The document discusses Drupal 8's plugin system and how to create custom plugins. It explains that all plugins should be placed in a src/Plugin/{plugin_name} directory and defined using annotations. Derivative plugins allow generating multiple plugin definitions programmatically. The plugin manager is responsible for plugin discovery, creation, and loading and utilizes different discovery methods like annotations, YAML, static definitions, and hooks. It provides an extendable architecture for modules and themes to define common plugin types.

1. HELLO!

2. I'MALEX

3. ZVIRYATKO

6. 5YRSAT

7. DRUPAL8
PLUGINAPI

8. WHATISPLUGININD8?
Did you remember ctools? Or any hook_info?
block, eld widget, formatter, form element, action, etc...
even cache backend.

9. src/Plugin/Block/SimpleMessageBlock.php
/**
* Defines a block with simple message.
*
* @Block(
* id = "simple_message",
* admin_label = @Translation("Simple Message"),
* )
*/
class SimpleMessageBlock extends BlockBase {
/**
* {@inheritdoc}
*/
public function build() {
return [
'message' => [
'#markup' => $this­>t('Just a simple message.'),
],
];
}
}

10. OK!BUTHOWTOADD
CUSTOMPLUGIN?
EASIERTHANIND7

11. WHERESHOULDIPUTMY
FILES?
All plugins should be placed in
src/Plugin/{PLUGIN_NAME}directory*

12. HOWTODEFINE?
USEANNOTATIONS
/**
* @Block(
* id = "simple_message",
* admin_label = @Translation("Simple Message"),
* )
*/

13. WHATISTHECODE?
ITDEPENDSONINTERFACE
class SimpleMessageBlock extends BlockBase {
/**
* {@inheritdoc}
*/
public function build() {
return [
'message' => [
'#markup' => $this­>t('Just a simple message.'),
],
];
}
}

14. LOOKSSIMPLE
ISITALL?
NO!

15. WHATISDERIVATIVES?
DYNAMICPLUGINS
foreach (module_implements('block_info') as $module) {
$module_blocks = module_invoke($module, 'block_info');
$blocks[$module] = $module_blocks;
}

16. DERIVATIVEEXAMPLE
core/modules/system/src/Plugin/Block/SystemMenuBlock.php
/**
* @Block(
* id = "system_menu_block",
* admin_label = @Translation("Menu"),
* category = @Translation("Menus"),
* deriver = "DrupalsystemPluginDerivativeSystemMenuBlock"
* )
*/
class SystemMenuBlock extends BlockBase {
// ...
}
This block is being used for all site menus

17. BUTHOWITWORKS?
Check the deriverannotation property
deriver = "DrupalsystemPluginDerivativeSystemMenuBlock"
core/modules/system/src/Plugin/Derivative/SystemMenuBlock.ph
class SystemMenuBlock extends DeriverBase {
// ...
public function getDerivativeDefinitions($base_definition) {
$blocks = $this­>menuStorage­>loadMultiple();
foreach ($blocks as $menu => $entity) {
$this­>derivatives[$menu] = $base_definition;
}
return $this­>derivatives;
}
}

18. WHATISPLUGINMANAGER?
Fat replacement of hook_*_infosystem
Plugin manager is responsible for:
Plugin discovery (annotation, yaml)
Plugin creation (factory)

19. WHYDOYOUNEEDIT?
Create extendable architecture
example: layouts
you can provide layouts from theme or module
and have not be hard linked to main module

20. HOWTOADD
mymodule/mymodule.services.yml
services:
plugin.manager.sandwich:
class: DrupalmymoduleSandwichPluginManager
parent: default_plugin_manager

21. mymodule/src/SandwichPluginManager.php
class SandwichPluginManager extends DefaultPluginManager {
public function __construct(
Traversable $namespaces,
CacheBackendInterface $cache_backend,
ModuleHandlerInterface $module_handler
) {
parent::__construct(
'Plugin/Sandwich', // subdir where to search plugins
$namespaces,
$module_handler,
'DrupalmymoduleSandwichInterface', // strict interface
'DrupalCoreAnnotationPlugin' // annotation class
);
$this­>alterInfo('sandwich_info');
$this­>setCacheBackend($cache_backend, 'sandwich_info');
}
}

22. HOWTOUSE
Get a list of available plugins:
$type = Drupal::service('plugin.manager.sandwich');
/**
* @var DrupalmymoduleSandwichInterface[] $plugins
*/
$plugins = $type­>getDefinitions();
In this case you will receive only objects that implement
your interface

23. PLUGINDISCOVERY
ANNOTATION
YAML
STATIC
HOOK

24. ANNOTATIONDISCOVERY
You already saw it
/**
* @Block(
* id = "system_menu_block",
* admin_label = @Translation("Menu"),
* )
*/
This is much better then ctools $plugin = array();
Using in plugin manager
new AnnotatedClassDiscovery(
"Plugin/Sandwich", // Subdirectory
$namespaces, // Service "container.namespaces"
"DrupalCoreBlockAnnotationBlock" // Annotation @Block
);

25. YAMLDISCOVERY
Usefull for theme plugins, like breakpoints or layouts
core/themes/bartik/bartik.breakpoints.yml
bartik.wide:
label: wide
mediaQuery: 'all and (min­width: 851px)'
multipliers:
­ 1x
DrupalbreakpointBreakpointManager::$default
contains all possible keys
$directories = $moduleHandler­>getModuleDirectories() +
$themeHandler­>getThemeDirectories();
new YamlDiscovery('breakpoints', $directories);

26. STATICDISCOVERY
Useful when you need to add 3rd-party class as plugin
class SandwichPluginManager extends DefaultPluginManager {
protected function getDiscovery() {
$this­>discovery = new StaticDiscovery();
$this­>discovery­>setDefinition('cheese_sandwich', [
'label' => new TranslatableMarkup('Cheese Sandwich'),
'class' => 'SomeVendorLibraryCheeseSandwich',
]);
return $this­>discovery;
}
}

27. HOOKDISCOVERY
Good old hook_info()
class SandwichPluginManager extends DefaultPluginManager {
protected function getDiscovery() {
$this­>discovery = new HookDiscovery(
$this­>moduleHandler,
"sandwich_info"
);
return $this­>discovery;
}
}
For hook_info_alter()use this
$this­>alterInfo("sandwich_info");

28. DISCOVERYDECORATORS
Combine them all together with decorators
$d = new AnnotatedClassDiscovery("Plugin/sandwich", $nmspaces);
$d = new ContainerDerivativeDiscoveryDecorator($d);
$d = new YamlDiscoveryDecorator($d, 'sandwich', $directories);
$d = new InfoHookDecorator($d, 'sandwich_info');
$d = new StaticDiscoveryDecorator($d, "callback");

29. ISITALLNOW?

30. THANX!
presentation
drupal.org/u/zviryatko
github.com/zviryatko
sanya.davyskiba@gmail.com
goo.gl/ynFqVo
QUESTIONS?