Services, plugins, hooks, events

The services, plugin types, hooks and events of the Sites modules. Each summary is the first paragraph of the docblock.

Services

Sites (sites)

Service	Summary	Tags
sites.kernel_request_subscriber	Negotiates each main request's site and answers 404 where it does not serve.	event_subscriber
sites.access_denied_subscriber	Converts a "not this site's" 403 into a 404 on a site host.	event_subscriber
sites.real_global_roles	Answers "does a REAL global role grant this permission".
sites.site_role_manager	Default site role manager backed by site_role_assignment entities.
sites.membership	Answers which sites an entity belongs to, and its canonical site.
sites.content_assignment	Decides who may put content on which site, and applies a site selection.
sites.field_membership_storage	Membership storage for entities carrying their site in a site_id field.	sites.membership_storage
sites.resolver	Default site resolver: route → claiming site, via applies().
sites.user_access	Answers which sites a user may work on, and builds site option lists.	event_subscriber
sites.content_support	Default content-support service derived from the sites' content setting.
sites.menu_tree_manipulators	Keeps menu links to entities on another site visible.
sites.context_provider.site	Provides the active site as the 'site' context for context-aware plugins.	context_provider
current_site	The current_site service: answers as the active site.
site_switcher	Runs code as another site, on a stack of switches.
sites.content_version_context	Answers which version a load delivers from the active site and the scopes.
sites.canonical_cron	Runs cron on the canonical version of site content.
sites.canonical_request_subscriber	Serves JSON:API and REST requests the canonical version of site content.	event_subscriber
sites.initial_site_subscriber	Claims a request for the main site whose host matches.	event_subscriber
sites.hostname_alias_redirect_subscriber	Redirects a site's alias hostnames to its hostname, permanently.	event_subscriber
sites.vbo_actions_subscriber	Keeps the site actions on offer in Views Bulk Operations.	event_subscriber
sites.action_site_context	The site a request's bulk actions are about.
sites.host_lookup	Answers host and prefix lookups from the plugin manager's definition index.
sites.overrider	The per-site configuration overrides, in one layer.	config.factory.override
sites.config_override_repository	Stores per-site configuration overrides and resolves them, cached per site.
sites.config_override_config_subscriber	Keeps the stored overrides consistent with the objects they override.	event_subscriber
sites.site_admin_permissions_subscriber	Tells the caches when administrator roles stand for something else.	event_subscriber
sites.file_usage	Keeps file usage in step with the files a site's settings point at.
sites.config_target_settings	Stores config_target settings as per-site configuration overrides.
sites.setting_layer_store	Reads and writes one layer of a setting plugin's values for a site.
sites.site_settings	Reads, validates and writes a site's settings outside the section form.
sites.lifecycle	Creates, enables, arranges and deletes sites.
sites.members	Lists a site's people and hands out its roles.
sites.scoped_entities	Files a section's entities on sites: one per site, each judged on its own.
sites.section_form_scope	Which section and which layer the current route edits.
cache_context.site	Varies by the ACTIVE site — the site the code is currently running as.	cache.context
cache_context.sites_context_site	Varies by the site a hub request acts in.	cache.context
cache_context.sites_negotiated_site	Cache context for the negotiated site: the site the request arrived on.	cache.context
cache_context.user.sites	Cache context varying by the viewer's per-site access profile.	cache.context
sites.user_sites_provider.roles	The role-assignment contribution to the 'user.sites' cache context.	sites.user_sites_provider
sites.site_setting_subscriber	Applies per-site setting overrides defined in settings.php.	event_subscriber
sites.site_settings_inheritance_subscriber	Gives a sub-site its main site's hostname and, on request, its settings.	event_subscriber
sites.trusted_hosts_middleware	Adds every site hostname and alias to the trusted host patterns.	http_middleware
url_generator.non_bubbling.decorator	Generates a URL that targets another site as that site, on its hostname.
sites.settings_resolver	Folds stored settings items into the resolved settings of a site.
sites.link_generator.decorator	Keeps links to another site from getting the active-trail class.
sites.sites_selection.summary_builder	Renders which sites an entity belongs to.
sites.access_check.site_content	Access check for content operations on a site.	access_check
sites.access_check.site_permission	Access check for a per-site permission on a route's {site}.	access_check
sites.capabilities	The capability answers, asked with the permissions of whoever is asking.
sites.entity_access	Decides what belonging to sites means for entity operations.
sites.access_check.site_admin_section	Access to a per-site admin section.	access_check
sites.access_check.setting_layer	Access to a section form's layer routes: only a layer the site has.	access_check
sites.access_check.site_admin_section_collection	Gates a section's core collection route in a site context.	access_check
sites.access_check.site_admin_section_config	Binds a section's config hub route to REAL global administrators.	access_check
sites.access_check.site_admin_section_scoped_overview	Binds a section's config hub route to REAL global administrators.	access_check
sites.route_subscriber.site_entity	Lets the site entity's own routes carry a machine name.	event_subscriber
sites.route_subscriber.site_admin_section_ui	Turns each section's core collection route into its hub entry point.	event_subscriber
sites.route_subscriber.site_admin_section	Clones each section's core routes under /admin/sites/{site}/….	event_subscriber
sites.access_check.real_global_permission	Gates an entity-less hub route on a REAL (assigned) global permission.	access_check
sites.access_check.sites_selection_create	Create access for the new-content selection modal.	access_check
sites.param_converter	Parameter converter for upcasting site IDs to site objects.	paramconverter
sites.param_converter.site_entity	Upcasts a site entity route parameter from the site's machine name.	paramconverter
sites.access_check.site_is_hub	Checks access based on whether the request arrived on the hub.	access_check
sites.access_check.create	Access for the content-creation site picker.	access_check
sites.access_check.create_any	Create-any-bundle access, OR-ing the per-site add capability in on the hub.	access_check
sites.route_subscriber.hub_only	Keeps the administration of sites on the hub.	event_subscriber
sites.route_subscriber.create	Bridges core's "add page" listing routes for per-site creators on the hub.	event_subscriber
sites.subscriber.create_intercept	Requires choosing a site before a content create form on the hub.	event_subscriber
sites.role_permission_calculator	The pure per-site role → permission math.
sites.pointed_site	Reads the site a request points at, and how far to trust the pointer.
sites.access_policy	Adjusts the Drupal-scope permissions for the site the request acts in.	access_policy
Drupal\sites\Form\RemoveContentFromSite	Provides a form to remove content from a site.
Drupal\sites\Form\AddContentToSite	Provides a form for adding content to a site.
Drupal\sites\Form\SitesSelectionModalForm	Builds a form for a modal which allows selecting sites.
sites.scoped_views	Which views the suite scopes, and how.
sites.scoped_view_scope	The one bounding step of a scoped view: what the viewer may select.

