This document discusses cacheability metadata in Drupal 8. It covers outputting responses and renderable arrays, using the cache system including max-age, tags, and contexts. Advanced features like Bigpipe and placeholders are explained to improve caching for dynamic or slow rendering blocks. The recap emphasizes page, dynamic page, and refreshless caching techniques.

1. Cacheability metadata in Drupal 8
Joris Vercammen | @borisson

4. • Quick response
• Personalized pages
• Avoid unneeded cache clears

5. • Outputting things
• Cache system
• Advanced features
• Extra cache modules

6. • Outputting things
• Cache system
• Advanced features
• Extra cache modules

7. Outputting things
• Responses
• Renderable arrays

8. Outputting things
• Responses
• Renderable arrays

9. Responses
• Symfony components
• Http Foundation

10. use SymfonyComponentHttpFoundationResponse;
class DefaultController extends ControllerBase {
public function hello() {
$date = (new DateTimeImmutable("now"))->format('H:i:s');
return new Response("<p>Hello world, the time is: {$date} </p>");
}
}

12. use DrupalCoreCacheCacheableResponse;
class DefaultController extends ControllerBase {
public function hello() {
$date = (new DateTimeImmutable("now"))->format('H:i:s');
return new CacheableResponse("<p>Hello world, the time is: {$date} </p>");
}
}

14. Outputting things
• Responses
• Renderable arrays

15. class DefaultController extends ControllerBase {
public function hello() {
$date = (new DateTimeImmutable("now"))->format('H:i:s');
return ['#markup' => "<p>Hello world, the time is: {$date} </p>"];
}
}

17. • Outputting things
• Cache system
• Advanced features
• Extra cache modules

19. Cache system
• max-age
• tags
• context
• advanced

20. Cache system
• max-age
• tags
• context
• advanced

21. class DefaultController extends ControllerBase {
public function hello() {
$date = (new DateTimeImmutable("now"))->format('H:i:s');
return [
'#markup' => "<p>Hello world, the time is: {$date} </p>",
'#cache' => [
'max-age' => Cache::PERMANENT,
],
];
}
}

23. class DefaultController extends ControllerBase {
public function hello() {
$date = (new DateTimeImmutable("now"))->format('H:i:s');
return [
'#markup' => "<p>Hello world, the time is: {$date} </p>",
'#cache' => [
'max-age' => 3,
],
];
}
}

25. Cache system
• When does the representation of the thing I'm rendering become
outdated?
• (Cache::PERMANENT, 5, 60*60*24)
• ~ HTTP's Cache-Control: max-age header

26. Cache system
• max-age
• tags
• context
• advanced

27.
class DefaultController extends ControllerBase {
public function hello() {
$date = (new DateTimeImmutable("now"))->format('H:i:s');
$title = (Node::load(1))->getTitle();
return [
'#markup' => "<p>Hello world, the time is: {$date}, node 1 title: {$title}</p>",
];
}
}

29.
class DefaultController extends ControllerBase {
public function hello() {
$date = (new DateTimeImmutable("now"))->format('H:i:s');
$title = (Node::load(1))->getTitle();
return [
'#markup' => "<p>Hello world, the time is: {$date}, node 1 title: {$title}</p>",
'#cache' => [
'tags' => ['node:1'],
],
];
}
}

31. • What causes the representation of the thing I'm rendering become
outdated?
• entities (node:5, taxonomy_term:23,
search_api_index:database_index)

32. Cache system
• What causes the representation of the thing I'm rendering become
outdated?
• entities (node:5, taxonomy_term:23,
search_api_index:database_index)

33. Cache system
• max-age
• tags
• context
• advanced

34.
class DefaultController extends ControllerBase {
public function hello() {
$date = (new DateTimeImmutable("now"))->format('H:i:s');
$arg = Drupal::request()->get('test');
return [
'#markup' => "<p>Hello world, the time is: {$date}, arg: {$arg}</p>",
];
}
}

36.
class DefaultController extends ControllerBase {
public function hello() {
$date = (new DateTimeImmutable("now"))->format('H:i:s');
$arg = Drupal::request()->get('test');
return [
'#markup' => "<p>Hello world, the time is: {$date}, arg: {$arg}</p>",
'#cache' => [
'contexts' => ['url.query_args'],
],
];
}
}

