interface CalculatedCacheContextInterface (View source)

Provides an interface for defining a calculated cache context service.

Methods

static string
getLabel()

Returns the label of the cache context.

string
getContext(string|null $parameter = NULL)

Returns the string representation of the cache context.

getCacheableMetadata(string|null $parameter = NULL)

Gets the cacheability metadata for the context based on the parameter value.

Details

static string getLabel()

Returns the label of the cache context.

Return Value

string

The label of the cache context.

See also

Cache

string getContext(string|null $parameter = NULL)

Returns the string representation of the cache context.

A cache context service's name is used as a token (placeholder) cache key, and is then replaced with the string returned by this method.

Parameters

string|null $parameter

The parameter, or NULL to indicate all possible parameter values.

Return Value

string

The string representation of the cache context. When $parameter is NULL, a value representing all possible parameters must be generated.

Exceptions

LogicException

CacheableMetadata getCacheableMetadata(string|null $parameter = NULL)

Gets the cacheability metadata for the context based on the parameter value.

There are three valid cases for the returned CacheableMetadata object:

  • An empty object means this can be optimized away safely.
  • A max-age of 0 means that this context can never be optimized away. It will never bubble up and cache tags will not be used.
  • Any non-zero max-age and cache tags will bubble up into the cache item if this is optimized away to allow for invalidation if the context value changes.

Parameters

string|null $parameter

The parameter, or NULL to indicate all possible parameter values.

Return Value

CacheableMetadata

A cacheable metadata object.

Exceptions

LogicException