Sites clone (sites_clone)

Service	Summary	Tags
sites_clone.mapping	Answers where a cloned entity ended up.
sites_clone.menu_cloner	Copies the links of a site's per-site menus into the clone.
sites_clone.cloner	Clones a site: the new one's basics, everything else from the source.

Sites content (sites_content)

Service	Summary	Tags
sites_content.membership_storage	Membership storage backed by site_content_relationship rows.	sites.membership_storage
sites_content.user_sites_provider	The membership contribution to the 'user.sites' cache context.	sites.user_sites_provider
sites_content.content_inventory	Answers the site→content direction: what belongs to a site, and how firmly.
sites_content.disposition	Detaches, reassigns or deletes a deleted site's content.
sites_content.site_resolver	Resolves content sites for a route via the membership storage.	sites.candidate_site_resolver

Sites content overrides (sites_content_overrides)

Service	Summary	Tags
sites_content_overrides.entity_types	Answers which entity types sites may override, from the module's settings.	event_subscriber
sites_content_overrides.cache_tags_invalidator	Withholds named cache tags from invalidation while an override is written.
sites_content_overrides.site_aware_entity_resolver	Resolves the revision a site serves and writes the override revisions.
Drupal\sites_content_overrides\Query\ServedVersionTables	Rewrites entity queries and views on a site's host to the served revisions.
Drupal\sites_content_overrides\Query\ServedRevisionIndex	Maintains the table of the override revision each site serves per entity.	needs_destruction
sites_content_overrides.memory_cache	Keeps the loaded entities of overridable types apart per content version.
sites_content_overrides.memory_cache_bin	Keeps the loaded entities of overridable types apart per content version.
Drupal\sites_content_overrides\Form\OverrideDestination	Keeps an override form's ?destination off an alias the submit removed.
sites_content_overrides.route_subscriber	Adds the override routes of every overridable entity type.	event_subscriber
sites_content_overrides.access_check.site_override	Grants a per-site override route only for the route's {site}.	access_check
sites_content_overrides.paramconverter.entity	Upcasts a route's entity to the version the route needs.
sites_content_overrides.entity.repository	Makes getActive() and getActiveMultiple() return the served version.
sites_content_overrides.service	Edits, validates, saves and reverts a site's override of an entity.
Drupal\sites_content_overrides\OverridingSites	Answers which member sites override an entity.
sites_content_overrides.config_subscriber	Updates entity definitions when the overrideable entity types change.	event_subscriber
sites_content_overrides.canonical_site_subscriber	Adopts or deletes a site's override as the content's memberships change.	event_subscriber
sites_content_overrides.override_cache_tags_subscriber	Tags a response about an entity with the override tag of its site.	event_subscriber
sites_content_overrides.layout_builder_site_context	Renders a layout in the site it is edited for.

