Cache contexts and tags¶

Look up the cache contexts and cache tags of the Sites modules: what each one varies by or stands for, and what invalidates it.

Which one to add where is on Caching. {id} is a site's ID (its machine name; default is the hub), {type} an entity type ID.

Contexts¶

Context	Value	Module
`site`	The active site's ID. A site switch changes it. With Sites preview, `{id}.preview` while previewing. Every render cache entry varies by it: Sites adds it to `renderer.config` `required_cache_contexts`.	`sites`
`sites_negotiated_site`	The ID of the site the request arrived on. Switches and previews leave it unchanged.	`sites`
`sites_context_site`	On the hub, the site a request acts in: the canonical site of the route's entity, else the route's `{site}`, else `?site_id`. `none` everywhere else. Its metadata carries the route entity's `site_content_membership:{type}:{id}` tag.	`sites`
`user.sites`	A hash of the viewer's per-site role assignments and site memberships; `anonymous` for anonymous users. Its metadata carries `user:{uid}`, `site_role_assignment:user:{uid}` and `site_content_membership:user:{uid}`.	`sites`
`environment`	The current environment's machine name; `default` when none is detected.	`environment_context`

None of them takes a parameter. The access policy of Sites varies the calculated permissions by site and sites_context_site.

A site object as a cacheable dependency (SitePluginBase) adds the contexts site, languages:language_interface, environment, theme and user.permissions, and the tag site:{id}.

user.sites reads its value from the services tagged sites.user_sites_provider (UserSitesProviderInterface): one for role assignments in sites, one for memberships in sites_content. A module that stores memberships its own way adds a provider.

Tags¶

Tag	Stands for	Invalidated when
`site:{id}`	A site's definition and settings. Every response rendered in the site's context carries it. Built by `MembershipCacheTags::sitePlugin()`.	The site entity is saved or deleted, along with the tags of its sub-sites; every site of a site type when the type is saved; a stored config override of the site is written.
`site_host:{id}`	A site's addresses: hostname, aliases, language domains, path prefix. Carried by links to the site from other sites' pages. `MembershipCacheTags::siteHost()`.	The site is created or deleted, or a save changes its status or an address setting; its sub-sites' tags with it.
`sites_list`	The list of sites, the site entity's list tag.	Any site entity write; a site type save.
`site_config_override_list:{id}`	A site's stored config overrides. Every configuration read in a site context carries it. `SiteConfigOverrideRepositoryInterface::LIST_TAG_PREFIX`.	A stored override of the site is written or deleted.
`site_content_membership:{type}:{id}`	One entity's memberships. `MembershipCacheTags::entity()`; `account()` for a user.	A membership row of the entity is written; the `site_id` field of a `SiteIdFieldEntityInterface` entity changes. The entity's own tag is invalidated with it.
`site_content_membership_site:{id}`	One site's set of member entities. `MembershipCacheTags::site()`.	A membership row of the site is written, or moved away from it.
`site_content_list:{type}:{id}`	One entity type's content on one site. A view with the cache plugin `sites_tag` (Tag based, per site) that lists the site's content on its host carries it in place of `{type}_list`. `MembershipCacheTags::siteList()`.	An entity of the type that belongs to the site is updated or deleted.
`site_content_membership_shared:{type}`	The entities of a shared-pool type (declared with `hook_sites_shared_pool_content_entity_types_alter()`) that belong to no site and show on every site. `MembershipCacheTags::sharedPool()`.	An entity of the type enters or leaves the pool; an entity in the pool is written.
`site_content_relationship_list`	Any membership. `MembershipCacheTags::ANY_MEMBERSHIP`.	Any membership row write (core's list tag).
`site_role_assignment_list`	Any per-site role assignment. `SiteAccessCacheability::ROLE_ASSIGNMENT_TAG`.	Any assignment write (core's list tag).
`site_role_assignment:user:{uid}`	One account's per-site roles. `SiteAccessCacheability::assignmentTag()`.	An assignment of the account is written.
`site_role_assignment:user:{uid}:site:{id}`	One account's roles on one site. `SiteAccessCacheability::siteAssignmentTag()`.	An assignment of the account on the site is written.
`site_content_override:{type}:{id}`	Which sites override an entity. `OverrideCacheTags::entity()`. Sites content overrides.	An override of the entity is saved, reverted or deleted; an aspect is set or reverted.
`site_content_override:{type}:{id}:{site}`	One site's version of an entity. Responses on routes with an overridable entity carry it. `OverrideCacheTags::site()`.	As above, for that site.
`config:system.menu.{menu}__{id}`	A site's links in a per-site menu. Sites menu.	A link of the per-site menu is written (core).

While an override revision is saved, Sites content overrides withholds the entity's own tags, its list and bundle list tags, 4xx-response and the other sites' site_content_list tags from invalidation; it invalidates the two site_content_override tags instead.

Section grants¶

A site admin section that declares no grant_cache_tags gets SiteAccessCacheability::DEFAULT_GRANT_CACHE_TAGS: config:user_role_list, sites_list and site_role_assignment_list. Declared tags replace them.