38. Cache system
• Does the representation of the thing I'm rendering vary by
permissions, by URL, by interface language, by … something?
• (url, user.permissions, pirate_day)
• ~ HTTP's Vary header

39. Cache system
• max-age
• tags
• context
• advanced

40. Cache system
• Cache tags (data dependencies)
• Cache contexts (context dependencies)
• Cache max-age (time dependencies)

41. Cache system
• max-age
• tags
• context
• advanced

42.
class DefaultController extends ControllerBase {
public function hello() {
$date = (new DateTimeImmutable(“now"))->format('H:i:s');
$node = Node::load(1);
return [
'#markup' => "<p>Hello world, the time is: {$date}</p>",
'#cache' => [
'max-age' => $node->getCacheMaxAge(),
'tags' => Cache::mergeTags(['test', $node->getCacheTags()]),
'contexts' => $node->getCacheContexts(),
],
];
}
}

43.
class DefaultController extends ControllerBase {
public function hello() {
$date = (new DateTimeImmutable(“now"))->format('H:i:s');
$node = Node::load(1);
$renderer = Drupal::service('renderer');
$renderer->addCacheableDependency($node);
return [
'#markup' => "<p>Hello world, the time is: {$date}</p>”,
];
}
}

44.
class DefaultController extends ControllerBase {
public function hello() {
$date = (new DateTimeImmutable("now"))->format('H:i:s');
$build = [
'#markup' => "<p>Hello world, the time is: {$date}</p>",
];
$cache_data = new CacheableMetadata();
$cache_data->setCacheMaxAge(20);
$cache_data->applyTo($build);
return $build;
}
}

45. • Outputting things
• Cache system
• Extra cache modules

46. Bigpipe

48. /**
* Class TestBlock
*
* @Block(
* id = "custom_block",
* admin_label = @Translation("Custom block")
* )
*/
class TestBlock extends BlockBase {
/**
* {@inheritdoc}
*/
public function build() {
$date = (new DateTimeImmutable("now"))->format('H:i:s');
sleep(4);
return [
'#markup' => "<p>The time is: {$date}</p>",
'#cache' => ['max-age' => 0],
];
}
}

50. Bigpipe
• Renderable in isolation + poor cacheability
• autoplaceholder

51.
renderer.config:
auto_placeholder_conditions:
max-age: 0
contexts:
- session
- user
tags: { }

54. Bigpipe
• Manual placeholders

55. services:
custom_test_module.service:
class: Drupalcustom_test_moduleTestService

56.
namespace Drupalcustom_test_module;
class TestService {
public function callback($test) {
sleep(4);
return [
'#markup' => $date = (new DateTimeImmutable("now"))->format($test),
'#cache' => ['max-age' => 0],
];
}
}

57. /**
* Class TestBlock
*
* @Block(
* id = "custom_block",
* admin_label = @Translation("Custom block")
* )
*/
class TestBlock extends BlockBase {
public function build() {
return [
'#lazy_builder' => [‘custom_test_module.service:callback’, ['H:i:s']],
];
}
}

58. class TestBlock extends BlockBase {
public function build() {
$p = crc32('placeholder');
$format = 'H:i:s';
$time = (new DateTimeImmutable("now"))->format($format);
return [
'#markup' => 'The time is: ' . $time . ' | lazy time is: ' . $p,
'#attached' => [
'placeholders' => [
$p => [
'#lazy_builder' => [‘custom_test_module.service:callback’, [$format]],
'#cache' => [‘max-age' => ['0']],
],
],
],
];
}
}

60. Refreshless

62. Recap

63. page cache

64. dynamic page cache

65. bigpipe

66. refreshless

67. Questions?

68. More?
• https://drive.google.com/file/d/0By-njQ7nKRX-VndLdVozYUZac0E/view - @marcvangend
• http://wimleers.com/talk/making-drupal-fly-fastest-drupal-ever-here
- @WimLeers
• http://wimleers.com/talk/bigpipe - @WimLeers
• http://wimleers.com/talk/drupal-8-render-pipeline @WimLeers