Sites content overrides Layout Builder (sites_content_overrides_layout_builder)

Service	Summary	Tags
sites_content_overrides_layout_builder.tempstore.route_enhancer	Pins the site on a section storage loaded from the layout tempstore.	route_enhancer
sites_content_overrides_layout_builder.service	Tells whether an entity's bundle allows per-entity Layout Builder layouts.

Sites content overrides revisions (sites_content_overrides_revisions_ui)

Service	Summary	Tags
sites_content_overrides_revisions_ui.route_subscriber	Adds the routes of a site's override revision history.	event_subscriber

Sites devel (sites_devel)

Service	Summary	Tags
Drupal\sites_devel\DevelDumperManagerDecorator	Opens Devel dumps to signed-in users in Sites development mode.

Sites Diff (sites_diff)

Service	Summary	Tags
sites_diff.overrides_operations_enhancer	Enhances the site overrides operation list with a diff comparison link.
Drupal\sites_diff\Hook\SitesDiffHooks	Adds a "Compare with canonical" diff link to the site overrides list.

Sites file (sites_file)

Service	Summary	Tags
sites_file.membership_storage	Computes a file's sites from the content that uses it, on every read.	sites.membership_storage

Sites language (sites_language)

Service	Summary	Tags
sites_language.overrider	Language configuration override per site.	config.factory.override
sites_language.languages	The languages a site speaks.
sites_language.isolation_subscriber	An entity page whose served translation the site does not speak is a 404.	event_subscriber

Sites menu (sites_menu)

Service	Summary	Tags
sites_menu.service	Maps a menu to the current site's own version of it.
sites_menu.site_menus	A site's own menus: which they are, who manages them, what they are called.
Drupal\menu_ui\Plugin\Validation\Constraint\MenuSettingsConstraintValidator	Site-aware replacement for core's MenuSettingsConstraintValidator.
sites_menu.membership_storage	Membership storage for links stored under per-site menu variants.	sites.membership_storage
sites_menu.capabilities	The capability answers, asked with the permissions of whoever is asking.
sites_menu.menu_link_tree	Loads the per-site variant of a menu in a site context.
sites_menu.menu_active_trail	Resolves the active trail against the per-site variant of a menu.
sites_menu.access_check.menu_links	Narrows the menu links overview and add-link form in a site context.	access_check

Sites Metatag (sites_metatag)

Service	Summary	Tags
sites_metatag.link_builder	The canonical URL and the hreflang alternates of a content page.

Sites path alias (sites_path_alias)

Service	Summary	Tags
sites_path_alias.alias_cleanup_subscriber	Deletes a site's alias for content that has left the site.	event_subscriber
Drupal\Core\Path\Plugin\Validation\Constraint\ValidPathConstraintValidator	Site-aware replacement for core's ValidPathConstraintValidator.
sites_path_alias.content_paths	Tells the system paths of site content from every other path.

Sites path prefix (sites_path_prefix)

Service	Summary	Tags
sites_path_prefix.parent_site	Provides the 'main_site' context.	context_provider
sites_path_prefix.service	Reads site path prefixes and the request path without its language prefix.
sites_path_prefix.path_processor	Processes inbound/outbound paths using the active site's prefix.	path_processor_inbound, path_processor_outbound
sites_path_prefix.path_processor_front.decorator	Serves a sub-site's front page at its bare prefix.
sites_path_prefix.initial_site_path_prefix_subscriber	Resolves a sub-site from the request's hostname and path prefix.	event_subscriber

Sites Pathauto (sites_pathauto)

Service	Summary	Tags
sites_pathauto.alias_generation_subscriber	Generates a site's pathauto alias when content joins the site.	event_subscriber
sites_pathauto.site_aliases_route_subscriber	Provides the per-entity bulk alias form route for site content types.	event_subscriber
Drupal\path\Plugin\Validation\Constraint\PathAliasConstraintValidator	Site-aware replacement for core's PathAliasConstraintValidator.

