core\Asset\AttachedAssetsInterface $assets
* The attached assets collection for the current response.
* @param array $placeholders
* The placeholders that exist in the response.
*
* @return array
* An array keyed by asset type, with keys:
* - styles
* - scripts
* - scripts_bottom
*/
protected function processAssetLibraries(AttachedAssetsInterface $assets, array $placeholders) {
$variables = [];
$maintenance_mode = defined('MAINTENANCE_MODE') || \Drupal::state()->get('system.maintenance_mode');
// Print styles - if present.
if (isset($placeholders['styles'])) {
// Optimize CSS if necessary, but only during normal site operation.
$optimize_css = !$maintenance_mode && $this->config
->get('css.preprocess');
$variables['styles'] = $this->cssCollectionRenderer
->render($this->assetResolver
->getCssAssets($assets, $optimize_css, $this->languageManager
->getCurrentLanguage()));
}
// Print scripts - if any are present.
if (isset($placeholders['scripts']) || isset($placeholders['scripts_bottom'])) {
// Optimize JS if necessary, but only during normal site operation.
$optimize_js = !$maintenance_mode && $this->config
->get('js.preprocess');
[
$js_assets_header,
$js_assets_footer,
] = $this->assetResolver
->getJsAssets($assets, $optimize_js, $this->languageManager
->getCurrentLanguage());
$variables['scripts'] = $this->jsCollectionRenderer
->render($js_assets_header);
$variables['scripts_bottom'] = $this->jsCollectionRenderer
->render($js_assets_footer);
}
return $variables;
}
/**
* Renders HTML response attachment placeholders.
*
* This is the last step where all of the attachments are placed into the
* response object's contents.
*
* @param \Drupal\Core\Render\HtmlResponse $response
* The HTML response to update.
* @param array $placeholders
* An array of placeholders, keyed by type with the placeholders
* present in the content of the response as values.
* @param array $variables
* The variables to render and replace, keyed by type with renderable
* arrays as values.
*/
protected function renderHtmlResponseAttachmentPlaceholders(HtmlResponse $response, array $placeholders, array $variables) {
$content = $response->getContent();
foreach ($placeholders as $type => $placeholder) {
if (isset($variables[$type])) {
$content = str_replace($placeholder, $this->renderer
->renderInIsolation($variables[$type]), $content);
}
}
$response->setContent($content);
}
/**
* Sets headers on a response object.
*
* @param \Drupal\Core\Render\HtmlResponse $response
* The HTML response to update.
* @param array $headers
* The headers to set, as an array. The items in this array should be as
* follows:
* - The header name.
* - The header value.
* - (optional) Whether to replace a current value with the new one, or add
* it to the others. If the value is not replaced, it will be appended,
* resulting in a header like this: 'Header: value1,value2'
*/
protected function setHeaders(HtmlResponse $response, array $headers) {
foreach ($headers as $values) {
$name = $values[0];
$value = $values[1];
$replace = !empty($values[2]);
// Drupal treats the HTTP response status code like a header, even though
// it really is not.
if (strtolower($name) === 'status') {
$response->setStatusCode($value);
}
else {
$response->headers
->set($name, $value, $replace);
}
}
}
/**
* Ensure proper key/data order and defaults for renderable head items.
*
* @param array $html_head
* The ['#attached']['html_head'] portion of a render array.
*
* @return array
* The ['#attached']['html_head'] portion of a render array with #type of
* html_tag added for items without a #type.
*/
protected function processHtmlHead(array $html_head) {
$head = [];
foreach ($html_head as $item) {
[
$data,
$key,
] = $item;
if (!isset($data['#type'])) {
$data['#type'] = 'html_tag';
}
$head[$key] = $data;
}
return $head;
}
/**
* Transform a html_head_link array into html_head and http_header arrays.
*
* Variable html_head_link is a special case of html_head which can be present
* as a link item in the HTML head section, and also as a Link: HTTP header,
* depending on options in the render array. Processing it can add to both the
* html_head and http_header sections.
*
* @param array $html_head_link
* The 'html_head_link' value of a render array. Each head link is specified
* by a two-element array:
* - An array specifying the attributes of the link. The 'href' and 'rel'
* attributes are required, and the 'href' attribute is expected to be a
* percent-encoded URI for proper serialization in the Link: HTTP header,
* as specified by RFC 8288.
* - A boolean specifying whether the link should also be a Link: HTTP
* header.
*
* @return array
* An ['#attached'] section of a render array. This allows us to easily
* merge the results with other render arrays. The array could contain the
* following keys:
* - http_header
* - html_head
*/
protected function processHtmlHeadLink(array $html_head_link) {
$attached = [];
foreach ($html_head_link as $item) {
$attributes = $item[0];
$should_add_header = $item[1] ?? FALSE;
$element = [
'#tag' => 'link',
'#attributes' => $attributes,
];
$href = $attributes['href'];
$rel = $attributes['rel'];
// Allow multiple hreflang tags to use the same href.
if (isset($attributes['hreflang'])) {
$attached['html_head'][] = [
$element,
'html_head_link:' . $rel . ':' . $attributes['hreflang'] . ':' . $href,
];
}
else {
$attached['html_head'][] = [
$element,
'html_head_link:' . $rel . ':' . $href,
];
}
if ($should_add_header) {
// Also add a HTTP header "Link:".
$href = '<' . $attributes['href'] . '>';
unset($attributes['href']);
if ($param = static::formatHttpHeaderAttributes($attributes)) {
$href .= ';' . $param;
}
$attached['http_header'][] = [
'Link',
$href,
FALSE,
];
}
}
return $attached;
}
/**
* Transform a 'feed' attachment into an 'html_head_link' attachment.
*
* The RSS feed is a special case of 'html_head_link', so we just turn it into
* one.
*
* @param array $attached_feed
* The ['#attached']['feed'] portion of a render array.
*
* @return array
* An ['#attached']['html_head_link'] array, suitable for merging with
* another 'html_head_link' array.
*/
protected function processFeed($attached_feed) {
$html_head_link = [];
foreach ($attached_feed as $item) {
$feed_link = [
'href' => $item[0],
'rel' => 'alternate',
'title' => empty($item[1]) ? '' : $item[1],
'type' => 'application/rss+xml',
];
$html_head_link[] = [
$feed_link,
FALSE,
];
}
return [
'html_head_link' => $html_head_link,
];
}
}
Classes
Title | Deprecated | Summary |
---|---|---|
HtmlResponseAttachmentsProcessor | Processes attachments of HTML responses. |
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