Perspectives.Representation.Class.Cacheable

type Identifier = String

Members of class Cacheable provide functionality to cache and retrieve their representation. Members are by definition also members of class Revision. We now have two dimensions:

• is an entitity in cache?

• do want to preserve the revision on overwriting the cache with a new value for the entity? This gives rise to four possibilities, one of which is nonsense (not cached before, but preserve the revision). These are the three remaining functions:

• cacheInitially;

• cachePreservingRevision: before overwriting the cached value, take its revision and store it in the new value to cache;

• cacheOverwritingRevision: just overwrite the cached value.

type Namespace = String

class (Identifiable v i, Revision v, Newtype i String) <= Cacheable v i | v -> i, i -> v where

Members

• cache :: MonadPerspectives (GLStrMap (AVar v))
• representInternally :: i -> MonadPerspectives (AVar v)

  Create an empty AVar that will be filled by the PerspectEntiteit.

• retrieveInternally :: i -> MonadPerspectives (Maybe (AVar v))
• removeInternally :: i -> MonadPerspectives (Maybe (AVar v))

Instances

• Cacheable PerspectContext ContextInstance
• Cacheable PerspectRol RoleInstance
• Cacheable DomeinFile DomeinFileId

readEntiteitFromCache :: forall a i. Cacheable a i => i -> MonadPerspectives a

Returns an entity. Throws an error if the resource is not represented in cache or not immediately available in cache.

cachePreservingRevision :: forall a i. Cacheable a i => i -> a -> MonadPerspectives (AVar a)

Caches the entiteit. This operation is neutral w.r.t. the revision value (ff it was cached before, ensures that the newly cached entiteit has the same revision value as the old one).

cacheInitially :: forall a i. Cacheable a i => i -> a -> MonadPerspectives (AVar a)

Store an internally created PerspectEntiteit for the first time in the local store.

cacheOverwritingRevision :: forall a i. Cacheable a i => i -> a -> MonadPerspectives (AVar a)

Modify a PerspectEntiteit in the cache. Overwrites the revision value.

type Revision_ = Maybe String

class Revision v  where

Members

• rev :: v -> Revision_
• changeRevision :: Revision_ -> v -> v

newtype ViewType

Constructors

• ViewType String

Instances

• Newtype ViewType _
• Generic ViewType _
• Encode ViewType
• Decode ViewType
• Show ViewType
• Eq ViewType

newtype EnumeratedRoleType

Constructors

• EnumeratedRoleType String

Instances

• Newtype EnumeratedRoleType _
• Generic EnumeratedRoleType _
• Encode EnumeratedRoleType
• Decode EnumeratedRoleType
• Show EnumeratedRoleType
• Eq EnumeratedRoleType

newtype EnumeratedPropertyType

Constructors

• EnumeratedPropertyType String

Instances

• Newtype EnumeratedPropertyType _
• Generic EnumeratedPropertyType _
• Encode EnumeratedPropertyType
• Decode EnumeratedPropertyType
• Show EnumeratedPropertyType
• Eq EnumeratedPropertyType

newtype ContextType

Constructors

• ContextType String

Instances

• Newtype ContextType _
• Generic ContextType _
• Encode ContextType
• Decode ContextType
• Show ContextType
• Eq ContextType

newtype CalculatedRoleType

Constructors

• CalculatedRoleType String

Instances

• Newtype CalculatedRoleType _
• Generic CalculatedRoleType _
• Encode CalculatedRoleType
• Decode CalculatedRoleType
• Show CalculatedRoleType
• Eq CalculatedRoleType

newtype CalculatedPropertyType

Constructors

• CalculatedPropertyType String

Instances

• Newtype CalculatedPropertyType _
• Generic CalculatedPropertyType _
• Encode CalculatedPropertyType
• Decode CalculatedPropertyType
• Show CalculatedPropertyType
• Eq CalculatedPropertyType

newtype ActionType

Constructors

• ActionType String

Instances

• Newtype ActionType _
• Generic ActionType _
• Encode ActionType
• Decode ActionType
• Show ActionType
• Eq ActionType