Sites preview (sites_preview)

Service	Summary	Tags
sites_preview.access	Decides who may render content in another site's context.
sites_preview.service	Holds the site the current request previews.
sites_preview.switcher	Where the viewer can go from a preview: another site's, or the real one.
sites_preview.language_overrides	Keeps URL language detection on path prefixes inside a preview.	config.factory.override
sites_preview.site_switch_subscriber	Switches into the site named by the reserved '/preview/{site}' prefix.	event_subscriber
sites_preview.admin_route_subscriber	Sends admin routes back out of the preview namespace.	event_subscriber
sites_preview.force_on_hub_subscriber	Forces a site's content into its preview when it is reached on the hub.	event_subscriber
sites_preview.front_page_subscriber	Sends the hub's own front page to a preview of the user's site.	event_subscriber
sites_preview.context_message_subscriber	Tells the viewer which site they are looking at, and offers the others.	event_subscriber
sites_preview.path_processor	Strips and re-adds the preview prefix around the site's own paths.	path_processor_inbound, path_processor_outbound
sites_preview.url_generator.decorator	Keeps preview URLs on the hub host instead of the previewed site's host.
sites_preview.menu_tree_manipulators	Decides a preview's admin links and tasks where they will be followed.
sites_preview.cache_context.site	Tells a preview of a site apart from a visit to it, within 'site'.

Sites Redirect (sites_redirect)

Service	Summary	Tags
sites_redirect.route_subscriber.ui	Turns /admin/config/search/redirect into the "whose redirects?" entry point.	event_subscriber
sites_redirect.service	Creates, validates, finds and deletes redirects per site.
sites_redirect.repository	Looks redirects up per site.

Sites RobotsTxt (sites_robotstxt)

Service	Summary	Tags
sites_robotstxt.route_subscriber	Serves /robots.txt through the site-aware controller.	event_subscriber

Sites Search API (sites_search_api)

Service	Summary	Tags
sites_search_api.post_request_indexing	Indexes after the request on the canonical version of site content.

Sites Shield (sites_shield)

Service	Summary	Tags
sites_shield.subscriber	Challenges every request to a password-protected site with a 401.	event_subscriber
sites_shield.page_cache_request_policy.disallow_basic_auth_requests	Keeps credentialed requests to a shielded site out of the page cache.	page_cache_request_policy
sites_shield.page_cache_response_policy.disallow_shielded_pages	Response policy that prevents caching pages of a shielded site.	page_cache_response_policy

Sites Simple XML Sitemap (sites_simple_sitemap)

Service	Summary	Tags
sites_simple_sitemap.config_subscriber	Rebuilds the site caches when simple_sitemap's entity types change.	event_subscriber
sites_simple_sitemap.route_subscriber	Makes simple_sitemap's routes site-aware.	event_subscriber
sites_simple_sitemap.membership_steering_subscriber	Gives a site that adopts an entity the canonical site's sitemap settings.	event_subscriber
sites_simple_sitemap.membership_storage	Membership of a configuration entity, kept in its third-party settings.	sites.membership_storage

Sites taxonomy (sites_taxonomy)

Service	Summary	Tags
sites_taxonomy.service	Answers the taxonomy admin's site scope and its site-content vocabularies.
sites_taxonomy.term_queries	Default implementation of the term-id scoping queries.

Sites UI (sites_ui)

Service	Summary	Tags
sites.site_cards	Renders sites as the card grid of /admin/sites.
sites_ui.breadcrumb_builder	Breadcrumbs for the Sites admin section (it lives in its own "sites" menu).	breadcrumb_builder
sites_ui.access_reporter	Read-only reporting over per-site role assignments and effective access.
Drupal\sites_ui\Controller\UnassignedContentReportController	The unassigned-content triage report.
sites_ui.content_summary	Aggregates a site's content membership into a "content at a glance" summary.
sites_ui.launch_checklist	The launch checklist shown on a fresh site's dashboard.

Sites Webform (sites_webform)

Service	Summary	Tags
sites_webform.membership_storage	Membership of a configuration entity, kept in its third-party settings.	sites.membership_storage
sites_webform.assignment	Reads and writes a webform's sites and lists webforms usable on given sites.
Drupal\sites_webform\WebformHostAccess	Which host serves a webform: the hosts of the sites it is assigned to.
Drupal\sites_webform\WebformGroupUpgrade	Adopts the webform assignments of the predecessor, sites_group_webform.

Plugin types

Sites (sites)

Plugin manager	Summary
plugin.manager.site	Discovers the sites the platform serves and indexes their hosts.
plugin.manager.site_setting	Discovers the site setting plugins and redacts sensitive values.
plugin.manager.sites_launch_step	Discovers the launch checklist steps and orders those a site shows.
plugin.manager.site_admin_section	The admin sections available per site.

Sites clone (sites_clone)

Plugin manager	Summary
plugin.manager.sites_clone_method	Discovers the clone methods and lists the ones offered for an entity type.

Hooks

Sites (sites)

Hook	Summary
hook_site_info_alter()	Add or alter site plugin definitions.
hook_site_setting_info_alter()	Alter the list of discovered site setting plugin definitions.
hook_sites_launch_step_info_alter()	Alter the list of discovered launch step plugin definitions.
hook_site_admin_section_info_alter()	Alter the list of discovered site admin section plugin definitions.
hook_sites_content_entity_types_alter()	Alter the content entity types sites may hold.
hook_sites_shared_pool_content_entity_types_alter()	Declare the content entity types whose site-less entities are on every site.
hook_sites_overview_views_alter()	Alter the views the suite scopes as content overviews.
hook_sites_inheritance_ignore_alter()	Alter the settings keys excluded from parent-to-child inheritance.
hook_site_access_alter()	Alter the site gate: whether the active site serves the requested route.
hook_site_SITE_ID_access_alter()	Alter the site gate of one site, by site ID.
hook_sites_site_delete_operations_alter()	Alter the batch operations that run before a site is deleted.
hook_sites_entity_site_badges_alter()	Alters the badges of the sites in an entity's site list.

Sites clone (sites_clone)

Hook	Summary
hook_sites_clone_method_info_alter()	Alters the clone methods a bundle can be cloned with.
hook_sites_clone_method_supports_entity_type_alter()	Alters whether a clone method is offered for an entity type.

Sites content (sites_content)

Hook	Summary
hook_sites_content_inventory_query_alter()	Alter a query of the site content inventory.
hook_sites_content_disposition_delete_alter()	Alter the deletion of content that is deleted with its site.

Sites content overrides (sites_content_overrides)

Hook	Summary
hook_sites_content_overrides_operation_alter()	Alters the operations available for a site override in the overview list.
hook_is_sites_content_overrides_field_overrideable_alter()	Alters whether a field is considered overrideable for a site.
hook_sites_content_overrides_has_override_for_site_alter()	Alters whether a site has an override of an entity.
hook_sites_content_overrides_pins_alter()	Alters the pins a site override save records.
hook_sites_content_overrides_pin_label_alter()	Alters the label of a pin on the revert form.
hook_sites_content_overrides_snapshot_alter()	Alters a site override snapshot while it is being built.
hook_sites_content_overrides_aspects()	Declares per-site override aspects of an entity.
hook_sites_content_overrides_revert_aspect()	Reverts one declared aspect to canonical behaviour on a site.
hook_sites_content_overrides_aspect_values()	Returns the site's current values of the declared aspects.
hook_sites_content_overrides_set_aspect()	Sets one declared aspect for a site, as its override form section does.
hook_sites_content_overrides_effective_override_alter()	Alters which override revision a site serves in place of the canonical one.

Sites Metatag (sites_metatag)

Hook	Summary
hook_sites_metatag_own_variant()	Whether a site serves its own variant of a content entity.

Sites Pathauto (sites_pathauto)

Hook	Summary
hook_sites_pathauto_entity_update_alias_alter()	Alter an entity just before its per-site pathauto alias is generated.

Sites UI (sites_ui)

Hook	Summary
hook_site_dashboard_alter()	Alter a site's dashboard.
hook_sites_status()	Add entries to the Sites status report.
hook_sites_status_alter()	Alter the entries of the Sites status report.

Events

Sites (sites)

Event	Constant	Summary
sites.content.add	ContentEvent::ADD_EVENT_NAME	Dispatched after an entity is added to a site.
sites.content.remove	ContentEvent::REMOVE_EVENT_NAME	Dispatched after an entity is removed from a site.
sites.content.canonical	ContentEvent::CANONICAL_EVENT_NAME	The canonical site of an entity was set or moved.
sites.initialize	InitialSiteEvent::EVENT_NAME	Dispatched before the request's site is sealed.
sites.settings_build	SiteSettingsEvent::BUILD	Dispatched once per site instance when its settings are resolved.